The District of Elkford required detailed floodplain mapping to investigate the combined hazards from flooding and geomorphic hazards. In 2018, ISL was retained to undertake a floodplain assessment, flood mapping and flood mitigation options for Elk River, Boivin Creek and Crossing Creek within the District boundary.
The study required complex hydraulic analysis in the vicinity of the water body confluences due to backwater and to coincident flood-peak effects.
The following main objectives were considered:
- The assessment of hydrology and flood hydraulics for Elk River, Boivin and Crossing Creeks
- The production of detailed flood mapping or floodplain mapping for Elk River, Boivin and Crossing Creeks.
- The comprehensive investigation of the combined hazard from flooding and geomorphic hazards
- The development of flood mitigation options for the Elk River and Boivin Creek
As part of this project, recommendations were made for the Elk River Flood Strategy, the effects of climate change, and the effects of land use change, as ISL develops the methodology to complete the hydraulic model. Key stakeholders for the project include the District, local residents, and local businesses.
Using ISL’s in-house GIS team, we created regional frequency analysis to be close to the natural discharges for various return periods.
ISL also calibrated the model using high watermarks and aerial photos of the 2013 flood.