Friday Apr 30 2010
River danger, full water deliveries a mixed blessing as above-average Sierra snowpack starts to melt
By: Gus Thomson, Journal Staff Writer
For 22 years, Bowman’s Bonnie Lightner has been enjoying a front-row seat from her home overlooking the North Fork American River to the ebbs and flows of the Sierra snowmelt. This past week things turned sensational. With the spring snow melt and rains continuing, Lightner watched as the water that continually spills over the Lake Clementine-North Fork dam began to flow more heavily. She judges by how many “dividers” at the top of the dam are obscured by the water and by Wednesday morning, the water was all the way across. That’s a rare occasion, Lightner said, and indicative of the amount of water now pouring downstream from the mountains. This past week’s rain caused rivers to rise but nothing like past events like January 1997’s storm that rose nearly to Highway 49 at the American River confluence. Another major storm occurred in 1995, when heavy rains and clogged creeks in the Roseville area led to flooding, declaration of Placer County as a disaster area and a visit by then-President Bill Clinton. Up in the Sierra, water forecasters have been attempting to determine the impact of the colder weather, sudden increase in spring storms and heavier-than-normal snowpack will have. Late-season snow and rain has meant a huge jump in Placer County’s Sierra snowpack to 154 percent of the average for this time of year, Placer County Water Agency reported last week. Pacific Gas & Electric Co. made the latest measurements Monday and snowpack received another boost Tuesday and Wednesday when another storm moved through. The measurements were made in the high Sierra watershed above the agency’s Hell Hole and French Meadows reservoirs. Steve Jones, agency power systems manager said average water content was an impressive 30 inches on a snow depth of 64.9 inches. He reiterated his comments made a month earlier when the snowpack had crept up to just more than 100 percent of average. “This tells us that we should expect a good year for water supply, power generation and public recreation,” Jones said. But a PG&E water analyst was urging caution. “Care should be taken in putting too much weight on the percent of average May numbers,” Gary Freeman said. “They suggest a delayed melt cycle for this time of year, rather than a large snowpack.” Reservoirs around the state have risen to above-average levels. Shasta, near Redding, is now at 109 percent while Folsom is at 107 percent. The increase reflects a 50 percent jump from early April snow surveys. Water content was 103 percent of average on the American River watershed in Placer County and 94 percent of average to the north on the Yuba-Bear river watersheds. With recent rains and warming weather increasing snowmelt, forecasts from the agency are for Hell Hole Reservoir on the American River’s Middle Fork to be full by June 1 and French Meadow Reservoir to rise to 86 percent of capacity. With melting snowpack and plenty of snow, agency General Manager David Breninger said conditions on the river could change quickly for people in or near the American or its tributaries. Breninger said people should be using extreme caution when near water that is not only very high and cold, but also subject to swift, turbulent flows and debris. On the plus side, Breninger said the agency expects to have adequate water supplies for drinking and irrigation needs throughout the agency’s customer base.