Project History

    Coats Marsh Regional Park is located on Gabriola Island and is co-owned by the Regional District of Nanaimo and The Nature Trust BC. The park is bordered by 707 Community Park to the north and east and by private property to the south and west. The land was received in part through a donation through the federal Ecological Gift Program, which is administered by Environment and Climate Change Canada.

    The park includes approximately 10 hectares of wetland which drains into Coats Marsh Creek, which travels through private property and regional park land before emptying into Hoggan Lake. The wetland area in the park is currently retained by a concrete weir and by a beaver dam. The concrete weir was pre-existing when the land became a Regional Park and its exact construction date is unknown. The beaver dam is located about 55m upstream of the weir and is about 1.0 - 1.2m higher than the top of the weir. The relative locations of the weir and the beaver dam have effectively created a lower pool located between the weir and dam and an upper pool whose water level is determined by the beaver dam elevation. The upper pool is considerably larger than the lower and forms the majority of the marsh.

    The existing concrete weir is regulated under the Water Sustainability Act and BC Dam Safety Regulation and has several deficiencies relative to current dam safety standards. To meet provincial regulations, the weir needs to be removed or replaced.

    In 2022 the RDN commissioned a study to examine weir replacement options. This study outlines five different weir replacement scenarios, including decommissioning the weir, and replacing it at four different elevations. The study includes regulatory considerations, estimated construction costs, and environmental impacts for each scenario. All five scenarios outlined in the report recommend removal of the beaver dam. From liability and engineering perspectives, these are sound recommendations. However, such an approach would cause significant disruption to the environment in the park through extensive construction activities and reducing or eliminating the aquatic habitat that the beaver dam supports.

    Through discussions with The Nature Trust BC, an alternative plan was developed to remove the existing concrete weir while keeping the beaver dam in place. Comments and analysis of this approach are included in the report (pg. 39). Removing the concrete weir while retaining the beaver dam offers a project approach that will minimize the construction activities in the park and maintain the existing aquatic habitat supported by the beaver dam.

    This project approach is supported by the Regional District of Nanaimo Board, The Nature Trust BC, and Environment and Climate Change Canada.

    When will construction take place?

    Construction is expected to take place in August and September 2024. Permitting delays, weather, and contractor availability may impact this schedule. 

    Why is this project needed?

    The concrete weir in the park is a provincially regulated structure under the Water Sustainability Act (2016). The weir does not meet the construction and safety standards in the Act and needs to be replaced or removed.