Sustainable Groundwater Management: Measurable Objectives Can Provide a Roadmap for California

September 10, 2015
Juliet Christian-Smith
Former contributor

Today, UCS is releasing Measuring What Matters: Setting Measurable Objectives to Achieve Sustainable Groundwater Management in California.

Much of the power of the Sustainable Groundwater Management Act, or SGMA (pronounced “sigma”), lies in its requirement for much greater specificity around management goals. Past groundwater management efforts have included vague goals that sounded good, but didn’t deliver. SGMA, on the other hand,  requires specific measurable objectives to avoid a series of “undesirable results,” such as the negative impacts caused by chronic lowering of groundwater levels and land subsidence. Measurable objectives are essential as it is impossible to achieve sustainability without defining what it means and how it will be measured.

Measurable objectives provide roadmap

In a previous post, I compared SGMA to a groundwater GPS, since the law requires that groundwater basins be managed with a specific destination in mind (sustainable yield) and a clear roadmap that explains how the basins will get to their destination (measurable objectives).

To understand how groundwater sustainability agencies might develop effective measurable objectives and to inform the regulations currently under development by the Department of Water Resources, the new report provides a summary of the state of knowledge and practice related to setting measurable objectives for groundwater management, finding that effective measurable objectives do the following:

  • Define clear baselines
  • Set quantitative thresholds
  • Develop protective triggers
  • Incorporate regular measurement and monitoring
  • Account for uncertainty
  • Adapt to changing conditions and new knowledge

It will be particularly important for measurable objectives to be coordinated across basins to allow for inter- and intra-basin cooperation since groundwater is a shared resource with transboundary impacts.

When a resource is shared, it is important to have clear directions to ensure people know which way to go.Shared resources can lead to “traffic jams”

When you have a shared resource like groundwater, actions must be coordinated some way to avoid one person’s actions negatively affecting another’s (see traffic jam below). That’s why, when it comes to transportation infrastructure, we have traffic signals and signs to get us going in the right direction, at the right speed, without running into one another. Similarly, when it comes to SGMA, there needs to be clear signage.

Common state framework needed

UCS convened a multi-stakeholder roundtable that concluded that the state needs to create a common framework for setting measurable objectives. In some cases, this framework may refer to existing state standards and statutes, like the Porter-Cologne Act’s anti-degradation policy. In many others, the state will need to provide clear guideposts for groundwater sustainability agencies to understand what is required to achieve sustainability.

One relevant example is minimum requirements to address land subsidence. Three weeks ago, NASA released an assessment of dramatic land subsidence throughout the Central Valley due to unprecedented levels of groundwater pumping. Like a shrinking sponge, as aquifers dry out, the land above is actually collapsing – as quickly as nearly a foot a year, in some places – and dragging important, public infrastructure down with it.

Hypothetically, without a common state framework one groundwater basin could consider current rates of land subsidence to be acceptable, while a neighboring groundwater basin could consider additional land subsidence to be unacceptable. In this case, continued land subsidence in one, could damage infrastructure in other and cause it to be out of compliance with SGMA. Thus, it would be extremely helpful if the state were to provide some signage, for instance specifying how much, if any, additional land subsidence would be considered acceptable to the state.

In my opinion, it’s hard to imagine a framework that would allow any additional land subsidence to be classified as “sustainable” given that inelastic land subsidence represents a permanent loss of groundwater storage, which is not reversible, and will therefore limit future generations.

Groundwater basins should be encouraged to develop thresholds that are more protective than minimum state standards by not penalizing ambitious basins from missing aspirational goals. This would create clarity around expectations, and ensure that neighboring basins were heading in a similar direction even if they get there at slightly different speeds.