The Mining and Lands Commissioner

Le Commissaire aux mines et aux terres

File No. CA 001-00

L. Kamerman
Mining and Lands Commissioner

Friday, the 14th day of February, 2003.

The Mining and Lands Commissioner in the matter of the Conservation Authorities Act

in the matter of

An appeal to the Minister of Natural Resources under subsection 28(15) of the Conservation Authorities Act against the refusal to grant permission for development through the construction of a single family dwelling on Lot 40, Plan M-16 in the Town of Innisfil (Gilmore Avenue).


Wesley Cooper


Lake Simcoe Region Conservation Authority


Upon hearing the appeal received February 23, 2000 and upon reading the documentary evidence filed;

  1. This tribunal orders that the appeal be and is hereby allowed and the appellant be and is hereby granted the permission requested in his application under the following conditions:
    1. A site plan for building on the property will be sited in accordance with the local by-laws to the northerly limit of the property;
    2. Any garage will be sited on the southern portion of the building;
    3. All windows will be constructed above the flood level elevation;
    4. Fill will be reduced to a minimum under the building envelope extending to the north edge of Lot 40 and to such further extent as may be reasonably necessary;
    5. An agreement would be registered on title acknowledging that the building is within an encroachment area and releasing the Lake Simcoe Region Conservation Authority from any liability with respect to its consent to the issuance of a building permit.

Reasons for this Order are attached.

Dated this 14th day of February, 2003.

Original signed by

L. Kamerman
Mining and Lands Commissioner

File No. CA 001-00

L. Kamerman
Mining and Lands Commissioner

Friday, the 14th day of February, 2003.

The Mining and Lands Commissioner in the matter of the Conservation Authorities Act

An appeal to the Minister of Natural Resources under subsection 28(15) of the Conservation Authorities Act against the refusal to grant permission for development through the construction of a single family dwelling on Lot 40, Plan M-16 in the Town of Innisfil (Gilmore Avenue).


Wesley Cooper


Lake Simcoe Region Conservation Authority


This matter was heard initially in the Courtroom of this tribunal, 24th Floor, 700 Bay Street, Toronto, Ontario, on the 11th day of January, 2002 and continued at the Delta Toronto East, 2035 Kennedy Road, Toronto, Ontario, on the 8th day of April, 2002.


Mr. Marvin Geist
Counsel for the Appellant, Wesley Cooper

Mr. Kenneth Hill
Counsel for the Respondent, the Lake Simcoe Region Conservation Authority


This appeal arises out of a 1999 application to the Lake Simcoe Region Conservation Authority ("LSRCA") resulting in the refusal to grant permission for development through the construction of a single family dwelling and placement of fill on Lot 40, Plan M-16 in the Town of Innisfil. The property is located on Gilmore Avenue in the town of Lefroy.

The Cooper property is located several blocks from Lake Simcoe, but is not so close as to be affected by any direct flooding from the lake resulting from a Regional storm. It is within the floodplain of Carson's Drain, which flows into Lake Simcoe . Its floodplain is shallow and wide, extending some distance and is up to 1,745 feet in width. The LSRCA administers this area as an informal two-zone area, having adopted encroachment lines within which development is quite restricted.

The frontage of all lots in the Lefroy Subdivision (the "Subdivision") are on those streets which run north and south, which in turn cross Carson's Drain at right angles. This has the effect of causing the encroachment lines to bisect the properties within the Subdivision across their length, rather than their width. The Cooper property, is bisected by the northern encroachment line, so that it rests partially within the floodway and partially within the flood fringe. As a result, no suitable building envelope exists outside the floodway as it is currently defined and implemented by the LSRCA.

The proposal(s) advanced on behalf of Mr. Cooper essentially involves a re-drawing of the encroachment lines throughout the Lefroy reach of the Carson's Drain. The effect of this proposal would have an impact on many of those lots currently bisected by the existing encroachment lines, but ultimately, would create full building envelopes on vacant lots in only two cases. In crafting three alternative proposals, the engineering firm of Cosburn, Patterson, Mather ("CPM"), hired by Mr. Cooper applied the parameters of the original Carson's Drain Study, conducted in 1983, to determine the impact of its proposal.

Facts relating to the subject property

Mr. Cooper owns Lot 40 on Gilmore Avenue, being part of Registered Plan of Subdivision M-16. The dimensions of the lot [Ex. 16] are 60 feet wide by 200 feet deep. Gilmore Avenue is paved and with a dead end to the north. Meaningful vehicular access and egress requires that one traverse through the deepest portion of the floodplain, crossing the Carson Drain, to exit to higher land located to the south side of the floodplain. The higher ground to the north is undeveloped and lacks road access. The lot is serviced and the area has sewers. The subdivision consists of Registered Plans of Subdivision M-15 and M-16 ("Plan M-15 or M-16" or the "Subdivision").

The Carson Drain, outlets to Lake Simcoe near Killarney Beach. The southern limit of the Cooper lot is 350 feet north of the Carson Drain.

The Cooper application made to the LSRCA (Ex. 2, Tab 1) dated September 20th, 1999 shows a single family home on a Fill Construction and Alteration to Waterways application. Section "a" shows the depth of the fill, Section b and Plan 2 illustrate the plan dimensions on the lot, measuring 30 by 40 with a small garage on the south side of the property and the home located on the north side.

The CCL study

The flood plain mapping used in the Subdivision is based upon recommendations contained in the Cumming-Cockburn & Associates Limited Study on Carson's Drain (the "CCL Report", the "CCL Study" or the "Carson's Drain Study"), dated January 27, 1984. The purpose of the CCL Study was to review the 1983 flood plain model with the following objective:

…to update… the existing hydraulic model and then to assess the impact of alternative development schemes of the Regional Storm floodline. Results of this investigation would be used to determine the sensitivity of the placement of fill within the floodplain….

The result was the determination that further development could be allowed in the floodplain and the identification of areas for such development. CCL examined two scenarios. The first proposed allowing development to the 1:100 year storm flood elevation. This was discounted as allowing little net additional land for development. The second was the drawing of encroachment lines, which were based on stated criteria. There was considerable evidence from witnesses as to whether these lines were in fact arbitrarily drawn. The resulting flood level elevations increased by a maximum of .6 ft. The average velocity increased by .2 ft per second, which was considered small relative to the flow velocities in the floodplain of less than 3 ft per second. This was considered sufficiently insignificant that it would not have an impact on the erosion potential associated with the flow.

The LSRCA adopted the second scenario of the CCL Study and determined that some additional development would be permitted in the floodplain in the Subdivision. Development would be allowed in the flood fringe portion of the floodplain, so long as structures were adequately flood proofed. The placement of fill was to be allowed and required for flood proofing purposes. The CCL Study acknowledged that considerable flooding would occur, so that new development would be subject to safety hazards, where roads, lawns and driveways would be flooded.

Considerable development has occurred outside the northern encroachment line with considerably less occurring to the south of the southerly encroachment line.

Nancy Ruth Mather

Nancy Ruth Mather, having been recognized by the tribunal on previous occasions as an expert witness, gave expert evidence involving engineering, flood plain management, hydrology and hydraulics on behalf of Mr. Cooper. Based upon the information ascertained in her review of the application, refusal, applicable provincial and LSRCA policies and her review of the historic hydraulic analysis of Carson 's Drain, Ms. Mather assessed and updated the LSRCA hydraulic model.

The issue for Mr. Cooper and for Ms. Mather's firm, CPM, was to examine how the encroachment line running through the Cooper property was drawn. Based upon her review, the drawing of the encroachment line was characterized as arbitrary. Ms. Mather pointed out that the entire flood plain experiences two of the criteria set out in the CCL Study as having been part of the basis upon which the limit of encroachment was established, being areas of shallow flooding and low velocities. In her opinion, no other meaningful criteria are used by the LSRCA when considering applications for development.

The thickness of the line drawn on the flood plain mapping may also be an issue, being described as being possibly ten to twenty feet wide. Coupled with the location of the adopted encroachment line, Mr. Cooper has been unable to site a suitable building envelope. The bisection of lots by the encroachment line was characterized as impractical to apply.

The issues identified by the LSRCA in its November 30th, 1999 LSRCA Staff Report were the following: 1) The Cooper Lot is in the centre of the floodplain and at the fringe of the floodway. Permission would result in an additional obstruction of the floodway which would have an adverse impact on adjacent properties; 2) Many of the existing homes were constructed prior to the 1983 CCL Study, when the extent of flooding was unknown; 3) The encroachment line is on Lot 40, so that the development (fill and construction of a residence) on Lot 41 is outside of the encroachment area; 4) Issues of zoning and servicing are immaterial to a determination of property being located within a floodway; and 5) Staff disagreed with the applicant and hold a different opinion concerning the location of the floodway.

CPM examined the reasons for denial. They included inconsistency with Provincial Policy, in that it would involve development 1) adjacent to a watercourse upon which flooding occurs; 2) in an area identified as a floodway; 3) which may aggravate the existing flood hazard on adjacent properties; 4) for which safe access may not be available during Regional Storm conditions. The proposal was also not consistent with sections 7.1(c), (e), (f) and (i) of the LSRCA's Watershed Development Policies in that (c) there is no safe access to the building site above the regulatory flood elevation; (e) there are significant increases in upstream or downstream flooding, taking into consideration cumulative impact; (f) that there can be no balanced cut and fill techniques in this case to maintain existing stage storage of the flood plain; (i) that the proposal will cause obstruction to flow.

Once her firm examined the reasons for denial, CPM looked at the engineering analysis conducted by CCL to determine its sensitivity. Based upon the shallow flooding, low velocities and flat topography of the floodplain with no discernible valley feature, the conclusion drawn was that the model applied to the Subdivision was neither sensitive nor severe.

CPM looked at the feasibility of moving the encroachment line to a more practical location, which Ms. Mather, suggested would be helpful throughout Carson 's Drain. This approach was not readily accepted by LSRCA throughout, with the result that several versions of modifications to the existing encroachment lines were developed by CPM. Each successive proposal attempted to deal with the concerns mounted by the LSRCA.

The first analysis, "Hydraulic Analysis, Wesley Cooper Property"
(Ex. 6), January 2001

When the hydraulic model was received by CPM from the LSRCA, it was coded to see whether the topography was accurately transposed to the model. Twelve errors were shown both for the existing and for the encroachment model. Downstream of Lot 40, some of the ground elevations were found to be inaccurate. The southern encroachment line crossed over to the north side of the Drain at cross-section 1700. It is outside the Regional Storm floodline at cross section 2913 and is looped northward without topographic reason in the vicinity of section 3265. CPM corrected these and other errors.

In Table A-1, CPM drew up a summary of existing and revised culverts. The inventory shows a significant increase in the sizes of four of the culverts: Ewart Street: 5.4' diameter to 5.8' diameter; Ferrier Avenue: 4.5' diameter to 5.7' diameter; Gilmore Avenue: 5.4' diameter to 5.7' diameter; and Corner Avenue 5.3' diameter to 6.6' diameter. In the fifth case, that of Barry Avenue, one 4.0 foot diameter culvert was replaced with two 5.2 foot diameter culverts.

Once the errors were corrected on the data for the new culverts, CPM re-ran the non- encroachment model with the revised data. The results were somewhat different than what had been modelled for the LSRCA. Ms. Mather stated that, generally, the revised model resulted in lower flooding levels. Downstream of Ferrier Avenue (west end of development), levels went down by .13 feet, although one area, cross-section 1700 which is located downstream in an unpopulated area, went up by half a foot. Between Gilmore and Ferrier, within the Subdivision, the maximum decrease was .44 feet. Upstream of Gilmore, the decrease was to a maximum of .2 feet with one increase of 1 foot. This base was used by CPM, there being no reason to believe that it was incorrect.

CPM's second step was to move the encroachment line to test its sensitivity. The northern encroachment line was moved 50 feet south of the Cooper line. The southern encroachment line remained constant, with the exception of the vicinity of cross-section 1700. This approach is similar to how the LSRCA established its approved increases in flood levels with the existing encroachment lines.

The results of this analysis were increases of up to .7 feet over the revised base model. When compared with the LSRCA encroachment model, there were decreases of up to .6 foot, but largely found in the .1 to .2 foot range. As a result of this analysis, CPM concluded that the Cooper lot could be developed, without having an adverse impact on the accepted levels of the LSRCA encroachment model.

Staff Report 1-00-BOD dated January 19, 2000, prepared by Reinie Vos,
Director of Watershed Management addressed to the Board of Directors:

The LSRCA staff response is found in its Staff Report. Based upon its inquiries, the staff confirmed the soundness of the CCL Encroachment Line Study. It did agree that there was a transposition error from the HEC II model to the mapping done by Dillon, which did not change the floodway elevation. The Staff position was that the error found was not used in assessing the acceptability of the Cooper application, as there were no resulting changes to the floodway elevations. The CCL Study was found to correctly predict the floodway elevations in this area.

Chronology of discussions and correspondence between CPM and LSRCA. (Ex. 18)

Ms. Mather characterized the ongoing correspondence between her firm and the LSRCA as frustrating in the extreme. The information contained in the document varies from being historical to technical, covering changes in the floodline to increases in velocity.

Ms. Mather drew the tribunal's attention to the five terms of a Conditional Settlement proposed by Mr. Geist and CPM:

  1. A site plan for building on the property will be sited in accordance with the local by-laws to the northerly limit of the property;
  2. Any garage will be sited on the southern portion of the building;
  3. All windows will be constructed above the flood level elevation;
  4. Fill would be reduced to a minimum; and
  5. An agreement would be registered on title acknowledging that the building is within an encroachment area and releasing the LSRCA from any liability with respect to its consent to the issuance of a building permit.

Following the first Pre-Hearing Conference held on site, CPM reviewed the site along with others in the area. Mr. Geist requested a second Pre-Hearing Conference to define the issues to be addressed at the hearing and to further attempt to settle the matter. Ms Mather referred to Mr. Hill's letter on behalf of the LSRCA, wherein he expressed concern that a second Pre-hearing Conference would merely add to the costs of the proceedings without much chance of accomplishing anything of significance.

Mr. Hill stated that the proposal, rather than being a case involving the fringe of a floodplain, must be distinguished as being within a special study area, involving a virtual encroachment line. The LSRCA has limited allowable development in accordance with the parameters of the CCL Study and is of the view that construction between the encroachment lines ought not to be permitted. The LSRCA is prepared to consider that the proposed construction could be accomplished without having an impact on the control of flooding. The LSRCA regards the engineering study provided by the Appellant as unreliable and inadequate as it deals with only one side of Carson 's Drain. There are other concerns as well. He went on to state that, unless there was new evidence of further new proposals to discuss, the parties would be unlikely to reach an accommodation. He asked to be advised of the proposed agenda for the Conference, but further urged that it be cancelled all together. Mr. Hill welcomed Mr. Geist's comments on his concerns.

Second modified CPM proposal of June 19, 2001

A proposal (the "Second Modified Proposal"), followed on the heels of the first Pre-Hearing Conference held on June 13, 2001. The parties and their representatives walked through the settlement proposal from the First Analysis of the modification changes to the encroachment line. The outcome was that the LSRCA staff was not receptive, but they submitted additional information, which permitted Mr. Cooper to go back to their executive for additional review.

CPM prepared a Second Modified Proposal in which the following issues were raised or addressed: 1) the errors were corrected, including fixing of bridge sections and relocating the encroachment line where it was within the channel; 2) the culverts were updated; 3) the as-constructed road profiles, prepared in connection with culvert and road improvements, was used reflecting the latest road elevations; 4) the encroachment line was moved by 40 feet or 12 metres and in several instances followed lot lines. The issue of the north and south encroachment lines bisecting lots was raised and addressed, by following the lot lines of 22 properties; 4) the Second Modified Proposal saw 22 lots which had been bisected by the existing encroachment line as now being outside the encroachment line. Looking at the four or five not actually built upon, Ms. Mather stated that from an historic perspective, only these would be acquiring development potential.

The hydraulic implications were highlighted. The tribunal's attention was drawn to the comparison points in its Hydraulic Analysis: 1) The CCL Study approved an increase to water levels during the Regional storm to a maximum of 0.6 feet (0.18 metres). The CPM Second Modified Proposal rendered increases to water levels during the same storm event by a maximum of 0.5 feet (0.15 metres), with only two sections having increased water levels beyond those already approved. On average, the revised modelling decreases water levels during the Regional Storm event by 0.4 feet (0.13 metres). 2) The average velocity increase in the CCL Study was 0.4 ft/s (0.12 m/s). The CPM Second Modified Proposal has an average velocity increase of 0.4 ft/s (0.12 m/s); equal to the approved increase; and 3) The LSRCA approved maximum velocity increase was 2.5 feet per second ( 0.75 metres per second). The CPM Second Modified Proposal has a maximum velocity increase of .21 feet per second (0.64 m/s) which is less than what was approved by the LSRCA. These last figures were not part of the original criteria considered by CCL.

CPM concluded that there was no adverse effect from the proposal. CPM mapped the reach a distance of 3,600 feet and remained within the allowable criteria.

Staff response to second modified proposal

In the Staff Report 73-01-BOD, dated September 12, 2001 (Ex. 18 Tab W), staff indicated that it would not support the Second Modified Proposal based upon the following: 1) There was a problem between the actual and "as constructed" road elevations used by the HEC-II analysis, showing differences of approximately 1.3 to 1.8 feet. Through the use of spot elevations, similar discrepancies were identified throughout the Subdivision. The town engineers have confirmed that there was no change to road elevations when the road alignments were adjusted. Therefore, the problem arose out of a lack of a consistent benchmark; 2) CPM did not use figures using the same benchmark. Rather, it used the lower "as constructed" road elevations and the higher general topographic elevations, resulting in an overestimation of the weir flow over the road and underestimation of flood levels; 3) A consistent benchmark must be used in the analysis for a valid comparison. To be able to use the surveyed road elevation, one must also use surveyed topographic information; and 4) Flood flows do not respect perpendicular property boundaries, so that proposed placement of encroachment lines is not an accurate reflection of what will occur during flood conditions.

The Executive Committee of the LSRCA turned down the application, by a vote of 8 to 7 on September 24th, 2001.

Third proposal

The crafting of the Third Proposal came to light only after the commencement of the hearing before the tribunal on January 11, 2002, during the presentation of Ms. Mather's evidence. Proceedings were adjourned to provide for service of background modelling information to the LSRCA, in order that it would have opportunity to prepare its cross-examination.

In the Third Proposal, CPM reverted to the old road profiles, being those in the Original LSRCA model and its own First Analysis. CPM acknowledged the differences in the old road profiles where the road reconstruction could not be replicated and ran its analysis again using the higher road profiles. It retained the correction of various errors and new culvert data. The northern encroachment line remains some 35 to 40 feet (15 metres) south of the LSRCA position, but there was modification to several of the lot lines, which had been, proposed to be followed in the earlier Second version.

Even with the higher road profiles and reversion to the existing encroachment lines in two, possibly three areas, Ms. Mather described the changes, as being within the range found acceptable in the CCL Report. To reiterate, those areas, which experienced increased flooding did so to a maximum of .6 feet. The acceptable increase, in velocities were described as being below .2 ft per second, which was similar to that of the CCL Study.

The Third Revision would affect five other properties in addition to Cooper, most of which have existing structures. If the LSRCA had approved the application, it would not be addressed in isolation, but rather through the whole reach. This is very conservative in terms of allowing the development. The hydraulics for those properties have already been evaluated. The cumulative impact of the Third Proposal would be minimal.

The storage and passage of water issue, namely the width of the floodway, is tied to increases in the level of the water and of the velocities of the flow. The LSRCA has already approved and recognized the loss of the floodway. It has demonstrated in other applications that it is prepared to accept some loss of storage capacity and some flooding to existing buildings. The CPM work attempted to stay within the parameters, and showed incremental and minor increases when compared with the CCL report, which has been approved an implemented.

As to the matter of access, all of the roads in the Subdivision would already be inundated during the Regional storm. Along Gilmore Avenue, water levels would not change under this proposal, compared with the Original LSRCA encroachment model, there being less than an inch difference between them. There are existing constraints to the homes north of Carson 's Drain.

As to precedent, Ms. Mather stated that the proposal is looking at the "whole reach" perspective. If approved, it might be precedent setting for three or four properties but most of the properties upon which there is an impact have already been built upon.

Ms. Mather stated that the current LSRCA line runs through a number of lots, which may be practical but cannot be implemented. The line itself is arbitrary. Ms. Mather maintained that the establishment of the line is not sufficiently specific to have to be set at that exact location. The issue should be regarded as one of implementation and she suggested that the matter of practicality does not appear to have been taken into account the first time. In Ms. Mather's estimation, the Third Proposal is reasonable and the circumstances unique.

In its activities on behalf of Mr. Cooper, CPM has updated the existing floodplain modelling several times in its various attempts to deal with the concerns of the LSRCA. In Ms. Mather's opinion, the real issue in this matter is the definition of the floodway, which in her estimation, was initially established in a largely arbitrary manner. Therefore, by making minor refinements, the conclusions of the CCL report would not be compromised.

Ms. Mather discussed several properties, those of Graham, Green, Simpson and Valcheff, located fully within the floodplain, whose earlier refusals would not change as a result of permission being granted in this appeal. Ms. Mather also referred to the case of Hampshire v. LSRCA, which involved obtaining a permit to build on the lakeshore, which was ultimately successful because the LSRCA acknowledged and accepted the impact of a modelling plotting error, which was resolved in favour of the applicant. The Allerton and Sprague applications, which are located further north on Ewart were both initially denied but ultimately received approvals on the basis of changing their policy regarding the drawing of the floodline in the area. The change to the encroachment line and approval in this case would have no impact on flooding, as the LSRCA has a policy and practice of allowing development in this floodplain. Having worked within their own previous proposal, Ms. Mather believes that this situation is unique.

Mr. Hill request for adjournment

The matter was adjourned, over the objections of Mr. Geist. The tribunal was satisfied that the issue was one of sufficient importance that the LSRCA staff should have adequate time to review and instruct counsel accordingly.

Cross-examination of Ms. Mather

Under cross-examination, Ms. Mather agreed that the flood during the Regional storm would extend to the site and the road. The distance from the northern edge of Cooper to the north limit of the floodplain is 835 feet. From the southern edge of Cooper, it is 870 feet to the south limit of the floodplain. The low depth at the CPM model of the regional storm was 738.96 feet. The spot elevation at the front of the property is 739.26 feet. The elevation of 736 commences two lots to the south and winds up at the frontage. The road in the model is 738 feet. Notwithstanding the model and the road elevations, flooding is anticipated.

Generally speaking, it is unusual to permit new construction in the floodplain. The CCL Study established areas where encroachment would be permitted, with the agreement that it would be important to leave other areas unobstructed. Allowable activities concerning existing buildings are not what are at issue, notwithstanding the current situating of the Cooper property within the floodway. The purpose of the various proposals, if accepted, would result in certain lots, such as Cooper's, being excluded from the floodway limits. Ms. Mather stated that by moving the floodway to a lot line within the Subdivision, as opposed to limiting it to Cooper's Lot, would allow the issues of cumulative effect and encroachment to be dealt with.

Ms. Mather described in detail the locations of those lots affected by the existing encroachment line and the First Analysis. Through the Third Revision, many of the lots affected were once again removed, as a result of its discussions with the LSRCA. Although CPM regarded its figures as being within the parameters set out in the CCL Report and with past approvals, it nonetheless did not think that the LSRCA would accept increases to depths of flooding in excess of .5 feet.

In the response of the LSRCA Regulations Officer, Mr. Tom Hogenbirk, to receiving the Third Proposal, on January 25th, 2002 (Ex. 20), a number of errors in the modelling table were pointed out, which, when corrected, would allow the LSRCA to review and comment. Ms. Mather stated that this was among the first of such letters, which provided CPM with detailed comments on their previous (Second Modified Proposal) August model. She stated that most of the errors appeared to be an understatement of the width of the floodplain when compared with the width it intended to use according to its map. The corrections were made, despite the fact that this would tend to understate the flood impact, whereas a wider area for flow might indicate lower flood level elevations. CPM re-submitted the results and its conclusions for consideration (Ex. 21). The conclusions did not change and were still in line with the range of allowable increases adopted from the CCL Report. Ms. Mather explained that the newer and additional culverts allowed for similar results, even with a narrower channel.

In his February 26, 2002 , response (Ex. 22), challenging the parameters for the comparison conducted by CPM Mr. Hogenbirk stated that it is not a fair basis for showing the impact of the proposed changes. The comparison is between the original CCL encroachment results and the CPM Third Proposal encroachment results. He suggested the proper course would have been to compare the original, but corrected CPM (i.e. errors and culverts) with the approved encroachment lines. Then, these results should have been compared to the CPM revised model run with the proposed encroachment lines. He indicated that the LSRCA has run the CPM revised model with the approved encroachment lines. The result is that most cross- sections show increases in flow velocities and flood levels, which would be in addition to the existing levels caused by the approved encroachment lines.

Exhibit 23, prepared by Ms. Mather, is a Comparison of Carson's Drain Hydraulic Modelling. There are five models shown, with three comparisons made. Model 1 is a representation of what is believed to actually occur on the ground under Regional Storm Conditions, as modelled by CCL. Model 2 is the CCL Study, with the approved encroachment lines added. Model 3 is the CPM 2001 model, in which corrections have been made and culverts updated. Model 3 represents an updated version of Model 1, showing how the floodplain will in fact operate. Model 4 is the CPM model with the proposed revisions to the encroachment lines. Model 5 is the CPM pre-encroachment model with the addition of the LSRCA approved encroachment lines added.

The three outcomes are described. 1) CCL results with the approved encroachment line, project a maximum Regional Storm elevation increase of 0.6 ft and an average velocity increase of 0.4 ft/sec in the upper reaches. 2) CPM results, using corrected floodplain data and proposal, project a maximum Regional Storm elevation of 0.6 ft. and an average velocity increase of 0.4 ft./sec in the upper reaches. 3) CPM and LSRCA adjusted encroachment line comparisons results in increases in the Regional Storm elevations of .09 ft or 1 inch and velocities increases, the latter of which are less than those approved in the original study.

According to Ms. Mather, the LSRCA had no concerns with Model 3. Model 4 is Mather's version of the addition of the revised encroachment line, settlement proposal and with revisions from the February 2002 model. This comparison met the pre-existing thresholds. Ms. Mather stated that her conclusion was that if the increases which had been deemed acceptable by the LSRCA, it should be regarded as an acceptable basis for the encroachment line. The LSRCA maintained that Model 5 was the valid comparison, which resulted in some net increases to depth and velocity.

The position of the LSRCA came as a surprise to CPM, which felt that it should have been made aware of the fundamental basis for their comments much earlier in the process. There was no ad item (consensus) as to which of the various models should be used to form a valid comparison. The rationale of the LSRCA was that any new proposed encroachment would have to withstand its current criteria of no increases. To see the impact of encroachment lines, one would compare the existing encroachment line, which was further updated with culvert and error correction data with the proposed encroachments. CPM does not agree that this is the appropriate comparison to determine the impact of the proposal.

Ms. Mather was not in possession of Mr. Hogenbirk's results or his model, nor did she ask for them. Asked about the increases predicted by Mr. Hogenbirk, she stated that the original CCL study acknowledged that there would be increases and the question, which it, addressed was the extent of such increases, which would be acceptable. The CPM proposal moves the encroachment line further, but still meets the tests of the original study.

Ms. Mather did not take into account the impact of additional construction and the placement of fill since 1984 within the floodway as it has not been allowed. She did not check to see whether any such activity took place without permission. It was explained that the model takes the flood fringe out of the model so that it does not reflect either construction or loss of flood storage, which might have taken place since that time. Ms. Mather stated that CPM looked at whether Mr. Cooper could build as is, without the addition of fill in the existing floodway and without moving the line as it bisects his lot. CPM's conclusion was that it was not practical.

Re-direct of Ms. Mather

Ms. Mather clarified that the Third Proposal no longer redraws the encroachment lines around many of the lots bisected by the existing encroachment line. It was in the Second Modified Proposal where CPM had proposed that all of those lots bisected be affected. This is no longer the case. Of those lots affected by the Third Proposal, some already have large structures and others would likely receive approval due to the orientation or extent of the lot found in the floodplain. Therefore, of the initial 22 lots, which would be affected by the CPM proposal, there are only two totally vacant lots, being that of Cooper and Lot 28 on Plan M-16. It is unclear whether Lot 28 is included in the lands held to the adjacent Lot 29, where a house is located. Ms. Mather stated, contrary to Mr. Hill's assertion in his letter of June 5, 2000, wherein he stated that there were other vacant lots in similar situations, only two lots would be affected by the proposal. In Ms. Mather's opinion, given the limited number of lots in the Subdivision, it would not be precedent setting to allow the building on one or two lots out of potentially 190 existing lots.

Referring to the provincial policies, Ms. Mather stated that this area is treated as a two-zone approach, having a floodway and a flood fringe, with development allowable in the fringe, with adequate flood proofing. The Provincial Floodplain Planning Policy Statement, Implementation Guidelines, Appendix B Two-zone Approach and Appendix C, Special Policy Area were referred to, with certain portions read into the record. Principles highlighted include provision of order and equity in the use of flood plain lands, and protection of society, including public institutions from having to bear the costs of what are characterized as "unwise individual choices". In the Implementation Guidelines, the rationale for the two-zone concept was referred to. Factors to be considered when analysis is undertaken of local conditions include critical flood depth and velocity, as they impact on threat to life and property, the extent of existing and proposed development and potential upstream and downstream impacts. It is not necessary that the two-zone approach be included in an Official Plan before being utilized. Ms. Mather stated that the CPM applied this in developing the approached used. Ms. Mather also referred to provisions of the Special Policy Area discussion.

Ms. Mather confirmed that no two-zone approach had been approved for this area. Rather, the policies utilized by the LSRCA are analogous to a two-zone policy. There is no evidence that this is a Special Policy area, which would have required the participation and approval of the Ministries of Natural Resources and Municipal Affairs and Housing.

Ms. Mather referred to Graham v. LSRCA, MLC , (unreported), (October 3, 1989), where Commissioner Ferguson noted that the LSRCA's policy for this area is "somewhat analogous" to a two-zone policy. Similarly, in Ditta v. LSRCA, MLC , (unreported), (October 28, 1988), it is noted, that:

These lines represent an area on which flooding in the event of a regional storm would not increase more than one-half of a foot and the respondent adopted the lines as a matter of policy and has treated lands above the encroachment limits as a special policy area.

In Valcheff v. LSRCA, MLC File No. CA 008-95, unreported, April 1, 1996, the tribunal noted that the Carson's Creek area, "a central floodway zone and a flood fringe zone were designated after a January 1984 Flood Plain Management Study by Cummings-Cockburn and Associates Limited." prohibited or restricted.

Thomas George Hogenbirk

Mr. Hogenbirk, a professional engineer and Regulations Officer with the LSRCA, was recognised as an expert witness by the tribunal in matters of flood plain management engineering, hydrology and hydraulics, having been so recognised in previous matters. He described the general drainage pattern in the Carson's Drain area along with flood characteristics on the subject property anticipated during Regional Storm conditions, which is based on Hurricane Hazel. The total drainage area upstream is three square miles, with flow moving from west to east. There is a significant off-site drainage area, so that area under discussion depicts only a small portion of what is involved. Modelling of the Regional Storm flowing through the area predicts the overtopping of several roads and flooding through the built up area. A very wide floodplain would be involved and would continue downstream draining into Lake Simcoe.

The anticipated flood depth on the Cooper property is in the order of two feet, with flooding expected on the road in front of the property as well, to a depth of approximately one and a half feet.

Mr. Hogenbirk stated that the purpose of the 1984 Carson's Drain Study was to recognise the built-up nature of this area and to help as much as possible to benefit the existing landowners within the floodplain. The purpose was to allow those landowners to build out using criteria, which would normally not be allowable, but for this special treatment. The general premise was to develop a measure by which as much of the development as possible could occur within the edges [indicating flood fringe], without having a detrimental effect on the flood elevations which would be experienced under a Hurricane Hazel type event.

Mr. Hogenbirk explained that the consulting engineers looked at several conditions in establishing the encroachment lines. They eliminated the spillways, so that no water is shown pouring out of these areas whereas under actual conditions, water would continue to pour out. However, much of the spill area will have already been filled with water, so that to be conservative and realistic, one cannot assume that the wall impeding the flow of water will be there. Secondly, they looked at whether the 1:100 year limit, as opposed to the Regional Storm of Hurricane Hazel, was a reasonable encroachment limit. The extent of flooding of the 1:100 year storm was examined throughout the area, and it was actually determined that there was no benefit at all to the landowners because this storm still causes flooding over an extensive area. Even with the elimination of the 1:100 year storm it was still not found to be sufficiently beneficial to many of the landowners who would have liked to have developed their land.

The approach in drawing the encroachment lines was to eliminate areas where the resultant flooding would be of shallow depth, such as on the edges of the existing floodplain. Such areas would clearly be considered as fringe areas. Similarly, the engineer excluded from the modelling those areas, which had fringe-like characteristics. As those areas are eliminated, one begins to establish what become known as the encroachment lines, which for purposes of the model means that an artificial wall is created. As one moves in from the outer limits to the watercourse, presumably moving in equidistant from both sides, one begins to develop what would be a reasonable location for the encroachment lines. The encroachment lines were drawn without any reference to existing lot lines within the Plan. The location of this artificial wall is then programmed into the model and it is determined what kind of flooding would be associated with such lines within the centre of the floodplain, or what is known as the floodway. At the point at which the lines are accepted, thus becomes the established line.

The Carson's Drain Study is used by the LSRCA to establish a floodway and flood fringe. Development has been allowed in the fringe without restrictions, through unlimited placement of fill and construction of whatever size residence. It is treated the same as any other normal development site, with the exception that it must be flood proofed to the expected Regional Storm elevation, and have minimum opening elevations set to above the regional flood level.

In the separate area called the floodway, no new development is allowed. Additions to existing homes are allowed provided that they are built in an area, which would not obstruct flow to any greater degree than currently occurs. There can be no placement of fill. Decks are allowed because they do not obstruct the flow of water. Sheds are allowed where they are located immediately behind the house, so that they do not obstruct flow. In general, however, new structures have been refused, where it is for a new home on a vacant lot.

Mr. Hogenbirk explained that, while the LSRCA is being very permissive in the flood fringe areas, the model requires that it be extremely strict in the floodway area. Should the LSRCA lose control over what happens in the floodway, the result could be that the actual flood line limits would shift outward. Essentially, the floodplain could become broader than according to current projections.

The Carson's Drain is not an official two-zone area and is not indicated as such for municipal purposes. The Carson's Drain Study and establishment of encroachment lines allows the LSRCA to treat the area inside the encroachment lines as the floodway and the outer area as fringe. In effect, the LSRCA is applying an analogous two-zone approach.

Anyone wishing to enter or exit this area would have to travel some distance through the floodplain, which would affect safe access. With the exception of emergency helicopter access, the road access is from the south. This means that anyone wishing to gain access would have to travel through the deepest part of the floodplain to access those homes on the north side of Carson's Drain.

Mr. Hogenbirk expressed concerns regarding the impact of the Cooper proposal on flood storage. Being within the flood fringe would permit large quantities of fill to be placed well in excess of that required for construction of the house, whether on the Cooper lot or on others, currently in the floodway, which already have existing structures. The whole lot could be filled or a pool could be installed. The potential was described by Mr. Hogenbirk as allowing a wholesale filling of the backyards, in the form of fully raised areas of depths of two or three feet of fill, which would severely impact on storage capacity. Any control currently exercised by the LSRCA would be lost, well beyond the requirement for flood proofing and openings at a minimum to the regional floodline elevation. The proposed movement of the encroachment line along those lots affected, as presented by Ms. Mather, would have further impact on the available storage capacity. It is recognised that the establishment of encroachment lines would cause storage within the floodplain to be lost. Moving the line would cause further encroachment, resulting in further loss of storage beyond what has been recognised as acceptable. Also, it is unrealistic to allow the floodplain to move at right angles, rather than following the natural contours of the land. Any movement of the encroachment lines would serve to further constrict flows.

Mr. Hogenbirk indicated that he would have very strong concerns with the obstruction of flows if the proposal were allowed. The area was modelled back in 1983. It has been remodelled as a result of this proposal. Some errors were corrected. Some changes were made in terms of the culvert sizes. The modelling done by CPM presumes a benefit to the area, but this should be viewed from a strictly modelled perspective. This approach allows one to ignore the possibility of the illegal placement of fill and other "detriments" which may have occurred without record. Many would be well beyond the Statute of Limitations to prosecute and seek their removal.

However, taking the model itself, and applying the current encroachment lines, results in a slight reduction in the floodline levels, which translates into a net benefit to the people in this area as a result of changes made to the culverts. The aspect of the CPM proposal of concern to the LSRCA is to use this net benefit and further constrict flows, so that the area is being returned to the old flood line elevations of 1983. Mr. Hogenbirk stated that the purpose behind implementing the CCL Carson's Drain Study was never to increase floodline elevations in the area. Rather, it was to allow some development in the area. There was never a target of increasing flood levels through the area and under current LSRCA policy, no flood level increase is permitted.

The initial intent of CPM in its First Analysis model was to move the northern encroachment line significantly and to not move the southern one. The Second Modified Proposal was to move the line back and do an equal amount of restructuring, effectively moving in on the encroachment line on either side. CPM obtained "add fill" drawings from the municipality which showed that according to the benchmark which had been used, a number of the roads in the area were significantly lower, in the order of a foot and a half, to what was shown on the original CCL Report model. At a time when one is talking about inches, a foot and a half through a profile is a big difference. The LSRCA did not expend a great deal of effort reviewing this model because the discrepancy in elevations was so inexplicable that it did not make sense. Two possible explanations were discussed. There could have been a relative difference throughout the area, which could be rectified only through a complete remodelling with new floodline elevations determined through a new benchmark. This would permit an evaluation of the relative impact of the proposal. The other alternative was to return to the original road elevations based upon the original 1983 benchmark.

Mr. Hogenbirk explained the significance of the road elevations. They will have a direct impact on flood elevation, because the roads act like weirs. If the road elevations drop, so do flood levels. The LSRCA conveyed its concerns, pointing out that it was the relative difference in elevations, which was critical. After the Second Modified Analysis, CPM had two choices, namely to go back and re-survey some of the area to determine the true and proper contours throughout, or to revert back to the old contour/road elevations for use in their model. CPM reverted to the old road elevations in its Third Proposal. The culvert elevations were kept slightly lower, but since the culvert flows are very insignificant based on the actual regional flow through the area, this was not sufficiently significant to pursue.

Mr. Hogenbirk stated that he reviewed the Third Proposal in considerable detail. He had concerns with the selective manner in which portions of the model had been left unmodified depicting the old encroachment limit and other portions changed to show the proposed limit.

In his January 25, 2000, letter (Ex. 20) to CPM, Mr. Hogenbirk set out in table format a list of errors at corresponding cross-sections. Also discussed was the width of the channel, which would have permitted water to flow across the spill zone. Mr. Hogenbirk also was concerned about the proposed narrowing of the channel, which would have an impact on flood flows. CPM reverted to the approved encroachment lines in several areas as a result.

Mr. Hogenbirk explained that the base model upon which comparison was to be made had been changed [also set out in his letter of February 26th, 2002 (Ex. 22)]. CPM made the corrections and modified the culverts using the old CCL non-encroachment model. It then ran its proposed encroachment lines and mapped them onto the corrected model. CPM's basis for comparison was the corrected non-encroachment model with the proposed encroachment model.

In Mr. Hogenbirk's opinion, the only way to see the impact of the proposed lines versus the approved lines is to work with the same base model and put the two encroachment lines on it. In other words, one should update the old non-encroachment model with corrections, run the model with the pre-existing approved encroachment lines, then run it again with the proposed encroachment lines. The basis for comparison should be the two encroachment line models, namely the corrected, but approved LSRCA model, with the proposed model. According to Mr. Hogenbirk, to do otherwise, would result in increases nested in the results of the approved encroachment lines. When the floodway is further constricted, an increase will be shown in comparing the two models. Mr. Hogenbirk's concern is that the area already shows an increase. The further encroachment will cause further increases. The concern was that it is making a bad situation worst by increments, which is something the LSRCA is unprepared to accept.

When asked for clarification by the tribunal, Mr. Hogenbirk stated that he took issue with the table, which compared the new CPM model with the old CCL model. This was because the base model had been changed by CPM. They corrected a few errors, increased the sizes of some culverts, resulting in changes to the base model. According to Mr. Hogenbirk, it doesn't make sense to go back to the base model ever again. Now that one has updated the model, which he termed "a proper model", in order to do a fair comparison, the new encroachment model must be compared with the proposed encroachment model. By using this approach, the same base model is used. At this point increases and decreases can be compared, using two equivalent models with the same base information and two different encroachment limits. This is what Mr. Hogenbirk did; comparing the two models with the same base information with different encroachment limits. He found that there was an increase, namely a general trend towards increases throughout, either in velocities or flood elevations. This occurred throughout the CPM model when compared to the LSRCA model.

Returning to the real floodplain issues, the model, according to Mr. Hogenbirk, is only one tool. This model does not account for any of the structures within the fringe. It assumes that the floodway is a proper floodway, namely a free-flowing channel, with no obstructions, no trees, no fences, no sheds, no gardens. If you took that as a modelling exercise, you might be able to show that some further encroachment would not have an impact. But, in reality, this is not the way that it is. This is not an ideal floodway. This is fully constricted, developed to an extent of between 60 to 70 percent, with some vacant lots, some smaller homes and some bigger homes. A restrictive situation already exists and further constriction will have an impact. The model may suggest that further encroachment on it will have an insignificant impact. However one must keep in mind the reality of what actually exists.

Returning to Exhibit 22, he stated that the proper comparison demonstrated a general increase in flood elevations and velocities, both overbank and in the channel. So it cannot be said that further encroachment will have little impact. The water must go somewhere. The further encroachment into the floodway, the further it will spill over into the flood fringe. So, typically, velocities and elevations increase. Often, it is a combination of the two. But the same amount of water is being forced through a decreased flow area. That includes all existing buildings and whatever other development is already on-site. The tables referred to in Exhibit 22 were taken directly out of the HEC II model. They are simply a comparison between the LSRCA approved encroachment lines and the CPM encroachment lines, using the same cross-sections. The bolded numbers indicate observed changes. Some, he conceded, are minor, but some are significant. But, part of this activity is to realize that those numbers depicted on the left are already an encroached floodway, with increases nested into those numbers shown. What is shown on the right is an additional increase beyond what would have already been occurring if the original encroachment lines were used. One must look at it in terms of whether it is significant, realising that this is merely an additional increase, not the entire increase.

Mr. Hogenbirk explained what he meant by "significant increases". He stated that his primary concern was an increase in velocity. Looking to section 3110, it shows an 1.2 foot per second increase. If you look at the overbank velocities, it is significant. Examining flood levels reveals an increase. This is not a coincidence; it is depicted as though the floodway is being squeezed in an area, as opposed to what was an actual opening up of the floodway. This "squeezing" causes velocities and elevations to go up. This cross-section is one of the worst areas and is of real concern. There is already a house in this location, but the proposal would allow full development of the rear of that lot, including the installation of any kind of pool, which would allow the placement of fill throughout.

Mr. Hogenbirk concluded, based on the additional work done by CPM, that the original CCL Study was correct. There were some minor changes as a result of some coding errors in the original model but the effect of those corrections was insignificant. He is quite satisfied with the original model and how it worked out. Mr. Hogenbirk did not feel that the information provided on behalf of the appellant addressed his concerns. Specifically, the benefit which has accrued to the area as a result of the culvert work and corrections of errors should not form the basis to go back and change the established encroachment lines to revert to greater flood levels, which would occur if the proposal were accepted. It would not be consistent with the LSRCA policy as it now exists. The other aspect in this proposal is the general loss of storage as a result.


Mr. Hogenbirk stated that he has never undertaken any field study of the floodplain covered by Carson's Drain. His familiarity is general, having been in the area. The area of the floodplain of Carson's Drain, is not bounded by hills or cliffs. The creek itself is in a channel. There is a significant rise once one moves to the north and an even more significant rise to the south. However, throughout the floodplain, it is relatively flat. Mr. Hogenbirk did not agree that it is a shallow floodplain, as flooding over significant portions of it exceed two feet. Mr. Geist suggested that CCL described it as shallow and flat. Mr. Hogenbirk responded by stating that one could use the term "less than one metre" which is the LSRCA criteria for building lots. If this is the case, then it is certainly less than one metre for the most part. He also agreed that there were low velocities in the area.

Asked whether the subject lot is located in the flood fringe, Mr. Hogenbirk stated that it appears to be half in the fringe and half in the floodway. Mr. Geist challenged the response by referring to the November 30th, 1999 Staff Report (Ex. 2, Tab 7) where Mr. Vos stated at page 28: "This property is located in the centre of the floodplain and on the fringe of the Carson's Drain floodway". According to Mr. Hogenbirk, this statement indicated that the property was located on the edge of the floodway. He did agree that the CCL Report acknowledges that there can be encroachment within the floodplain without a significant change to the regional storm flood line.

There are no identifiable features on Lot 40. There is no high water mark, because such would be indicative as a result of relatively recent flood events. There is no bank on the property. There is no ridge. There is an abutting house to the south, a house in behind to the east, one directly across the street, at least by half, as well as the house on fill to the north. The lot, in other words, is surrounded by existing homes. This can be described as an infill situation, in terms of other buildings in the area.

Referring to the home built upon fill immediately to the north of Mr. Cooper's lot, Mr. Hogenbirk agreed that it was built in the floodplain, but outside of the floodway. He stated that the placement of fill involved did result in loss of storage, but that this had been recognised and accepted by the CCL Report. Changes within the floodplain in the area defined as the fringe are deemed to be acceptable. Unsure of an exact number, Mr. Hogenbirk responded that ten was a conservative estimate of the number of new homes constructed or alterations to existing homes which have occurred in the fringe. He estimated that ten homes have been allowed to be built on Gilmore Avenue itself. Given the location to the north of Carson's Drain, most of those in new homes would have to cross through the deepest part of the floodway to be able to exit the floodplain, having to pass Mr. Cooper's lot to do so. Mr. Hogenbirk stated that it was also possible to head north, although one could not drive to safety.

Mr. Hogenbirk agreed that the LSRCA recognised the risk in allowing development along the northerly portion of Gilmore Avenue. Notwithstanding that they would have further to travel by car, Mr. Hogenbirk stated that the situation was less risky, because those home owners would have much closer to travel to the northern edge of the floodplain. Large emergency vehicles can get through in depths up to .9 to 1.2 metres, or 3 to 4 feet. However, in an emergency evacuation situation, helicopters can be used.

Carson's Drain is a maintained watercourse, which is dredged and straightened. Its banks are steeper on the north side than on the south and there is a discernible grade to the Drain. Based upon the elevations shown, Mr. Hogenbirk agreed that the left side of the bank (north) was receiving fill from dredging and further agreed that, should any overtopping of the Carson's Drain occur, it would happen first to the south. Mr. Hogenbirk pointed out, however, that the water will also back up through the ditch and over the road.

Mr. Hogenbirk did not agree that the previous decisions and policies of the LSRCA would remain intact with the revised encroachment lines proposed on behalf of Mr. Cooper. Once one starts to move the line, questions will arise concerning any property along the encroachment lines. It is a slippery slope.

Mr. Hogenbirk stated that the characterisation by Ms. Mather of the drawing of the encroachment line as arbitrary suggests that there was no rationale behind it, when in fact there was. Mr. Geist suggested that Mr. Hogenbirk never did respond to Ms. Mather on this issue. The definition of "shallow" and "low" is found at line 1 of the CCL Study, page 2, 5.1.2: "removal of areas where flooding is shallow and the flow velocities are low." Asked what this meant, Mr. Hogenbirk stated that it was open to interpretation. The encroachment line was set, through a series of approaches by which they initially looked at the 1:100 year event and tried to determine whether it was a worthwhile encroachment limit. It was found to exclude most of the lots within the floodplain for further development. Then, another case was looked at, whereby an artificial wall was generated, and it was approached from two directions, slowly moving towards the watercourse and to determine the point at which the flood levels jump up significantly. That is the point, which is defined as the "limit of encroachment". The line which was taken as the decision from the LSRCA was a whole series of factors pertaining to that floodplain to assist in the establishment of the line the model was developed.

In correspondence found at Exhibit 18, Tab M, a letter to CPM dated April 25, 2001, which Mr. Hogenbirk signed, the following paragraph was read into the record:

In general the encroachment lines were set at equal distances from the centre of the creek, wherever possible, through the built up area, Plans M-15 and M-16.

Mr. Hogenbirk was not sure whether the measurements taken were from the toe of the slope, the top of bank or some other point of reference. He responded that, if one looks at the Plans themselves, in most instances, there are equal amounts of floodway on either side of the creek, so that it is not a matter of whether it is the centre line of a one metre wide creek. Mr. Geist pointed out that the opposite sides of the Creek are not identical, but similar. Asked again, whether it is from the top of bank to top of bank, or in general from the centre, Mr. Hogenbirk stated that it is actually neither. It is measured from the chainage of each station in the HEC2 model. There is a zero chainage starting in this case on the south side and working northward. In terms of establishing a reasonable location when looking at this, one does not automatically take the top overbank at the north side and cut in half the size of the overbank on the south side. The approach is, if both sides are equivalent in terms of areas, to have the equivalent areas on either side of the creek as the floodway approach.

However, Mr. Hogenbirk agreed that the line does move, but not from where it is measured. The point from where the encroachment line is established is from station "zero/zero" which is the south limit of each one of the cross sections. The line is established at zero and then measured precisely. So many feet from that point is the first encroachment line. So many more feet is the second encroachment line and so on. The fact that it tends to be equidistant between the creek centre line and the north line and between the creek centre line and the south line represents the general approach used. However, the actual siting of the lines is done from a common station at the south limit of the cross sections.

Referring to Exhibit 2, Tab 5, Mr. Hogenbirk estimated that the thickness of the floodway line on the Cooper property was about 20 feet, but agreed that it could be more. He was asked from which side of the line should measuring be done from. Conversely, the line shown on the second last page of Tab 7 appears to be in the order of 10 feet.

According to Mr. Hogenbirk, the increases to the regional storm water level and velocities within the floodplain range across the board. Referring to the CCL Study, he read into the record:

The results of the regional flood profile computations as summarized in Table 1 indicate that the maximum increase in regional storm flood elevations would be .6 of a foot. This is immediately upstream of Allan Avenue, along the lower reach of the drain, downstream of Ferrier, the maximum increase in only .2"

Mr. Hogenbirk reiterated the position of the LSRCA, namely that it has accepted and implemented the location of the encroachment lines established by the CCL Study. This is in contrast to the position advanced on behalf of Mr. Cooper that the LSRCA has accepted increases in water levels and velocities of set magnitudes. The resulting increases were not the target, nor the purpose of the study. The purpose of the study was to establish the development line.

Mr. Hogenbirk stated that the summary in the CCL Study was of the result of the selected encroachment line. The .6 was merely the target. And this target will increase velocities. Mr. Hogenbirk maintained that the CPM Third Proposal will result in an additional increase beyond what would have been experienced and was challenged on this response. Mr. Hogenbirk conceded that, had these been actual targets set by the LSRCA, then the criteria would be met. However, he stated that he did not believe that the new proposed encroachment line would be consistent with the approach taken by the LSRCA in its having adopted the CCL Study. Asked how many lots would be affected, Mr. Hogenbirk stated that the approach was to do an entire detailed study of existing conditions. What was used was the topography existing at the time, effectively a snapshot.

The Subdivision is not being treated as a special policy area, but is being treated analogous to a two-zone approach. Asked whether access issues have changed from the approved encroachment line, Mr. Hogenbirk stated that by allowing Mr. Cooper to build creates another instance of poor access. Mr. Geist pointed out that this is exactly the same situation as with those homes to the north on Gilmore Avenue which have received approval.

The LSRCA does permit additions and improvements to existing dwellings within the central floodplain, provided that they don't obstruct any additional floodway. This was the case with Lot 72, because it had sufficient land outside the encroachment lines to make this possible. Although he could not tell from the photograph, Mr. Hogenbirk stated that it appeared that the driveway was to the south, so that construction took place outside the floodway and that this was a reasonable approach.

Mr. Hogenbirk reviewed the conclusions of the CCL Report. These were that flooding is shallow with low flow velocities. The second scenario examined showed that there could be significant encroachment into the floodplain without causing significant increases in the flood line elevation. Nor would there be a significant increase in erosion as the average increase in flow velocity would be .2 feet per second. Isolated areas of fill could be allowed, so long as structural flood proofing was undertaken at each site. Notwithstanding the placement of fill, anyone developing within the floodplain would be at risk to safety hazards, such as flooded driveways, roads, and lawns.

According to Mr. Geist, the CCL Report has deemed increases to be acceptable. Mr. Hogenbirk continued to take exception to the Cooper proposal, which, according to the site plan submitted, is for a house which fills the entire lot and then the rest would be filled to the order of two feet. It was acknowledged that Mr. Cooper did write and did seek and acknowledge a willingness to make accommodations, that he was willing to flood proof, and that minimum openings would not be below the regional storm elevation, along with acceptance of liability on title.

Mr. Hogenbirk maintained his position that to alter the encroachment lines in keeping with the targets for flood depths and velocities set by the original CCL Study, the policies of the CCL Study would not apply. He reiterated that the CCL Study represents a snap shot of the floodplain at that time. To alter the lines would require a comprehensive assessment of all changes in the floodplain which have taken place since that time. In so doing, the LSRCA would be required to apply a whole set of different criteria. The current CCL model is outdated in terms of allowances for increases throughout and did not include existing structures. The old approach assumed that most of the areas were open, with cottages, which occupied very little in the way of a footprint. He stated that any new study would have to fall under the current LSRCA criteria and would need to show structures. That is how flood reduction studies are done in today's terms, in that the structures have a huge impact, so if the model was done today, it would be done with current criteria.

It was pointed out that the purpose of the proposal was not to start up a new model, but rather to work with the model established by the CCL Study and applied by the LSRCA. Mr. Hogenbirk agreed that the LSRCA acts on encroachment lines established in 1984. Asked for an explanation as to why the limits which would be acceptable in today's terms are different from those accepted before, Mr. Hogenbirk merely stated that those are the limits of the study and those are the limits which the LSRCA works with. Asked if the proposal were still within the criteria set by the CCL Study, Mr. Hogenbirk responded that the intention of the Study was to not cause increases through the area.

Mr. Hogenbirk stated that the benefits, which have accrued to the area as a result of the improvements made to the culverts, which have caused flood levels to drop, should not be utilized in such a fashion so as to eliminate those benefits. To do so would, in his opinion, be a mistake.

Returning to the fact that the lot lines had been ignored in the regional study in 1983, Mr. Geist pointed out that the purpose of the study had been to deal with development opportunities to benefit the Lefroy community. Mr. Hogenbirk disagreed with the suggested approach of having the encroachment line follow lot lines because the LSRCA could be accused of going to an artificial line. A lot line would stand in artificial contrast to establishing an encroachment line based on all the other measures which result in extremely smooth lines delineating the floodway. The LSRCA does not have it jogging in and out around lot lines. That was the idea behind a floodway type of approach.

The CPM Third Proposal of February 2, 2002, showing increases in depth of less than or equal to .6 feet and velocities of less than or equal to .4 feet per second. Asked whether these were similar to the CCL Report, Mr. Hogenbirk reiterated his position that the encroachment lines were set and whatever increases resulted were accepted at the time. It was pointed out that those increases have not changed, that no resolution has been put before the Executive, no changes have been made to the criteria and the depths and velocities remain the same.

Mr. Hogenbirk insisted that the proposal would have the effect of requiring that the whole area be re-evaluated. He stated that the CPM approach is basically re-evaluating the location of the encroachment lines, which have been applied for twenty years. This is the first attempt by an applicant/appellant to challenge and move those lines.

Mr. Geist pointed out that this was the first time, at this hearing on this date, that it has been heard that the CCL acceptable increases are no longer acceptable and that the LSRCA is now applying different standards from those applied in 1984. Mr. Geist reiterated that the LSRCA has not set and approved those different standards asserted by Mr. Hogenbirk. Furthermore, his client had never been told that it is unacceptable to attempt to challenge the lines, despite the numerous attempts by CPM to produce acceptable changes within existing parameters. Mr. Geist stated that to redo the study was not the purpose of the hearing, but rather that this client's intent was to massage the line. In doing so, his experts were unaware that new criteria would be applied.

Mr. Cooper is prepared to meet reasonable conditions, such as no placement of fill on the site, just like several other cases (Piccirilli v. LSRCA, Sprague v. LSRCA and Allerton v. LSRCA). Asked if there is something wrong with that condition, Mr. Hogenbirk stated that the LSRCA would look with favour upon that type of commitment, but the other problem is that the proposed house occupies most of the width of the lot. Had the house been sited so that it was primarily on the north side of the lot, with the driveway on the south side, this would make no difference as, according to Mr. Hogenbirk, the proposal involves a garage. Mr. Hogenbirk stated that he was limited in his responses to that which was placed before the LSRCA. Mr. Geist countered this position and pointed out that the LSRCA, in all those cases which were settled, were done on the basis of having no plans in front of them.


There are no curbs and sidewalks on Gilmore Avenue. Looking at the photograph of the stream, Mr. Hogenbirk could not respond as to the storm rating of the culverts. He stated that the typical situation is a year storm type culvert. For residential areas, some culverts may be even less than that, but that number is typical. In the event of a 1:100 year storm, the water would overtop the road. Not to the same degree as the Regional Storm, but it would overtop. On the use of the term "infilling", the LSRCA has no policy; his employment of the term was simply in his capacity as a civil engineer.


Mr. Geist

The issue is the location of the encroachment line established by the LSRCA when it adopted the CCL Report based upon the Carson Drain Study.

  1. The encroachment line is arbitrary and could and should be modified to be practicable and one which can be implemented.
  2. The encroachment line is unfairly drawn and unreasonable, as it traverses the subject lands and prejudicial. It impacts on Cooper's use on the regional plan of subdivision.
  3. The evidence tendered allows a modification of the encroachment line, not being precedent setting, but reasonable, equitable and practical.
  4. The floodplain management study and prepared CCL Study establish that the enclosure line allows fill and structures to be placed within the floodplain.
  5. The relief requested is consistent with flood plain planning policies and specifically with the Provincial Policy Statements, guidelines, providing equity, order and flexibility.

Mr. Geist reviewed Ms. Mather's evidence and highlighted facts in relation to his client's case. The LSRCA has acknowledged that improvements have been made to the culverts, which have had an impact on floodline elevations, yet maintains that it is irrelevant. The encroachment line was based upon the removal of areas of shallow flooding. The LSRCA acknowledges the existence of areas of shallow flooding and low velocities in the Subdivision. CPM reviewed the purpose behind the original CCL Report and has given evidence on the objectives, findings and conclusions. The profile for this location indicates that there would be an increase in floodline elevations of a maximum of .6 feet and in velocities of .2 feet per second. By adopting the CCL Report, the LSRCA has acknowledged its objectives and has accepted that certain changes in velocity and elevations of flooding are acceptable risks.

The tribunal has been shown that Cooper's proposal can stay within the parameters of the existing CCL Report. Ms. Mather has shown that it can stay within the existing guidelines and Mr. Cooper is prepared to indemnify the LSRCA as one of the conditions of the LSRCA's consent to its proposal.

It was not until the last day of the hearing on April 8, 2002 that Mr. Hogenbirk advised that any current changes to the location of the encroachment line would require application of modelling which shows all of the structures and fill placed in the floodplain. Underlying the approach which the LSRCA states must now be used was the fact that the heretofore accepted thresholds of .6 feet and .2 feet per second would no longer be acceptable. Mr. Geist submitted that there is no authority for the LSRCA to take this position. The LSRCA has implemented an arbitrary encroachment line. Yet, in attempting to question the placement of the line, Mr. Cooper has now been told that the very means by which it was originally placed across his land is no longer available for review. A new standard must apply.

The CCL study has been recognized by the LSRCA as setting up an unofficial two-zone or special policy area and has been treated as such. According to Provincial Policy and Implementation Guidelines, development is permitted, with site alteration, provided that no new hazards are created, that there is no erosion, and no issues of access and egress. Mr. Geist pointed out that at least 10 homes have been constructed north of Mr. Cooper's lot. These homes are on a dead end street. He questioned whether this would have been allowed had such a danger existed.

The only reason Mr. Cooper was turned down was because of the mapping and the encroachment line bisecting his property. Mr. Geist referred to Exhibit 18, which is the correspondence between the parties in this matter, and submitted that the LSRCA has not been overly co-operative in this matter. At no time until after the hearing commenced, did the LSRCA do anything other than ask questions and point out flaws in the various models proposed by CPM. Mr. Hogenbirk only reviewed the HEC II modelling proposed after the hearing commenced. The LSRCA did not offer to meet and discuss the various proposals.

Mr. Cooper is asking for a slight modification and deviation from the existing encroachment line. His proposed model conforms to the existing parameters. The acceptable test was set in 1984 and should continue. The resulting flood levels and velocities are consistent with those approved by the LSRCA.

Mr. Geist quoted extensively from the Provincial Policy Statement and Implementation Guidelines. Their purpose is to introduce order and equity in the use and non-use of flood prone lands. It is not to force the Province to accept additional costs. The municipality in question has, through its Official Plan and zoning, given the authority to the LSRCA to implement these policies, which in turn it has acted upon. There have been no fewer than three cases in this very subdivision in which the tribunal has set out that the LSRCA has treated this area as either a special policy or two-zone area. Referring again to the Policy, it is acknowledged that the objectives of the policy are clear and to be achieved, require flexibility. The two-zone concept requires additional flexibility to allow for additions, alterations and infilling. It is submitted that Mr. Cooper's proposal meets these criteria.

The various proposals made on Mr. Cooper' behalf have been within the parameters of the Provincial Policy. Discrepancies were found in the existing model and corrected. Culvert modifications were noted. The suggestion was made that bi-secting lots should be changed to eliminate disputes and create two more lots which could be developed. As for making the encroachment lines equidistant from the creek, as suggested by the LSRCA in correspondence (Ex. 18, Tab M), Mr. Geist pointed out that this is impossible. One cannot tell where the centre of the creek is located, whether it must be drawn from the bank, the water itself, the toe of the slope, from one high bank to the other. The location of the encroachment line can change depending upon which of the foregoing is chosen. There are, in Mr. Geist's submission, discrepancies as to where it goes and where it is drawn. It can also change as a result of how it is drawn. One line suggests it is 10 feet wide, another 20 feet wide.

Mr. Geist submitted that his client is bound by the LSRCA and tribunal rules. His client, however, was frustrated in its pursuit. Exhibit 18 sets out the chronology of events. There were no technical responses forthcoming from the LSRCA and what Mr. Cooper's consultants were dealing with were closed minds. The responses were general in nature, without specific details as to shortcomings.

Mr. Geist discussed the various steps taken to consult and attempt to reach agreement as to issues or receive comments. All steps taken by CPM in connection with the Second Modified Proposal were consistent with the original CCL Report and recommendations. It was acknowledged that the encroachment line was arbitrary, the mapping was poor and that the LSRCA altered its policies. There had been doubts raised when it came to those cases, but Cooper is on a smaller budget.

As for cumulative effect, water passage, precedent, velocities and increased risk, Ms. Mather assessed the proposal with no input from the LSRCA. Yet, the LSRCA has accepted the results of the CCL study with respect to these factors. Mr. Geist referred to Dick v. Ausauble Bayfield CA, File No. CA 003-94 (June 8, 1995) (unreported), in which the applicant sought permission in a special policy area, considered to be residential infill. At page 4 of the Reasons, the tribunal reviewed in detail the Flood Plain Planning Policy, including section 6, and paragraph 2.1.1. Mr. Geist submitted that this case is similar. Plans M-15 and M-16 are fully developed and do not constitute a new intrusion into the floodplain. Ms. Mather, in her evidence, discussed the retroactive (or not) aspect of the policy statements.

Mr. Geist referred to the test set out in Seigel,which the tribunal adopted in Dick in determining whether or not to apply a policy. This discussion is found at pages 26 and 27:

In that decision [Segal v. The General Manager, The Ontario Health Insurance Plan (Gen. Div., Div. Ct. ) unreported, 347/94. November 24, 1994, Hartt, Saunders and Moldaver JJ.], Divisional Court determined that, where the General Manager of OHIP had adopted a policy as the basis for exercising his discretion the Health Services Appeal Board was bound to consider that policy and not follow it if considered it to be unreasonable. Once it had considered and adopted a general policy with respect to hospital services in general, the Board need not reconsider the policy in each subsequent case unless there were special circumstances before it. The Court determined, however, that even if the Board did not find the policy to be unreasonable, it was still the duty of the Board in each case to consider whether the application of the policy was reasonable in the circumstances before it.

Mr. Geist submitted that the position of the LSRCA was untenable.

Mr. Geist referred to the third last page of De Cosimo v. Credit Valley C.A., MLC File No. CA-004-96, wherein the tribunal characterized the property. He asked that the tribunal compare that with the current appeal, with the line being between 10 and 20 feet wide. Allerton v. LSRCA, MLC File No. CA 001-95, (unreported) (March 25, 1996) case involved poor mapping. The line is arbitrary. The staff report is contrary to the position of the executive.

In 1984, the LSRCA adopted the CCL report recommendations. The criteria established allows for development within the floodplain, particularly in the fringe. The drawing of the encroachment line is submitted to be arbitrary. The proposal is an attempt to massage the location of the line, to permit this otherwise unusable lot to be developed. It is in keeping with the equitable intent of the Provincial Policy and Implementation Guidelines. The LSRCA has been implementing its acceptance of the CCL Report on this basis for years, and it is submitted that it should continue to be implemented on that basis. To do otherwise would result in the placing of an unfair and heavy burden on the appellant, which is unreasonable. In this vein, Mr. Geist submitted that the conduct of the LSRCA in this matter has been unreasonable. Referring to the argument in Dick v. Ausauble Bayfield CA, he submitted that the conclusions drawn there apply to this case as well.

Mr. Cooper has always been willing to accept reasonable conditions. He merely wants to be able to build on his lot, which has services. The requirement for placement of fill would be minimal. There is no reason, in his submission, that conditions cannot be applied in this case. The matter could have been completed some time ago, but for the intransigence of the LSRCA. Looking to Exhibit 18, Mr. Geist submitted that it is there in black and white that Mr. Cooper is willing to see the placement of fill kept to a minimum.

Mr. Hill

Mr. Hill stated that it is confusing to know what the appellant is asking to do. The proposal for the construction of a home with the garage sited to the south, as found in the settlement proposal. The LSRCA has also been asked to remove the existing encroachment lines to a position located in pink. This had been done for the second settlement conference. How can this be viewed as a settlement if other property owners would be allowed to build as well as a result?

Mr. Hill submitted that all of the proposals raise the same general issues. The proposal will create a further obstruction of the floodway. At no time has the proponent come forward with a proposal to limit the construction, which would eliminate or limit the obstruction. The possibility of constructing a house on stilts or one which is wider on top was raised in settlement and not in the case before the tribunal.

In determining whether to grant permission to build, unless the tribunal is satisfied that the proposed development can meet with the concerns raised by the LSRCA, permission should not be granted.

As to the issue of whether the drawing of the encroachment line is arbitrary, the LSRCA never denied that the location of the lines is arbitrary, but it is, nonetheless, based on a rationale. The encroachment lines follow the natural flow of the watercourse. They do not jog or zig and zag according to artificial property lines. Once one goes down the road of attempting to follow lot lines, it creates a whole host of problems, not the least of which is the determination of what should be included and excluded.

Mr. Geist has submitted that this situation is unique and not precedent setting. It is conceded that the proposal no longer would see these lines moved to the same extent as proposed initially. However, Mr. Geist is still insisting that the encroachment lines should be moved to follow the pink lines set out in Exhibit 16. The tribunal has heard evidence from Ms. Mather that the rationale for this approach is that if the lines are moved for Cooper, they should be moved for everyone else.

The cumulative effect of this proposal requires that one consider all of the 22 lots which would be affected. Even though only 22 lots are involved, two of which are currently vacant, the policy as it is applied permits unlimited development within those lands. This means the placing of unlimited quantities of fill, further additions and alterations. Mr. Hill respectfully submitted that there will be a severe impact if filling without existing restrictions imposed in the floodway is permitted, even to the extent proposed by the appellant.

According to Mr. Hill, the idea that there has been a change in LSRCA policy is a misunderstanding, which occurred during the cross-examination of Mr. Hogenbirk. This is not correct and it is not a fair representation of the evidence. If the LSRCA were looking to change the encroachment lines, it would do so by applying the current up to date policies and procedures. This does not mean to say that the LSRCA is going to do it. Rather, it has adopted the 1984 CCL Study, applied it consistently and will continue to do so.

Mr. Hill referred to the Provincial Planning Policy Statements, stating that there is a problem with those statements in the Implementation Guidelines. Where a two-zone policy is in effect, development in the floodway is prohibited. This is clear. In the current appeal, the evidence is that the LSRCA developed its own policy analogous to a two-zone. To be able to get to the next level, that of a special policy area, requires ministerial involvement. Ms. Mather did not even suggest this. Rather, she indicated that the Municipality has given authority to the LSRCA with respect to these documents merely recognizes the authority of the LSRCA to control development in regulated areas. There is nothing overt concerning recognition of either a two-zone or special policy area.

The Decisions in Valcheff, Graham and Ditta (supra) were misleading in this regard, wherein the tribunal referred to a special policy area. The term as used was not intended to be that found in the Provincial Policy Statement. Mr. Hill felt he could state this as a fact, having been the counsel involved in those three cases. Looking at the details of the cases, Mr. Hill submitted that the tribunal looked at whether the appellant had not been given the benefit of the existing policy of the LSRCA. In his respectful submission, the tribunal recognized that the LSRCA developed a special policy of its own to apply to this area.

Referring to Dick (supra), starting with the reference on December 24, 1980. See page 28:

Is the policy of the ABCA at issue here reasonable? I have concluded that it is not. It has already been conceded that there is no such thing as a "Registered Development Plan" under current legislation. The policy of the ABCA means that, unless a landowner can persuade the ABCA that his or her property is within some registered development plan, they will be denied permission to construct a non-agricultural residence. This is so regardless of the state of development of the property, the risk of flooding, and whether the proposed construction will affect the control of flooding or the conservation of land. That this is so is confirmed by the decision of the Board of Directors of the ABCA in its letter of May 26, 1993, that, provided that the lot could be included in the Defore subdivision, approval would be granted. As a consequence, the appellants applied for appropriate amendments to the official plan and zoning by-law, only to be told by township officials that they did not consider this necessary. The appellants have been caught up in a veritable bureaucratic nightmare, being batted like a pingpong ball between the ABCA and the town. The ABCA says it is only implementing the Special Policy Area provisions of the town's Official Plan and zoning by-law, and the appellants must obtain appropriate amendments to these documents before it will consider granting permission. The town, on the other hand supports the application. Apart from the designation and zoning of the subject property, there is virtually nothing to distinguish it from properties within Defore Acres for which permission was granted when considering site factors such as elevation, proposed floodproofing and access and egress. One can only sympathise with the sense of frustration of the appellants. The tribunal finds the position of the ABCA in this regard to be simply untenable. This is more than simply a case of line drawing.

Another difficulty with the appellant's position is that, should it in effect change encroachment lines, as asked, how can Mr. Cooper commit on behalf of the others? Mr. Hill submitted that he cannot. The tribunal is reminded that the property is well within the floodplain and mostly within the floodway. The original study relied upon predicts the impact of the placement of fill within the encroachment lines. However, it does not take into account the additional construction, which will have occurred in the meantime. Therefore, as there is no way to take this into account, this is the reason behind the need to strictly adhere to the lines as they are drawn.

The suggestion by the appellant that the encroachment lines be moved to the property line will serve to narrow the floodway. This could create dire circumstances. Rather, any change in the lines should be moved outward, if one were going to move the lines at all. The rationale behind this is that it relates to actual anticipated conditions. Under extreme flood conditions, the floodwaters will not respect property lines. One problem with this approach for the LSRCA is that it creates uncertainty and may create pressure on the limits of the floodway. The position of the LSRCA is that the study has been relied upon since 1984, has been consistently applied and been upheld by the tribunal on three previous occasions.

Referring to Graham v. LSRCA, (supra), the tribunal stated at page 6:

None of the recognized exceptions to the principle of prohibiting building in flood plains were established by the evidence.

In passing it may be noted that special policy areas are exceptions to the general principle and frequently involve remedial works to reduce the risks of a regional storm in the area. In this case there was no evidence of any remedial works and it can only be concluded that the adoption of the special policy area does not decrease the risk in the special policy area and by reason of the utilization of the flood plain in that area increases the risks in the remainder of the flood plain. Where such an area is established, it becomes essential that principles of flood plain management be applied to the remainder of the flood plain and be applied strictly.

Similarly, in Ditta v. LSRCA (supra), the tribunal states at page 4:

The emphasis of counsel for the appellant was that the granting of permission to construct the large garage on the lot immediately to the north indicated that the respondent was satisfied that a building of this size can be inserted in the flood plain without affecting the control of flooding, pollution or conservation of land as was said in the reasons of the respondent. The tribunal is satisfied that this conclusion does not follow from that action. That action is a usual exception used by conservation authorities and in effect relates to the more effective utilization of an existing building in a flood plain. Inherent in such an exception is the principal that such matters are affected but the exception is created to enhance or utilize the existing building.


The tribunal was satisfied in this case that the respondent was justified in adopting a strict policy in respect of the remainder of the watershed in view of the special policy adopted for the upper levels of the watershed. It may appear to create inequality among landowners in the entire watershed but the policy was undoubtedly adopted for the benefit of those landowners at the edge of the watershed and as the evidence indicated was adopted in light of the engineering evidence that the degree of flooding would be minimal. There was no evidence that if the vacant lots in the remainder of the floodplain were fully developed that a minimal effect would be the result and the tribunal is satisfied on the evidence produced by the respondent that there is a need for a strict application in the remainder of the watershed.

There was no evidence produced to show that the appellant has been dealt with in a manner different from other landowners in the portion of the watershed below the encroachment limits.

In Valcheff v. LSRCA (supra), the tribunal noted, commencing at the bottom of page 6:

However, the evidence places the subject lot clearly and entirely within the floodway for Carson's Creek. Allowing the proposed development would be contrary to the applicable regulations and policies for wise flood plain management. The tribunal accepts the Conservation Authority's evidence that new development within the floodway could adversely affect floodwater storage and passage and floodwater levels and velocities. Although incremental in its impact, the proposed development would tend to increase the risk of flood damage and the social and economic burdens noted in the provincial flood plain policy.

This appeal has been described as one involving infill. If one looks to the other cases relied upon in support, they are all infill as well and all have been denied. Mr. Hill respectfully submitted that according to both witnesses, the engineering study was fundamentally sound. However, on the key point of narrowing of the floodway, it could produce unacceptable results. The work done by Mr. Hogenbirk confirms that there will be an impact if the floodway is narrowed.

Even if there is doubt as to the adverse impact, the existing lines are clear and have been in place for years. Once they are moved, an element of uncertainty is introduced. Great caution should be required before any attempt is made to move the lines. The appellant is able to look at conditions, which have changed and demonstrate an apparent improvement. The thesis is that if one narrows the floodway, one can produce similar results to the original study. There is a flaw in logic in this approach. Just because one can demonstrate that no change occurs does not mean that one should go ahead and do it. Similar results can be achieved which is not to say that they should be implemented. The benefit achieved could be left for all who own property in the floodplain and have developed those properties. This is the same as those who are outside the floodway being allowed and those within the floodway being denied.

The appellants must satisfy the tribunal that the proposal will not affect pollution, the control of flooding or the conservation of land. The question is often asked whether the applicant is denied the benefit of the policy. It is clear that the appellant is treated in the same way as others who have property within the floodway or flood fringe who have applied. The former are denied and the latter are allowed. The appellant is on the borderline. In these circumstances the onus is on the appellant to satisfy the tribunal that there is no adverse impact created either within or outside the floodway. Otherwise, if an adverse impact is created, this could have a cumulative effect on storage capacity and flooding.

The Policy could be changed if there were valid reasons or if either the LSRCA or tribunal were acting inconsistently. In this regard, it would have to be shown that a valid risk is taken. The LSRCA is not prepared to increase the existing risk to other property owners.

The LSRCA requested a dismissal of the appeal. Mr. Hill submitted that his client has not acted unreasonably or obstructively, as has been suggested. The LSRCA has always considered proposals and is always open to review. It always acts consistently and has not thought that development is feasible and it should not be faulted.

Mr. Geist

In referring to Graham, Ditta and Valcheff (supra), it is pointed out that each of those properties is closer to the creek than the Cooper property. They do not have the encroachment line running through them. Mr. Geist submitted that Mr. Cooper has been discriminated against due to precedent. The LSRCA consistently says no. It is applying a policy, which it is required merely to have regard to. It can change its decision under appropriate circumstances. There are two lots extremely adversely affected by the arbitrary drawing of the encroachment line. Every application should be determined on its own merits and not be lumped in with a pre-determined refusal.

The CCL Report allows development in the floodplain. The LSRCA assumed the risks and allowed all those homes to be developed. It has accepted far more than is being proposed by allowing construction which is taking place to occur. When the line is examined only two lots are affected. The issues of precedent and cumulative impact are red herrings. Those cases cited stipulate the two-zone and special policy. That is how the LSRCA has been implementing the CCL Report. Conditions have now changed. Benefits have accrued, things were not made worse than before the culverts and straightening of the channel occurred. Mr. Cooper is seeking to benefit from the improvements.

Mr. Cooper is not asking to be treated differently than the others. He has demonstrated acceptable increases in velocity and flood depths as concurred with and shown in the CCL Report. For the LSRCA and this tribunal to do otherwise than to allow the appeal would not be equitable. This application is about the application of the two-zone approach.

Conditions may always be imposed in this matter. Exact plans were not submitted for any one of Piccirilli v. LSRCA, MLC , File No. CA 003-96, (unreported) (August, 1996), Sprague v. LSRCA, MLC , File No. CA 006-94, (unreported), (March 25, 1996) or Allerton (supra). Mr. Geist stated that his client will draft a plan which will meet with the LSRCA's approval.

This is not a question of opening the doors or the metaphoric floodgates. Examining the lines will reveal that only two lots would be affected. Anyone else can appeal, but their property would receive the same answer, that they are located wholly within the floodway.

The Dyck (supra) case reviews the Provincial Planning Policy Statement and the unreasonableness of the manner in which the ABCA proceeded. Dyck went through to that stage – one where infill was requested – except that ABCA did have a special policy area. This is the same situation, only save for the fact that it does not have the sanction of the Minister. The LSRCA continues to be unreasonable. Mr. Cooper did not hear until the final day of the hearing that the CCL Study increases are not acceptable.


The issue in this appeal is whether established encroachment lines, modelled and mapped by the engineering consulting firm, CCL and adopted and implemented by the LSRCA in 1984, can and shouldbe modified or changed to create a viable building lot. The appellant, Cooper, through his engineering consultant, CPM, bases his case on several factors: errors in the original 1984 modeling; improvements to infrastructure having an impact on regional storm and encroachment flood plain modeling; an arbitrary encroachment line which bisects the subject lot rendering it virtually impossible to build on; and 1988 Provincial Flood Plain Planning Policy Statement principles extending beyond mere flood plain management concerns to include order and equity.

The respondent, LSRCA, maintains that the encroachment line, initially modeled and adopted in 1984, should be strictly applied and not be tampered with under any conditions. [See references to Grahamand Ditta, below.] Through strict application of the encroachment lines, the modeling of the proposed encroachment line (Third Proposal) does result in increases to flood levels and flow velocity, such that the appeal should be dismissed. To successfully make a case to move the encroachment lines, an entire new flood plain management study of the Subdivision would be necessary, taking into account all activity within the floodplain which may have taken place, either lawfully or unlawfully, between 1984 and the present.

The technical positions of the parties can be expressed as follows. CPM has adjusted the base line pre-encroachment model to correct for errors and improvements to/additions of culverts. Then, as an alternative to the LSRCA encroachment lines, it has run its own proposed encroachment lines. CPM maintains that the resulting increases in flood depths and velocities are within the same range tolerated by the original CCL Study. The LSRCA accepts the correction of errors and data relating to new culverts and therefore the new base line for the pre-encroachment model. To this, the approved LSRCA encroachment lines must be run through the model to provide new depths of flooding and velocity figures. Then the CPM proposed figures for encroachment must be run through the model. The resulting differences between the LSRCA updated encroachment model and the CPM Third Proposal encroachment model show moderate increases at certain cross sections of flood depths and velocities. The position of the LSRCA is that no net increases in depths or velocities can be tolerated.

The issue under appeal is unusual, if not unique. Typically, the modeling of flood line elevations and velocities in a Regional storm, or any other storm for that matter, are determined by numerous factors. These include data relating to the storm profile [i.e. rainfall amount, duration, intensity and time distribution], the land [topography, contours, vegetative cover vs. impermeable surfaces, soil type and density, existing saturation] and characteristics of both the watershed and watercourse involved. The location of the floodline elevation and velocity of flood flows is an important end product of the model. This modeling essentially summarizes the one zone concept. It is the end product, the resultant depths and velocities, which will govern whether a piece of land is amenable, strictly from a flood plan management perspective, to proposed development.

In many appeals and applications, to the extent that there may have been challenges to the location of the floodline or depth of flooding modeled, these have been based upon changes to the data input into the model. For example, actual data may not be collected for the land in question and so the model must extrapolate from known data to that situation. When actual data is collected in the field, such as spot elevations, and the model is run with data for a new cross section affecting the specific land involved, the newly calculated flood depths and velocities may well change. In addition, on rare occasions, the challenge to the end result may come in the form of a challenge to the actual model which should be used to calculate the floodline. The HEC II is not the only available model for such calculations, but it is the model most often used.

What makes this appeal unusual and unique is the challenge to the location of the encroachment lines themselves. Encroachment lines used in the two-zone concept are an artificial construct. Virtual walls are modeled based upon criteria, which are grounded at least in part, if not wholly, in flood plain management principles from a strictly hydrological point of view. In the terms used by the 1988 Flood Plain Planning Policy:

Portions of the flood plans that could potentially be safely developed with no adverse impacts…The extent of the floodway is to be determined based on local watershed conditions, such as critical flood depth and velocity, existing and proposed development and the potential for upstream and downstream impacts.

The sighting of the original encroachment lines provided the flood level and velocity data which was used in the model to measure the impact of the virtual wall. The impact was then evaluated, and the risk measured was found acceptable and adopted.

What is unusual in this appeal appear to be peculiar to the two-zone concept [and perhaps to the special area concept] is the idea that what has been heretofore regarded as a constant can actually be variable or be subject to one-time changes. From one perspective, this is true, in that the actual baseline floodline model is constant, barring new data. It is the location of the encroachment lines which are "chosen". These lines, theoretically, can change location under a number of circumstances. The Cooper appeal seeks to rely on correction of errors and data from updated culverts, arguing that their impact is sufficiently significant to essentially provide more room within the floodplain for development. In so stating, it is argued that CPM's Third Proposal meets the same parameters as the original study.

This novel appeal may constitute the first examination in this forum of the extent to which strict principles of flood plain management may have to be balanced with planning concerns. The issue was raised, if not fully explored, in two of the cases dealt with by Commissioner Ferguson. In Graham v. LSRCA, (unreported) (October 3rd, 1989), at page 6, he stated:

In passing it may be noted that special policy areas are exceptions to the general principle and frequently involve remedial works to reduce the risks of a regional storm in the area. In this case there was no evidence of any remedial works and it can only be concluded that the adoption of the special policy area does not decrease the risk in the special policy area and by reason of the utilization of the flood plain in that area increases the risks in the remainder of the flood plain. Where such an area is established, it becomes essential that principles of flood plain management be applied to the remainder of the flood plain and be applied strictly.

and in Ditta v. LSRCA (unreported) (October 28th, 1988) at pages 4 and 5, Commissioner Ferguson stated:

The tribunal is satisfied in this case that the respondent was justified in adopting a strict policy in respect of the remainder of the watershed in view of the special policy adopted for the upper levels of the watershed. It may appear to create inequality among landowners in the entire watershed but the policy was undoubtedly adopted for the benefit of those landowners at the edge of the watershed and as the evidence indicated was adopted in light of the engineering evidence that the degree of flooding would be minimal. There was no evidence that if the vacant lots in the remainder of the flood plain were fully developed that a minimal effect would be the result and the tribunal is satisfied on the evidence produced by the respondent that there is a need for a strict application in the remainder of the watershed.

The tribunal has historically applied a strict approach to the LSRCA policy with respect to building within the floodway. This was certainly covered by the evidence of Ms. Mather when she spoke of the various refusals involving Graham, Ditta, Simpson and Valcheff, all of which are located fully within the floodway and for whom a successful outcome in the current appeal would have no bearing on the earlier outcomes.

However, the current appeal differs significantly and can be distinguished. The appellant relies on problems with data and culvert improvements which it is alleged could have the effect of diminishing the certainty of the original modelled location of the encroachment lines. CPM asserts on Cooper's behalf that his property properly should be located wholly within the flood fringe. The changes proposed to the encroachment line involve the whole Subdivision and not merely Cooper's Lot 40. This is a strategic risk on the part of his counsel, Mr. Geist, as the potential negative impacts from the model could be greater than if the proposed change (i.e. narrowing of the floodway) was modelled solely for the subject property. However, the reliability of the alternative model increases substantially with this expanded scope, by raising and answering the questions of cumulative impact and precedent. In the words of the 1988 Provincial Flood Plain Planning Policy, "the extent of the floodway is to be determined based on local watershed conditions…". CPM's approach on behalf of Mr. Cooper is not limited to the one lot, but proposes changes to the encroachment lines and evaluates how they impact upon the Subdivision in its entirety.

Before leaving this issue of the Two-Zone concept, the tribunal notes that there has been some confusion as to the status of the Subdivision. Commissioner Ferguson recognised this Subdivision as analogous to a two-zone concept in Graham, at page 5 and as a special policy are in Dittaat page 2. Deputy Commissioner Robb does not make specific findings in Valcheff v. LSRCA, (unreported) File CA 008-95 (April 1, 1996), but does note that the subject property was wholly within the floodway, implying a two-zone approach.

The tribunal finds and recognises that the LSRCA implements an analogous two-zone concept to the Subdivision. Based upon the modelling, the flood fringe has been identified and separated from the floodway. This separation is mapped, but has no structure or flood works on the ground. Its location is based upon prior determinations of no adverse impacts, critical flood depth and velocity and potential upstream and downstream impacts. The evidence was that formal implementation of the two-zone concept, through the planning process, was not followed. There is nothing untoward in applying the two-zone concept on an informal basis.

The CCL study

The purpose of the CCL Study is stated on page 1 (Ex. 5) under the heading "2.0 Study Objectives":

The purpose of the investigation was to update, where required, the existing hydraulic model and then to assess the impact of alternative development schemes on the Regional Storm floodline. Results of this investigation would be used to determine the sensitivity of the placement of fill within the floodplain on the Regional water surface profiles.

The case 1 scenario modelled encroachment to the 1:100 year storm level. However, due to the characteristics of this flood plain, there was no significant difference between this and the Regional Storm, so that no significant encroachment [infilling] would be possible. This approach was not recommended as it did not meet the objective of providing significant additional land for development.

The criteria for the Case 2 Encroachment to Prescribed Limit are found on page 3. The limits of encroachment were based on the following criteria:

  1. Removal of areas where flooding is shallow and the flow velocities low
  2. Removal of areas that are affected by ponding (e.g. bays, etc.)
  3. Removal of spill areas.

The resulting maximum increase in Regional flood elevations from Case 2 would be 0.6 ft, immediately upstream of Allan Avenue (now known as Gilmore). The lower reach, downstream of Ferrier, which is at the east end of this Subdivision, experiences increases of 0.2 ft. The average increase in flow velocities was 0.2 feet/second. The Study specifically states,

…As the flow velocities within the floodplain are less than 3.0 ft. per second under existing conditions, the small increase in anticipated flow velocity would not have a significant impact on the erosion potential associated with the flow.

The potential increase in the area inundated under the Regional Storm event with encroachment to the Case 2 limits is shown (as a shaded area) on Figure 1. As evident, the increase was insignificant.

Figure 1 depicts a number of lines. The lines relevant to the CCL Study are the encroachment limit, 1:100 year storm, the regional storm under existing conditions and the regional storm with the case 2 encroachment. The area which experiences increased flooding as a result of the case 2 encroachment is shown as a shaded area, located between the two regional storm lines. The area of increased flooding is, as described in the CCL Study, so small as to be considered insignificant. That having been said, the tribunal has examined Figure 1 and using the scale has noted that the width of the increased flooded area ranges from a minimum of substantially less than 25 feet in most areas to a maximum of 50 feet in several areas.

The tribunal finds that the CCL Study does not set increased flooding or velocity parameters or thresholds per se, as has been asserted by the appellants. [There is a discrepancy between the CCL Study, cited above, noting an average increase in velocity of .2 feet per second and the assertions of CPM that an increase of .4 feet per second is comparable. This will be dealt with in greater detail below.] Nor is there any indication that such thresholds were set by the LSRCA in the terms of reference for the CCL Study. Rather, the CCL Study analyses the results of its locating encroachment lines based upon the criteria referred to above. It must be said that it is essential to the running of the model that some encroachment line be drawn – a location must be chosen. Arguably, it would be possible to include all lands up to the banks of Carson's Drain in the encroachment area, but for the impacts of such a choice. Despite shallow flooding throughout, at some point, the resulting increases to flood level elevations and flow velocities will dictate the location of the encroachment lines, not to mention the extent of upstream and downstream impacts.

The tribunal finds that the main issue in this matter has been reduced to an argument of semantics, serving to cloud the real question. Whether the CPM Third Proposal meets the same thresholds as those of the CCL Study versus the established encroachment lines must be strictly applied are the opposite sides of the same question. In an analogous two-zone concept, given that the location of the encroachment lines will determine the level of flooding and flow velocities, must their locations be fixed, for reasons of certainty and implementation of flood proofing measures elsewhere, or are there circumstances under which the lines can be moved?

The impact of the original and any modified encroachment

The rationale of the CCL Study was to model flooding within the entire floodplain so as to keep floodwaters outside of the flood fringe and within the floodway, pursuant to a two-zone concept. The virtual floodwall created by the model has the theoretical effect of containing all or most of the floodwaters within the area it defines, namely the floodway. This theoretical analysis permits calculation of the extent of the outlying fringe areas upon which it would be safe to build. It also calculates the extent to which the flooding will exceed the limits of the non-encroachment line Regional storm. This is an important concept. It was not emphasised in evidence, but the effect of the two-zone concept is to experience flooding during a Regional Storm beyond what would be experienced in the non-encroachment model. As noted above, floodwaters were expected to exceed their limits as a result of this model minimally in most places but in others to an extent of 50 feet.

Allowable development [building and placement of fill] within the flood fringe has been made conditional on the placing at the building site of adequate fill and flood proofing of all openings to projected flood elevation levels. This is the critical juncture in any proposed change to the encroachment line. All intervening development between 1984 and 2003 will have been flood proofed to this level only. The approved model also places development within the zone referred to above, the 25 to 50 foot extension of the breadth of the floodplain, into the fringe area which also required adequate flood proofing measures.

Any additional flood elevation would put any of the properties in the fringe areas developed in the interim at risk. Furthermore, should the resulting extension of the floodplain beyond its original non-encroachment boundaries be experienced, this would mean lands which may have been developed as non flood prone lands would have been rendered flood prone without adequate flood proofing requirements implemented.

Errors, culverts

CPM identified changes made to culverts through upgrading and enlargement and installation of a second culvert at one location, all having occurred downstream. A number of errors were also uncovered by CPM. Details are found under the heading Hydraulic Analysis on page two (Ex. 6):

Twelve error messages were also read within the model, mainly due to improper coding of bridge and ground cards at each culvert (see Appendix B for error output). Ground profiles were based on the floodplain mapping for Carson's Drain, which is at a 1":200' scale and has 2 foot contour spacing. This mapping is of poor quality and has not been updated since 1984. The accuracy of ground profiles obtained from this mapping cannot be assured. Based on the mapping provided, a number of sections had the southern encroachment located within the limits of the stream. The southern encroachment at Section 1700 was located 200 feet north of the stream channel, which would require enclosing the stream channel. It should be noted at this point that there was development in the area before the encroachment line was designated, thus some existing houses are within the approved floodplain.

The errors were also discussed in correspondence between the LSRCA and solicitor for the appellant, where Mr. Geist states in part on March 13, 2001, (Ex. 18, Tab K):

…More specifically please explain why the approved southern encroachment line is: (1) on the north side of the creek at section 1700; (2) outside of the Regional Storm floodline elevation in the area of section 2913; (3) looped northward without topographic reason in the area of section 3265.

In the response (Ex. 18, Tab M) dated April 25, 2001, from Mr. Hogenbirk, the questions are answered as follows:

Cross Section 1700 – There is a small error in establishing the south line in this area. It should have been located just to the south side of the creek rather than the north side.

Cross Section 2913 – There is a drafting error at this point; the south encroachment line should have ended at the flood line.

Cross Section 3265 – It appears that the south encroachment line coincides with the 1:100 year flood line at this point, which was one of the design parameters.

Mr. Hogenbirk noted that, generally speaking, encroachment lines are set equidistant from the creek in a built up area. He also expressed serious concerns regarding CPM's attempts to reposition the encroachment line. As early as his letter of March 13, 2001, (Ex. 18, Tab J), he states that CPM's approach confirms the findings and recommendations of the CCL Study. The second point he makes:

2) Your report has revised the original modelling to reflect improvements in the capacity of several of the culvert crossings for Carson's Drain. In order to fairly represent all the changes in the area since 1984, your analysis needs to be extended to include any placement of fill in the encroachment area, additional structures such as sheds and all other potential obstructions. This can only be done by using an up-to-date topographic map of the Carson's Drain area as what was done in 1984.

The tribunal notes that Mr. Geist submitted that his client learned for the first time on the last day of the hearing that the LSRCA would require information on fill placement and new structures in the floodway. This letter pre-dates Mr. Geist's assertion.

Arbitrary or other factors in siting encroachment lines

As previously stated, all areas of the floodplain outside the main channel of Carson's Drain appear to have shallow flooding. Moreover, the contour lines in the flood plain show a consistent pattern. There are closely drawn contour lines along the Carson's Drain, depicting the sides of the bank. However, beyond these, the contours run north and south in meandering lines depicting no discernible topographic differences. The lines are very widely spaced. For example, there is a 736 contour running along and just east of Gilmore. The next contour, being 734, runs in a similarly meandering fashion immediately to the west of Ferrier. What is significant about the lines running at a ninety-degree angle to Carson's Drain is that the slope in this area is very gentle and drops eastward towards Lake Simcoe.

As suggested by Mr. Hogenbirk, throughout the Subdivision proper, it is drawn relatively equidistant from Carson's Drain with the following exceptions. West of Corner Avenue, the northern line veers sharply so that it is very near the Drain. East of the Subdivision the southern line turns sharply towards the channel, crossing over at one place, apparently due to the spill area to the south. It would make little sense to have the spill area inside the modelled encroachment lines. With the move inward towards the channel on the south, there is a corresponding move further away from the channel to the north. This occurs in the vicinity of the 1700 cross section.

The tribunal finds that, in addition to the three criteria set out above, there was another factor involved in siting the encroachment lines. The drawing of the encroachment line was not arbitrary, nor based wholly on those criteria set out. Logic dictates that the line must be drawn somewhere between the channel and the limit of the floodplain. Neither the 1:100 year flood line nor the regional storm flood lines can be described as anything but irregular in shape. By contrast, the modelled encroachment line is relatively regular. It does not follow the orientation of the channel exactly. It veers off to the north, when the channel jogs south, encompassing the largely undeveloped lands to the east of the subdivision, perhaps as compensation for the change in direction of the southern line to circumvent the spill.

The drawing of the encroachment lines represents a cut-off point, determined through the running of the HEC II model, of how far the virtual walls can be erected beyond which the risk which the LSRCA must assess is determined to no longer be manageable. Their location must make sense from a flood plain planning perspective, as well as take into account pre-existing detrimental or potentially damaging development. Examples of pre-existing factors include constrictions to the watercourse found in very old communities. The tribunal further finds that, once established, the location of encroachment lines may be subject to change where previously fixed parameters have changed, so long as there is no significant increase in flood elevations or flow velocities, working from meaningful data.

Wholesale changes to the encroachment lines without corresponding changes to parameters (i.e. fixing errors, works etc.) would be felt in terms of greater depths, velocities and flood waters. For this Subdivision, it would mean flow beyond the 25 to 50 feet outside the non-encroachment floodplain shown in Figure 1 to the CCL Study.

The tribunal finds that test, which requires strict adherence to the location of the encroachment lines, once established, cannot be changed in an arbitrary manner. There are, however, exceptions to their strict application. These include, but are not limited to 1) correction of modelling, data or plotting errors; 2) collection of additional, reliable data, such as spot elevations, which have been verified through a common benchmark; and 3) improvements which have an effect on flood waters, such as public works. This list is not exhaustive.

Impact of the twelve error messages

The tribunal finds that the twelve error messages in the original model were significant. They have had the effect of throwing the entire existing CCL Study (model) into question. While not all of the specific details are known to the tribunal, but elements of unreliability exist. This, coupled with encroachment zones which cross the stream bed, a physical impossibility, throws into question the numerical accuracy of the predictions. If the problems were limited to plotting alone, the tribunal finds it puzzling why the plotting problems had not been corrected within the past eighteen years. The fact that these errors exist is sufficient, in the tribunal's estimation, to justify some degree of rerunning of the model.

CPM proposals

The appellant has done considerable modelling throughout the life of this application. It is unfortunate that CPM did not perform a corrected version of the floodplain limited to the correction of the twelve errors from the earlier mapping. Those results may have lent stronger substance to potential findings as to the extent to which the encroachment line established proposed by the CCL Report and adopted by the LSRCA may have been in error.

Benefit of improvements in a two-zone concept area

The LSRCA's position, essentially, is that the encroachment line stands, unless the entire floodplain were to be remodelled, using both advantageous data (culverts and errors) and disadvantageous data (fill and construction within the floodway) since 1984. It does not acknowledge that the encroachment line can be modified through use of improvements only, essentially stating that the effect of the improvements experienced should inure to the benefit only of those already located in the defined flood fringe.

The LSRCA did not dispute that the new culverts and straightening of the channel served to change the extent of flooding within the floodplain to some extent, although their capacity is not such as to prevent flooding during a Regional storm. Presumably, they were paid for by the property taxes collected from all properties in this Subdivision and beyond. There was no evidence that this was a capital expenditure for a project within the meaning of sections 24 through 27 of the Conservation Authorities Act.

The tribunal finds that it cannot agree with the LSRCA that the benefit derived from such public works should accrue to the benefit of those property owners in the flood fringe, as currently defined by the LSRCA. The new culverts were installed by the Municipality and were not intended to be the type of flood control infrastructure seen installed in Special Policy areas. Similarly, the culverts were not updated and installed for the benefit of those in the flood fringe only as the flood elevation levels of all in the pre-encroachment model will be affected.

Nor does the tribunal agree with Mr. Hogenbirk's statement that to adopt the CPM Third Proposal encroachment lines would cause the LSRCA to revert to greater flood levels. If he means that the LSRCA approved encroachment lines would result in lower flood line elevations than the Third Proposal, when both are applied to the modified non-encroachment model, based on this evidence, this would be the case. However, CPM is asserting that the effect of the Third Proposal would be to cause comparable increases in flood line elevations and flow velocity to what has already been approved. Stated another way, CPM's position is that the LSRCA approved encroachment lines based upon erroneous and out of date data. Whatever errors were in the original model, the result was concrete numbers of increases in flood levels and velocity. Once corrected and updated, those same numbers in increases of flood levels and velocity can be attained or matched, even though different, less conservative siting for the encroachment lines are used. This is quite different from an outright increase in figures, which is misleading in this context.

Finally, the LSRCA has argued that, even if it can be demonstrated that the proposed encroachment lines can be moved without undue changes in flood level elevations and flow velocities is not to say that such changes should be implemented. The LSRCA relies on a precautionary approach to any attempt to move the existing location, which has been in place for years. With the greatest respect, the tribunal finds that it cannot follow this line of reasoning. Errors were found in the original model. Improvements have been made to the culverts. Both have had an impact on flood levels and flow velocities. The findings of the original CCL Study are called into doubt. This state of affairs could have continued on unchallenged. The fact is, however, that the calculations supporting the pre-existing location of the encroachment line has been challenged and that challenge has been successful. The tribunal finds under these circumstances that some movement in the location of the encroachment lines is justified.

Impact of improvements in a two-zone concept area

The two-zone concept is a flood plain management tool which has potential for areas where pre-existing community development and continuing community viability are brought into issue by the municipality and the conservation authority. In order for the two-zone concept to be applied within a portion of a watercourse, projected flood levels and flows must lend themselves to establishment of a floodway and flood fringe. These terms are now defined in the 1997 Provincial Policy Statement 1. The provisions of the Policy relating to natural hazards are set out:

3.1.3. Except as provided in policy 3.1.2, development and site alteration may be permitted in hazardous lands and hazardous sites, provided that all of the following can be achieved:

  1. the hazards can be safely addressed, and the development and site alteration is carried out in accordance with established standards and procedures;
  2. new hazards are not created and existing hazards are not aggravated;
  3. no adverse environmental impacts will result;
  4. vehicles and people have a way of safely entering and exiting the area during times of flooding, erosion and other emergencies; and
  5. the development does not include institutional uses or essential emergency services or the disposal, manufacture, treatment or storage of hazardous substances.

The Flood Plain Planning Policy Implementation Guidelines (Ex. 26) are still of assistance in determining when the two-zone concept is applicable. On page 22, under the heading 3.5.1 entitled "Explanation", the rationale is set out. The following are the highlights: 1) the two-zone concept is an option; 2) its application is limited to selective areas; 3) if applied, no one standard applies as watershed conditions vary throughout the province or throughout watersheds themselves; 4) determination of the most hazardous portion of a flood plain is to be determined based on analysis of local conditions; 5) factors to be considered include but are not limited to: a)critical flood depth and velocity in relation to threat to life and property; b) extent of existing and proposed development and its location in the watershed; and c) potential for upstream and downstream impacts.

Application of the two-zone concept recognizes areas of shallow flooding and low velocities as having potential for development, notwithstanding that the areas may be flooded, or even that they may be flooded for great distances, such as in the case of the Subdivision. As long as there is adherence to flood plain management principles, the actual decision to apply the two-zone concept is based, in part, on land use planning concerns, such as economic and social considerations and community viability.

This is an extreme and seemingly abrupt departure from the historical approach taken by this tribunal in hearing appeals under section 28 of the Conservation Authorities Act, which has been an examination of whether the land could inherently withstand the proposed development. The tribunal is of the opinion, that under the correct circumstances, there is justification for moving the existing encroachment lines to create additional sites for development where the data used in the original HEC II calculations has changed.

The tribunal finds that, based upon the existence of errors in the CCL Study model which require correction and improvements made to the culverts which served to lower flood level elevations within the floodplain, a sufficient case has been made for the moving of the encroachment line.

Sensitivity of model to change

The sensitivity of the model to changes was asserted by the LSRCA. Noted at page 4 of the Staff Report 109-99-BOD (Ex. 2, Tab 7), dated November 30, 1999, in the first full paragraph, it states:

Of all the above mentioned Watershed Development Policies, policy 7.1(i) is the most significant, given the findings of the "Floodplain Management Study for the Carson's Drain". That study indicated that further obstruction of the floodway would have significant impacts on adjacent properties. Further to that issue, a substantial amount of redevelopment has been approved by the Conservation Authority within the adjacent encroachment areas identified by that study. That development was approved on the basis that there would be no changes in the flood elevations. There may be additional liabilities on the Authority by approving any proposal that has the effect of increasing flood levels.

The tribunal could find no such statement to the effect that "further obstruction of the floodway would have significant impacts on adjacent properties" in the CCL Study.

The statement concerning the sensitivity of the floodplain to reduction of the floodplain is also found in the letter from Mr. Hogenbirk to Ms. Kirsten Mills of CPM dated March 13, 2001 (Ex. 18, Tab J), where he states at page 2:

  1. The original 1984 report by CCL derived maximum expected flood levels based on recommended encroachment limits. The proposed change in encroachment limits put forward by CPM will result in small increases in these 1984 maximum expected flood levels in four cross section locations in the lots in Plans M-15 and M-16. This demonstrates that the area is extremely sensitive to any further reduction in the floodway beyond what is defined by the current encroachment limits. As such, we conclude that the proposal put forward by CPM will adversely affect the control of flooding.

The appellant asserted that the model used to assess risk allows for alternative sighting of the encroachment lines, which can still meet acceptable standards of risk. This is in contrast to the assertion by Mr. Hogenbirk that the encroachment lines are chosen logically by gradually moving from the actual floodline towards the watercourse. Flood levels are modeled at each potential location of the encroachment line until the resultant flood levels jump significantly. This suggests that there is a point at which something in the formula of the model causes a significant jump in flood levels.

Mr. Hogenbirk's description of what happens to flood level elevations during the modeling of encroachment is difficult to understand. The tribunal is uncertain whether he intended to state that flood levels increase in an exponential relationship to the width of the encroachment rather than in a linear relationship, or whether the "significant jump" denotes a spike. The last seems highly unlikely, mathematically, and the tribunal will give Mr. Hogenbirk the benefit of the doubt. Perhaps what he is attempting to describe is the point in encroachment at which the resultant figures are no longer acceptable due to safety and erosion concerns.

Tribunal's calculations

Rather than rely on the assertions of the witnesses, the tribunal has performed its own comparative analysis of the data submitted in this appeal preparing Charts, A through F. The data on these charts is taken directly from the documentary evidence filed in this matter.

In Chart A, the data from the non-enclosure and enclosure models is laid out for the original CCL Study and the three CPM proposals, shown in feet. Chart B depicts the non-encroachment model base model with corrections, the LSRCA approved encroachment lines applied to the corrected base and the CPM Third Proposal encroachment model. Also noted are the increases and decreases between the two encroachment models, as advocated by the LSRCA and the increases and decreases between the corrected base model and proposed CPM model, as advocated by CPM.

Referring to Chart A, it is immediately apparent that corrections and adjustments to the base non-encroachment model have indeed resulted in downstream increases to the updated non-encroachment model in the 1700 and 2260 cross sections. These correspond with what is an apparently undeveloped stretch downstream and Ferrier Avenue [as it appeared in 1984, according to Ex. 16]. The increase in the non-encroachment level for cross-section 1700 is .47 feet, with the original level being 729.52 feet and the revised level being 729.98 feet. This latter figure is greater than the original encroachment level modelled for this cross-section of 729.83 feet. However, the increase due to the Third Proposal .07 feet, and not the .31 feet modelled initially by CCL.

At cross-section 2260, the non-encroachment level increases from the original 733.26 feet to 733.78 feet, a difference of .52 feet. The original encroachment level was modelled at 733.35, with the Third Proposal encroachment level of 733.48 feet, an increase of .13 feet over the original CCL Study model, but a decrease of .30 feet from the revised base model.

It's noted that these figures were not before CCL and were not part of the original CCL Study. However, there was no suggestion from the LSRCA that it did not accept the new base model figures. No issue was made of the revised base figures. Rather, the inquiry concerned the impact of the encroachment (LSRCA and proposed) on those revised base figures. Therefore, the increases in the two cross-sections are found to be acceptable by the tribunal.

If the LSRCA were concerned, it may well be time to carry out a full scale re-analysis of the Subdivision, taking into account the changes to the base model as well as the development which has taken place since 1984. An up-to-date study could address the very real concern raised about the 1:200 and two-foot contours of the mapping used as the basis for the CCL Study. The tribunal and is concerned about the extent of computer generated extrapolation which has had to occur in performing the original and updated calculations. This floodplain is very flat, and there is topographical information, which may likely be unaccounted for in relation to the gentle slope.

The tribunal does not consider the re-mapping of the flood plain to be necessary in this appeal. The responsibility for this type of comprehensive study, in the tribunal's opinion, rests with the authority and not with an appellant. The appellant has uncovered sufficient reasons for adjusting the base model, working with the LSRCA's base model, found errors, calculated changes in the culverts, without having to undertake to do what is, in essence, the job of the LSRCA. Additional survey work to discover or determine locations for legal and illegal development, which may have taken place, properly rests with the LSRCA.

The tribunal does not disagree that a proper analysis of the intervening activity in the floodway should enter into any proper recalculation of the location of the encroachment lines. However, that is not what is being sought in this appeal. CPM on behalf of Cooper is seeking to modify the existing line through correction of errors and with data from newly improved culverts. In so doing, CPM is attempting to use its expertise to establish a building lot for Cooper on Lot 40. Such attempted modification of existing lines is found to be acceptable in the circumstances outlined in these findings.

Any undertaking to re-survey an entire Subdivision or the extent of the floodplain may well reduce the amount of uncertainty which is apparent in this appeal, from the problematic spot elevations through no consistent benchmark, the unknown development through construction and placement of fill, and lack of detailed information on the profile of the Subdivision through its original two foot contour mapping. However, such a re-survey is regarded as well beyond the scope of the owner of a single parcel wishing to develop his lot. If the LSRCA has doubts concerning the continuing correctness of the degree of encroachment which exists within the floodway, then it should be the LSRCA and not a prospective applicant who should proceed to re-evaluate the LSRCA's approach to the Subdivision, through a thorough survey and re-mapping.

Referring to Chart B, following the approach advocated by the LSRCA, the differences between the two encroachment models range from a decrease of -.02 to increases of up to .09. The approach advocated by the LSRCA is that its existing encroachment lines must enter into the comparison, and there can be no net increases to flood levels between its updated but approved encroachment lines and the CPM proposed encroachment lines.

Examining the differences, according to the approach advocated by CPM, resulted in differences ranging between a decrease of -.30 to an increase of .61. Such an increase, if rounded, as was done on the original CCL Study, would result in no increases beyond those originally adopted by the LSRCA. This is the point which as been repeatedly and vehemently asserted by CPM.

The tribunal finds that the approach advocated by CPM results in no additional increase in flood level elevations than what was originally modelled and calculated in the CCL Study. The approach advocated by the LSRCA assumes that the figures of the CCL Study are immutable. While this supports the strict approach to their application, the tribunal can no longer apply the strict approach to the facts of this case, where the underlying figures were in error, in some cases, or fundamentally changed due to improvements to the culverts.

Turning to velocities, the tribunal has examined the data for the original non-encroachment and encroachment CCL Study (two pages found at the end of Appendix B of Exhibit 6). It has compiled the data into Chart C in a manner similar to that done in Exhibit 21 by CPM, and calculated the increases and decreases to velocities in the third set of columns. The increases in the velocities for left over bank, channel and right over bank average (referred to hereafter as VLOB, VCH and VROB, respectively) .24, .09 and .38 feet per second, respectively. The maximum increases are 1.99, 1.42 and .97 feet per second, respectively.

The tribunal calculated the average flow velocities for the Original Non-encroachment and LSRCA encroachment models, in an attempt to better comprehend the basis upon which CCL made its findings and recommendations. For the non-encroachment model, VLOB, VCH and VROB are 1.68, 5,89 and 1.41 feet per second, respectively. Their average is 2.99 feet per second. Although not shown on the Chart, the tribunal has also made a calculation, disregarding channel velocity, in an attempt to understand the meaning of the phrase "velocities within the floodplain", the average of VLOB and VROB is 1.58 feet per second. For the LSRCA encroachment model, these figures are 1.92, 5.93 and 1.79 feet per second, respectively, with averages of 3.23 feet per second, including VCH, and 1.86 feet per second, excluding VCH. Given the statement in the CCL Study that "the flow velocities within the floodplain are less than 3.0 ft. per second [with respect to the non encroachment model] under exiting conditions", the tribunal will assume that the average flow velocity is to include that of the channel.

These are the velocities examined by the CCL Study in making its recommendations concerning the proposed encroachment lines. The purpose in examining average velocities was not explained to the tribunal. Nor was there an explanation as to why the various versions of the models [i.e. the first, second and third CPM models] reflect a number of different cross-sections. One wonders whether average velocities can be skewed, based upon data from the particular cross-section reflected. This question, however, was neither asked nor answered.

In the CPM letter of February 18, 2002, (Ex. 21) it states on page 2, under the second bullet under "Comparison"

  • The approved Conservation Authority HEC-II backwater model average velocity increase from Section 1700 to 3700 was 0.4 ft/s (0.12m/s). The updated CPM model has an average velocity increase of 0.4 ft/s (0.12 m/s); equal to the approved increase.

The tribunal attempted to determine where CPM's figure of .4 feet per second came from. To better understand this assertion, the tribunal has reviewed the Revised Hydraulic Analysis, (August, 2001) (Ex. 13). At page 3, the second bullet under conclusions contains the same statement set out above. Referring to the Appendix, as directed by the Conclusions in Exhibit 13, the tribunal notes that the "Approved Velocity Increase" in the right over bank is .40 ft/s or 0.12 m/s. Therefore, this figure of "average velocity increase" reflects only one of the three sets of figures, that of the ROB, whose average is .38 feet per second. The average increase (not shown) in Chart C for the three velocity increase/decrease figures is .24 feet per second.

The CCL Study commentary at page 4 only discussed the average increase of the three velocity figures. This is found in the second full paragraph under heading 5.1.2 Case 2 – Encroachment to Prescribed Limit:

When considering flow velocities, the average increase was in the order of 0.2 ft/sec. As the flow velocities within the floodplain are less than 3.0 ft per second under existing conditions, the small increase in anticipated flow velocity would not have a significant impact on the erosion potential associated with the flow.

No explanation for the selective use of data was provided. At the time of the hearing, neither the LSRCA nor the tribunal asked for an explanation.

The approach advocated by CPM is captured in Chart F, a compilation of data for comparison of velocities between the updated, non-enclosure model with the CPM 3rd Analysis Proposed Enclosure. The average increases for VLOB, VCH and VROB are .43, .39 and .41 feet per second, respectively, with maximum increases being .92, 2.13 and .93 feet per second, respectively. Therefore, the assertion by CPM that similar velocity increases, are achieved are based upon the velocity increase for the right over bank of.41 feet per second. There was no similar assertion that the average increase for all of the data, namely comparison with .24 feet per second, would meet the test, because the average of the increases shown in the last columns of Chart F would be .41. Therefore, the average of the increases advocated by CPM is comparable to the average increase in the ROB originally modelled by CCL. This selective use of the data, however, should have been brought to the attention of the tribunal and highlighted. That would have allowed for more information as to the significance of the choice of certain comparative data over other data.

In Chart F, the CPM non-encroachment model has actual average velocity figures of 1.66, 5.55 and 1.5 feet per second, VLOB, VCH and VROB, respectively. In turn, the average of these three figures is 2.9 feet per second. This average velocity for the floodplain is comparable to the average shown for the pre-encroachment floodplain on Chart C, of 2.99 feet per second. Both figures are under the 3 feet per second discussed by CCL when it has determined that velocities are sufficiently low under non-encroachment conditions to withstand the Case 2 encroachment.

Looking at the other increases between the updated non-encroachment model and the CPM Third Proposal, found in Chart F, despite the number of increases in the channel velocity which exceed 1 foot per second, the average increase in channel velocity is .39 feet per second. In fact, the increases for left and right over bank are similar, pegged at .43 and .41 feet per second, respectively. Their overall average increase is .41 feet per second.

The approach advocated by the LSRCA is to utilize the modified base model and apply the LSRCA approved encroachment lines. The increases in velocity, which will be experienced are those accepted by the CCL Study, although in fact, these figures differ. This data has been compiled by the tribunal and is reflected in Chart E. The average increases experienced in VLOB, VCH and VROB are .34, .26 and .34 feet per second, respectively, with maximum increases of .82, 2.1 and .85 feet per second. The average increase in velocity is .31 feet per second.

Chart D represents the next step of the approach, as advocated by the LSRCA, involving the comparison of the LSRCA approved, modified encroachment lines with the CPM Third Proposal. The increases experienced in VLOB, VCH and VROB are .13, .138 and .085 respectively and maximums are .52, 1.19 and .47, respectively. According to the LSRCA, there can be no net increase over the LSRCA approved levels. Chart D demonstrates that there are such increases over and above those experienced in Chart E. Their average is between .138 and .085 feet per second, which is the addition of approximately one inch per second, a relatively nominal amount, but an increase, nonetheless, according to the LSRCA.

Mr. Hogenbirk singled out the above noted maximum figures found in Chart D in his evidence relating to cross section 3110, where he characterized the increases shown as being significant and an area of concern. The tribunal has examined the data from cross section 3110:

cross section 3310 VLOB VCH VROB
Orig. non enc. 1.30 3.94 1.27
Orig. LSRCA enc. 1.30 3.42 1.30
mod. non enc. 1.35 4.13 1.31
mod. LSRCA enc. 1.38 3.71 1.38
CPM prop enc. 1.90 4.90 1.85

The data shows that, as suggested, there has been a marked increase between the updated LSRCA approved enclosure lines and the CPM Third Proposal lines of the magnitude described above. However, that does not tell the whole story. For reasons which are not known, the LSRCA proposed encroachment lines have had the result, in both the original and updated model, of lowering the channel velocity at this cross section. Therefore, the difference shown between the LSRCA encroachment model and the CPM Third Proposal, being in the order of 1.2 feet per second, is in fact an increase over the adjusted base model of .77 feet per second.

Examining the approach advocated by the LSRCA, the tribunal calculated increases between the modified non-encroachment model and the CPM Third Proposal. The resulting increases, shown on Chart D, range from decreases of .23 to increases of 1.19 feet per second, with the averages being .13, .138 and .085 feet per second for the VLOB, VCH and VROB, respectively. This results in an average increase of .12 feet per second, when the three figures are rounded to the second decimal.

When the average increases calculated in Chart D are added to those in Chart E the resultant average increase is .43 feet per second. This compares with the average of .41, using the approach advanced by CPM, shown in Chart F. The difference of .02 feet is equal to .24 inches. This is an increase of less than one quarter of an inch per second. The tribunal finds this to be negligible. T he tribunal points out in Exhibit 22 that the LSRCA has questioned increases of as little as .01 feet in floodline elevations and velocity increases of as little as .01 feet per second where the actual mapping only shows two foot differential in contours. It becomes difficult to give much weight to the approach advocated by the LSRCA, given that the mapping itself does not distinguish elevations to such a degree.

Also, Mr. Hogenbirk singled out the increases in velocity of cross section 3110, as set out in Chart D, being nearly 1.2 feet per second. In addition to the critical analysis of the origins of this figure, set out above, the tribunal noted the following. When Chart C and the Original data is examined it reveals that five cross sections experience increases of greater than one foot per second, and one of these, 3265, is found in the LOB and not the channel. Similarly, when examining the updated non encroachment base model compared with the LSRCA approved encroachment lines in Chart E, there are five cross sections with increases in velocity of over one foot per second, all appearing in the channel.

The tribunal has come to the conclusion that the data presented in this case has been extremely self-serving at times and more particularly, the data has been selectively referred to by both CPM and the LSRCA to paint either an extreme or overly moderate picture of their relative positions. This has not been particularly helpful. Quite the contrary. The tribunal has found itself in the position of having to perform its own data analysis to ensure that the figures discussed are relevant to the decision to be made.

Returning to the assertion by the LSRCA that the floodplain is extremely sensitive to any encroachment, the tribunal concludes that this is not the case. The flood plain is extremely broad and shallow, having low velocities of modelled floods and with a very gradual slope towards Lake Simcoe. The tribunal has used the figures provided by the LSRCA and CPM to determine that, given the errors and changes to culverts, this floodplain can withstand the degree of encroachment proposed by the Third Analysis without additional flooding or velocities beyond those, which CCL modelled in the first place. The narrowing of the floodway at Lot 40 is found to be to a degree, which can still meet floodplain management concerns as acceptable.

While no threshold was set in the parameters of the CCL Study, the tribunal finds that it rejects the approach advocated by the LSRCA. Applying the same encroachment lines to the updated base model without a critical assessment of the resulting data would be to effectively "grandfather" the location of those lines without critical assessment. A critical assessment would render the calculations within the acceptable range, but lower than what was found in the CCL Study. This is due to the benefit of the culvert works and the correction of the errors. Failing any other standard to apply in the circumstances, the tribunal finds that those implied by the CCL Study can be applied to the Third Proposal.

The proposed modifications in the CPM Third Analysis, which excludes the proposed changes to Lot 9 in Plan M16 and Lots 6 and a portion of Lot 7 on Plan M15, has given the figures used by the tribunal in its own analysis, above. These figures have found to be acceptable, given that the difference in flood level elevations is calculated to be one-quarter inch. If the figure of .42 is rounded to .4, there is no difference. The original CCL Study only modelled to the first decimal place and based its recommendations accordingly.

Similarly, the increases to velocity for the applicable over bank are comparable to that having been modelled by CCL . The tribunal has examined the figures provided by LSRCA and CPM and finds that, owing to the errors and installation of culverts, there is virtually no difference between the modelled flood level elevations and relevant velocities which would result. This being the case, the tribunal finds that CPM has successfully shown that the Third Modified Proposal will result in no increases to floodline elevations and velocities. Also, upstream and downstream impact is found to be within the same limits, tolerated by the CCL Study results.

Lot lines

CPM has raised an interesting issue with respect to the drawing of the encroachment lines within an analogous two-zone concept area by following lot lines to render more developable land. This was opposed by the LSRCA, asserting, and the tribunal agrees, that flood waters do not follow lot lines, nor do they make right angle or even angular turns. It is an issue which will be best determined on the characteristics of the particular floodplain and existing development. In this Subdivision, given the bisection of lots along their length, moving with lot lines can be accommodated from a floodplain perspective and makes sense from a community viability perspective.

Cumulative impact and precedent

The significance of the issue of cumulative impact in a two-zone concept differs from that of a one zone concept. The fact is that in a two-zone concept, policy regarding development in the floodway will be strictly applied, so that issues of cumulative impacts need seldom arise.

This case is unique in that it involves the moving of encroachment lines for very good reasons, namely errors and public works of benefit to overall flood levels within the reach. Its cumulative impact has already been examined and found to be within tolerable limits, as the Third Proposal did not move the encroachment lines along one lot only, but selectively throughout the Subdivision. Several locations were examined and subsequently discarded.

The tribunal finds that the cumulative impact of any other properties likely to be affected by the proposal has been taken into account in the calculations performed in connection with the Third Proposal. The resulting depths and velocities have been found to be within the same limits found by the original CCL Study.

There is no doubt that the result in this case sets a precedent for the redrafting of encroachment lines generally. However, the test set is, regarded by the tribunal as equitable, within the meaning of section 121 of the Mining Act. The test does not allow for the wholesale modification of encroachment lines in any two-zone concept area. There must be some good and compelling reasons for considering such action. These include but are not limited to errors in the original modelling of a number and to such an extent as to render the model questionable and unreliable; new data such as spot elevations obtained using a common benchmark, infrastructure which will affect flood flows and may more accurate and better mapping, showing greater definition of contours.

Narrowing of channel

The tribunal is satisfied, based upon the data generated, that the narrowing of the channel discussed by the LSRCA as a result of the proposal, will not cause adverse impact either in the Subdivision or upstream or downstream.

However, there remains an element of uncertainty with the data throughout this appeal. The two foot contour lines on the mapping and necessary extrapolations to perform calculations are of concern. The tribunal has examined the Conclusions in the CCL Study at page 5 and notes that the third point speaks to isolated areas of fill being allowed to occur within the encroachment area. The tribunal takes this to mean that only such fill as may be necessary to support the proposed construction is anticipated in the Conclusions. The date of the CCL Study pre-dates the 1999 Provincial Flood Plain Planning Policy and so its recommendations and the approach to a two-zone concept may differ between them.

Given that the original CCL Study appears to have anticipated the minimal placement of fill in the encroachment area, and the appellant has proposed minimum quantities of fill, the tribunal finds that it will take a precautionary approach to the redrafting of the encroachment lines in the following manner. Notwithstanding that the encroachment lines are accepted as modelled in the Third Modified Proposal, the tribunal finds that

  • all newly created areas outside the encroachment lines will be limited in the placement of fill to creation of a building envelope, and to such further extent as may reasonably be necessary under the circumstances
  • siting of prospective structures, wherever possible, should be oriented towards the lot line which is furthest away from the earlier encroachment line
  • all prospective outbuildings are limited to being built immediately behind the housing, so as to not cause any obstructions within the flood fringe

Access and egress

The tribunal notes that Mr. Hogenbirk raises the issue of safe access and egress in his letter of March 13, 2001 (Ex. 18, Tab J) to CPM. His third point ends with the following comments:

"… The extensive floodplain north of the stream would suggest that this area would be unsuitable for any further new home building closer to the creek than is currently allowed (i.e. the current encroachment limit). Safe access to properties in the north floodplain requires that an extensive length of flooded roadway to be traversed during the Regional storm event. Southward movement of the north encroachment line would increase this distance even more. [emphasis added.]"

These last two statements make absolutely no sense, given the layout of the Subdivision. The egress to the north is to the end of a dead end street. True vehicular egress for any of the homes to the north of the encroachment line would require that the vehicle be driven through the entire floodway to the southern limit of the floodplain. While the comment is correct on its face, the tribunal, frankly, regards this as no more than grasping at straws.

The homes one lot further north have no restrictions regarding construction or the placement of fill. The LSRCA has already determined, in respect of all properties north of the encroachment line, that the risk of having to either traverse through the deepest part of the floodplain or alternatively walk on foot to the northern edge of the floodplain is manageable when balanced with the viability of the Subdivision. Using this argument at this time and in this way holds absolutely no weight with the tribunal, given the manner in which the CCL Study has been implemented in the Subdivision since 1984.

The tribunal finds that safe access and egress is no greater an issue for Lot 40 than it is for any of the homes further north along Gilmore Avenue.


Mr. Geist made a request that, if successful, his client be permitted to make written submissions as to costs. The tribunal does not share Mr. Geist's sense of moral outrage at the manner in which the original application and this appeal has proceeded. This has been a case, perhaps the first before the tribunal, in which the strict adherence to the encroachment lines set out in an analogous two-zone concept have been challenged. The basis for the challenge was valid, in that original figures used have proved suspect, the mapping of two foot contours may have over-simplified the computer analysis, and improvements were made to culverts.

The reluctance of the LSRCA to consider any deviation from a set location of pre-existing and modelled encroachment lines is, frankly, understandable from the tribunal's perspective. In prospective applications and appeals, the potential for flexible encroachment lines could undermine not only the certainty with which the LSRCA or any authority proceeds in applying a two-zone concept. Any potential for unlimited movement or "tweaking" a term employed by Mr. Geist, of the lines has the very real potential to change the flood level elevations and flow velocities affecting properties on which development has already occurred. The tribunal is satisfied that, in the current appeal, it has set out a test under which conditions it will consider movement of the existing encroachment lines. None of the items set out are seen as being very common or even very likely.

Notwithstanding that the tribunal regards this appeal as a test case for the movement of encroachment lines in an analogous two-zone concept, the tribunal grants Mr. Geist's request. Mr. Geist will be given 60 days from the date of the Order to file Mr. Cooper's written position as to costs. Mr. Hill will have 90 days from the date of the Order to file the position of the LSRCA with respect to costs. Mr. Geist will then have a further 15 days to reply. These dates corres-pond to April, 15, May 15 and May 30, 2003, respectively.


The appeal is granted with the following conditions:

  1. A site plan for building on the property will be sited in accordance with the local by-laws to the northerly limit of the property;
  2. Any garage will be sited on the southern portion of the building;
  3. All windows will be constructed above the flood level elevation;
  4. Fill will be reduced to a minimum, under the building envelope and to such further extent as may be reasonably necessary; and
  5. An agreement would be registered on title acknowledging that the building is within an encroachment area and releasing the Lake Simcoe Region Conservation Authority form any liability with respect to its consent to the issuance of a building permit.

Counsel for the parties will be given sixty, ninety and a further 15 days respectively to make written submissions on costs.

Chart A: Data original LSRCA and CPM proposals - no encroachment and encroachment models

Cross Sec. Orig. CCL no enc.* Orig. CCL enc. CPM 1st analysis no enc. CPM 1st analysis enc. CPM 2nd mod prop no enc. CPM 2nd mod. prop with enc. CPM 3rd revised prop'al no enc. CPM 3rd revised prop'al enc.
1700 729.52 729.83 730.0 730.1 729.98 730.05 729.98 730.05
2050         732.08 732.56    
2260 733.26 733.35 733.3 733.4 733.78 734.02 733.78 733.48
2315 734.77 734.89 734.6 734.7 734.39 734.41 734.44 734.67
2316 735.06 735.30 734.8 735.1        
2335 -       734.67 734.82 734.79 734.94
2357 735.15 735.41 735.0 735.3        
2358 735.13 735.39 735.1 735.3 734.69 735.85 734.81 734.96
2420 735.24 735.51 735.1 735.4 734.92 735.03 735.02 735.24
2545         735.36 735.71 735.38 735.71
2620 735.78 735.98 735.7 736.0 735.66 735.88 735.66 735.88
2820 737.11 737.22 737.1 737.2 737.12 737.19 737.12 737.19
2870 738.96 739.26 738.9 739.4 738.79 739.19 738.84 739.34
2871 738.20 739.79 739.2 739.7        
2890         739.14 739.58 739.18 739.73
2912 739.31 739.90 739.3 739.9        
2913 739.29 739.88 739.4 740.0 739.08 739.51 739.15 739.69
2965 739.44 740.04 739.4 740.1 739.34 739.82 739.38 739.98
3065         739.39 739.89 739.43 740.04
3066         739.40 739.86 739.43 740.00
3110 739.60 740.16 739.6 740.2 739.52 739.97 739.55 740.01
3265 740.68 740.73 740.7 740.8 740.68 740.72 740.68 740.71
3315 743.36 743.60 743.3 743.6 743.61 742.81 743.22 743.52
3316 743.73 742.2 743.7 744.0        
3355         743.02 743.20 743.47 744.01
3357 743.89 744.29 743.7 744.3        
3358 743.85 744.20 743.9 744.3 743.15 743.34 743.80 744.16
3420 744.22 744.58 744.1 744.5 743.63 743.82 744.08 744.60
3700 746.09 746.16 746.1 746.1 746.06 745.99 746.06 746.12

* updated from data found in Exhibit 13, Appendix C.

Chart B: LSRCA flood level comparison

Cross Sec. Orig. CCL enc. CPM Revised 3rd prop'al with no enc. CPM revised 3rd prop'al with LSRCA enc. lines CPM prop'd enc. (3rd prop'al) Differ'ce between revised LSRCA and CPM enc. lines Differ'ce between revised CPM no enc. and prop enc.
1700 729.83 729.98 730.05 730.05 .00 .07
2260 733.35 733.78 733.47 733.48 .01 -.30
2315 734.89 734.44 734.62 734.67 .05 .23
2316 735.30          
2335   734.79 734.88 734.94 .06 .15
2357 735.41          
2358 735.39 734.81 734.91 734.96 .06 .16
2420 735.51 735.02 735.16 735.24 .08 .22
2545   735.38 735.63 735.71 .08 .33
2620 735.98 735.66 735.82 735.88 .05 .22
2820 737.22 737.12 737.18 737.19 .01 .07
2870 739.26 738.84 739.29 739.34 .05 .50
2871 739.79          
2890   739.18 739.65 739.73 .08 .55
2912 739.90          
2913 739.88 739.15 739.61 739.69 .08 .54
2965 740.04 739.38 739.89 739.98 .09 .60
3065   739.43 739.95 740.04 .09 .61
3066   739.43 739.95 740.00 .05 .57
3110 740.16 739.55 740.03 740.10 .07 .55
3265 740.73 740.68 740.81 740.79 -.02 .11
3315 743.60 743.22 743.52 743.52 .00 .30
3316 742.20          
3335   743.47 744.01 744.01 .00 .54
3357 744.29          
3358 744.20 743.80 744.16 744.16 .00 .36
3420 744.58 744.08 744.60 744.60 .00 .52
3700 746.16 746.06 746.12 746.12 .00 .06

Chart C: Comparison of velocities from original non-enc. and LSRCA enc. lines

Cross Section VLOB Orig. LSRCA no enc. VCH VROB VLOB Orig LSRCA enc. VCH VROB inc/dec VLOB inc/dec VCH inc/dec VROB



1700 2.59 5.82 2.01 0.00 0.00 2.62 -2.59 -5.82 .61
2260 2.41 7.16 1.47 2.34 6.53 1.51 - .07 - .63 .04
2315 1.38 9.44 1.38 1.73 10.70 1.85 .35 1.26 .47
2316 1.16 2.72 1.17 1.52 3.06 1.60 .36 .34 .43
2357 1.18 2.79 1.18 1.51 3.06 1.59 .33 .27 .41
2358 1.11 5.37 1.11 1.42 5.86 1.49 .31 .49 .38
2420 1.10 4.17 1.02 1.41 4.74 1.34 .31 .57 .32
2620 1.89 6.86 1.37 1.77 5.71 1.55 -.12 -1.15 .18
2820 2.31 8.00 1.44 2.66 8.82 2.41 .35 .82 .97
2870 1.35 9.14 1.37 2.02 11.61 2.04 .67 2.47 .67
2871 1.18 2.71 1.20 1.65 3.08 1.66 .47 .37 .46
2912 1.32 3.30 1.34 1.76 3.48 1.77 .44 .18 .43
2913 1.26 6.34 1.28 1.66 6.46 1.67 .40 .12 .39
2965 1.02 2.64 .72 1.18 2.83 .89 .16 .19 .17
3110 1.30 3.94 1.27 1.30 3.42 1.30 0 -.52 .03
3265 2.50 8.20 1.44 4.49 9.62 1.84 1.99 1.42 .40
3315 1.56 10.00 1.50 2.00 11.28 1.87 .44 1.28 .37
3316 1.32 2.81 1.25 1.65 3.06 1.58 .32 .25 .33
3357 1.89 5.19 1.82 2.19 4.94 2.05 .30 .25 .23
3358 1.76 9.44 1.70 2.09 9.26 1.95 .33 -.18 .25
3420 .94 2.45 .89 .85 2.14 .83 .09 -.31 -.06
3700 4.49 11.12 3.09 4.94 10.85 3.94 .46 -.27 .85
Avg. 1.68 5.89 1.41 1.92 5.93 1.78 .24 .09 .38
Max.             1.99 2.47 .85
Avg.   2.99     3.23        

Chart D: Comparison of velocities for modified LSRCA encroachment model and CPM 3rd analysis

Cross Sec. VLOB CPM mod with LSRCA app enc. VCH VROB VLOB CPM 3rd analysis enc. VCH VROB inc/dec VLOB inc/dec VCH inc/decVROB



1700 .31 4.20 2.93 .31 4.20 2.93 0 0 0
2260 2.14 5.80 1.45 2.12 5.72 1.44 -.02 -.08 -.01
2315 2.31 9.29 2.53 2.44 9.38 2.68 .13 .09 .15
2335 2.09 1.65 2.25 2.32 1.77 2.51 .23 .12 .25
2358 1.94 8.20 2.09 2.10 8.64 2.31 .16 .44 .24
2420 1.65 6.23 1.65 1.74 6.35 1.74 .09 .12 .09
2545 1.45 4.13 1.38 1.40 3.92 1.33 -.05 -.21 -.05
2620 1.94 6.46 1.66 1.90 6.26 1.68 -.04 -.20 .02
2820 2.81 6.93 .23 2.85 6.93 0.00 .04 0 -.23
2870 1.95 9.46 1.97 2.08 9.76 2.07 .13 .30 .10
2890 1.84 1.12 1.86 1.96 1.15 1.95 .12 .03 .09
2913 1.85 8.65 1.87 1.95 8.68 1.93 .10 .03 .06
2965 1.26 3.05 .97 1.32 3.09 1.00 .06 .04 .03
3065 1.14 3.82 1.16 1.14 3.71 1.15 0 -.09 .01
3066 1.14 3.82 1.16 1.52 4.54 1.41 .38 .72 .25
3110 1.38 3.71 1.38 1.90 4.90 1.85 .52 1.19 .47
3265 3.32 9.02 1.82 3.42 9.33 1.87 .10 .31 .05
3315 2.72 11.25 2.56 2.72 11.28 2.56 0 .03 0
3335 2.26 1.36 2.16 2.26 1.36 2.16 0 0 0
3358 2.64 10.78 2.51 2.64 10.78 2.15 0 0 .36
3420 .84 2.13 .83 .84 2.13 .83 0 0 0
3700 5.02 11.07 3.98 5.02 11.07 3.98 0 0 0
Avg. 2.0 5.02 1.84 2.09 6.18 1.79 .13 .138 .085
Max.             .52 1.19 .47
Avg.   2.95     3.35        

Chart E: comparison of modified base model with LSRCA approved encroachment lines

Cross Section VLOB CPM 3rd mod, no enc. VCH VROB VLOB Modif. LSRCA app enc. VCH VROB inc/dec VLOB inc/dec VCH inc/dec VROB



1700 0.00 3.91 2.17 .31 4.20 2.93 .31 .29 .76
2260 1.62 4.28 1.03 2.14 5.80 1.45 .52 1.52 .42
2315 2.18 10.13 2.17 2.31 9.29 2.53 .13 -.84 .36
2335 1.57 1.36 1.58 2.09 1.65 2.25 .52 .29 .67
2358 1.54 7.13 1.54 1.94 8.20 2.09 .40 1.07 .55
2420 1.22 5.03 1.21 1.65 6.23 1.65 .43 1.20 .44
2545 1.50 4.82 1.22 1.45 4.13 1.38 -.05 -.69 .16
2620 2.07 7.66 1.50 1.94 6.46 1.66 -.13 -1.20 .16
2820 2.48 6.26 1.45 2.81 6.93 0.24 .33 .67 -1.21
2870 1.49 9.41 1.51 1.95 9.46 1.97 .46 .05 .46
2890 1.23 .89 1.26 1.84 1.12 1.86 .61 .23 .60
2913 1.37 8.18 1.39 1.85 8.65 1.87 .48 .47 .48
2965 1.05 2.75 .74 1.26 3.05 .97 .21 .30 .23
3065 1.10 4.22 1.01 1.14 3.82 1.16 .04 -.40 .15
3066 1.09 4.22 1.01 1.14 3.82 1.16 .05 -.40 .15
3110 1.35 4.13 1.31 1.38 3.71 1.38 .03 -.42 .07
3265 2.50 8.20 1.44 3.32 9.02 1.82 .82 .82 .38
3315 1.90 9.15 1.84 2.72 11.25 2.56 .82 2.10 .72
3335 1.68 1.23 1.61 2.26 1.36 2.16 .58 .13 .55
3358 1.94 9.46 1.87 2.64 10.78 2.51 .70 1.32 .64
3420 .98 2.61 .93 .84 2.13 .83 -.14 -.48 -.10
3700 4.56 11.29 3.13 5.02 11.07 3.98 .46 -.22 .85
Avg. 1.66 5.74 1.50 2.0 6.00 1.84 .34 .26 .34
Max.             .82 2.1 .85
Avg.   2.97     3.28        

Chart F: Comparison of velocities for modified non Eng. & CPM 3rd proposal enc.

Cross Section VLOB CPM mod, no enc. VCH VROB VLOB CMP 3rd analysis enc. VCH VROB inc/dec VLOB inc/dec VCH

inc/dec VROB

1700 0.00 3.91 2.17 .31 4.20 2.93 .31 .29 .76
2260 1.62 4.28 1.03 2.12 5.72 1.44 .05 1.44 .41
2315 2.18 10.13 2.17 2.44 9.38 2.68 .26 -.75 .51
2335 1.57 1.36 1.58 2.32 1.77 2.51 .75 .41 .93
2358 1.54 7.13 1.54 2.10 8.64 2.31 .56 1.51 .77
2420 1.22 5.03 1.21 1.74 6.35 1.74 .52 1.32 .53
2545 1.50 4.82 1.22 1.40 3.92 1.33 -.10 -.90 .11
2620 2.07 7.66 1.50 1.90 6.26 1.68 -.17 -1.40 .18
2820 2.48 6.26 1.45 2.85 6.93 0.00 .37 .67 -1.45
2870 1.49 9.41 1.51 2.08 9.76 2.07 .59 .35 .56
2890 1.23 .89 1.26 1.96 1.15 1.95 .73 .26 .69
2913 1.37 8.18 1.39 1.95 8.68 1.93 .58 .50 .54
2965 1.05 2.75 .74 1.32 3.09 1.00 .27 .34 .26
3065 1.10 4.22 1.01 1.14 3.71 1.15 .04 -.51 .14
3066 1.09 4.22 1.01 1.52 4.54 1.41 .43 .32 .40
3110 1.35 4.13 1.31 1.90 4.90 1.85 .55 .77 .54
3265 2.50 8.20 1.44 3.42 9.33 1.87 .92 1.13 .43
3315 1.90 9.15 1.84 2.72 11.28 2.56 .82 2.13 .72
3335 1.68 1.23 1.61 2.26 1.36 2.16 .58 .13 .55
3358 1.94 9.46 1.87 2.64 10.78 2.15 .70 1.32 .64
3420 .98 2.61 .93 .84 2.13 .83 -.14 -.48 -.10
3700 4.56 11.29 3.13 5.02 11.07 3.98 .46 -.22 .85
Avg. 1.66 5.55 1.50 2.09 6.13 1.84 .43 .39 .41
Max.             .92 2.13 .93
Avg.   2.9     3.35        


Floodway (for river and stream systems):
means the portion of the flood plain where development (other than uses which by their nature must be located within the floodway, flood and/or erosion control works, or where appropriate, minor additions or passive, non-structural uses which do not affect flood flows) and site alteration could cause a danger to public health and safety or property damage.
Where the one zone concept is applied, the floodway is the entire flood plain.
Where the two-zone concept is applied, the floodway is the inner portion of the flood plain, representing that area required for the safe passage of flood flow and/or that area where flood depths and/or velocities are considered to be such that they pose a potential threat to life and/or property damage. Where the two-zone concept applies, the outer portion of the flood plain is called the flood fringe.

Flood fringe (for river and stream systems):
means the outer portion of the flood plain between the floodway and the flooding hazard limit. Depths and velocities of flooding are generally less severe in the flood fringe than those experienced in the floodway. The flood fringe is the area where development and site alteration may be permitted, subject to appropriate floodproofing to the flooding hazard elevation or another flooding hazard standard approved by the Ministry of Natural Resources.

*updated from data found in Exhibit 13, Appendix C.