Burns Bog Edge Conceptual Restoration Plan
Client:
City of Delta
Location:
Lower Mainland, British Columbia
Dates:
April 2024 – December 2025
Background:
Burns Bog is a 5,000-year-old raised ombrotrophic bog covering approximately 30 km2 (3,000 ha) of the Fraser River in Delta. Historically, encroachment of agriculture and industrial land uses has resulted in a reduction in size while the hydrology and ecology of the remaining Bog has been further disrupted by peat extraction and related activities dating back to the late 1800s. However, the Bog is believed to have maintained enough of its ecological integrity to allow its restoration over time, and since the 1990s efforts in protecting and restoring impacted areas of Burns Bog have gained increasing attention. The restoration pilot initiated by the City focused on a 10.4 ha disturbed area along the edge of the Bog (i.e., the lagg area of the Bog) bordered by agricultural land.
Services Provided:
Hatfield services included a desktop investigation of the Bog edge setting and hydrology using existing data and prior studies, detailed topographic and vegetation mapping (native vegetation and invasives such as birch and blackberry), the installation of two piezometer transects to monitor spatial and temporal variations in groundwater levels, the development of a water balance for the Project Site under existing conditions and a literature review of potentially applicable restoration methods.
Understanding of current site conditions was used by us to develop a Conceptual Restoration Plan for restoring ecohydrological functioning at the Project Site with an associated order of magnitude cost estimate. This pilot initially aims to create a 4.0 ha shrubby swamp lagg zone dominated by hardhack. Key components of the Conceptual Restoration Plan include the installation of an impermeable barrier along the edge of the Project Site to limit water losses to adjacent agricultural ditches combined with vegetation treatments and replanting to remove invasives, restore native vegetation and limit high evapotranspiration losses caused by birch trees. The plan also includes a 5-year monitoring period to evaluate restoration success and potential adaptive management measures should the desired restoration trajectory not be achieved. The City of Delta used the plan to pursue implementation funding and are hopeful that implementation of the Bog edge restoration pilot will proceed in the next couple of years.
