One might think that losing 88,000 gallons a day from the Pardee water system is at least a small reason a new dam is proposed.

Among East Bay Municipal Utility District facilities, Pardee Reservoir is by far the leakiest - in terms of volume lost. EBMUD confirms reports last summer by Oakland-based KTVU Television, which statistics were the fruits of a string of state Public Records Act requests to the utility. Officials say little has changed since the news broke last summer. EBMUD has proposed to build a new, taller Pardee Dam to increase its long-term water supply.

Pardee Reservoir leaks an average of 70,000 gallons daily. In the East Bay area, Central Reservoir in Oakland leaks 36,000 gallons each day, and North Reservoir in Richmond leaks an average of 11,000 gallons each day. For the past 50 years or so, the Pardee Tunnel pipeline has leaked an average of 18,000 gallons daily.

Any earth-floored reservoir will lose water into the ground, but Amador Water Agency officials differed on how to interpret the volume lost at Pardee. EBMUD officials defended the situation. An EBMUD engineer went so far as to say a new dam would lose roughly the same water amount as does the current one.

"If they're losing that much, they're wasting," said AWA governing board Director Debbie Dunn.

Agency general manager Jim Abercrombie said he guessed Pardee's comparatively high volume lost could be explained by Pardee's having far greater capacity than have EBMUD's Central or North reservoirs.

EBMUD director of engineering Xavier Irias said, "It's in a normal range. That's not just our opinion."

Pardee Reservoir holds nearly 200,000 acre-feet of water, said Charles Hardy, EBMUD spokesman. An acre-foot is 325,851 gallons. Central Reservoir in Oakland holds just 2,220 acre-feet, and North Reservoir in Richmond is even smaller, Hardy said. Pardee loses some water to evaporation, as well as to some small cracks in the dam, EBMUD officials said. Central and North reservoirs are capped to cut evaporation, Hardy said.

The arithmetic suggests that Pardee is comparatively efficient in the EBMUD storage system.

"We've not been trying to reduce losses," Irias acknowledged.

EBMUD's 325,000 acre-foot allotment of Mokelumne River water is 90 percent of the agency's delivery each year. That delivery serves some 1.3 million people in much of Alameda and Contra Costa counties, the most populous region of the San Francisco Bay Area.