As of Tuesday, May 23, 2017
It’s “water, water everywhere,’ according to the Natural Resources Conservation Service (NRCS) that reports precipitation levels are above or well above average across Idaho, since the water year started last October.
On how well, NRCS — in its monthly water supply outlook — lists that lowest amount within Idaho is in the Clearwater Basin, which is reporting 123 percent of average.
“The challenge this year is not too little water – as all of Idaho’s 2,000-plus lakes and reservoirs will fill this year,” said Ron Abramovich, Water Supply Specialist for NRCS Idaho. “Rather, the concern is limited storage space if inflows continue to exceed outflows and fill the little remaining storage space.”
For the Clearwater Basin, NRCS noted after an unusually wet March, April brought more normal precipitation amounts to the area (118 percent of average), leaving water year-to-date precipitation at 123 percent of average. Cooler than normal temperatures and steady precipitation throughout April resulted in little high elevation snowpack loss. Overall, the Clearwater basin snowpack is 117 percent of median.
Streamflow forecasts are similar to Feb. 1 numbers, with all these between 110-117 percent of average. Near normal water supplies are expected, which will provide adequate amounts for water users including fishing and rafting recreationists.
Salmon River Basin
The Salmon River Basin received 127 percent of average precipitation during April. Once again, the western half of the basin received the most precipitation with respect to normal. Water year-to-date precipitation is 141 percent of average. Snowpack in the basin increased between April 1 and May 1, and it is now 158 percent of median.
According to NRCS, it will take several months to melt the incredible snowpack that resides on the highest peaks that feed the Salmon River, and some north-facing slopes may hold snow throughout the summer.
Continued above average precipitation during April helped maintain high forecast volumes. May to July forecasts call for 176 percent of average for the Salmon River above Salmon and 190 percent of average for Main Fork Salmon River, while the other rivers are forecast in the 150 percent of average range.
The much above normal high elevation snowpack provides the potential for high peak flows, depending on spring weather. This will keep river levels high long into the summer for the Salmon River and its tributaries.