Drainage of the prairie itself is maintained through Sumas Canal and the Barrowtown Dam Pump Station that discharges into the Sumas River and Vedder Canal, and eventually discharging into the Fraser River.

Emergency response focused on closing the breach to stop flowing water from the Sumas River entering Sumas Prairie. Working under conditions of flowing flood water, partially underwater, and during intense precipitation, made it impossible to use fine-grained soils to close the breach and reinstate the dike structure. Therefore, the entire closure of the breach was constructed using crushed granular fill of varying sizes and the result was that seepage would continue through the body of the dike until a core or other suitable low-hydraulic conductivity barrier could be installed.

As part of the Emergency Works between November 19, 2021, and January 25, 2022, field reviews were completed by a Senior Geotechnical Engineer from Kontur who visually assessed the breached dike section, surrounding nearby dike damage, and monitored the subsequent emergency construction works. Field observations were documented in field review summaries issued separately to the City. Key challenges included significant loss of dike integrity near the breach, materials hauling and construction along the top of a narrow dike, working immediately adjacent to water with depths in excess of 4m at some locations and weather.