One of the driest summers in a century for some parts of the state has left northern Utah reservoirs at critical levels, and water officials are hoping for a wet winter.

Officials say unusually dry weather and the accompanying high agricultural water use has dramatically lowered reservoir levels. Readings at the end of August show Echo, Pineview and Willard Bay reservoirs were below 1977 drought-year levels, according to the National Weather Service."If it isn't any better winter than last winter, it is really going to be tight," Ivan Flint, manager of the Weber Basin Water Conservancy District, said.

According to the Palmer Index, used to measure soil content and gauge long-term trends in weather, the Wasatch Front is in an extreme drought. The index shows only 12 percent of normal soil moisture along the Wasatch Front and 29 percent of normal in northern mountains, the National Weather Service said.

Weather stations in Brigham City, Brighton, Corinne, Echo Dam and Wanship reported this was the driest summer since records have been kept. Farmington station reported it was the driest summer in 90 years. In Salt Lake City, it was the second driest in 115 years.

Flint estimates there will be only 40 percent of a two-year supply left in the district's seven reservoirs when irrigation supplies are traditionally shut off on Oct. 15. Weber Basin reservoirs held 70 percent of a two-year supply of water at the beginning of 1986 and 50 percent this year, Flint said. The district could shut down irrigation supplies as soon as Oct. 1 if the danger of depleting water becomes too great.

"We're losing ground," Flint said, noting that this year the district had started with 63,000 acre-feet less water in its system. That water deficit, enough to fill Rockport Reservoir, could grow substantially again without an ample snowpack.

Besides this year's small runoff, Pineview and Echo reservoir levels were affected when Weber Basin personnel lowered them to fill East Canyon Reservoir to 101 percent of a two-year supply.

"East Canyon is really tough to fill in a dry year," Flint said, explaining it is fed by a small tributary of the Weber River. Because Weber and Ogden rivers feed Pineview and Echo reservoirs, they could fill next spring with less precipitation.

Pineview Reservoir is at 46 percent of its average, and Echo Reservoir is at one-third of its average. Willard Bay, which is at 60 percent of average, is 6 percent below 1977 levels.

Flint encouraged water users in the district to continue conserving water throughout the next month. He praised voluntary conservation efforts this spring and summer.

"That's the only reason we are in as good a shape as we are," Flint said.

Weber Basin Water Conservancy District stores water in Pineview, Rockport, Willard Bay, Causey, Smith and Morehouse, Lost Creek and East Canyon reservoirs. The district provides irrigation and culinary water in Davis and Weber Counties.