Monday, September 12, 2011

California Groundwater in 2011

In 1995, the Pacific Institute published a report that summarized the condition of the water supply in California stating that “California’s current water use is unsustainable. In many areas, ground water is being used at a rate that exceeds the rate of natural replenishment…” In their 2005 the Pacific Institute published another report. Pointing out that water demand and use continued to exceed sustainable supply. Mining of groundwater unconstrained by environmental or ecological limits will doom California.

In addition to NGOs the State of California has routinely prepared water scenarios and projections as part of long-term water planning. The California Water Plan, a regular analysis published by the California Department of Water Resources (DWR) is the major guide book for water planning within the state. The latest version of the Plan was released for public review in January 2009 and stated: “We must adapt and evolve California’s water systems more quickly and effectively to keep pace with ever changing conditions now and in the future. Population is growing while available water supplies are static and even decreasing.”

In August 2009 the Environmental Water Caucus published California Water Solutions Now under a grant from the Goldman Institute pulling together a unified view and list of recommendations from a diverse group of stakeholders. The report points out that California’s state water agencies cannot report on how much water is actually being used, where it is being used, where it is being diverted to, how much is being diverted, or how many diversions are illegal. Where it does have such data, the State Water Board estimates that the number of illegal diversions may be over 40 % of the number of active permits and licenses, which also fails to comply with the law in many cases.

No one has publically questioned the conclusions of these studies, yet life went on as before with unsustainable water use in the Central Valley where massive surface-water diversions cannot meet all the agricultural and urban water demand and the groundwater has continued to be used to meet the deficit. California lacks the political will to balance their water budget, and nature is an unforgiving banker. Whenever you pump water from a well it has to be balanced by a loss of water from storage in the groundwater aquifer. Groundwater is recharged from rain and sources of surface infiltration. If too much water is pumped, water tables can drop in unconfined aquifers, water pressure fall in confined aquifers, surface water and ecology could be impacted and in some locations with fine grained soils compaction and subsidence can take place. Some of the storage capacity of the groundwater basins has been permanently destroyed.

According to U.S. Department of Commerce, California’s GDP (gross domestic product) was slightly more than $1.8 trillion in 2007. GDP is the value of all goods and services produced in California. According to the U.S. Department of Agriculture, USDA, the total value of the agricultural output from the state’s farms and ranches was $36.6 billion in 2007, up from $31.8 billion the year before. This means that crop, meat and dairy sales account for about 2% of the state economy. However, when you count all the secondary economic impacts: wine making and sales, chesse making, olive oil production, juice making, food processing and packing this number grows to 7.9% of the California economy.In terms of national agricultural output, $36.6 billion in revenue represents 12.8% of the U.S. total. The state accounted for 17.6 % of crops, and 7 % of the U.S. revenue for livestock and livestock products. California produces about half of U.S. grown fruits, nuts, and vegetables. Several of these crops are currently produced only in California and California agriculture is entirely dependent on irrigation. Over 75% of all surface water is diverted to agriculture. California does not have adequate water to meet the demands of the agricultural sector. California feeds much of the nation.

The U.S. Geological Survey’s (USGS) Groundwater Resources Program is conducting large-scale multiyear regional studies of groundwater availability in the United States. The USGS has found that the volume of groundwater stored in the earth is decreasing in many regions of the United States especially California. The extent of groundwater level declines across the United States has not been monitored before now. Our demands on the groundwater have increased and our understanding of groundwater has improved. It is now very clear we are running a groundwater deficit.

In general the Sacramento Valley receives more precipitation than the San Joaquin Valley, which includes the San Joaquin and Tulare Groundwater Basins, and despite the surface water diversions from the Sacramento Valley they are using less groundwater than the drier San Joaquin Valley and the groundwater level as reported by the USGS Central Valley Ground Waster Study has remained fairly stable in the past few decades, falling less than 10 million acre feet of groundwater storage near the end of drought periods and making up that loss and more after wet periods. The Tulare Groundwater Basin at the southern most portion of the San Joaquin Valley has seen a loss of 70 million acre feet of groundwater storage since 1962. Half of this loss, about 35 million acre feet has taken place since 1985.

In the early 1960s, groundwater pumping caused water levels to decline to historic lows on the west side of the San Joaquin Valley, which resulted in large amounts of surface subsidence. In the late 1960s, the surface-water delivery system began to route water from the wetter Sacramento Valley and Delta regions to the drier, more heavily pumped San Joaquin Valley. The surface-water delivery system was fully functional by the early 1970s, and there was some groundwater-level recovery in the northern and western parts of the San Joaquin Valley where subsidence was limited. The Tulare Groundwater Basin, the hottest and driest part of the Central Valley, has continued to have declines in groundwater levels and accompanying depletion of groundwater storage. The limits of the water not the Sacramento budget problems might be the limiting factor in California’s future.

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