View Full Version : New Water Year Begins

Dan Bacher
10-03-2007, 07:01 AM
This is a summary of current water storage conditions and the forecast for the new water year from the Department of Water Resources.

News for Immediate Release

October 1, 2007


Amy Norris, Public Affairs Office, (916) 654-3755
Ted Thomas, Information Officer, (916) 653-9712
DWR, California Enter New Water Year

Sacramento -- Today (October 1) is the beginning of the 2007-2008 water year which will last until September 30, 2008.

During this period, Department of Water Resources (DWR) hydrologists and meteorologists will measure precipitation (the combination of rain and snow) and runoff in the Northern Sierra and other key watersheds and produce runoff forecasts.

The northern Sierra and southern Cascades are of particular importance because that's where most of the state's water supply accumulates. Measurements are taken in the watersheds of the major rivers, including the Sacramento, Feather, Yuba and American. Snow surveys are conducted throughout the Sierra range and other mountains to measure snow depth and water content.

The data that is gathered is evaluated to forecast water supply for the spring and summer, the heaviest months of water use by farms and homes.

For the Sacramento River basin the past 2006-2007 water year finished as the 18th driest in the 102 year record of stream flow measurements. The San Joaquin River region was drier, finishing up as 8th driest, based on preliminary information.

The northern Sierra snowpack was measured at 40 percent of normal on April 1, 2007, which was the lowest since 1988. Early melting reduced the snowpack to only 25 percent of average by May 1.

Snowmelt, which normally continues through June, had virtually ended by June 1 this year. Overall precipitation for the state ended at 60 to 65 percent of average. The dry year may impact water deliveries further but as of now, State Water Project Contractors are scheduled to receive 60 percent of requested deliveries.

National Weather Service (NWS) long-range forecasts indicate a somewhat above average chance of wetter than normal precipitation in Northern California through the coming fall and winter months, but show a good chance that dry conditions will persist in Southern California.


As of August 2007, statewide water storage was at 20.4 million acre feet (MAF), which is about 84% of average for that date. Last year, storage was at 29.2 MAF at the end of August. Lake Oroville, the State Water Projectís principal storage reservoir, today (October 1) has 1,568,221 million acre-feet in storage, or 70 percent of average for the date. Lake Oroville, 70 miles north of Sacramento, has a capacity of 3.5 million acre-feet. Lake Shasta, principal storage reservoir for the federal Central Valley Project, today has 1,879,144 acre-feet of water in storage, or 67 percent of average for the date. Lake Shasta, north of Redding, has a capacity of 4.5 million acre-feet. An acre-foot is 325,851 gallons, or enough water to cover one acre to a depth of one foot.

Storage for the four largest reservoirs on the Lower Colorado River was about 51 percent of capacity as of August 2007, down from 53 percent last year. California's allocation from the Colorado River is 4.4 million acre-feet.

Precipitation in Sacramento River Basin the source of much of California's water supply, was about 62 percent of normal during water year 2007 compared with 150 percent of average the previous year. In the San Joaquin Basin, precipitation ended at 60 percent of average compared to 145 percent of average during water year 2006. As a result, water supply conditions have been designated as dry in the Sacramento Valley, and critical in the San Joaquin Valley.

The Department of Water Resources operates and maintains the State Water Project, provides dam safety and flood control and inspection services, assists local water districts in water management and water conservation planning, and plans for future statewide water needs.