The province has announced a Level 3 drought rating for Vancouver Island and the Gulf Islands.
That means residents, industry, farmers and municipalities are being asked to voluntarily restrict their use of water by 30 per cent.
The Ministry of Forests, Lands, Natural Resource Operations and Rural Development says a number of important salmon streams are approaching critical environmental flow thresholds for ecosystems and fish, including juvenile steelhead, coho and chinook salmon.
The Koksilah River, in particular, is experiencing low flows that are threatening fish populations.

If voluntary reductions of water use are not enough to maintain flows above critical levels, the ministry may consider regulating water use.