Stamford’s water supplier declared an emergency Tuesday, the result of the regional drought, and asked city residents to reduce water use by 15 percent.

BHC Co. entered what it calls “Emergency Phase 1” in Stamford, the third of its five-stage water management plan. Residents must save water now to avoid more stringent conservation measures this spring and summer, the utility warned.

“While we’d like to be optimistic, present conditions do not look good for the spring and summer, when water use is highest,” said Howard J. Dunn, BHC’s vice president of supply operations.

Stamford’s reservoirs are 51 percent full. Normally this time of year they are at 83 percent capacity, BHC said.

The utility also declared a drought alert for reservoirs serving Ridgefield, New Canaan, the Greater Bridgeport and New Haven Valley areas. Those residents are asked to reduce water use by 10 percent.

Normal Greater Bridgeport reservoir storage for mid-February is 94 percent. The reservoirs are 62 percent full.

BHC does not have the power to enforce mandatory restrictions; those must come from municipalities, said Adrienne Vaughan, BHC spokeswoman. Water and local officials are planning to meet, but she could not say yet what action will be taken.

To save water, BHC recommended: turning off water while shaving, brushing teeth and washing; repairing leaks, taking shorter showers and installing low-flow showerheads.

For the first time since the drought of the early 1960s, the Regional Water Authority recently issued a water supply advisory, asking customers to reduce use by 10 percent. Connecticut Water, which serves eastern Connecticut, put a water supply watch into effect.

–Associated Press