Healthy groundwater?

September 12, 2020 by Fred Allebach

Sonoma Valley has a Groundwater Sustainability Agency (GSA) that is working to produce a Groundwater Sustainability Plan (GSP) by January 1, 2022. The GSA is a Joint Powers Authority (JPA) agency made up of the Sonoma County, the City of Sonoma, Sonoma Water, Valley of the Moon, Water District, North Bay Water District, and the Sonoma Resource Conservation District.   

The GSA process was mandated by state law in 2015, by the Sustainable Groundwater Management Act, or SGMA. Sonoma Valley is a SGMA-defined high priority groundwater basin for multiple reasons, large dependence on groundwater, possible seawater intrusion, and that in some areas, withdrawals are exceeding recharge.

This GSA work has a lot of acronyms and interested members of the public have to master them.

 Dr. Thomas Harter, Robert M. Hagan Endowed Chair for Water Resources Management and Policy at the University of California, Davis, uses a bodily-health metaphor for understanding groundwater policy. This metaphor is helpful to conceptualize what the local GSP process is doing. Sustainability and health have a lot of cross-over meaning.

In Harter’s metaphor, groundwater “health” is looked at through the frame of six Sustainable Management Criteria or SMC indicators. Each indicator assesses groundwater health through Measurable Objectives (MOs), Undesirable Results (URs), and Minimum Thresholds (MTs.)

Being at an MO means being healthy, where you want to be. URs indicate a problem, maybe reversible with supply enhancement or demand reduction. If you cross the MT, that means you are critically ill and need to go to the emergency room.

The six sustainability indicators are: groundwater levels, groundwater storage, land subsidence, seawater intrusion, groundwater quality, and interconnected surface water. Each of the six indicators addresses a potential “health problem” and each has a thermometer with an acceptable operating range to show if there is trouble or not.

Harter says, “…it is important that stakeholders and GSAs come to an agreement over what they consider “healthy” (“measurable objective” in SGMA language), and what is not tolerable (“significant and unreasonable undesirable results). The latter sets the “minimum threshold” in SGMA language… the GSP is how we measure and evaluate the “health” of our basins.” 

 When unhealthy conditions arise, negative signs and symptoms trigger a decision-making process. Is it a slight problem or big? What type of problem? Trying to be healthy, we plan for and hope that the Undesirable Results are still reversible and health can be restored. For the Sonoma groundwater basin, health means that there will be a  sustainable yield of groundwater for all beneficial users into the future. The GSP has a 50-year planning horizon.

To assess health, doctors use tools, methods, and evidence, and they draw these together with multiple lines of questioning to figure out what to do if there’s a problem. This is a science-based process. The GSA Advisory Committee receives detailed staff presentations and suggestions, and with staff guidance gives advice to the GSA Board of Directors (one from each JPA member agency) , which then decides what actions to take based on the best objective evidence, plus other factors such as feasibility, constituent preferences, cost, and access to funds.  

Restoring health has two basic pathways for groundwater: supply enhancement and/or demand reduction. Need to cut back on the metaphorical potato chips? The GSP will develop a Water Budget that measures and models healthy “caloric” groundwater input and output. Then, management options and possible projects will be considered. If you don’t have insurance or the money for expensive treatments, you may have to be disciplined and do the best you can on your own. Or if you really like chips, maybe you decide for a threshold that allows more.

If we as groundwater basin stakeholders fail to take effective measures to restore health (keep a sustainable yield), if we haven’t had a robust enough plan to address our issues, then things could go bad. Minimum Thresholds would be exceeded and it’s time to go to the emergency room.

The “emergency room” is when the state Department of Water Resources steps in to take over. No more local control. The state will set limits and assess fees to pay for them. (Similar state intervention happens when housing gets to “unhealthy” levels.   

In a groundwater basin we are also dealing with society, a collective situation where all are in together. One person’s choices affect others. Individuals may have the right to destroy their own bodies through unhealthy eating choices, but they don’t have the right to drag the rest down with them, with costs that all must bear. This is where GSAs arrive at tensions between private property rights and a reasonable expectation by the public for protection of the groundwater common pool resource. 

If voluntary cooperation can’t manage or reduce groundwater demand, then mandatory cooperation (regulation) must come in, to set limits on how individual choices affect the groundwater sustainable yield into the future.

The local control granted by SGMA in crafting the GSP is our chance to agree on what basin groundwater health should be. The GSP is the basin’s health and insurance plan, where all stakeholders must make a shared agreement that accounts for our individual and collective groundwater health interests.

Fred Allebach is Chair of the Sonoma Valley Groundwater Sustainability Agency Advisory Committee