Mud Creek Restoration - Reach 1
Toronto and Region Conservation Authority (TRCA), in partnership with Toronto Water, and Toronto Parks, Forestry & Recreation has restored a section of Mud Creek - a tributary of the Don River - located adjacent to the Evergreen Brick Works located at 550 Bayview Avenue in the City of Toronto.
The erosion issues affecting Mud Creek have been a concern to both the City of Toronto and TRCA for several years. Although the majority of Mud Creek is now piped underground, there are six (6) fragmented sections of open watercourse remaining between Moore Avenue and the outlet to the Don River near the Brickworks, all of which exhibit varying degrees of channel erosion, debris blockages and slope instability.
|Figure 1. View of channel erosion facing downstream toward outlet to the Don River, May 2011. Source: Geomorphic Solutions.|
In 2010, Toronto Water retained Geomorphic Solutions to complete a geomorphic assessment of Mud Creek to characterize the watercourse in support of comprehensive channel restoration works using the principles of natural channel design. The results of the study identified the most downstream section of open watercourse (Reach 1) as the top priority area for maintenance works, leading to the completion of a detailed channel restoration design for Reach 1 in late 2011.
Details of Work
The scope of work for Reach 1 included replacing existing failing gabion baskets with armourstone along the channel banks for approximately 70 metres. The remaining 75 metres of creek from the armourstone to the outlet to the Don River was re-graded and stabilized with a vegetated buttress (quarry rock interspersed with live stakes) and native shrubs along its banks.
Access was gained from Bayview Avenue south of the project site, where construction equipment traveled north along the Belt Line Trail to the work area. Intermittent trail closures were necessary during construction as a result - the patience and cooperation of the public during these times was greatly appreciated.
Work commenced the week of January 23, 2012 and was originally anticipated to take approximately eight (8) weeks to complete, excluding site restoration which was scheduled to be completed inthe spring of 2012 as weather conditions permitted.
Several trees were removed to accommodate construction equipment, re-grading and to reconstruct the channel to a stable configuration. Roughly 60% of trees to be removed were less than 19 cm dbh (diameter at breast height) and over 70% were non-native and/or highly invasive.
TRCA is currently working with City of Toronto Urban Forestry staff to implement a high-quality forest management strategy to replace removed trees, increase species diversity and add to the ecological value of the Moore Park Ravine. At this site, the first phase of restoration commenced with the installation of more than 6,000 live stakes and bare root shrubs over the winter and spring of 2012 to help stabilize the newly constructed channel.
April 3, 2012
As of April 3rd, 2012 approximately 40m of the armourstone wall and bed control had been constructed, as shown above. Unfortunately due to erratic weather and unfavourable ground conditions, the restoration work fell approximately four (4) weeks behind schedule. The new tentative completion date was April 30, 2012, with final site restoration to commence immediately upon the completion of the channel work as weather conditions permitted.
October 5, 2012
Construction works were completed in April 2012, and the site now continues to be monitored by TRCA staff. Recent photos from the site are shown below.
As shown in the last photo above, many of the live stakes above the armourstone wall at this location did not survive and require replacement. It is likely that this section was planted too late in the season, however difficult growing conditions (heavy canopy of predominantly Norway maple) also likely contributed the high failure rate here.
Additional live stakes will be installed over the late fall and winter of 2012-2013 to encourage root development during the optimal window, with additional monitoring to be completed over the spring and summer of 2013 to determine the success rate of the replacement plantings.
Long Term Management Plan
Notices and Contact Information
The following Notice of Project Commencement has been prepared for circulation to the local City Councillors, Kristyn Wong-Tam (Ward 27) and Mary Fragedakis (Ward 29); local Residents' and Ratepayers' Associations, stewardship groups, and homes nearby the project site:
NOTICE OF PROJECT COMMENCEMENT (PDF - 193kb)
Signage will also be erected north and south of the site to advise the public of the restoration work, along with contact information where more details about the project can be obtained.
For more information about the project, please contact:
Moranne McDonnell, B.E.S.
Senior Manager, Environmental Engineering Projects
Toronto and Region Conservation Authority
1 Eastville Avenue, Toronto, ON M1M 2N5
Tel: (416) 392-9725