The Great Salt Lake is not living up to its name this year, despite a wetter-than-normal winter and a cool spring.
The lake is shrinking again and could approach the same near-record low levels seen in 2004.
Given this spring's large snowmelt, the Utah Geological Survey's Wallace Gwynn was "anticipating the lake to rise."
The Great Salt Lake is already a foot lower than it was a year ago.
Gwynn said he was shocked when he saw the July 1 lake level at Saltair of 4,195.7 feet above sea level. It was 4,196.8 feet on July 1, 2007 and 4,197.8 feet on July 1, 2006.
"I thought, 'What's going on here?"' and he began investigating. "I'm still gathering information."
Gwynn suspects the main culprit in the lake's unexpected shrinking during a wet year may rest with groundwater levels.
He said that before this year's spring runoff, much of the Wasatch Front had a groundwater soil concentration of about 58 percent. By July 1, that concentration had increased to 80 percent.
"We had some very low groundwater levels," he said. "A lot of the runoff this year went into the ground, instead of the creeks."
Stream runoff is much of what feeds water into the Great Salt Lake. Then, being a closed basin, the only way water departs the lake is to evaporate.
Brian McInerey, hydrologist for the National Weather Service in Salt Lake City, said groundwater is just one factor. McInerey believes that reservoir managers stored a lot more water than usual to fill up, and that meant less inflow to the Great Salt Lake.
"We had a very good runoff year," he said.
McInerey says the Weber and Provo rivers ran higher than normal.
"I think it had to do with how the (river) water was diverted. ... We filled about every one but Bear Lake."
The Bear River is the lake's greatest inflow, but that's where the mystery is, he said. The Bear ran 100 percent of normal not far from its Uinta Mountain headwaters. However, by the time it reached Stewart Dam, near Bear Lake, it was down to less than 60 percent of normal and far less when it reached the Great Salt Lake.
Neither Gwynn or McInerey agree with a local TV report last week that concluded that the many unusually dry storms passing over the Great Salt Lake this past winter sucked a lot of its water out, like a giant straw.
"That doesn't sound right," McInerey said.
He said the lake rises each year until about May and then evaporation begins pulling it down.
If this summer remains unusually hot and dry, Gwynn expects the lake level could drop another foot, to near 4,194 feet above sea level roughly the same low it reached in 2004. That lake level of four years ago was the lowest the Great Salt Lake had been since the early 1960s.
Gwynn's not expecting the lake to ever completely dry up, like some scientists predicted in the latter part of the 19th century. However, it is definitely in a multi-year low cycle overall.
Notwithstanding, he also said, "it is a possibility" that some decades hence the Great Salt Lake could rise again to near-record highs, like it did in the mid-1980s making the pumping of the 1980s needed again. That scenario all depends on the overall moisture for a long term.The lake's all-time low was about 4,191 feet in 1963. Its all-time high, at 4,212, was not all that long ago, in 1986-87. As of Friday night, the lake level had dropped two 10ths of a foot to 4,195.5 feet. The lake's most recent low was 4,194.1 feet in October 2004.