The Graves Bridge boat access site was devastated by the 2013 flood, whereby access to the river was only possible by crossing a large new gravel bar to the river’s edge. Unfortunately, the gravel bar became a vehicle recreational area. Measure needed to be taken to protect this environmentally sensitive area.
Calgary’s River Access Strategy was mandated to improve river access within the City and became the agency to develop a plan to assure continued river access at Grave Bridge but also protect the adjacent environment. The decision was made to restrict vehicle access to the gravel bar outside of that needed to launch boats. The placement of two lanes of concrete lock blocks across the the gravel bar from the existing boat ramp to the low flow river edge became the short-term fix. It is recognized that a more permanent solution will be needed in the future.
The following details the Calgary Parks Department development process for the project:
Graves Bridge Lock Block Placement
At the onset of this project City Water Resources prepared a technical memorandum that provided a summary of possible options and the hydraulic analysis of these options. The technical memo concluded that the lock block option would have a negligible effect on water levels in the area.
To further investigate the lock block option Calgary Parks commissioned a consultant to undertake an analysis of the effects of placing lock blocks on the gravel bar. The consultant completed a Fish Habitat Assessment Report. This assessment report covered the following:
-Investigation of biophysical characteristic of the project area.
-Assessment of potential disturbance to fish habitat.
-Regulatory Approvals considerations (Water Act, Public Lands Act, Fisheries Act).
-Mitigation measures to be implemented during project works (placing the lock blocks on site).
The placement of lock blocks followed the recommendation of the assessment report.
The lock block option is only a temporary solution to control vehicle movement on the gravel bar.
The City recognizes that a permanent solution to re-introduce water back up to the concrete boat ramp is still needed, however, this work is currently unfunded so there is no scheduled timeline for a permanent solution.
Bow River Trout Foundation continues to engage with the City of Calgary on the Graves Bridge river access site and other River Access Strategy proposals.