Soft Shoreline Engineering Case Studies
St. Rose Beach Park - Site #42
Project Goals and Objectives: Stabilize shoreline and enhance wildlife habitat
Project Description: Several shoreline sections of St. Rose Beach Park had severe bank instability and erosion, and required immediate stabilization by replacing failing asphalt capped gabion baskets and installing a rock armour veneer. The city of Windsor’s planned activity presented an excellent opportunity to incorporate more extensive and purpose-built fish habitat enhancement features into the design.
The objective of this project was to capitalize on the opportunity that the scheduled shoreline stabilization works create by ‘piggy backing’ fish habitat enhancement features into project design and construction.
Two hundred thirty meters of shoreline riparian habitat was rehabilitated and substantial enhancements to submerged fish habitat were provided to the shoreline of St. Rose Beach. The submerged fish habitat enhancement features to increase fish use for spawning, rearing and refuge as well as benefit in protecting the embayment from swift current regimes and wave action.
Partners: City of Windsor and Essex Region Conservation Authority
Ecological Effectiveness: Prior to restoration, the shoreline consisted of a vertical concrete retaining wall along the eastern and western shores. Some rock and broken concrete rubble existed at the toe of each wall. Along the central portion of the embayment, there was a small beach area and a failing, asphalt capped gabion basked retaining wall. Restoration activities were completed in 2000 and included the maintenance of a shallow beach area, replacement of the concrete retaining wall with a rock riprap shore and rock placement at the concrete vertical wall. Monitoring was performed in 2001 and a SCUBA survey of the area found small perch (5-8 cm), darters, round goby (Neogobius melanostomus), minnows and sunfish (Lepomis sp.). Substrate was silty clay overlaid with a shallow layer (3-8 cm) of soft consolidated sediments. Plant growth began in the nearshore area about 15 meters offshore at a water depths of 25-30 cm. Plant coverage was either sparse or very dense with coverage ranging between 3 and 30%, depending on the location within the embayment. At the edge of the embayment, plant growth was nearly 100%. Plant densities ranged from nine plants per ten cm2 in the denser growth pockets within the mid-embayment area to 17 plants per ten cm2 throughout the offshore area. Wild celery (Vallisneria Americana) Richardson’s pond weed (Potamageton richardsoni), and Nais Flexlis were the main species found. Benthic invertebrates were dominated by midge larvae and snails in the nearshore area. This reflected a change from aquatic worm dominance observed in pre-construction monitoring. Offshore, invertebrate numbers were reduced compared to nearshore, although midge larvae and snails remained the predominant taxa. Additional monitoring is required to fully document ecological effectiveness.
Restoration contact: City of Windsor
Monitoring Contact: Essex Region Conservation Authority