Persistent drought and rising temperatures only continue to threaten groundwater supplies
TULARE COUNTY – As California’s groundwater aquifers continue to deplete at what experts consider to be an alarming rate, the state passed a comprehensive groundwater management law in 2014 that is changing how this precious resource is used for the next 20 years and beyond.
Under the law, the state established groundwater sustainability agencies, which are tasked with drafting extensive plans on managing groundwater for their designated water basins. The Greater Kaweah Groundwater Sustainability Agency (GSA), which is one of three for the Kaweah subbasin, covers most of the subbasin throughout Tulare and Kings counties.
Greater Kaweah GSA has received a handful of comments on its plan since it was released to the public in September, most of them inquiring about the technical parts of groundwater management. But one comment struck at a concern for many: What actions does the GSA plan to take to address the realities of climate change?
Eric Osterling, the general manager for the Greater Kaweah GSA, said the key to addressing climate change for the next two decades is multi-benefit partnerships that involve groundwater management agencies, nonprofits, grant funding and landowner cooperation. The plan also includes projections extending to 2070.
The Greater-Kaweah GSA released its draft plan for sustainable groundwater management on Sept. 16. The plan is one of many throughout California that will determine how groundwater is managed in the state under the Sustainable Groundwater Management Act (SGMA).
SMGA was signed by then-Gov. Jerry Brown to address the failures in groundwater management during California’s recent drought. The law established the first framework for sustainable groundwater management in the state’s history.
The public can comment on the draft until Dec. 16. At which point, the GSA will edit the plan before sending a final version to the state by Jan. 31, 2020.
Carole Combs, the executive director of the Tulare Basin Watershed Partnership, sent in the question to Greater Kaweah asking about climate change.
The effects climate change has on groundwater supplies are extensive and varied. Longer periods of drought, for example, mean surface water supplies, like canals and dams, are drained and groundwater is expected to make up the difference. However, this dependency means aquifers are harder to access and supplies are limited.
The San Joaquin Valley, in particular, has long relied on a consistent snow melt from the Sierra Nevadas. But higher temperatures and fewer snow days have made that water supply less reliable, so the Valley depends on groundwater supplies more than ever.
Combs, whose organization has a seat on the GSA’s advisory committee, asked in an email where in Greater Kaweah’s Groundwater Sustainability Plan (GSP) there is an “in-depth treatment/assessment of [Greater Kaweah] GSA climate change vulnerability and perspectives/options regarding potential adaptive or mitigating actions to provide resilience needed for real sustainability over time.”
Osterling said, under SGMA, GSAs are required to include a projected 50-year hydrology, which essentially means anticipating how groundwater will behave during that time period. That projection must anticipate any scenario where climate change will impact groundwater and access to the resource.
Over time, climate change estimates will be updated and replaced with actual data as the plan’s model continues to be implemented. In the near future, changes in supply and demand due to climate change will be fairly subtle, Osterling said.
Climate change mitigation, meaning actively reducing the impacts of global warming, is not required by SGMA, Osterling said. However, Greater Kaweah does include plans to partner with organizations to alleviate climate change’s effects and to seek funding for projects that would protect ecosystems.
Such partnerships would seek plans that’d benefit the GSA, local nonprofits and landowners, which could include maintaining soil health and protecting wildlife and its environment. The California Department of Fish and Wildlife, for example, offers such grants to protect ecosystems and mitigate climate change.
“We are looking for multi-benefit projects in management actions, and if a particular piece of property that we are converting the land use of can be converted for habitat mitigation banking or other restoration purposes that would make us eligible for grant funding,” Osterling said. “That’s of course something I think the GSA should be supportive of and work with our partners.”
After she heard this explanation from Osterling, Combs said she felt the GSA is meeting the standards she expects for addressing climate change, as are the other GSAs she’s asked. At an Oct. 28 meeting for Greater Kaweah GSA stakeholders, Combs addressed her comment and said her organization will encourage projects aimed at mitigating climate change.
“I re-stated the question previously posed to Eric and stated that the Tulare Basin Watershed Partnership (TBWP) will encourage multi-benefit projects that include ecosystem resilience components wherever feasible going forward to advance regional climate change adaptation,” Combs said.
Aside from Combs’ comment, Osterling said the GSA received a letter from the Tulare County Farm Bureau that was also sent to the Mid-Kaweah and East-Kaweah GSAs, the other two agencies in charge of the subbasin’s groundwater. He said Greater Kaweah had already addressed the issues the Farm Bureau brought up in the letter.
The letter asked that the GSA’s plan is a “fluid, living, breathing, adaptive document” that would allow for the agency to maximize water resources for farm and rural communities, protect agriculture land from fallowing (meaning retirement from ag use), incentivize groundwater recharging and educate growers and landowners throughout implementation.
Karen Yohannes, who Osterling said has been an active voice throughout Greater Kaweah’s plan development, brought up two points in her comment: allocations for seepage (how water returns to groundwater wells) and concerns about enacting a voluntary water market.
Water markets are exactly what they sound like: Groundwater users would be able to buy and sell water allocations on a platform managed by an agency, whether it’s a GSA or an irrigation district. While GSAs are empowered under SGMA to establish these markets, it’s a controversial option and one that Osterling said his GSA is cautious about pursuing.
Del Strange submitted a comment asking that Greater Kaweah seriously considers and understands subsidence, which occurs when a groundwater aquifer has been over-pumped to the point that it’s overall storage capacity is lessened. Osterling ensured that subsidence is thoroughly addressed throughout the GSA’s report.
Osterling said he is also paying close attention to the comments sent to the other Kaweah agencies since many of the concerns they might receive could impact Greater Kaweah’s plan.