Officials are asking people to conserve water in areas affected by low rainfall and the extreme heatwave in late June and early July.
The province says drought is affecting most of southern British Columbia and the central Interior.
There is water scarcity on Vancouver Island and low flow levels in waterways there as well as in the entire Thompson-Nicola region, the Cariboo, Shuswap and Okanagan.
"British Columbia ranks drought levels from 0 to 5, with drought level 5 rated as the most severe with adverse impacts to socio-economic or ecosystem values being almost certain," said the province in a release.
Most of eastern Vancouver Island, as well as the Salmon River watershed in the Shuswap, is now at drought level 4.
'Maximum water conservation'
"In these areas, adverse impacts on fish are now very likely," said the release. "Maximum water conservation for all water users and licensees is being urged."
The Nicola and Coldwater watersheds near Merritt, the Kettle River watershed near Grand Forks, western Vancouver Island, the Middle Fraser Basin/Cariboo region and the entire Okanagan Valley are classified as drought level 3.
The province says fourteen other areas in B.C. are under either drought level 2 or drought level 1 conditions.
Officials are asking people and businesses to conserve water in all areas affected by drought.
This includes abiding by water bylaws that limit outdoor watering, but also taking shorter showers and not leaving taps running.