Hyrologist: Utah could face water shortages soon

Sep 26 2012 - 7:29pm

OGDEN -- The 2011-12 water year still has four days to go, so a Biblical deluge that fills Utah's half-empty reservoirs is possible, but don't count on it.

A summary of the past 12 months' conditions, released Wednesday by the National Weather Service, shows record heat, bad snowpack and zilch watershed. Reservoirs, in some cases, have less than a year's worth of water left in them. If the coming winter is like the last one, Utah is looking at severe water shortages.

National Weather Service hydrologist Brian McInerney said it is hard to believe that the water year that ends Oct. 1 actually started 12 months ago amid concerns about how to manage reservoirs in case the 2010-11 winter's heavy snowfall was repeated.

Last October started out with rain all over Utah, he said, raising worries that reservoirs, still full even after a summer of irrigation, would have to be lowered as winter progressed.

"It feels ridiculous that we were talking about this," he said, "but it was a concern in October, and things were doing OK for most of the state."

That worry didn't last. The numbers, he said, tell the tale.

The amount of water in the snow that fell during the 2010-11 water year was more than 175 percent of normal. By comparison, the amount in the water year that ends Sunday was only 65 percent of normal.

The spring runoff in 2012, such as it was, started in March instead of the normal June, and "hardly produced any runoff at all," McInerney said. What snow there was melted and soaked into the ground, evaporated or was sucked up by plants.

Temperatures over the year played a part. October was 1.8 degrees above average, he said, but November and December were slightly cooler.

In January, he said, a high-pressure mass parked itself over the Utah-Arizona-Colorado area, forcing the jet stream with its storms to curve north through Idaho. Temperatures in Utah averaged 3.4 degrees above normal in January, 5.4 above normal in February and another 3.5 above normal in March.

That 3.5 degrees in March is misleading, he said. Some days the temperatures soared 20 degrees above normal, melting what little snowpack there was in the mountains months before the normal runoff.

The high temperatures continued all summer. August set a record as measured at the Salt Lake International Airport with an average temperature of 81.7 degrees. The June-August average was the second-highest on record, at 79.2 degrees, just below the 2007 record of 79.3.

When it got hot, it got very hot. The record for days above 90 degrees was set in 1961 with 82 days, he said, and the average is 56. The past water year saw 72.

The extreme is more stark with days over 100 degrees. The record for that was also set in 1961, with 21 days, and 2012 saw 11, more than double the average of five.

What it all means is, there is now very little water left over in reservoirs.

The reservoirs in the Weber Basin Water Conservancy District, which serves most of Top of Utah, hold a two-year supply when full. They ended the last water year at capacity, but with so little rain and runoff this year, they're like the savings account of someone who lost their job, showing the strain of heavy use.

Pineview Reservoir is at 38 percent of capacity, Willard Bay is at 68 percent and East Canyon is at 51 percent.

McInerney said nobody knows what this coming winter will be like. All he can do is wait and see what sort of winter comes and make his water supply forecasts beginning in January.

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