The California Department of Water Resources (DWR) has released the final version of the 2011 State Water Project (SWP) Delivery Reliability Report. The report is the latest in a series of reports that began in 2002, which report the delivery reliability of California's State Water Project, the largest state-built and operated water and power system in the United States. The SWP provides at least some of the water consumed by 25 million Californians and used to irrigate about 750,000 farmland acres. Of SWP water deliveries, about 70 percent goes to cities and 30 percent to farms.
The newest report updates estimates of current (2011) and future (through 2031) SWP deliveries, taking into account pumping restraints to protect Delta smelt, salmon, and other fish species as well as variations in precipitation and impacts of climate change. The perspective applied assumes no significant changes will be made to convey water past the Sacramento-San Joaquin Delta or to store the more variable runoff expected with climate change.
Due to increased public interest in pumping water from the Delta, a new chapter focuses specifically on SWP exports at the system's Harvey O. Banks Pumping Plant in the Delta. The report documents that the SWP continues to be subject to delivery reductions caused by fishery agency Biological Opinions intended to safeguard threatened and endangered fish.
While the report is very detailed and includes the results of extensive computer modeling, a few basic conclusions in the executive summary include:
- Estimated average annual SWP exports under 2011 conditions are 12% less than the estimates made for 2005 conditions.
- Estimated average annual SWP exports decrease 86,000 acre-feet per year (about 3%) between the existing- and future-conditions scenarios.
DWR also states that California's population has grown rapidly in recent years. From 1990 to 2005, the state's population increased from about 30 million to about 36.5 million. Based on this trend, California's population could exceed 47.5 million by 2020. By 2050, the population could rise to nearly 60 million -- virtually double the 1990 population -- according to trends cited in the 2009 Update to the California Water Plan.
The final 2011 State Water Project Delivery Reliability Report is available from DWR online here.
If you have any questions concerning this report, please contact Hanspeter Walter or the KMTG attorney with whom you normally consult.