Boundary Bay & Mud Bay Floodplain
Boundary and Mud bays occur at the south-east corner of Surrey and are bounded to the west by the Corporation of Delta. They encompass a wide variety of habitat areas and land uses such as intertidal mud flats, estuaries, marshes, farmland and suburban areas. Boundary Bay is a 250 kilometre stretch of seashore that is strongly influenced by the seawaters from the South Georgia Strait. Mud Bay is more locally influenced by freshwater through the discharge of the Serpentine and Nicomekl rivers into the enclosed bay area which creates a strong brackish influence. Both the Serpentine and the Nicomekl rivers are tidally influenced and have dykes, floodgates and sea dams installed along portions of them to mitigate flooding and facilitate farming.
Colebrook and Mud Bay Dyking Districts
The Colebrook Dyking District is responsible for maintaining the dyke along the north shore of the Serpentine River downstream of the King George Boulevard sea-dam to Mud Bay Park. The District serves an area of 2,080 acres with approximately 5.2 km in length of sea dykes and it is crossed by Provincial Highway 99, and by the Southern Railway line.
The Mud Bay Dyking District is responsible for maintaining the sea dykes along the Serpentine and the Nicomekl rivers downstream of the King George Boulevard sea dams. The District serves an area of 1,110 acres with approximately 8.7 km in length of sea dykes and is crossed by Provincial Highway 99 and Burlington Northern Railway.
The City of Surrey is responsible for the dykes along the south bank of the Nicomekl River which extend from the sea dam to Elgin Park area, including the Nico Wynd golf course. The City’s dykes are open for public access. Dykes under control of the other dyking authorities (Surrey, Colebrook & Mud Bay) are closed to the public.
The community of Crescent Beach is situated at the confluence of Boundary Bay and Mud Bay in the City of Surrey. The community is mainly comprised of single family residential development, with small pockets of commercial and multi-family land use. The area is surrounded by a dyke system, as ground elevations ranges from 0 to 3 metres above sea level. Climate change, tidal fluctuations, seasonal groundwater fluctuations, land subsidence, redevelopment and densification, and inadequate and aging drainage infrastructure are impacting the community, resulting in poor drainage conditions.
The area is serviced by a small pump station and also through some localized pipes, rock pits and on lot infiltration systems.
In 1982 a storm surge caused severe damages to frontage properties resulting in some reinforcement of shoreline areas. Additional storms in 1997 and 200 resulted in some more extensive flood protection works along the frontage areas
Being that the community is lowlying adjacent to Boundary bay and influenced by ocean levels and tidal cycles, the City of Surrey conducted a Climate Change Adaptation Study. Key items in the study included the relationship of tides and groundwater patterns, rate of ocean level rising and also local area subsidence. This study represents the City’s first initiative towards understanding and developing strategies to adapt to climate change.