The state’s 2014 Sustainable Groundwater Management Act takes a big step in protecting ecosystems that depend on groundwater, but now the hard work of incorporating that mandate into sustainability plans begins.

When California passed its landmark groundwater law in 2014, there was a collective “it’s about time” across the West. But even though California may have been late in issuing a robust groundwater management law, it does set a high bar in at least one key area.

“In regards to the environment, it is actually quite progressive in that it actually explicitly mentions that groundwater-dependent ecosystems need to be identified and there can’t be impacts to them,” said Melissa Rohde, a groundwater scientist at The Nature Conservancy.

If you’re not quite sure what a groundwater-dependent ecosystem (GDE) is, you’re not alone. Many newly formed groundwater sustainability agencies that have resulted from California’s Sustainable Groundwater Management Act (SGMA) are also just figuring that out.

GDEs are any plant or animal communities that need at least some groundwater to survive. Across California, GDEs include diverse ecosystems such as seasonal wetlands in the Central Valley, palm oases in the desert, riparian forests and coastal estuaries.

They often serve important ecosystem functions like reducing flood risk, sequestering carbon, providing wildlife habitat and food and improving water quality. But too much groundwater pumping can damage or destroy GDEs, which can be bad for both wildlife and humans.

So as groundwater sustainability agencies in California are now tasked with writing their required groundwater sustainability plans as part of the implementation of SGMA, they need to consider the impacts of groundwater pumping on “beneficial users” of groundwater. Under SGMA, GDEs are one of those users.

But despite this inclusion of GDEs in the law, “There’s the chance that people might overlook it or downplay the importance of it,” said Rohde. To counter that, The Nature Conservancy has been working to provide a suite of resources to help groundwater sustainability agencies, including highlighting some on-the-ground examples of what’s working when it comes to trying to manage groundwater to protect GDEs.

Laying the Groundwork

One of the first things groundwater sustainability agencies need to do is identify where in their groundwater basins they have GDEs. So, The Nature Conservancy has worked in partnership with California’s Department of Water Resources to develop a database to inventory GDE locations. “It’s a starting point,” Rohde said of the database. Groundwater sustainability agencies will then “have to use local hydrologic knowledge to groundtruth the mapped ecosystems in the dataset and also fill in any missing gaps to create a basin GDE map.”

The database, Rohde said, found 2.2 million acres of likely GDEs across California, half of which are in desert subbasins. GDEs in desert areas are some of the most vulnerable, she said, because overpumping of even a single well could draw down a desert spring that provides critical water and habitat for wildlife.

One of the reasons protecting GDEs is such an important part of SGMA is that we don’t have many of them left. The state has lost around 95 percent of its historic wetlands. Much of the remaining wetland and riparian habitat is highly fragmented. A number of native fish species are being pushed toward extinction.

“We’re really at this tipping point,” said Rohde, “where what’s left is just hanging on and SGMA gives us the opportunity to not head down that decline and instead to protect these really important ecosystems that make California the great state that it is.”

She acknowledged that writing groundwater sustainability plans is a big deal and “these agencies have a huge task in front of them,” she said. “I have a lot of faith that they are going to pull through, and we want to make this as easy and straightforward as possible so ecosystems are not left out of the equation.”

The Nature Conservancy also has created the Groundwater Resource Hub and a guidance document to help groundwater sustainability agencies identify potential impacts to GDEs from groundwater pumping.

“We recognize that a lot of groundwater agencies have to communicate the importance of these ecosystems to their constituents, and so we have educational materials about what GDEs are, why they are important, how groundwater pumping impacts them and also what SGMA requires of agencies,” said Rohde.

The resources include information on how to incorporate GDEs into a biological and water quality monitoring network, and how to create a management plan that protects and improves GDEs.

Already there are a few places in the state where efforts are being made to include environmental representatives in the planning process to create groundwater sustainability plans. That could make a big difference in adequately planning for GDE impacts, said Rohde.

For example, Fox Canyon Groundwater Management Agency in Ventura County, which is preparing groundwater sustainability plans for three groundwater basins, has a seven-member technical advisory group that includes a representative with environmental expertise. And the six other groundwater sustainability agencies in Ventura County have all included environmental representatives on their governing boards.

“Now the environment has a voice at the table when decisions are being made about what thresholds are appropriate or not,” she said.

Fox Canyon has completed a draft of its groundwater sustainability plan, and has used the state’s dataset and The Nature Conservancy’s guidance document to help incorporate GDEs into its plans, said Rohde.

When it comes to resources, though, there’s still more work to do in one really crucial part of the process: determining which biological and hydrological thresholds need to be set to keep the various plant and animal communities in GDEs thriving. “The holy grail of all of this,” said Rohde, “would be to be able to give [groundwater agencies] threshold numbers, so that they can focus on management activities to sustain that.”

Sustainability in Action

Since groundwater sustainability agencies haven’t yet finished writing and implementing their plans, there aren’t a lot of examples to point to in California where there’s been active management of groundwater-dependent ecosystems. But the Owens Valley in the Eastern Sierra Nevada is one.

The valley’s water was infamously first taken by Los Angeles a century ago. But in the 1960s, when L.A. began to construct a second aqueduct, which would be filled in part by increased pumping of groundwater from the Owens Valley, a multidecade legal struggle ensued. The end result was the Inyo-L.A. water agreement in 1990, a court order that limits how L.A. is able to exercise its water rights in the valley, explained Bob Harrington, water director for Inyo County.

While many groundwater settlements usually dole out strict pumping numbers for the parties involved, this one instead focused on avoiding undesirable ecosystem impacts – much the same way that SGMA now requires of California groundwater users, which makes the work that’s been done in Owens Valley a useful example for groundwater sustainability agencies.

“The desirable component of the agreement is that it doesn’t set a pumping number, it sets an environmental condition that’s desirable,” explained Harrington. “And then you work from there to discover what that pumping number is, and it varies from year to year based on water availability to maintain those desirable conditions.”

The arrangement means more involved monitoring, but without the agreement in place, the Owens Valley would be much drier and dustier. “The water agreement has been a really significant thing in maintaining the valley in some state of greenness,” he said. If pumping had continued at the same pace or even likely increased, “We would have seen a lot of significant effects to groundwater-dependent meadows and shrub communities on the valley floor,” said Harrington. “These would be a dust emissions problem. That would have been a pretty sad state for the valley.”

One piece of advice Harrington has for those starting out in this process with groundwater management is to have a process in place for how your plan is going to be updated in the future after you’ve been implementing it and gathering data on the impacts for a few years.

“Some people will be happier than others, and you’re going to want to have a framework for resolving disputes and you’re going to want to have a commitment to revising the plan,” he said. “You are going to want to improve your management based on that accumulation of data, so you’ll need to think about your process for doing that and have agreement on how that will occur.”

The Owens Valley groundwater basin has the second largest area of GDEs in the state.

“If everyone had started monitoring groundwater-dependent vegetation and setting thresholds in the 90s, maybe we’d have a lot more [GDEs],” said Rohde. “But it gives me hope [for what SGMA can do].”