Drought conditions are intensifying across southern B.C. after a long, hot summer with very little rain.

On Friday, the province announced that the South Thompson, Kettle and Granby watersheds are now experiencing a Level 4 drought, which means that conditions are extremely dry.

"Stream flows are approaching critical environmental low-flow thresholds for fish populations," a government press release warned.

Those low water flows could endanger kokanee, chinook and sockeye salmon in the South Thompson watershed and rainbow and brown trout in the Kettle and Granby watersheds, according to the release.

The province has five drought levels, ranging from normal conditions to complete loss of water supply.

The Salmon, Similkameen, Nicola and Coldwater watersheds all reached Level 4 drought earlier in the season.

Officials are recommending that everyone living in these watersheds reduce their water use as much as possible. For now, restrictions on water use are voluntary.

Greater Vernon area reaches Level 3

Meanwhile, a Level 3 drought has been declared in the Greater Vernon area, and there's no rain in the forecast. Level 3 indicates "very dry conditions" that could hurt the local economy.

The Regional District of North Okanagan (RDNO) said some streams in the region are very low and most aren't supplemented by reservoirs.

An RDNO statement said the concern is keeping streams high enough for fish and at levels that can sustain the region through irrigation season.

Residents are on the first stage of water restrictions despite the drought declaration, meaning watering is allowed three days a week.

The region said it's avoided tightening water restrictions over the summer because of careful municipal management, paired with good efforts from residents to save water.

There's minimal rain in the forecast for the Okanagan and hot temperatures are expected to continue. The region has been characteristically bone dry all summer, with wildfire risk at an extreme level.