The Department of Water Resources (DWR) released their third
Snow Survey for the 2009-2010 winter season at the beginning of
March. The survey indicated that water content in California’s
mountain snowpack is 107 percent of normal for the date. This time
last year, snow water content statewide was 80 percent of
normal.
BY SHAWN NOVACK
The Department of Water Resources (DWR) released their third Snow Survey for the 2009-2010 winter season at the beginning of March. The survey indicated that water content in California’s mountain snowpack is 107 percent of normal for the date. This time last year, snow water content statewide was 80 percent of normal.
“Today’s readings boost our hope that we will be able to increase the State Water Project allocation by this spring to deliver more water to our cities and farms,” said Department of Water Resources (DWR) Director Mark Cowin. “But we must remember that even a wet winter will not fully offset three consecutive dry years or pumping restrictions to protect Delta fish so we must continue to conserve and protect our water resources.”
Lake Oroville, the State Water Project’s principal storage reservoir, is recovering slowly after three dry years. Despite recent storms, its storage level as of March 17 is only 57 percent of average for the date. It is also expected that dry soil conditions will absorb much of the snowpack’s water content that otherwise would help to replenish streams and reservoirs during the spring and early summer melt.
Lake Shasta, the principal storage reservoir for the federal Central Valley Project (CVP), was at 82 percent of capacity, and 104 percent of the historical average for the same date.
Tucked in the hills near Pacheco Pass is the San Luis Reservoir. The District connects in to this facility to receive water from the CVP. The water arrives through the California Aqueduct and the Delta-Mendota Canal, and is pumped from the O’Neil Forebay into the main reservoir. From there it’s pumped through Pacheco Pass where the San Felipe Project distributes water to our county and local growers while some of this water is stored in our local reservoir (San Justo) and some has been used to recharge our local groundwater supplies in past years.
San Luis Reservoir was at 79 percent of capacity and 88 percent of average as of March 17.
These numbers look good, but they’re deceiving. Even though the federal reservoirs have a pretty good supply of water, the CVP allocations for 2010 are far less than our historical averages.
To understand this, one must understand the history of the CVP.
Sixty-six percent of the states precipitation occurs north of the Delta whereas 66 percent of the demand for this water lies below the Delta (including San Benito County). The state recognized this early on and it was decided to come up with a system to move this water south.
The idea for the CVP was discussed formally in the 1920s. In 1933, the State legislature passed the California Central Valley Project Act. Voters approved the issuance of $170 million in revenue bonds, which were issued for the Project. However, because of the Depression, the bonds did not sell and the project was never started. In 1935, the Rivers and Harbors Act was enacted, and President Roosevelt transferred $20 million of reimbursable funds for the authorization and construction of the Federal Central Valley Project.
The Rivers and Harbors Act was reauthorized in 1937 and placed the Project under United States Bureau of Reclamation (USBR) law, which provided that the first function of the dams and reservoirs was flood control and improved navigation; the second for irrigation and domestic use; and the third for power generation.
The Central Valley Improvement Act (CVPIA) was signed into law in 1992. It amends previous CVP authorizations to include fish and wildlife protection, restoration, and mitigation as project purposes having equal priority with irrigation and domestic uses; and fish and wildlife enhancement as a project purpose with priority equivalent to power generation.
The CVP supplies seven million acre-feet of water – nearly 20 percent of California’s developed water supplies – to 3.4 million acres of farmland and more than 50 California cities, counties and rural communities. The CVP also supplies more than 1.5 million acre-feet of water for fish and wildlife purposes.
The USBR announced on February 26th that settlement contractors with claims to senior water rights along the Sacramento and San Joaquin Rivers will be allocated 100 percent of their contract quantities this year (delivery of approximately 2.4 million acre-feet (MAF). Wildlife refuges north and south of the Delta will be allocated 100 percent of their “Level 2” water (about 400,000 acre-feet delivered), most of which will likely be delivered after the irrigation season. Municipal and industrial water contractors will receive an allocation of 55 percent (about 275,000 acre-feet). However, Reclamation may deliver CVP water to all municipal and industrial contractors at not less than a public health and safety level if CVP water is available, not to exceed 75 percent of contract total.
Under the conservative forecast, and taking into consideration below average carryover storage and CVP operational constraints imposed by water quality and endangered species requirements, agricultural water service contractors north and south of the Delta will be allocated 5 percent (about 120,000 acre-feet) of their contract quantities.
On March 16 the USBR announced they were increasing the allocations to agricultural water service contractors south of the Delta to 25 percent of their contract quantities – up from 5 percent. This includes water delivered to San Benito County. Although this is still far below our historical average it’s a whole lot better than their initial announcement.
What this all means is there are many different interests (legal, environmental and contractual) competing for the water that works its way down the state. Hopefully, the USBR will be able increase water allocations to ag customers as we get closer to our peak irrigation season.
In summary, the biggest reason water supplies have diminished for ag customers are due to the pumping restrictions that were put in place to protect the Delta. This has been aggravated by the drought conditions that have plagued our state for the last several years.
For his views on environmental issues and what it means locally, see the rest of this analysis in the Pinnacle on Friday.
Shawn Novack is water conservation program manager for the Water Resources Association of San Benito County.
