Final Draft Report Foster Stormwater Management Facility Environmental Study Report Prepared for City of Ottawa August 2013 1101 Prince of Wales Drive Suite 330 Ottawa, ON K2C 3W7 COPYRIGHT 2013 BY CH2M HILL • COMPANY CONFIDENTIAL Contents Section Page 1. Introduction ......................................................................................................................................... 1-1 1.1 Overview .......................................................................................................................................... 1-1 1.2 Background ...................................................................................................................................... 1-1 1.3 Purpose and Objectives ................................................................................................................... 1-2 2. Municipal Class EA Planning Process .................................................................................................... 2-1 2.1 Ontario Environmental Assessment Act .......................................................................................... 2-1 2.2 Municipal Class EA Process .............................................................................................................. 2-1 2.3 Municipal Class EA Schedule ........................................................................................................... 2-4 2.4 Problem Statement .......................................................................................................................... 2-4 3. Existing Conditions ............................................................................................................................... 3-1 3.1 Study Area........................................................................................................................................ 3-1 3.2 Jock River Reach One Subwatershed Study ..................................................................................... 3-1 3.3 Geology and Soils ............................................................................................................................. 3-3 3.4 Geomorphology ............................................................................................................................... 3-3 3.5 Hydrology and Hydraulics ................................................................................................................ 3-4 3.6 Phase 1 Environmental Site Assessment ......................................................................................... 3-4 3.7 Aquatic Habitat ................................................................................................................................ 3-4 3.8 Archeology ....................................................................................................................................... 3-5 3.9 Summary of Constraints and Opportunities .................................................................................... 3-6 4. Evaluation of SWM Alternatives ........................................................................................................... 4-1 4.1 Preliminary Alternatives .................................................................................................................. 4-1 4.2 Alternative Selection ....................................................................................................................... 4-1 5. Recommended Alternative .................................................................................................................. 5-1 5.1 Proposed Foster SWM Facility ......................................................................................................... 5-1 5.1.1 Geotechnical Considerations .............................................................................................. 5-8 5.1.2 Phase 1 ESA Recommendations ......................................................................................... 5-9 5.1.3 Fish Habitat Recommendations .......................................................................................... 5-9 5.1.4 Additional Considerations ................................................................................................ 5-10 5.2 Existing Foster SWM Facility .......................................................................................................... 5-10 6. Consultation Program .......................................................................................................................... 6-1 7. Conclusion ........................................................................................................................................... 7-1 8. References ........................................................................................................................................... 8-1 Appendixes A South Nepean Urban Area Master Servicing Study (1997) – Selected Excerpts B Jock River Reach One Subwatershed Study (2007) – Selected Excerpts C Geotechnical Report D Fluvial Geomorphology Report E Fish Habitat Assessment F Archaeological Assessment G Public Consultation 391871A104_WBG070413113303OTT III COPYRIGHT 2013 BY CH2M HILL • COMPANY CONFIDENTIAL CONTENTS, CONTINUED Section Page Tables 5-1 Foster Pond Water Quality Requirements, based on a Wet Pond with Enhanced 80% Long Term S.S. Removal .................................................................................................................................................. 5-1 5-2 Foster Pond Preliminary Design Details ........................................................................................................ 5-1 5-3 Foster Pond Diversion Structure Preliminary Details ................................................................................... 5-4 5-4 Foster Pond Outlet Control Structure Preliminary Details ........................................................................... 5-4 Figures 2-1 Overview of the Class Environmental Assessment Planning Process ........................................................... 2-2 3-1 Foster Drain Catchment Area ....................................................................................................................... 3-2 3-2 Proposed Foster SWM Facility Construction Constraints and Opportunities .............................................. 3-7 4-1 Proposed Foster SWM Facility Footprint Alternatives ................................................................................. 4-2 5-1 Proposed Foster SWM Facility Plan .............................................................................................................. 5-2 5-2 Proposed Foster SWM Facility Plan .............................................................................................................. 5-3 5-3a Foster Ditch XP-SWMM Model Photo Overlay ............................................................................................. 5-6 5-3b Foster Ditch XP-SWMM Model Photo Overlay ............................................................................................. 5-7 iv 391871A104_WBG070413113303OTT COPYRIGHT 2013 BY CH2M HILL • COMPANY CONFIDENTIAL 1. Introduction 1.1 Overview The South Nepean Urban Area has been undergoing significant development and urbanization since the mid 1990s. To plan for this the former City of Nepean and the new City of Ottawa has undertaken planning studies to address how the subwatershed will be managed. Two studies that have addressed both Master Servicing and Subwatershed Planning were the South Nepean Urban Area Master Servicing Study – Environmental Study Report (J.L. Richards & Assoc. Ltd., 1997) and the Jock River Reach One Subwatershed Study (Stantec 2007). Both of these studies recommended a stormwater management (SWM) plan to address both the existing and future lands in the South Nepean Urban Area. CH2M HILL was retained by the City of Ottawa (City) to prepare a SWM plan consistent with recommendations from these previous studies. The project initially included both the Foster Ditch catchment area as well as the Kennedy-Burnett SWM Facility catchment area. Generally, the study area encompasses part of the Barrhaven Community north of the Jock River, west of Greenbank Road and east of Highway 416. The study is planned under Schedule C of the Municipal Class Environmental Assessment (October 2000, as amended in 2007 and 2011). A Notice of Study Commencement was published on July 24, 2009 and a Public Open House for the project was held on November 18, 2009. The project purpose, background, constraints and opportunities and a summary of ongoing supporting studies were provided. The two areas of proposed construction (i.e. Foster and Kennedy- Burnett SWM facilities) are discontinuous and the requirement for potential property acquisition is different, therefore they were separated in order for design and construction to proceed independently of each other if necessary. Since the November 18, 2009 Open House, the City has decided to advance the Foster SWM Facility independent of the Kennedy-Burnett Facility. As such, this report details the SWM plan for the Foster SWM Facility. 1.2 Background The South Nepean Urban Area Master Servicing Study (MSS) Environmental Study Report (J.L. Richards & Assoc. Ltd., 1997) recommended that an end-of-pipe SWM facility be constructed downstream of McKenna Casey Drive to service both the O’Keefe Drain and Foster Ditch catchment areas. The facility was intended to