Loading...
HomeMy WebLinkAboutINS-11-032 - EA Strasburg Creek Ponds 65 66 and 611 Staff Re ort p Krr~.~-~~,i~iER ~nfrastru~ture Servrces Department www.kitthenerta REPORT T0: Community & Infrastructure Services Committee DATE OF MEETING: May 30, 2011 SUBMITTED BY: Steve Allen, P.Eng., Manager Engineering Design and Approvals (519-741-2584) PREPARED BY: Diana Lupsa, P.Eng., Design & Construction Project Manager (519-741-2815) WARD(S) INVOLVED: Ward # 5 DATE OF REPORT: May 16, 2011 REPORT NO.: INS 11-032 SUBJECT: ENVIRONMENTAL ASSESSMENT STUDY REPORT FOR STRASBURG CREEK (NORTH BRANCH) PONDS 65, 66 & 61 RECOMMENDATION: THAT the Strasburg Creek (North Branch) Ponds 65, 66 & 61 Municipal Class Environmental Assessment Report (Schedule B) prepared by Aquafor Beech Ltd., dated April 5, 2011 be received; and further, THAT the Strasburg Creek (North Branch) Ponds 65, 66 & 61 Municipal Class Environmental Assessment Report (Schedule B) be filed with the Ministry of Environment for the mandatory thirty (30) day review period as required by the Environmental Assessment (EA) Act. BACKGROUND: In 2009, the City of Kitchener received funding to improve 12 stormwater management (SWM) facilities from the Federal and Provincial governments as part of the Economic Action Plan Investments in Ontario and the Infrastructure Stimulus Fund. As part of that project, the Stormwater Management Facility Retrofit, Class EA Report (Schedule A+) was completed by the engineering consultant Aquafor Beech Ltd. A key recommendation of the 2010 EA (Schedule A+) report was for additional studies be undertaken to address information gaps and other environmental concerns for ponds 65 and 61. Upon further discussions with GRCA and the City of Kitchener, the study team concluded that in regards to ponds 61 and 65 the Class EA Schedule should be revised from a Schedule A+ to a Schedule B in order to appropriately evaluate and manage the existing environmental conditions and future considerations. To allow for a broader, more holistic approach for the improvement of the North Branch of Strasburg Creek to take place, Pond 66 was added to the study in addition to the respective connecting channels. Hence, the 2010 Class EA (Schedule A+) was expanded to fulfill the requirements of a Class EA (Schedule B) for the North Branch of Strasburg Creek from McBrine Drive to downstream of the intersection of Strasburg Road and Battler Drive. 16-1 1 Staff Re ort p Krr~.~-~~,i~iER ~nfrastru~ture Servrces Department www.kitthenerta Pond 65, 66 and 61 are existing on-line facilities built around 1980 - 1990. They have been designed and functioned as flood control facilities without any provisions for water quality treatment. The ponds have been identified in the 2001 City of Kitchener Stormwater Management (SWM) Policy as having the potential for retrofit by incorporating the water quality features. REPORT: The Strasburg Creek (North Branch) Ponds 65, 66 and 61 Municipal Class Environmental Assessment Report (Schedule B), was completed in accordance with Municipal Engineers Association document, October 2000, as amended in 2007. As part of the Schedule "B" Class EA, the following phases have been completed and documented in the report: Consultation with affected parties; Consideration of a reasonable range of alternatives; • Identification and consideration of the effects of each alternative on all aspects of the environment; Systematic evaluation of alternatives in terms of their advantages and disadvantages, to determine their net environmental effects; • Provision of clear and complete documentation of the planning process followed, to allow "traceability" of decision-making with respect to the project. The overall objective of this Class EA is to select a preferred design alternative for each of the three existing stormwater management facilities (pond 65, 66 and 61) and the respective connecting channels (Reaches 1 to 4) with the goal of improving water quality within the North Branch of Strasburg Creek. Additional objectives include the improvement and restoration of local aquatic and terrestrial habitat, the removal of fish barriers, improvement of baseflow and in-stream temperature regimes, the improvement of future operations and maintenance activities and the retrofit of existing concrete channels so as to represent a more natural stream channel design. Five (5) areas of concern were identified: 1. Poor Water Quality - due to no water quality control within the study area, on-line ponds, concrete lined connecting channels, erosion issues and lack of riparian buffers and shading; 2. Loss of baseflow -due to high impervious levels of surrounding lands as well as concrete bed and bank treatments within connecting channels; 3. The lack of fish habitat features -lack of diverse channels features, loss of continuity of flow and the presence offish barriers; 4. Degradation of terrestrial vegetation features - as a result of ongoing beaver activities, development pressures and infrastructure failures; and 5. Erosion -Ongoing erosion in the upstream channel of Pond 61, resulting in potential risks to the adjacent private property and sediment accumulation in the ponds. 16-2 1 Staff Re ort p Krr~.~-~~,i~iER ~nfrastru~ture Servrces Department www.kitthenerta The details of alternatives suggested for each stormwater management pond are provided below. The alternatives range from a Do Nothing approach, which involves no action to a Full Retrofit option that includes a variety of retrofit works: Alternatives for Pond 65 • Alternative No 1. - Do Nothing • Alternative No 2. -Selective Works outside Significant Vegetation • Alternative No 3. -Full Retrofit (Wet Pond) • Alternative No 4.- Selective Works with Channel Bypass (Off-line Facility) -preferred alternative Alternatives for Pond 66 • Alternative No 1. - Do Nothing • Alternative No 2. -Partial Retrofit (Cell 1): Wet Pond • Alternative No 3. -Wetland Restoration (Cell 1) -preferred alternative • Alternative No 4. -Full Retrofit: Wet Pond (Cell 1) and Dredging (Cell 2) • Alternative No 5. -Wetland Restoration (Cell 1) and Dredging (Cell 2) Alternatives for Pond 61 • Alternative No 1. - Do Nothing • Alternative No 2. -Retrofit Inlet and Outlet • Alternative No 3. -Retrofit Inlet and Outlet and Dredge • Alternative No 4. -Full Retrofit: remains on-line • Alternative No 5. -Full Retrofit: Channel Bypass (Off-line Facility) -preferred alternative Alternatives for the Connecting Channels (Reach 1, 2, 3 and 4) • Alternative No 1. - Do Nothing • Alternative No 2. -Selective Works (works completed at selected locations) • Alternative No 3. -Geomorphic Referenced River Engineering (GRRE) (creation of a relatively static channel based on principles of geomorphology) -preferred alternative reach 4 • Alternative No 4. -Natural Channel Design (NCD) (creation of a dynamically stable channel) -preferred alternative reach 1, 2 and 3 The evaluation of the alternatives was based on the study objectives, the established technical considerations and criterion under the general categories of Physical/ Natural Environment, Social/ Cultural, Economic criteria and TechnicallEngineering criteria. Upon application of the established criteria, the preferred alternatives for the three existing SWM facilities and the four (4) reaches of the North Branch of Strasburg Creek include: • Pond 65 -Bypass Channel & Selective Works (Off-line Facility) The preferred alternative for pond 65 will include the design of a wet pond outside the identified significant vegetation area, the design of a sediment forebay at the inlet, a microwetland with a cooling facility at the outlet and the inclusion of a bypass channel which bisects the significant vegetation area. 16-3 1 Staff Re ort p Krr~.~-~~,i~iER ~nfrastru~ture Servrces Department www.kitthenerta • Pond 66 -Wetland Restoration (Cell 1) This alternative involves the restoration of the existing historical wetland within Cell 1 (north cell). The wetland component is designed to remove suspended sediment, provide extended detention and allow for enhanced biological removal for low flows (frequent rainfall events). The wetland alternative would provide improved water quality, improved terrestrial habitat potential, additional thermal mitigation (sustaining cool water habitat downstream) and would integrate well with existing infrastructure, environment, site conditions and the adjacent land-use. • Pond 61 -Channel Bypass (Off-line Facility) This alternative includes the design of a sediment forebay, a wet pond, the re-design of the damaged inlet off of Battler Dr. and the reconstruction of the poorly performing facility outlet. The wet pond will be constructed with a forebay designed to remove suspended sediment and a permanent pool to provide extended detention and continued pollutant removal. This alternative would also include the incorporation of a bypass channel. By constructing a bypass channels, the facility would become an off-line facility. • Reach 1 -Natural Channel Design (NCD) The preferred alternative for Reach 1 is naturalizing the existing channel within the existing corridor by modifying the trapezoidal channel cross-section configuration and creating fish habitat within the channel through developing riffle-pool sequences. Replacement or modification of the concrete banks would be undertaken to enable establishment of vegetation. Given the proximity of private property to the channel corridor, maintenance of bank toe protection should be considered. • Reach 2 -Natural Channel Design (NCD) The preferred alternative for Reach 2 is to naturalize the existing channel corridor for the purpose of creating fish habitat. This can be accomplished by creating slow-flow channel that has a diversity of depth and width through developing pool-riffle morphology. Given the potential risk to public and private lands, protection of the channel corridor slope must be maintained. • Reach 3 -Natural Channel Design (NCD) The preferred alternative for Reach 3 is to naturalize the existing channel corridor for the purpose of creating fish habitat. This can be accomplished by creating slow-flow channel that has a diversity of depth and width through developing pool-riffle morphology. Given the potential risk to public and private lands, protection of the channel corridor slope must be maintained. • Reach 4 -Geomorphic Referenced River Engineering (GRRE) The preferred alternative for Reach 4 is primarily to protect private property from erosion and to enhance existing channel form and function particularly as it relates to fish habitat. Given that the channel is situated within a well vegetated (wooded) floodplain, extensive channel realignment may not be warranted. Instead, in addition to providing bank protection at erosion sites and completing any associated in-channel works, restoration should consider reconnecting the channel to its floodplain and augmenting/developing in-channel features to improve fish habitat locally. 16-4 1 Staff Re ort p Krr~.~-~~,i~iER ~nfrastru~ture Servrces Department www.kitthenerta Central to the decision to expand the previous 2010 EA and undertake a Schedule B Class EA for the North Branch of Strasburg Creek was to allow for a broader, more holistic approach for the improvement of the North Branch of Strasburg Creek to be undertaken and to ensure that the overall preferred solution provides for the greatest degree of net environmental benefit. The net environmental benefits of the proposed preferred solution include, but are not limited to the following: • The retrofit of two (2) existing water quantity SWM facilities (Pond 65 and 61) to include water quality control, and the restoration of the historic wetland at Pond 66. Water quality control for 79 ha of high impervious land-use (previously no WQ control); • Removal of the downstream fish barrier at Pond 61; Creation of 1.3 km of continuous stream channel using natural channel design principles; • Removal of 430m of concrete lined channel resulting in the improvement of baseflow conditions within the surface drainage system; • Restoration of approximately 700m of riparian area; • Naturalized landscape of approximately 20,OOOm2 of land. Configuration and species incorporated into planting to achieve wildlife management objectives (i.e. Canada Geese and Beaver populations) and to promote to the extent possible habitat conditions for other species; • Restoration of flood control capabilities and permanent pool volumes at ponds 61, 66 and 65, including the removal of more than 6500m3 of accumulated sediments; • Removal of invasive vegetation (Phragmites australis) and opportunity for improvement future management; and • Restoration of riparian buffer communities and the naturalized landscape plantings are anticipated to result in the improvement in the overall North Branch temperature regime. COMMUNICATIONS: As part of the Class EA project two (2) Public Information Centre (PIC) were conducted on January 26, 2010 (2010 EA -Schedule A+) and March 9, 2011 (2011 Expanded EA -Schedule B). In March 24, 2011 the project was presented to the City of Kitchener Environmental Committee. The public, agencies, stakeholders, interested and affected parties were provided with an opportunity to review and comment on the study findings including preferred alternative, along with the other alternatives considered. The direct mail-outs, along with the newspaper advertisement advising the public and property owners of the project and the Public Information Centres, provided a project overview, as well as contact names and information for those interested. Furthermore there were many project meetings with Grand River Conservation Authority (GRCA) to co-operatively select the preferred alternatives. FINANCIAL IMPLICATIONS: The anticipated overall cost of the preferred alternatives for the retrofit of the three ponds is $3.4M (2011 dollars). The approximate overall cost of the remediation/enhancement of the respective interconnecting reaches is $1.3M (2011 dollars). Table 1 provides details of the estimated costs for each preferred solution. 16-5 1 KITCx~i~~R Staff Report ~nfrastrurture Services Department ~w.k~t`~~~r~erca Table 1: Overall Preferred Solution -Capital Cost Estimate Preferred Solution Capital Cost Estimate Pond 65 -Bypass Channel & Selective Works (Off-line Facility) $ 1,688,000 Pond 66 -Wetland Restoration (Cell 1) $ 484,000 Pond 61 -Channel Bypass (Off-line Facility) $ 1,197,000 Reach 1 -Natural Channel Design (NCD) $ 215,000 Reach 2 -Natural Channel Design (NCD) $ 375,000 Reach 3 -Natural Channel Design (NCD) $ 345,000 Reach 4 -Geomorphic Referenced River Engineering (GRRE) $ 330,000 TOTAL $ 4,634,000 The timeline for implementing these projects is based on the City's capital budget. As it currently stands, the earliest City of Kitchener could move to address these projects would be around 2014. CONCLUSION: The North Branch of Strasburg Creek within the Huron Business Park has experienced significant alterations to both form and function of the system as a result of development pressures, historic works and wildlife management issues, and as a result is not achieving the management objectives as outlined in previous works by the City of Kitchener, the GRCA and others. It is in this regard that the Class EA for Strasburg Creek (Schedule B) proposes what is considered to be the greatest net environmental benefit possible for the system given the technical considerations and criterion established through amulti-disciplinary and collaborative approach. Therefore Staff recommend that the Strasburg Creek (North Branch) Ponds 65, 66 and 61 Municipal Class Environmental Assessment Report (Schedule B) be filed with the Ontario Ministry of the Environment for the mandatory thirty (30) day review period as required by the Environmental Assessment Act. ACKNOWLEDGED BY: Pauline Houston, Deputy CAO Infrastructure Services Department 16-6 1 KITCx~i~~R Staff Report ~nfrastrurture Services Department ~w.k~~~~~r~erca ,~r~p _ -- - - = 3= Iii' iii N ~, i ~~`~ ~°4'~ ~~ r age ,~'e ~~ ~ '~ ~~5 ~ ~~ ~ ~ '~ d ~* 41 ~,; r ,r ~. e: «,~ -~ ~ ~ti~ a ~~~~ _ ~,~ ~j ~ , A Reach 1 ~ tii~ ~J ~"~ n _ Pond 65 r ~ ~~ 4 ~ ~~ ~-r ~ r~r ~ +~ w ~ ~ ~, Reach 2 _ ~ ~ ~- u ~~ 1~4~~'S",~~ ~ ~~~:~aL1F~~ ~~~~ Reach 4 do - ~" ~'r~-r~l~~each 3 ~- -- . _ ~~~,~~ ~~ ~~ ~ ~.r~.-,. ~ it ,~ ~ ~ ~ Pond 66 ~ ~~~J ~. p ~~ ~~~~~~ti~~ '~} ~ Pond 61 ~~ ~ ~ ~ ~ ~ ~~ '~.~ f ~ ~~ ~ . ~~ ~~ ~ ~~ Finn ~~' ~~~~ Overview of study area and location of reaches along Strasburg Creek 16-7