There is no question that California’s current drought has altered the discussion of more direct groundwater management by state government. In the absence of reliable surface water supplies in recent years, overdraft of groundwater in the Central Valley and other areas has caused land subsidence and compaction, poor water quality, and lowered water tables, which have all led to less available water and significant soil degradation and compaction problems that will have long-term impacts.
As a result, agriculture and urban water suppliers, who previously would have treated any discussion of a statewide groundwater regulatory scheme as a non-starter, are indicating that it might be time for more state management and oversight of groundwater pumping. While many have long-thought it is nonsensical for the state to so closely manage and regulate the use of surface water, but yet have very little state oversight of groundwater, the current problem has led water suppliers and agriculture water users to also begin to question this approach.
But with the clamor and changing attitudes, legislators cannot lose sight of the fact that groundwater remains a property right and state regulation of groundwater has limits, both legal and physical. There are several challenges the state would face in managing an extremely complicated and expansive natural resource that isn’t visible. Finally, the importance of surface storage in this discussion cannot be understated. As we have seen consistently through the years, groundwater overdraft is directly proportional to the amount of surface storage available, and you can’t begin to “fix” California’s groundwater problems until you address the lack of sufficient surface storage.
Groundwater use in a typical year makes up 35 percent of California’s freshwater needs. During drought years when surface water is unavailable, this percentage can increase to as much as 40 to 60 percent. In some regions that have limited access to surface water such as the Central Coast, over 80% of the water used is groundwater.
The amount of local groundwater management and oversight varies greatly from highly managed in some regions to very little management at all in others. There are 525 identified groundwater basins and sub-basins statewide, but of these 525 basins, only about 120 of them account for 95% of groundwater used as public supply, municipal and agricultural pumping.
It is estimated that the state’s groundwater aquifers can hold 850 million acre-feet of water, or 20 times the amount of water that can be stored behind California’s dams. However, only about 250 million - 450 million acre feet of groundwater can be economically reached. i
Groundwater overdraft is defined as a withdrawal of water from an aquifer in excess of the amount of water that recharges the basin over a period of years during average periods of precipitation and recharge.ii With surface water deliveries at historical lows, water suppliers and growers have looked to increased groundwater pumping to provide water for people to drink and grow crops. A lack of available surface water, or precipitation, also means groundwater recharge is currently virtually non-existent in many basins.
Overdraft is not a new problem. Prior to the construction of the State and Central Valley water projects from the 1940’s - 1960’s, groundwater overdraft was significant, and subsidence, the gradual sinking of the land surface due to overdraft, was prevalent. In one area of the San Joaquin Valley near Mendota, the land surface subsided nearly 30 feet between 1925 and 1955. Groundwater levels recovered somewhat upon completion of the state’s water project as pumping was reduced with the availability of new surface water supplies. By 1955, nearly one fourth of the total groundwater extracted for irrigation in the United States was pumped in the San Joaquin Valley. More than 400 feet of water level decline occurred in some west-side areas.iii
Other than subsidence, overdraft can bring about significant economic and ecological harm. Overdraft can lead to an overall reduction in water quality, which can make the water more expensive to treat for drinking water suppliers. Overdraft of basins near the coast can draw seawater into the basins making them unusable without desalination. As the water table drops in the Central Valley, deeper and deeper wells need to be drilled which not only increases energy usage, but can lead to the pumping of more brackish groundwater that can damage crops and lead to long term soil degradation. Most disturbing, soil compaction that occurs with subsidence can mean a complete loss of future storage capacity in the aquifer. And finally, areas that are overdrafted will tend to draw more surface water into the depleted aquifer, impacting surface water users who have specific rights to use those surface water supplies.
Groundwater is not restricted to political or property boundaries on the surface and as a result, it presents a classic “tragedy of the commons” in that each groundwater user has an incentive to use the common, limited resource, to the detriment of other users who extract water from the same groundwater supply. The incentive increases as the price of water rises and surface supplies diminish.
Since 1914, water agencies, landowners, and local governments have generally held that the state does not have a role in the management of groundwater pumping and groundwater rights, and other than taking steps to encourage and occasionally force local agencies to provide more oversight and management, the state has largely accepted its limited role.
The current drought and subsequent overdraft problems are changing this view.
As recently as 2010, the Association of California Water Agencies (ACWA) declared that, “the one-size-fits-all approach of statewide regulation would be counterproductive.”iv But ACWA has backed off that language and earlier this year released a list of recommendations for “Improving Groundwater Sustainability,” that included the recommendation for “new uniform requirements for groundwater management planning and performance reporting.”v In addition, the recommendations suggested, “new state administrative measures to ensure local groundwater management accountability,” where previously, the association suggested that “local expertise and direct reliance on the resource ensures immediate response to problems and trends, and provides the strongest basis for collaborative regional approaches.”
Additionally, the California Water Foundation recently released a report on the need for more state oversight of groundwater that included a recommendation for “clear and meaningful state roles… needed to protect state interests.”vi The steering committee of stakeholders for this report included representatives from local governments, local water agencies, and agriculture, all traditional opponents of further state oversight of groundwater.
The writing is clearly on the wall for reform of our groundwater management system at the state level and to date, two bills have emerged that appear to be the primary vehicles for any such change. SB 1168 (Pavley) is the Senate vehicle that is rumored to eventually implement the changes called for by the California Water Foundation, while AB 1739 (Dickinson) contains some provisions similar to those called for in the ACWA recommendations. AB 1739 would currently go so far as to impose a development moratorium on local agencies that do not establish groundwater management plans, which was not called for in the ACWA recommendations.
Just last week, the Brown administration released proposed language that, in addition to other things, would implement a groundwater management “backstop” when local action has not occurred or has been insufficient. There may be an effort to put this language into a trailer bill and/or make any renegotiated bond passage contingent upon its enactment.
The concern over a rushed proposal has, in recent days, forced the agriculture and water supply communities to rethink the issue with concerns now being expressed from the Western Growers Association and the California Farm Bureau Federation, among other agricultural water users. These organizations are now rightly concerned that legislation rushed through the process with little opportunity for public input would be a recipe for disaster.
These groups also contend that we cannot look at the groundwater crisis in a vacuum. There is a reason that groundwater is being pumped at unsustainable rates. The state has simply outgrown its water system. It is no longer capable of serving the needs of 38 million people and the ever-expanding list of environmental regulations. We cannot look to regulate groundwater without addressing the larger issue of overall water supply reliability as the two are very directly related.
The Real Problem
As previously indicated, the last time the state of California had a groundwater overdraft problem was prior to the construction of the State and Central Valley water projects. Once these projects provided a reliable supply of water to the Central Valley communities and agriculture, the need for groundwater pumping was reduced and the aquifers were able to recover quite dramatically in the 1970’s. In some places the aquifers recovered as much as 200 feet.vii Now, due to increased demand, drought, and environmental regulations that have reduced surface water deliveries significantly, the overdraft problem is again upon us. While more state management over groundwater could help us avoid further problems on a temporary basis within some overused basins, it won’t ultimately address the underlying problem.
Not only does a reliable surface water supply help preclude groundwater pumping and overdraft, but the surface water itself can help recharge the aquifer as water percolates and replenishes the groundwater basin. Agricultural conservation measures in the Central Valley are both a mandate and a necessity for farmers, as the cost of water increases have actually contributed to a lack of groundwater recharge and in essence exacerbated the problem. Drip irrigation can be highly efficient and deliver water to crops in a very targeted manner, but the lack of any runoff can significantly reduce groundwater recharge.
Principles For Any State Oversight Of Groundwater
While the question of whether to more closely regulate groundwater at the state level may be a foregone conclusion given the various legislative proposals, with the mounting support, and the administration’s actions, lawmakers should read any legislative proposal through a filter that contains the following principles:
- Overlying property rights to groundwater must be maintained.
- Development (commercial, industrial, or agricultural) proposals should not be subject to completed and certified groundwater management plans as these plan may take years to adopt at great expense.
- New groundwater mandates and any potential future role for the state should be limited to those areas with the greatest need and potential for negative impact to long-term resources.
- The definition of “sustainable yield” must be as specific as possible, lacking any vagueness that could be subject to creative interpretation by state officials.
- A comprehensive plan that includes the addition of surface storage development and groundwater recharge must be discussed as part of the solution.
- Any state authority or oversight needs to include clear goals and targets that once attained would reestablish local authority.
And this list doesn’t include anything about how the state oversight and management should or could be funded, another very important consideration for lawmakers.
The attitudes toward more state management of groundwater have evolved substantially with the concern over groundwater overdraft which this latest drought has exacerbated. But more state oversight of groundwater needs to be carefully considered, open to public input, and must involve a discussion of more comprehensive water supply needs for California.
i Water Education Foundation, “Laypersons Guide to Groundwater”, page 2
ii Water Education Foundation, “Laypersons Guide to Groundwater”, Glossary, page 3
iii San Joaquin Valley, Largest human alteration of the Earth’s surface, Devin Galloway and Francis S. Riley, USGS
vii San Joaquin Valley, Largest human alteration of the Earth’s surface, Devin Galloway and Francis S. Riley, USGS
For more information on this report or other Natural Resources & Water issues, contact Todd Moffitt, Senate Republican Office of Policy at 916/651-1501.