LCA Environmental Consultants

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1 April 28, 2014 Fonthill Gardens Inc Yonge Street, Suite 230 Toronto, ON M2P 2A9 Dear Mr. Allen, Re: Watercourse Realignment Feasibility Assessment, Village of East Fonthill Town of Pelham LCA Environmental Consultants were retained by Fonthill Gardens Inc. and the Town of Pelham to evaluate the existing watercourse feature and associated functions on the subject lands and determine the feasibility of channel relocation. The subject watercourse, a headwater tributary of the Singer s Drain, is located along the southern limit of the proposed Village of East Fonthill development area, located in the northeast portion of the East Fonthill Secondary Plan Area, along Regional Road 20 and Rice Road in the Town of Pelham. Background Information A comprehensive review of the existing data pertaining to the Singer s Drain was completed in preparation of the East Fonthill Secondary Plan (LCA, 2009). Field evaluations completed in 2007 and 2008 confirmed that the northern-most tributary of Singer s Drain originates in the area of Station Street, capturing a portion of the parking lot runoff of the existing commercial development along Regional Road 20 before entering and traversing the subject lands. According to the Pelham Urban Boundary Expansion Subwatershed Plan (Proctor & Redfern 1996), it was recommended that the branches upstream of the confluence of the north and south branches be classified as Poor in terms of relative ecological function. The report indicated that fish habitat was very limited within the intermittent upper reaches as the branches were not defined and likely lacking bank full stages. During their investigations, these reaches primarily functioned as storm/snow melt conveyance for the downstream channels. The historical report indicated that fish habitat was limited within the study area (extending to the confluence downstream) due to the impacts associated with drainage improvements and channel alteration. Proctor & Redfern (1996) did not observe or document any fish species within the tributaries during field visits and access to the channels by fish was considered limited as these areas were restricted by culverts, lack of instream cover, and obstructions such as cattail clumps (Proctor & Redfern December/Jan 1996). 1

2 Although the downstream reaches beyond Rice Road were not studied in detail in the preparation of the East Fonthill Secondary Plan report due to site access limitations, the lack of fish and suitable habitat was confirmed in the various tributaries within the study area limits through multiple seasons across several years. Dry channel conditions, in-channel barriers such as rock piles and debris, and land use impacts associated with the surrounding agricultural uses confirmed that these systems currently do not provide suitable habitat requirements for the various fish life stages. Several of the culvert structures at Rice Road also created impediments to flow and currently pose barriers to potential fish migration (i.e. perched culverts). The subject watercourse was also assessed by Beacon Environmental in 2012 as part of the field assessments completed for the Village of East Fonthill Environmental Impact Study. The observed channel features and context of fish habitat according to the revised Federal Fisheries Act were discussed in detail in the EIS report. Accordingly, the channel does not constitute fish habitat under the Federal Fisheries Act, but does provide base flow contribution indirectly to potential downstream habitat. Therefore, in accordance with the recommendations detailed in the East Fonthill Secondary Plan, it is suggested that the channel remain as an open-channel system with minor realignments, subject to a permit from Niagara Peninsula Conservation Authority. Field Site Evaluations In addition to the detailed field assessments completed in preparation of the East Fonthill Secondary Plan Area, pre-development water quality and flow data was collected through 2009 and 2010 at representative times (freshet, wet weather and dry weather) to assess water levels and water quality in the various tributaries of the Singer s Drain. As well, a 2012 field assessment of the northern channel was completed to further document the existing conditions of this channel. The existing watercourse is highly channelized in the headwaters, running immediately adjacent to the rear of the existing commercial development and along the edge of the coniferous plantation, with right angles at both turns in the channel, beyond which the channel cuts diagonally though the subject land and south before exiting through the culvert at Rice Road. The channelized portion is visually represented in the photographic records presented in Appendix A. The channel substrate is predominantly silt and clay with no defined riffle-pool sequence and minimal habitat diversity for benthic invertebrates. There is currently minimal riparian buffer along the channel, consisting primarily of herbaceous and shrub thicket less than two metres in width. The vegetated buffer increases to approximately two to five metres of shrub thicket with the occasional willow tree cluster in the channel, causing the channel to be undefined through those areas. In-stream vegetation is prevalent through the drier summer months when the channel is intermittent with only residual pockets of pooled water. 2

3 Channel Realignment Considerations As discussed within the Environmental Impact Study Natural Heritage, Village of East Fonthill report submitted by Beacon Environmental (April 2014), the subject watercourse does not constitute fish habitat as defined pursuant to the Federal Fisheries Act (as amended in Bill C-38, 2012). However, the channel does provide both base flow and nutrient input into the downstream habitat and should be considered as indirect habitat. The tributary measurements and profile data collected during the field investigations were provided to Upper Canada Consultants (UCC) for consideration in the design phase of the channel realignment. In consultation with UCC, the existing channel dimensions and substrate characteristics were evaluated to classify the channel according to the principles of natural channel design. This information was reviewed in conjunction with the expected flow requirements and elevations to produce a channel design that would provide a stable meandering channel along the southern limits of the subject property extending to the Rice Road culvert. Based on the input data, the realigned channel will require a belt width of approximately 33 metres to accommodate the meander wavelength and stable slopes for riparian planting (see Appendix B, Natural Channel Design). As well, the proposed channel belt width will provide for the prescribed 15 metre vegetated buffer from the proposed development areas. Although the channel realignment will not negatively impact fish habitat on the subject property, the existing channel extends beyond the subject lands, south to Rice Road. As such, it is recommended that the entire channel, extending from the northwest corner of the subject lands to the outlet at Rice Road, be realigned at the same time and in advance of development of the southern lands so that the channel has time to stabilize and the riparian buffer grow before the development is scheduled. The designed channel provides for a consistent and stable meander pattern, alleviating the right angles and channelized segments that were contributing to erosion and sedimentation in the channel. The designed belt width allows for a natural meander to the channel and the installation of riffles to diversify the channel substrate and improve the benthic habitat within the watercourse as well as promote natural sorting of the fine particles. In addition to the mitigation strategies detailed in the Environmental Impact Study Natural Heritage, Village of East Fonthill, the following mitigation should be considered: 1) In the area of Street C, adjacent to the channel, the road and curb should be graded such that the runoff flows into a storm sewer directed towards the stormwater management. There should be no direct runoff from the street into the channel. 2) In the Block 1 development area, the slopes and upland areas should be appropriately planted to provide an effective vegetated buffer. 3) It is assumed that the Block 6 SWM facility will be suitably bermed from the channel with an appropriate channel outlet 3

4 4) Block 19 is a dedicated park area adjacent to the channel and should be appropriately planted to provide and effective vegetated buffer. Fencing along the top of bank may be required to limit access in this area. 5) The balance of the channel to be realigned to the Rice Road outlet, south of the proposed development area, should be constructed as designed in order to maintain continuity and stability in the channel. Planting the riparian buffer after the channel construction is completed is recommended in order for the vegetation to establish. Opportunities to transplant some of the existing vegetation are possible through the placement of vegetation mats or direct transplant of existing riparian material. Additional planting along the length of the realigned channel will improve the riparian function, especially through the sparsely vegetated, channelized portions of the watercourse. In summary, the proposed channel realignment will provide net benefits to the existing channel through the application of natural channel design and best management practices for construction. The above comments and recommendations reflect the results of the field assessments and review of the existing relevant reports and current legislation. While the proposed channel realignment does not require authorization under the Federal Fisheries Act, a permit will be required from NPCA under the Generic Regulation for alteration of a watercourse. We trust that this report addresses your requirements and will assist in the detailed site planning stages. Should you require any additional information, please do not hesitate to contact our office. Sincerely, Lisa Campbell, M.Sc., C.C.E.P. Director LCA Environmental Consultants 4

5 Appendix A Northern Channel, Village of East Fonthill Photographic Records 5

6 Photograph 1: Headwaters of northern channel, view west (upstream). Photograph 2: Headwaters of northern channel, view east (downstream). 6

7 Photograph 3: Downstream limit of northern channel at Rice Road, view west (upstream). Photograph 4: Downstream limit of northern channel at Rice Road, view east (downstream). 7

8 Appendix B Natural Channel Design Calculations 8

9 NATURAL CHANNEL DESIGN Upper Canada Consultants Martindale Road St. Catharines, ON L2W 1A1 Project : Rice Road (River Realty),Town of Pelham Design: Project No : 0482 Reviewed: Watercourse: Upper portion of channel to culvert Date: Adam Keane, P.Eng. Jason Schooley, P.Eng. April 28, 2014 Upstream Elevation: Strait Block Length (m): m Downstream Elevation: Thoretical Strait Slope (%): 1.39% Fall (m): 5.69 Meander Length (m): m Meander Slope (%): 1.44% Block Width (m): 33.0 Mean Meander Wavelength (m): (C.W.Carlston, 1965) Curvature of Meander Radius (±15%) (m): 29.4 to 39.8 (B.P.Leopold, 1957) STORM FLOWS (Leave Blank If Not Known) Q 100 = m3 /s (Flood Full Storm Event) Q 25 = m3 /s Q 10 = m3 /s Q 5 = m3 /s Q 2 = m3 /s (Bank Full Storm Event) Q 25mm = m3 /s NOTE: Minor storm events determined from standard curve fitting to EPA Normalized Type Storm Distribution. CHANNEL GEOMETRY Soil Type: Clay Maximum Stable Slope: 38 Bottom Width = 5.00 Substrate : Earth, winding, weedy banks Side Slopes (H:V) = 10.0 (5.7 ) Manning's n: 0.05 Safety Factor: 5.0 Height Top Width Flow Area R (hydraulic) Flow Velocity Shear Stress Stable D 50 (m) (m) (m 2 ) (m 3 /s) (m/s) Strait Bend (mm) (N/m 2 ) Depth 100 = Depth 25 = Depth 10 = Depth 5 = Depth 2 = Depth 25mm = ROSGEN CLASSIFICATION OF NATURAL RIVERS MEANDER RATIO : 1.0 : LOW SINUOSITY LOW WIDTH / DEPTH RATIO : 40.8 : HIGH WIDTH / DEPTH RATIO HIGH ENTRENCHMENT RATIO : 1.3 : ENTRENCHED MED STREAM TYPE : D - STABLE Wide channel with longitudinal and trasverse bars, potential braiding. Very wide channel base with flat eroded banks.

10 NATURAL CHANNEL DESIGN Upper Canada Consultants Martindale Road St. Catharines, ON L2W 1A1 Project : Rice Road (River Realty), Town of Pelham Design: Project No : 0482 Reviewed: Watercourse: Lower portion of channel from culvert to outlet Date: Adam Keane, P.Eng. Jason Schooley, P.Eng. April 28, 2014 Upstream Elevation: Strait Block Length (m): m Downstream Elevation: Thoretical Strait Slope (%): 0.44% Fall (m): 2.01 Meander Length (m): m Meander Slope (%): 0.46% Block Width (m): 33.0 Mean Meander Wavelength (m): 95.8 (C.W.Carlston, 1965) Curvature of Meander Radius (±15%) (m): 26.9 to 36.5 (B.P.Leopold, 1957) STORM FLOWS (Leave Blank If Not Known) Q 100 = m3 /s (Flood Full Storm Event) Q 25 = m3 /s Q 10 = m3 /s Q 5 = m3 /s Q 2 = m3 /s (Bank Full Storm Event) Q 25mm = m3 /s NOTE: Minor storm events determined from standard curve fitting to EPA Normalized Type Storm Distribution. CHANNEL GEOMETRY Soil Type: Clay Maximum Stable Slope: 38 Bottom Width = 6.50 Substrate : Earth, winding, weedy banks Side Slopes (H:V) = 12.0 (4.8 ) Manning's n: 0.05 Safety Factor: 5.0 Height Top Width Flow Area R (hydraulic) Flow Velocity Shear Stress Stable D 50 (m) (m) (m 2 ) (m 3 /s) (m/s) Strait Bend (mm) (N/m 2 ) Depth 100 = Depth 25 = Depth 10 = Depth 5 = Depth 2 = Depth 25mm = Calculate Flow Values ROSGEN CLASSIFICATION OF NATURAL RIVERS MEANDER RATIO : 1.0 : LOW SINUOSITY LOW WIDTH / DEPTH RATIO : 41.1 : HIGH WIDTH / DEPTH RATIO HIGH ENTRENCHMENT RATIO : 1.2 : ENTRENCHED MED STREAM TYPE : D - STABLE Wide channel with longitudinal and trasverse bars, potential braiding. Very wide channel base with flat eroded banks.