Posts tagged: Sierra Nevada

California releases results from fifth and final snowpack survey

The California Department of Water Resources announced the results from its fifth and final snowpack survey May 1. The survey confirmed the snowpack’s low water content, which will affect water and power deliveries in California this year.

Overall, the average water content of California’s snowpack was 40 percent of normal. The relative composition of the Sierra Nevada snowpack, from which Western’s Central Valley Project relies on to fill reservoirs and generate hydropower, was 70 percent of normal for the northern Sierras, 35 percent of normal for the central Sierras and 20 percent of normal for the southern Sierras.

Last year’s snowpack water content state-wide was 190 percent of normal by this time, which will reduce the impact of the scarce snowpack this year.

“The impact of a below-normal water year has been somewhat mitigated by above-average reservoir storage levels due to unusually wet conditions during the 2010-2011 operating season,” said Sierra Nevada Power Marketer Sonja Anderson.

However, operators of both the state and Federal water projects have already announced reduced water and power deliveries for the upcoming year, including from Western’s Central Valley Project.

California releases fourth snowpack survey

The California Department of Water Resources announced that the results from the fourth of five surveys confirming below-normal water year conditions.

“An unusually wet March improved conditions, but did not make up for the previous dry months,” said DWR Director Mark Cowin.

The average water content of California’s snowpack was still only 55 percent of the expected April 1 normal. The relative composition of the Sierra Nevada snowpack, from which Western’s Central Valley Project receives snowmelt, was 78 percent of April 1 normal for the northern Sierras, 55 percent of the April 1 normal for the central Sierras and 39 percent of the April 1 normal for the southern Sierras. At the same time last year, the snowpack water content showed 173 percent of the April 1 average for the northern Sierras, 161 percent in the central Sierras, and 155 percent for the southern Sierras.

Both the State and Federal water projects have announced reduced deliveries for the upcoming water year.

“The reduced water deliveries are expected to result in reduced hydropower generation output for the Central Valley and State Water Projects,” said Western’s Sierra Nevada Region Power Marketing Manager Sonja Anderson. “However, the impact of reduced water deliveries is somewhat mitigated by last year’s above-normal precipitation, which has resulted in higher than average starting reservoir storage levels.”