Stillwater Creek Slope Stabilization Project

RVCA was contracted by the City of Ottawa to design and implement remediation of an eroded bank of Stillwater Creek adjacent to Nautica Private and Carling Avenue and into the Ottawa River. Erosion of the slope is being caused by fluctuating flow and velocity in the creek and this project will help prevent potential slope failure.

East Bank Erosion		East Bank Erosion

The headwaters of Stillwater Creek begin in the National Capital Commission’s Stoney Swamp. Stoney Swamp is almost 2000 hectares in size, and is a mix of woodland, wetland and regenerating fields. From Stoney Swamp, Stillwater Creek runs through a heavily channelized and impacted area adjacent to Robertson Road. The creek turns into its natural morphology downstream of Robertson Road until the Highway 417 crossing. It then becomes channelized again, as it runs through Wesley Clover Park on Corkstown Road. The creek flows through another large wetland before Moodie Drive crossing, and from there runs parallel between Highway 417 and Corkstown Road until it turns north flowing through residential neighborhoods before emptying into the Ottawa River between the Nepean Sailing Club and Andrew Haydon Park.

The first phase to be completed is on the west bank of the creek in the treed area. The highlighted blue area is the East bank portion of the work to be completed as the second phase.

Map of the Work Area

Further erosion of the bank of Stillwater Creek at Nautica Private could be detrimental to the properties on Nautica Private and to the safety of the residents. 

Rock Toe Berm Construction

RVCA looked into multiple alternatives for the slope stabilization of the banks of Stillwater Creek. RVCA decided on the construction of a rock toe berm to stabilize the east bank of the creek. Once the design was complete, RVCA had it checked by a third-party local geotechnical engineering firm.

The rock toe berm has been designed to make a “key” at the base of the slope to be filled with large “rock protection” sized stones. The slope will then be backfilled at a 1.5:1 (h:v) slope and the large stones will extend above the creeks assumed 100-year flood elevation. The work is expected to protect the properties on Nautica Private from further property damage due to erosion.

Timing

The project took place from approximately December 2, 2019 – February 28, 2020.

Project Partners

City of Ottawa
Rideau Valley Conservation Authority

Information

Terry K. Davidson, P.Eng.
Director of Engineering & Regulations