Shawnigan Lake

A weir at Shawnigan Lake stores water so that it is available for the communities of Shawnigan Lake and Mill Bay. The community of Shawnigan Lake withdraws water from the Lake.  Some users in Mill Bay withdraw water from Shawnigan Creek.  However, most of the community of Mill Bay is supplied by groundwater.  A lake level gauge was installed in May 2021 at the Decca Road water intake for the Shawnigan North Community water system. The following graph shows the change in lake level since the gauge was installed.

Real-time Shawnigan Lake levels are tracked through the province’s water data monitoring tool.  

NOTE:  We are experiencing technical issues with the graphs. If no graph is visible, try hitting refresh a few times or try with a different browser.

An available water storage estimation can be made once additional lake level data is gathered and compared to lake level data gathered at the weir.  The available water storage calculation is based on 100% storage corresponding to the crest of the weir and 0% corresponding to the level of the gate when it is fully lowered. The lake is physically capable of storing water beyond 100% available water storage, however water stored above the crest of the weir is not released into the river at a controlled rate and so this volume is not considered “available storage”. For Shawnigan Lake, the target for water storage is to keep the lake level above the rule curve, a regulated minimum set by the Province for the amount of water that can be stored from March 15 to October 1.