Hydrologists with the Los Angeles Department of Water and Power have released the April 1 Eastern Sierra snow survey and the numbers are grim.
Overall, the Eastern Sierra snowpack is 30 percent of normal, which means there is 70 percent less water in the mountains than what can be expected in a “normal” year.
As winter gives way to spring each year, the melting snow supplies water flows that fill the many creeks and lakes in the area. The Eastern Sierra snowpack plays a vital role as the primary water source for more than 3.5 million Los Angeles residents, with about 65 percent of the city’s water coming from the eastern slopes of the Sierra.
Many important decisions that the LADWP and Inyo County Water Department make each spring, including the availability of water for irrigation needs, reservoir storage and operation, groundwater pumping levels, hydroelectric generation, maintenance programs, recreation availability and even the possible need for water rationing, depends on accurate water supply forecasting. That forecasting begins with the April snow survey.
The annual snow survey covers five areas, from Mammoth Lakes to Lone Pine. In the Mammoth Lakes area, which contributes about 25 percent of the Owens River Basin runoff, the snowpack is 35 percent of normal. In the Rock Creek area north of Bishop, which accounts for about 16 percent of the runoff, the numbers were worse, at 24 percent. In the Bishop area, which supplies about 20 percent of the runoff, the snow survey came in at 38 percent of normal; and in the Big Pine area, which supplies about 13 percent of the runoff, the snowpack was at 25 percent of normal. Farther south in the Cottonwood area, which supplies that last 25 percent of the runoff, the snowpack was at 17 percent of normal.