Soft Shoreline Engineering Case Studies
Little River at Twin Oaks - Site #24
Project Goals and Objectives: Stabilize 1,150 meters (3,773 feet) of shoreline, reestablish the natural floodplain and reestablish the riparian vegetation to improve fish and wildlife habitat
Project Description: The Little River Rehabilitation Project was implemented on the Little River at the former site of the Twin Oaks Golf Course in the City of Windsor. The Twin Oaks site is bordered by the E.C. Row Expressway to the north, the Lauzon Parkway to the west and CPR railway to the south.1
The City of Windsor is servicing an 81 ha (200 acre) parcel of land (Twin Oaks Business Park) in the south-east portion of the city for future commercial and industrial development. The land is traversed by a 1,150 m (1,258 yds) section of Little River. The 1992 Little River Comprehensive Stream Study (LRCSS) identified the section of Little River at Twin Oaks as having degraded environmental quality. This degradation had been largely attributed to effects of channelization and construction of a river dam. These channel adjustments were made prior to the development of regulations that prevent such activities. Preliminary analysis of the natural features in the Little River and Turkey Creek subwatershed study identified this section of the Little River as having high potential for re-naturalization.
The following activities were undertaken: restoration of the natural floodplain in a 1 km (0.62 mile) river section; restoration a 1 m (1.1 yd) deep low flow river section; restoration of 2,300 m (2,515 yds) of riparian habitat (in-stream and along banks); installation of a stormwater quality system; construction of a trail linking habitat corridors and providing public access; and monitoring of habitat and water quality improvements.
Restoration initiatives included the creation of a low flow channel as part of a 1 km (0.62 miles) natural stream channel design. A stormwater quality system was also constructed to ensure that the naturalized river section would not be degraded by runoff from the development complex.
Granular stone was placed on the bottom of the meandering stream channel to improve habitat for aquatic invertebrates and fish. Vortex weirs will be installed in the summer of 1998 to create riffle and pool sections to further enhance fish habitat. Ephemeral pools will be established within meandering flats of the river. These pools will intermittently become flooded during high water events and will retain water for extended periods providing habitat, particularly for amphibian reproduction during the spring season.
Bioengineering techniques, such as live staking, were used along the lower slopes of the floodplain to stabilize the banks and prevent erosion during high water periods. Sandbar willow cuttings (0.5 m (0.55 yd) in length) were staked into riverbanks and have begun to grow. Once mature, the stakes will prevent erosion and provide shading and riparian wildlife habitat. The entire floodplain has been planted with a cover crop of white clover, perennial rye, creeping red fescue, tall fescue, bird's foot trefoil, and timothy grass to stabilize the newly graded floodplain. During the summer of 1998, volunteers from local schools and the Little River Enhancement Group will be planting more than 3,000 shrubs, 900 bareroot trees, and 150 large trees. A trail is also being constructed to allow general public access to this newly restored natural area.
This project contributed to achieving Detroit River RAP recommendations, delisting fish and wildlife habitat impaired beneficial uses in the Area of Concern and meeting Canada-Ontario Agreement Habitat Targets.
Cost: $ 1 million
Partners: The City of Windsor, Little River Enhancement Group, Essex Region Conservation Authority, University of Windsor's Great Lakes Institute for Environmental Research (GLIER), Ontario Ministry of Natural Resources (OMNR), Ontario Ministry of the Environment (OMOE), Lafontaine, Cowie, Buratto & Associates, Great Lakes 2000 Cleanup Fund.
Ecological Effectiveness: No quantitative post-project assessment: only visual observation
Restoration Contact: Essex Region Conservation Authority