Challenges

Water supply in the Koksilah is a problem that is growing. Low flows in the summer are no longer meeting the needs of fish and residents. The risk of winter floods in the lower reaches is growing.

Koksilah flows are naturally variable are a result of:

• Location - east side of Vancouver Island where summers are warm and dry.
• Elevation -no high mountains so little snow pack; precipitation is mainly rain.
• Flow Regulation -water is stored and released from the small lakes, numerous wetlands and underground aquifers of the watershed. Without a big lake to store and gradually release water throughout the year, stream flows tend to change rapidly and often dramatically when it rains. Flash floods in the winter and low flow conditions in the summer are common.

And today water supply is more erratic due to:

• Land Use - Tree removal, an extensive road system, development and water use have exacerbated the natural “flashiness” and low flows.
• Climate Crisis - we are experiencing warmer, wetter winters and hotter drier summers and it is going to get worse. Scientists are predicting an extreme drought event now will be an average summer 30 years from now.