CA Department of Water Resources: Critical Basin Overdraft Report

By Sheryl Hamlin 

California’s Depart of Water Resources (DWR) has been reviewing groundwater conditions and has produced a new list of the basins exhibiting the most critical overdraft conditions. This is a draft list. DWR is taking questions and comments on the report. The list may be read here. In Ventura county, the Oxnard Basin made the list of basins in critical overdraft. When the list has finished the public hearing process, the DWR Bulletin 118 will be updated with this list.

Bulletin 118 is DWR’s comprehensive report on California groundwater including the following:

• Chapter 1: Growing reliance on one of California’s most important natural resources
• Chapter 2: Complex legal and institutional framework and the current groundwater management system
• Chapter 3: Recommendations for a model groundwater management ordinance and groundwater management plan
• Chapter 4: The effect of recent activity in the Legislature and at the ballot box
• Chapter 5: State and federal programs with a variety of objectives
• Chapter 6: Concepts and definitions for a wide audience
• Chapter 7: Basin characteristics and concerns in California’s 10 hydrologic regions

The full report may be downloaded here. Bulletin was last updated in 2003. Since then California has been in extreme drought, the Governor has issued several executive orders dealing with water and the legislature passed the Strategic Groundwater Management Act (SGMA).

The following graph shows the time period used to calculate a baseline for the overdraft condition, which is shown in the timeline. California’s water recording data is accurate since 1895 according to DWR. The baseline includes a period of time above average rainfall and a period below average rainfall.

The major criteria used to determine overdraft are shown in this chart.

There are 515 groundwater basins identified in California. Of those, 21 made the list of critical overdraft conditions. Why is this important? The new law signed in 2014 creates Groundwater Sustainability Agencies (GSA) responsible for monitoring the groundwater levels using a Groundwater Sustainability Plan (GSP) as a measuring device. Those basins deemed in critical overdraft MUST submit the GSP two years earlier than basins not in overdraft.

The GSA for the Oxnard basin is the Fox Canyon Agency. For a complete list, click here and use the keyword ‘ventura’.

Notably missing is the Santa Paula Basin, which is an adjudicated based. According to SGMA, an adjudicated basin does not need a GSA, but must still provide groundwater measurements to DWR. It is not clear who will perform that function for the Santa Paula Basin. This function is called a “watermaster” and is defined on page 14-15 of this document. The Santa Paula Basin Pumpers Association does not list its membership and shows only an address on Cummings Road near Limoneira. According to one source, the SPBP is organized as a mutual benefit corporation, so is not required to divulge its membership list or minutes. The “watermaster” must do the following by 2016:

With proposed development in several locations (East Area I, West Area I, Adams Canyon, Peck/Foothill), the actual water measurements as submitted to the State of California would be important information for decision making in the Santa Paula Basin. As it stands now, there is no transparency about groundwater levels in the Santa Paula Basin other than the report produced annually by the United Water Conservation District which appears to cover only the southern part of the county, although their Groundwater Conditions report does include the Santa Paula Basin. So, at this point, someone must step up and become the “watermaster” for the Santa Paula Basin and submit these numbers to the DWR.

To ask questions of DWR about the SGMA, email [email protected].

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