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The Perils of Over-Pumping Groundwater

March 2014

The perils of over-pumping groundwater were the focus of a panel of five state and local water experts convened by the Delta Stewardship Council (Council) at its Feb. 27 meeting. The problem has become pervasive during the State’s current drought conditions as groundwater has become an important substitute for a lack of surface supplies, including diversions from the Delta.

The depletion of underground aquifers is known as “overdrafting.” The practice is known to cause land to subside, or sink, causing serious damage to roads, railways, canals, and other above and underground infrastructure. The subsidence can also lead to irreparable damage to the aquifers. As they collapse, those portions are unable to further collect and hold water.

“We’re seeing subsidence ranging from a half inch a year to a foot a year,” said Michelle Sneed, a hydrologist with the U.S. Geological Society (USGS).

One of the panel members, Sneed laid out the problem squarely when she told the Council about the conclusions of a USGS report entitled Land Subsidence along the Delta-Mendota Canal. Using a Power Point presentation, she said about 1,200 square miles in the northern part of the San Joaquin Valley have been affected by land subsidence. In some areas the land has sunk five feet between 2008 and 2013 alone.

“Subsidence is occurring from Merced on the north to Mendota on the south and from Interstate 5 on the west to Highway 99 on the east,” Sneed said.

The issue is discussed in length in the Council’s recently adopted Delta Plan, which includes four recommendations aimed at state and local agencies to improve groundwater management. If implemented the recommendations are designed to help mitigate the overdraft problem thereby furthering a more reliable water supply for California – one of the state’s coequal goals.

Among the Delta Plan recommendations is:

WR R9 – Update Bulletin 118, California’s Groundwater Plan. The recommendation says this Department of Water Resources (DWR) document should include, among other things, a systematic evaluation of major groundwater basins to determine sustainable yield and overdraft status.

“Bulletin 118 hasn’t been updated since 2003,” said panel member Mary Scruggs, a supervising engineering geologist with DWR. Her presentation illustrated for the Council how DWR is complying with WR R9. “We need to promote more public education, improve the sharing of information, and develop guidelines to develop better groundwater management plans.”

Another Delta Plan recommendation is:

WR R10 – Implement Groundwater Management Plans in Areas that Receive Water from the Delta Watershed. This recommendation says that water suppliers who receive water from the Delta watershed and that obtain a significant percentage of their long-term average water supplies from groundwater sources should develop and implement sustainable groundwater management plans that are consistent with both the required and recommended components of local groundwater management plans identified by DWR Bulletin 118.

A 1903 California Supreme Court decision allows overlying land owners to extract groundwater without a permit – as long as the pumping is considered “reasonable and beneficial” per the State Constitution. Although some groundwater basins have water rights set by the courts (adjudicated) and others are managed by public agencies, most are unregulated with myriad management plans that all the panelists said are sometimes closely guarded.

“There are silos of information in the community, whether they’re in public hands or in private sources, that are hard to get to,” said panel member Walt Ward, Water Resources Manager for Stanislaus County. “There are institutional barriers and confidentiality protections where people are really hesitant to share their information.”

In his presentation, Ward showed the Council how he is going to “try and break that” cycle with the formation of a county-based water advisory committee comprised of public agency and private industry (ag and urban) representatives. Within the next hundred days he hopes to map all of the county’s wells, standardize how the wells are measured in size, obtain their pumping data, and determine how pumping stressors are affecting the aquifers.

“Each entity seems to have its own standard, cookie-cutter, kind of groundwater management plan,” said Ward. “What I want to do is take all of those plans and synthesize them into one county-wide plan.”

Council member Frank Damrell praised the idea. “It could be very dramatic if every county had a similar advisory group that took into account all the cities and communities and cultural interests and promoted exactly what the County of Stanislaus is doing.”

A third Delta Plan recommendation is:

WR R11 – Recover and Manage Critically Overdrafted Groundwater Basins. This recommendation says the State Water Resources Control Board (Board) should take action if local and regional agencies with groundwater basins identified as being in critical condition of overdraft don’t develop and implement a sustainable groundwater management plan by the end of this year. The Board’s action could include an attempt at preventing the destruction of, or irreparable injury to, the quality of the groundwater through actions such as adjudication, where a court steps in and issues a decree.

“Adjudication offers some stabilization and assurances about what everyone’s rights are, but getting there usually requires civil litigation, which can be quite cumbersome,” said panel member Andrew Fahlund, a deputy director at the California Water Foundation (CWF).

The CWF is a non-profit organization that supports innovative projects and policies that address water challenges by bringing together experts, stakeholders, and the public to achieve long-term, science-based solutions. It will hold groundwater workshops designed to elicit ideas that in turn will hopefully produce policy proposals for the Brown Administration and the Legislature.

“I don’t think that a purely voluntary program is going to deal with the spectrum of groundwater problems that exist,” said Fahlund. “So, before we reach a level of conflict, we should ask if there is a better way to reach peace among parties.”

The final Delta Plan groundwater recommendation is:

WQ R6 – Protect Groundwater Beneficial Uses. This recommendation says the Board should complete development of a strategic work plan for protection of groundwater beneficial uses, including groundwater use for drinking water.

As aquifers are stressed from depletion, the possibility of extracting non-potable water increases. Without uniform statewide guidelines and/or regulations, the possibility of people drinking contaminated water increases as well.

Panel member Eric Oppenheimer, a Director with the Board’s Office of Research, Planning and Performance, used a Power Point presentation to update the Council on the Board’s development of a concept paper for an overall strategic work plan, and to demonstrate the severity of contaminated wells throughout the state.

“The most commonly detected contaminant in our 10 years of analysis was arsenic, which is naturally occurring,” said Oppenheimer. “Our quality challenges also include nitrates from farming sources, wastewater sources, and, of course, naturally occurring contaminants.” Some key concepts include:

• The Board does not have the resources to solve the entire groundwater problem.
• Local and regional agencies have many of the tools and authorities needed for effective management.
• When local and regional agencies are not successful, the State should play a supporting role and provide a backstop if action is needed.

Following the almost two hours of presentations, the Council queried the panelists. A few also offered commentary, such as Council member Larry Ruhstaller.

“I just think we need to stop talking and start doing something – and that means what Stanislaus County is doing is what other counties should be doing,” said Council member Ruhstaller. “Otherwise all we’re going to have is a lot of nice plans that just sit on the shelf the minute the rains start again.”

Coequal goals

The Delta Stewardship Council was created in legislation to achieve the state mandated coequal goals for the Delta. "'Coequal goals' means the two goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem. The coequal goals shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place." (CA Water Code §85054)