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Sustainable Groundwater Management Act (SGMA) Update

As most of you are aware, the implementation of the Sustainable Groundwater Management Act (SGMA) is in full swing. Most of the Central Valley dairy industry is located in groundwater subbasins the California Department of Water Resources (DWR) categorizes as “critically overdrafted” (see map on next page). This means that these areas are mandated by law to produce a Groundwater Management Plan (GSP) that identifies how the area will reach sustainability by 2040. The absolute deadline for submitting these plans is January 31, 2020. Since the SGMA law requires that the public be given at least 60 days to comment on these plans before they can be submitted to DWR, and because the Groundwater Sustainability Agencies (GSAs) must respond to those comments, in reality, drafts of these plans will be available within the next few months.

I have been actively following the progress of these plans in the subbasins stretching from Kern in the south to Merced and the Eastern San Joaquin Subbasin around Stockton in the north. The Sacramento Valley is not in critical overdraft. Neither is Southern California. In the critically overdrafted Central Valley, every area has its unique situation. There is a bit of a have, and have not, situation in each of these subbasins. Those landowners who are in irrigation districts or own significant private ditch company stock are in a much better position than those areas that have no access to surface water at all. But even among those who are part of irrigation districts, some districts have lots of senior water rights and others have very little. If you have not done so yet, you need to know your farm’s situation. DWR has a very good mapping website where you can put in the address of your farm and it will tell you what GSA you are in and give you contact information for that GSA. Access DWR the site here.

The plans that GSAs are coming up with must include a water budget for their area. The native groundwater available ranges from a low of about 4 inches per year per acre in the Kern Subbasin to as much as 18 inches in the subbasins further up the Valley. Some GSAs are contemplating allocating those amounts of water to their growers right now, but in addition, allowing more pumping even though it will perpetuate the overdraft condition. The reason for this is that implementing a hard restriction on pumping would be economically devastating. Also as a practical matter, the GSAs are too new to have figured out how to actually enforce whatever rules they put in place. But change is coming and dairy farmers need to be doing things now to be prepared.

All dairy operations in the Central Valley operate under Waste Discharge Requirements issued by the Central Valley Regional Water Quality Control Board (Regional Board). These permits include a nutrient management plan, describing how a dairy operation manages its nutrients, including how they are utilized by the crops grown by the dairy. The nutrient management plans are usually pretty specific about how much farming must be done to keep the dairy in nutrient balance. Obviously it takes water in addition to the dairy’s nutrient water to grow those crops. One question each dairy operation should attempt to calculate is how much water it needs to grow the crops required by your nutrient management plan. There is a very useful tool developed by Cal Poly that can give you the amount of water each crop will consume. The term used to describe what the crop consumes is evopotranspiration or ETo for short. You can access the Cal Poly ETo website here. Crop ETo is the measurement many GSAs will be using to keep track of water consumption for agriculture in the subbasin. Since cropping decisions for a dairy also involve Regional Board permit requirements, knowing how much water you need could be important information for your GSA to know before they start imposing pumping restrictions on you. SGMA does give each area 20 years to reach sustainability. In this initial round it allows the local GSAs to set the rules. All the GSAs I am following are concerned about the economic health of their farming constituents, but reaching sustainability is a requirement that cannot be avoided – it can only be delayed. However, that delay may be critical in order to give the Subbasin an opportunity to find more surface water and come up with other alternatives that will take time to develop.

One other thing to mention is that over the next few weeks and months there may be opportunities to take advantage of flood waters running by your facilities. Very few GSAs actually have an accounting system set-up to give anyone credit for on-farm recharge. But I predict that in time most of them will. If you have a chance to grab some flood water and put it out on your land for recharge you should do it and make a good faith effort to measure and keep track of that water. If you have credible records on how much water you spread, particularly if you can match that with credible records of how much water you used on those field during the growing season, by using either ETo estimates or actual meters on your wells, you will have a good case to make someday to your local GSA that you should get some credit for the recharge activities you did this year and in the following years before they actually get their credit system up and running. Who knows, if we have a run of wet years and we can get the federal and state governments who control the big surface water projects to use some common sense, maybe we can stabilize our groundwater levels without the most severe restrictions being placed on us.

SGMA will be a tough deal for some of our producers. Getting knowledgeable about your local situation, doing your own water budgeting and tracking, and getting organized with your neighbors, particularly if you are in an area that does not have an irrigation district, are all things that that are worth doing.

The MPC Board of Directors decided early last year to make an investment in this issue. They thought that it was worth it to our members and the dairy industry to get actively involved in SGMA implementation. They gave me the privilege of carrying out that responsibility which I am honored to do. If you have any questions I can help you with, feel free to contact me at

Geoff Vanden Heuvel

Director of Regulatory and Economic Affairs

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