Norwich — Water levels in Norwich Public Utilities' two major reservoirs dropped to 60 percent, the lowest level in 30 years, prompting NPU to issue a water supply warning Wednesday and enact water conservation measures for both commercial and residential properties until conditions improve.

“We are rapidly approaching a serious water supply situation and strongly encourage our customers to be aware how they are using water,” NPU General Manager John Bilda said in a news release.

Bilda said Wednesday he has not seen levels this low in his 30-year career at NPU. He said NPU is asking customers to try to reduce water usage by 10 percent. For the average homeowner using 75 gallons per day, that would amount to a reduction of 7.5 gallons of water.

As of Friday, there has been only 1.97 inches of precipitation at NPU’s Deep River Reservoir in Lebanon and 2.72 inches at the Stony Brook Reservoir in Montville during October. NPU’s total reservoir capacity is 60 percent, which is approximately 200 days' supply of municipal water.

At 100 percent capacity, NPU’s two reservoirs have nearly 1.8 billion gallons of water — 321 days' supply.

As part of the water supply warning, NPU will contact major water users to determine the potential for emergency conservation and request that they reduce consumption.

The utility also will evaluate emergency supply options, such as bringing the backup Norwichtown well online, which could provide an extra 1 million gallons of water per day. NPU spokesman Chris Riley said the well is connected to the NPU system and is used at times when maintenance is being done on other primary water sources.

NPU also is encouraging residential customers to reduce their day-to-day water use by taking a few steps that should not impact their lifestyle. These measures include:

[naviga:ul]

[naviga:li]Take shorter showers.[/naviga:li]

[naviga:li]Run dishwashers and clothes washers only with full loads.[/naviga:li]

[naviga:li]Limit nonessential water use, such as watering lawns and gardens and washing cars.[/naviga:li]

[naviga:li]Do not refill swimming pools.[/naviga:li]

[/naviga:ul]

NPU provides water to nearly 11,000 customers in Norwich, Preston, Bozrah, Montville, Lebanon, Franklin, Sprague and Lisbon, and Mohegan Sun.

“If we get to 50 percent, which would be really unusual,” Riley said, “we'll have to take additional measures.”

Drought conditions usually ease once frost sets in, and water levels usually start to recover in reservoirs, Riley said.

Ron Gaudet, director of Groton Utilities, said that utility's reservoirs now are at 68 percent of capacity. The utility's policy calls for voluntary conservation measures when the level hits 50 percent. Gaudet said utility officials are considering raising that minimum threshold to 60 percent to to be “a little more proactive.”

Gaudet said utility water officials will meet on Friday morning to discuss the drought and water levels. Groton Utilities flushed hydrants earlier this summer and has no large maintenance projects underway that would consume large amounts of water, he said.

c.bessette@theday.com