Media Corner

Central Basin Municipal Water District
The Central Basin Groundwater Storage Plan:
A Blueprint for Future Reliability

Frequently Asked Questions

Who is CBMWD and why is it doing a Groundwater Storage Plan?

Central Basin Municipal Water District (CBMWD) is a potable and recycled water provider in southeast Los Angeles County. The California Legislature passed the Municipal Water Act of 1911, which enabled the creation of CBMWD in 1952. The actual vote to create CBMWD occurred in December 1952. It passed by a "six to one majority vote to form the Central Basin Municipal Water District" (source: "The Story of Water Development in Los Angeles County" by Carl and Ruth Fossette, page 116). By 1954, CBMWD had joined the Metropolitan Water District of Southern California, in order to supplement the dangerously depleted groundwater supplies with water imported from the Colorado River and through the State Water Project. CBMWD has worked diligently to ameliorate the effects of pumping on the groundwater table by making water available for groundwater replenishment, as well as by implementing innovative conservation and recycled water programs.

As established in our Founding Act, a primary mission of our District is to promote, manage and protect the Central Groundwater Basin. CBMWD has a statutory authority and duty to undertake and accomplish this purpose. To fulfill this duty, CBMWD is developing a comprehensive and environmentally sound Groundwater Storage Plan that will maximize the storage potential for the benefit of the public.

Does CBMWD have statutory authority to undertake and manage groundwater storage?

Yes. As mentioned above, CBMWD was formed by the California Legislature under the Municipal Water District Law of 1911 (Water Code Section 71000). Under the Water Code, CBMWD can "Acquire, control, distribute, store, spread, sink, treat, purify, recycle, recapture, and salvage any water including sewage and storm waters for the beneficial use or uses of the district, its inhabitants, or the owners of rights to water in the district," (Water Code Section 71610).

What are the threats facing the Central Groundwater Basin?

CBMWD is moving forward with a groundwater storage plan because there are threats to the integrity of the Central Groundwater Basin. Namely, the Water Replenishment District (WRD)—the agency with the singular responsibility of replenishing the groundwater basin—has failed to do its job, allowing the groundwater table to decline, and allowing portions of the basin to fall to very low levels. Furthermore, WRD has rebuffed a Superior Court order by allowing groundwater storage. This will actually increase groundwater pumping and force the water table to even lower levels. The potential collapse of even a portion of the Central Groundwater Basin would be catastrophic for Southern California.

How does Central Basin’s Groundwater Storage Plan Benefit the Public?

Through this plan, Central Groundwater Basin, as a public resource, will be protected and managed in a safe and efficient way to the benefit of all residents of the region. With the plan in place, the public can remain confident that their precious groundwater supply, which retail suppliers depend on year after year to meet daily water demand, will always be there.

Background Questions

What is the Central Groundwater Basin?

The Central Groundwater Basin is a series of three large natural aquifers below the ground that stretch from Whittier to Long Beach and from Los Angeles to Orange County. The groundwater it provides is the primary drinking water supply for 2.5 million people in the region. The Basin is adjudicated, which means that a court has stipulated who can pump groundwater, and the amount of groundwater that can be pumped on an annual basis. These are called groundwater rights. Cities and agencies can pump those rights into their water supply system as long as they pay a replenishment assessment, or "RA," to the Water Replenishment District (WRD) for each acre-foot of water. WRD carries a legal responsibility to use those funds to replenish the Central Groundwater Basin.

In recent years, WRD has continued to implement the RA and even raised it by 19% in 2010, although they have only secured minimal amounts of water to replenish the Basin. Thus, while WRD now has more than $40 million in reserves, the agency has allowed the Central Groundwater Basin water levels to decline in certain areas.

Finally, pumpers in the Central Basin have long subsidized the cities and agencies in the West Coast Basin (located in the South Bay) by paying a rate disproportionately higher than the cost of service. This means that the water rates in the Central Basin are higher than they need to be in order to keep rates lower in the beach cities!

What is an "overdraft?"

An overdraft in a groundwater basin is really just over-use of the resource. If left unchecked, overdraft of a groundwater basin can cause major problems to groundwater pumpers and to the environment. The most evident problem is a lowering of the water table beyond the reach of existing wells. If a groundwater basin is overdrafted too much, a portion of the aquifer can actually collapse. According to WRD, the current groundwater level is 141,000 acre-feet below the "optimum overdraft level" the agency has established. It is important to note that this data pertains to both the Central Basin and the West Coast Basin. No data has been provided to show the actual overdraft levels for the respective Basins.