Above average water supply forecast
The April Water Supply Outlook shows precipitation in the upper Snake River Basin totaled about 140% of normal. Year-to-date precipitation is at about 110% of average.
Snow accumulation continued through mid-April in the higher elevations, before widespread melting took over for the second half of the month. The May 1 snowpack was 120% of normal above American Falls.
The Natural Resources Conservation Service (NRCS) reports most of the region’s reservoirs are near normal for the time of year. But there are exceptions. Ririe is 117% of average, Jackson is 147% and Blackfoot at 149% of capacity.
The Snake River near Heise is expected to run at 100% of average flow for May through July and from May through September. Additional spring precipitation could promote greater system carryover and allow for increased aquifer recharge in the Snake River plain.
