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HomeMy WebLinkAboutPD-59-98DN: PD-59-98 THE CORPORATION OF THE MUNICIPALITY OF CLARINGTON REPORT Meeting: General Purpose and Administration Committee File# lam. r~~da9 Date: May 4, 1998 Report #: PD-59-98 FILE #: PLN 17.9.3 Res. #~-,PVC-~~.c~o-~~~ By-law # Subject: BIRCHDALE VILLAGE ENVIRONMENTAL IMPACT STUDY FILE: PLN 17.9.3 Recommendations: It is respectfully recommended that the General Purpose and Administration Committee recommend to Council the following: 1. THAT Report PD-59-98 regarding the Birchdale Village Environmental Impact Study be received for information; 2. THAT Mr. Carlo Aloe be thanked for his work as the citizen representative on the Steering Committee for the Environmental Impact Study; and 3. THAT a copy of Council's decision be forwarded to all delegations and interested parties. 1. PURPOSE OF REPORT 1.1 The purpose of this Staff report is to advise Committee and Council of the process related to and the conclusions of the Birchdale Village Environmental Impact Study. This Study was undertaken in accordance with Section 4.3.8 of the Official Plan for Subdivision Application 18T-95029 and Rezoning Application DEV 95-020 submitted by Blackcreek Developments to permit the development of a residential subdivision in the Glenview Neighbourhood, Courtice. 1.2 A copy of the final Environmental Impact Study is available for review in the Planning and Development Department. 659 REPORT NO.: PD- 59-98 PAGE2 2. BACKGROUND 2.1 Map C of the Official Plan indicates that the proposed subdivision is traversed by a cold water stream and is located partially within and adjacent to the Trulls Road Woods and the Lake Iroquois Beach (see Attachment No. 1). As required by the Official Plan, the Environmental Impact Study is required to examine these features in detail, to identify the potential impact of the proposed development on the features, and to recommend measures to mitigate the impacts. 2.2 In September 1996, the applicant advised Staff that he had retained the consulting firm of Gartner Lee Limited to prepare an Issues Paper on the environmental features in the area. Staff agreed that the Issues Paper, which was completed in October 1996, would form Phase 1 of the Environmental Impact Study and that, upon completion of Phase 1, the Municipality would retain Gartner Lee, at the expense of the applicant, to complete the balance (Phase 2) of the Study. Gartner Lee is one of the four consulting firms on the Municipality's roster of consultants for the preparation of Environmental Impact Studies. 2.3 The study area for Phase 2 of the Environmental Impact Study generally encompassed the lands bounded by Nash Road, Pebblestone Road, Courtice Road and Trulls Road, with the proposed subdivision being studied in detail. The consultant commenced work in January 1997. An interim report was submitted in August 1997 and the final report was submitted in January 1998. This timetable enabled the consultant to monitor conditions in the study area over four seasons. 2.4 A Steering Committee was created to oversee the progress of the Study and met three times - at the commencement of the Study, in September 1997 after the submission of the Interim Report, and in January 1998 after the submission of the draft final report. The Committee was comprised of staff from the Planning and Public Works Departments, the Central Lake Ontario Conservation Authority and the Durham Region Planning Department, as well as Mr. Halminen and his b60 REPORT NO.: PD- 59-98 PAGE 3 consultant. Liza Developments which owns property adjacent to the development site, and a citizen representative also sat on the Committee. The final Phase 2 Environmental Impact Study submitted by Gartner Lee was adopted by the Steering Committee. 3. PUBLIC PARTICIPATION 3.1 Meaningful public participation in the Environmental Impact Study process was important to ensure that their concerns related to environmental impact were appropriately addressed. A resident of the existing subdivision to the east of the development site was invited to sit on the Steering Committee. Steering Committee meetings were also open to the public and were attended by a number of area residents. 3.2 Two Public Information Centres were held at the Courtice Secondary School. The first Centre was held in October 1996 after the submission of the Phase 1 Issues Summary Paper, while the second Centre was held in October 1997 after the submission of the draft final report. Planning and Works Department Staff, as well as the Municipality's and the applicant's consultants, were present at the Information Centres. Approximately 40 residents attended each of the Centres. 3.3 Residents expressed the following concerns with respect to the proposed development: • impact of the proposed development on adjacent wells and septic systems • fragmentation of Trulls Woods and the impact on wildlife habitat • impact of the proposed development on groundwater recharge to Black Creek. These concerns were specifically addressed by the consultant through the preparation of the Study and in the final report. 4. OVERVIEW OF ENVIRONMENTAL IMPACT STUDY 4.1 The Environmental Impact Study examined the existing environmental conditions 661 REPORT NO.: PD- 59-98 PAGE 4 on the proposed development site, including ground and surface water, vegetation, and wildlife. The Study also identified the potential impacts on these features resulting from the proposed development and recommended a number of mitigative measures to address the impacts. 4.2 Existing Environmental Conditions Surface and Ground Water 4.2.1 There are two tributaries of Black Creek on the development site -the main tributary that enters form the north and a smaller tributary, which enters the site from Courtice Road and joins with the main tributary on the development site. The water flowing in both tributaries is warm, indicating that surface water, not ground water, is the primary source of flow. The tributaries are also intermittent, having no flow during the summer. As such, neither tributary can be considered as fisheries habitat. 4.2.2 The consultant examined borehole data and information available from other reports to determine ground water conditions on the development site. It was determined that the water table lies at the surface in the spring (March -May) and the fall, and drops in the summer. 4.2.3 The development site lies within a distinct ground water basin. A layer of fill lying to the north of Nash Road creates a barrier to the southerly flow of ground water. As a result, the site does not provide a significant ground water contribution to Black Creek. Contribution from the development site to Black Creek is provided mainly by surface flow in the intermittent tributary which crosses the site. 4.2.4 A small wetland, which the consultant characterized as a 'mineral thicket swamp', is located in the northwest part of the proposed development site. Vegetation 4.2.5 The development site is located at the extreme south end of Trulls Woods. Large bbl REPORT NO.: PD- 59-98 PAGE 5 portions of the Woods were cleared in the early 1970's. As a result, most of the Woods, including the development site, is in an early successional deciduous state, dominated by fast growing species like poplar and birch. These species will not form the mature forest under the existing soil and water table regime, and are subject to wind damage, snapping off or blowing over due to shallow root systems that have developed in response to the high water table. The trees are somewhat more mature in the northern portion of the Woods. 4.2.6 Two annual and five perennial regionally significant plant species were identified on the development site. All of these plants occur in association with the main tributary and are present because the disturbed state of the forest provides a relatively open canopy which allows sunlight to penetrate. Some of the plants bloom in the spring, while others bloom in the fall. The plants are dependent on the high water table and become dormant in the summer when the water table drops. The consultant noted that the plants may disappear even without development if the tree canopy closes and shades out these species. Wildlife 4.2.7 A total of 31 species of birds, representing a mixture of wetland and upland species, were recorded on the proposed development site. The consultant indicated that the subject site may only provide marginal habitat for the birds and that they may be using better habitat located to the north and east for breeding. 4.2.8 A number of urban-adaptive mammals, such as squirrels, racoons and foxes, were noted on the development site, although White-tailed deer was also sighted. The consultant noted that the wildlife corridor function of the Trulls Woods extends no further south than the development site due to the presence of existing urban development and Nash Road. 663 REPORT NO.: PD- 59-98 PAGE 6 4.3 Anticipated Impact of Development Impact on the Water Table 4.3.1 The proposed development will cause a net drop in the water table due to a number of factors. The introduction of impermeable surfaces such as rooftops, roads and driveways to an area which was previously forested, will reduce the amount of precipitation available for infiltration to the ground water system. As well, because of the presence of the high water table, any excavations below the water table will encounter flowing sands. It will be necessary to dewater during construction and the installation of buried services in order to temporarily lower the water table. 4.3.2 Buried water, sewer and storm services on the site will be installed in beds of compacted granular material. These granular soils will act as a conduit for groundwater flow because the natural soils are less permeable than the granular pipe bedding. As well, the use of foundation drains used to keep basements dry will cause a drawdown in the water table during high water table conditions. The changes in the level of the water table on the development site as a result of all of these factors are anticipated to be smallest adjacent to the tributary and greater on higher ground. 4.3.3 As noted earlier, residents in the adjacent subdivision were concerned that the lowering of the ground water table on the development site could negatively affect their wells and septic systems. However, the consultant found that ground water flows from the existing subdivision towards the proposed development site. As such, the existing residential wells are not dependent on ground water flow from the development site. Rather, the silty sands, which underlay the existing subdivision, have a significant capacity to hold water and the precipitation on the lots is generally sufficient to maintain well levels. The consultant concluded that there should not be a noticeable change in well water quantity and quality as a result of the proposed development, nor should there be an impact on the operation of septic systems . 664 REPORT NO.: PD- 59-98 PAGE 7 Impact on Surface Water 4.3.4 The proposed development will remove the minor tributary that extends to Courtice Road. This is an intermittent stream that provides no fisheries habitat and limited corridor functions. The main tributary is to be preserved within an open space corridor which will run through the proposed subdivision 4.3.5 The construction of the George Reynolds/Cecil Found Drive extension east of Trulls Road will necessitate the crossing of the small thicket swamp in the northwest portion of the subject site. The geometry of the site leaves no alternative for this alignment in the vicinity of the swamp. However, the consultant has noted that this habitat type is well represented in the area, and specifically can be found around the proposed storm water management pond on the development site. Therefore, opportunities will still exist on-site for species to use swamp habitat, albeit in a reduced form. Vegetation and Wildlife Habitat 4.3.6 The trees will be removed in the areas of proposed construction, resulting in the loss of forest habitat. However, the tree species present would constitute a hazard in a built-up area for reasons noted earlier. Most of the wildlife species found on the site are generalists and will still find opportunities for breeding and foraging in the open space areas along the tributary. 4.3.7 The proposed development may affect the significant plant species found on the site either by displacement through habitat loss, or by lowering the existing water table. The area of suitable habitat for these plants will shift closer to the main tributary where the new water table position will stabilize. The annual species will be relatively unaffected by the change in the water table. Their ability to produce a large number of seeds with good dispersal characteristics will allow them to colonize further downslope where the new water table position will stabilize. However, the perennials regrow from the same root stock every year and produce 6b5 REPORT NO.: PD- 59-98 PAGE s fewer seeds with poorer dispersal characteristics, and will therefore be less adaptable to a change in water table level. The consultant suggested that the perennial plants may need to be relocated. 4.4 Proposed Mitigative Measures Water Table 4.4.1 The seasonally high water table will require dewatering during construction. The Study recommended that the deeper construction items such as sewers should be constructed in the summer months to avoid excessive dewatering, although it is anticipated that some will still be required. As many of the buried services as possible should be located on high ground. Discharge water resulting from dewatering will have to be controlled to prevent excessive erosion and siltation. 4.4.2 To offset the potential for granular bedding material around buried services to intercept groundwater, the Study recommended the use of trench plugs along all buried services greater than 10 metres in length. Trench plugs which consist of compacted material placed at specific intervals along the granular service bed, effectively reduce the drawdown effect. It is expected that the zone of drawdown influence will be reduced to less than 5 m from the bedding material. 4.4.3 To mitigate the drawdown effect of foundation weepers on the water table, the Study recommends that groundwater collected by the weepers not be discharged to the storm sewer. Rather, the weeper water, which will be clean cold groundwater, could be collected by a third pipe and discharged in the tributary downstream of the stormwater management pond. This will result in a minor augmentation of stream flow. The Study also recommends that clean rooftop water not be directed to the storm sewer system, but rather be discharged directly to the individual yards. This would help compensate for the loss of infiltration to the ground water due to the introduction of impervious surfaces. 666 REPORT NO.: PD- 59-98 PAGE 9 Vegetation and Wildlife Habitat 4.4.4 The Study recommended that no detailed tree preservation plan be prepared for the subdivision, but that forest removal should be limited to only the construction area. The preparation of a plan showing areas to be preserved is recommended, and such areas should be fenced off during construction to prevent intrusion by heavy machinery. Construction materials are to be disposed of off-site. 4.4.5 An open space corridor along the main tributary is recommended. This corridor would be a minimum of 50 metres wide (25 metre development setback from each bank of the tributary). This corridor will provide foraging and habitat opportunities for birds and other wildlife on-site and will permit wildlife movement to the retained portion of Trulls Wood to the north. Dependent on the layout of the final plan of subdivision, lots may be setback even farther from the valley and these lands could be added to the valley system. Most backyards are to face onto the valley, and there is no provision for a trail in order to restrict access to the linkage. All works in the wetland will be constructed to maintain water movement through the area, and to maintain the high water table adjacent to the tributary. 4.4.6 The Study recommended that the George Reynolds/Cecil Found Drive extension should be built through the wetland in such a way as to preserve the groundwater and surface water flow through the area. The intersection of the subdivision road and the road extension could be designed to preserve a small portion of the wetland, preferably on the southeast corner, which would remain connected to the valley system. This would enhance biodiversity and preserve some of the present habitat on-site. 4.4.7 The Study recommends that the populations of the seven species of regionally significant plants be marked and mapped to facilitate removal and/or avoidance where appropriate. Any of the perennial plants located where vegetation is to be cleared should be dug up and transplanted within the area where the forest is to be 667 REPORT NO.: PD- 59-98 PAGE l0 retained. The annuals need not be transplanted; however, the Study suggested that their seed capsules be collected and the seeds randomly spread near the storm water pond and in the forest retention area. 5. CONCLUSIONS 5.1 The conclusions and recommendations of the Birchdale Village Environmental Impact Study will serve as important input into the Glenview Neighbourhood Design Plan. As well, the specific recommendations from the Study related to subdivision design and construction methods will be incorporated into the Conditions of Draft Approval for the proposed plan of subdivision. Given the highly environmentally sensitive nature of the development site, the applicant will be required to prepare an Environmental Construction Management Plan to ensure that the recommendations of the Environmental Impact Study are implemented through the development of the subdivision. 5.2 The Birchdale Village Environmental Impact Study was the first study undertaken pursuant to Section 4.3.8 of the Official Plan. From Staff's perspective, the process was quite successful. Public participation in the process through the Public Information Centres and specifically the inclusion of a resident representative on the Steering Committee proved to be effective mechanisms for gathering and addressing residents' concerns. Respectfully submitted, Reviewed by, Franklin Wu, M.C.I.P., R.P.P. W.H. Stockwell, Director of Planning & Development Chief Administrative Officer. JAS*DC*FW*cc April 22, 1998 Attachment No. 1 - Natural Features on Birchdale Village Development Site 668 REPORT NO.: PD- 59-98 PAGE 11 Persons to be notified of Committee and Co uncil's decision: Gartner Lee Limited Mr. and Mrs. Robert Marsh 140 Renfrew Drive 51 Westmore Street Suite 102 COURTICE, Ontario L1E 2H7 MARKHAM, Ontario L3R 663 Ronald and Olive Munro Liza Developments 24 Lynwood Avenue 30 Wertheim Court COURTICE, Ontario Ll E 2H9 RICHMOND HILL, Ontario L4B 1 B9 George and Lesley Maguire Carlo Aloe 11 Jane Avenue ~ COURTICE, Ontario L1E 2H9 /~ L1E 2H7 D.G. Biddle and Associates 96 King Street East OSHAWA, Ontario L1 H 1 B6 L1E 2L6 Robert D. McKenna nents Limited 18 Fourth Street COURTICE, Ontario L1E 2H7 L1 E 2T1 Stanley Simmons 3260 Courtice Road COURTICE, Ontario L1E 2L7 _lE 2H9 Helen and John Jozkowski 11 Lynwood Avenue Donna Frances Ferreira COURTICE, Ontario L1 E 2H8 6041 Middle Road R.R.#1 Matthew and Jessie Scott BOWMANVILLE, Ontario L1C 3K2 17 Jane Street COURTICE, Ontario L1 E 2H9 Mr. and Mrs. Gebelhoff 29 Westmore Street Ivan Perun COURTICE, Ontario L1E 2H8 R.R.#1 HAMPTON, Ontario LOB 1J0 Marg Ellis 8 Lynwood Avenue Kerri and Mike Novak COURTICE, Ontario L1 E 2H8 7 Jane Avenue COURTICE, Ontario L1 E 2H7 Dave Unwin 47 Westmore Street COURTICE, Ontario L1 E 2H7 bb9 e REPORT NO.: PD- 59-98 Elwin White 10 Fourth Street COURTICE, Ontario L1E 2H7 D. Cowle 43 Westmore Street COURTICE, Ontario L1E 2H7 J.A. Hayman R.J. Howes 22 Jane Avenue COURTICE, Ontario L1E 2H9 William Bowden 4 Glenview Road COURTICE, Ontario L1E 2H9 Nancy Whitehead 8 Jane Avneue COURTICE, Ontario L1E 2H9 Christine Lowe 12 Jane Avenue COURTICE, Ontario L1E 2H9 Edward Zavitsky 32 Lynwood Avenue COURTICE, Ontario L1E 2H9 Kerry Meydam 3828 Trulls Road North COURTICE, Ontario L1 E 2L3 Mary Martinelli 60 Westmore Street COURTICE, Ontario L1 E 2H7 Dineen Leger 12 Glenview Road COURTICE, Ontario L1E 2H9 W.D. Manson 20 Clematis Road WILLOWDALE, Ontario M2J 4X2 PAGE 12 Stan Racansky 3200 Hancock Road COURTICE, Ontario L1 E 2M1 Janet Sikora 34 Lynwood Avenue COURTICE, Ontario L1 E 2H9 Peter Bramton 21 Jane Avenue COURTICE, Ontario L1E 2H9 Chris Darling Regional Planning Department 1615 Dundas Street East WHITBY, Ontario L1 N 6A3 Carole Seysmith Friends of the Second Marsh 100 Whiting Avenue OSHAWA, Ontario L1 H 3T3 Linda and Julie Walsh 25 Jane Avenue COURTICE, Ontario L1E 2H9 Bill Bickle 7 Glenview Road COURTICE, Ontario L1E 2H9 Gordon Heard 18 Jane Avenue COURTICE, Ontario L1 E 2H9 LesJagoda 569 Townline Road North COURTICE, Ontario L1E 2J4 L. Little 3075 Trulls Road Group 6, Comp. 10 COURTICE, Ontario L1E 2L1 670 REPORT NO.: PD- 59-98 Joe McKenna 13 Poolton Crescent COURTICE, Ontario L1E 2H4 Ted Mosolanczki 4 Fourth Street COURTICE, Ontario L1E 2H7 E. Nowasad 3732 Courtice Road COURTICE, Ontario L1E 2L5 Teresa and Roy Palonen 55 Westmore Street COURTICE, Ontario L1E 2H7 Neil Ryan 39 Westmore Street COURTICE, Ontario L1E 2H7 Ken Livingston 12 Glenview Road COURTICE, Ontario L1E 2H9 671 PAGE 13 Ai IHI:h'~MtNI ~1 NATURAL FEATURES ON BIRCHDALE VILLAGE DEVELOPMENT SITE DEV. 95-020 18T-95029 LOT 30 LOT 29 ~ '~ 1'~ Y-• 1.1. ~+ , n . r t~,~ 7 YS~~I y.~ r . f 7 y- ~ r y~e R~.y?)"'~~D ~.,~'~Y'la~•nYi~,)i~y7~~ ~,~ tY~n ~f~ ~1 ~ 9~~'n~`5. „,ry. -3".~1 ,~,Yyry ray ' _. ?bti ~ Z ^~''.:h7~j+~f .. ..• . i^'~~'~~: ~~ 1. ~ R•~,'.. ~ O ~ Y fv K a ^~ . ~ ~. ~~ { ~ ~~ ^y!' 'wry __ ,~~, ,s3, -.:,~ rs ~' . o -- .,~.., ~0. ~ 7 _ _11 U 1 ~` ~: - _ Z '''~. f O ^ ..., .r~ ~ ~ O z. "'`"' U --~ °f:•' ,y,:. ~ I ~- J ~ ~ - - ~ -- ~ ~ ~_ _~ _ ~-. T __ ~ - i _ __~,. - -~ ~ ~ I ~- ~ ~ ~ '~~ SUBJECT SITE LAKE HROQUOIS I BEOi4CH c~oaG°~uc~~ 96 AOS 672