SUSTAINABLE CONSERVATION: Protecting Water Quality While Recharging Aquifers

Over 600,000 Californians rely on nitrate-contaminated public supply wells for their household water needs.  However, those numbers are even greater as they don’t include the many others who struggle with contaminated groundwater from domestic wells.  Balancing long-term groundwater sustainability and water quality will help California weather future droughts, ensure safe drinking water, and support our thriving agricultural community that feeds the nation.

One tool for groundwater sustainability is groundwater recharge, where water is intentionally spread on the ground and allowed to infiltrate into the underlying aquifer.  However, there is much concern that groundwater recharge can increase water quality issues, especially when the recharge water is spread upon agricultural lands.

In November of 2021, Sustainable Conservation held a webinar featuring a panel of experts who discussed how California can work to replenish our aquifers while protecting water quality for the health of our communities.

Click here to read this post.

The deceptively simple plan to replenish California’s groundwater

From National Geographic:

From afar, the rows of knobby grapevines blend into the landscape of pink-blossomed almond trees and fragrant citrus. But get up close and you’ll see something strange: The trunks of the vines are standing in several inches of glistening, precious water. 

These grapes, at the Kearney Agricultural Research Center in California’s San Joaquin Valley, are part of a grand experiment that many hope will help solve the state’s deepening water crisis. Here, in the state that provides some 40 percent of all the fresh produce grown in the United States, a 20-year-long drought has left growers and communities desperately short of water. To make up the persistent shortfall from rain and snow, they are pumping groundwater—and doing so far faster than water can trickle down from the surface to replenish underground aquifers. … ”

Read the full story at National Geographic here (note: registration required): The deceptively simple plan to replenish California’s groundwater

California Spent Decades Trying to Keep Central Valley Floods at Bay. Now It Looks to Welcome Them Back

Land and waterway managers labored hard over the course of a century to control California’s unruly rivers by building dams and levees to slow and contain their water. Now, farmers, environmentalists and agencies are undoing some of that work as part of an accelerating campaign to restore the state’s major floodplains.

Click here to read this article from Western Water.

PPIC: Creating Collaborative Recharge Partnerships in the San Joaquin Valley

Bringing the San Joaquin Valley’s groundwater basins into balance by the early 2040s is going to be challenging, but two neighboring groundwater sustainability agencies (GSAs) in Madera County are collaborating to move the process forward.

The PPIC spoke with one engineering consultant and one general manager—Joe Hopkins of Aliso Water District Groundwater Sustainability Agency and Sarah Woolf of the Triangle T Water District—to hear about their agencies’ efforts to comply with the 2014 Sustainable Groundwater Management Act (SGMA).

Click here to read this article from the PPIC.

PPIC FACT SHEET: Groundwater Recharge

Groundwater recharge is an important water management practice in California.

  • Recharge occurs when water seeps into the ground to replenish underground aquifers. Although some recharge happens incidentally—water flowing into the ground from rivers, unlined canals, or excess irrigation—intentional recharge can restore groundwater levels and store water for later use.
  • In coastal areas, intentional recharge prevents salty ocean water from entering freshwater aquifers. Recharge can also help prevent impacts from groundwater pumping, such as dry wells or sinking lands, while providing wetland habitat for birds, reducing flood risk, and storing water for droughts.
  • Active recharge is a longstanding practice in much of urban Southern California and parts of the Bay Area, Central Coast, and Central Valley.

Click here for the fact sheet in English from PPICHaga clic aquí para ver la hoja informativa en español de PPIC.

Sustainable Conservation Releases Key Water Quality Guidance for On-Farm Recharge

From Sustainable Conservation:

Sustainable Conservation, a San Francisco- and Modesto-based non-profit, has developed two key resources to inform on-farm recharge practices that are protective of water quality.

Protecting Water Quality

Over 600,000 Californians rely on nitrate-contaminated public supply wells for their household water needs. Many others struggle with contaminated groundwater from private, domestic wells – so the numbers are even greater. Recharging groundwater with water quality as a top priority will help the San Joaquin Valley – our nation’s premier farming region – manage through California’s inevitable droughts, ensure safe drinking water for farm-adjacent communities, and support a thriving agricultural economy as the region complies with the Sustainable Groundwater Management Act.

Achieving Groundwater Sustainability

Conceived in coordination with a diverse group of stakeholders and supported by a committee of San Joaquin Valley leaders, our nitrate management brief and water quality research paper compile the best available science with Sustainable Conservation’s decade-plus of on-the-ground experience with groundwater recharge. Replenishing aquifers by allowing surface water to seep into the ground has great potential to help water managers and agricultural communities achieve groundwater sustainability. However, when recharging on farm fields – a practice known in water management circles as Agricultural Managed Aquifer Recharge (AgMAR) – the potential mobilization of nitrate and salts is a serious concern, and this guidance suite presents field- and regional-scale considerations to protect community water quality.

Sustainable Conservation will share its new guidance widely with growers, water managers, community organizers, and our broader audience of friends and supporters through our various events, webinars, and publications. For all media inquiries, please contact Christa Harader, Sustainable Conservation Digital Content Producer. If you need technical assistance or would like to request a small group presentation for your community or organization, please contact Taylor Broadhead, Sustainable Conservation Water and Dairies Project Manager.

Click here to read the full press release.

PPIC Fact Sheet: Groundwater Recharge

Groundwater recharge is an important water management practice in California.

    • Recharge occurs when water seeps into the ground to replenish underground aquifers. Although some recharge happens incidentally—water flowing into the ground from rivers, unlined canals, or excess irrigation—intentional recharge can restore groundwater levels and store water for later use.
    • In coastal areas, intentional recharge prevents salty ocean water from entering freshwater aquifers. Recharge can also help prevent impacts from groundwater pumping, such as dry wells or sinking lands, while providing wetland habitat for birds, reducing flood risk, and storing water for droughts.
    • Active recharge is a longstanding practice in much of urban Southern California and parts of the Bay Area, Central Coast, and Central Valley.

Click here to view/download fact sheetTambién disponible en español.

Ancient River Channels Could Speed Groundwater Recharge

By the time California finally began regulating groundwater use in 2014, most of the San Joaquin Valley was in critical overdraft. The Public Policy Institute of California estimates that groundwater pumping in the region has exceeded replenishment by an average of 1.8 million acre-feet per year over the last few decades. This imbalance was even worse during our last drought, when overuse shot up to 2.4 million acre-feet per year.

Overpumping puts groundwater aquifers at risk of compaction, permanently reducing their water storage capacity and making surface lands sink. Now, however, San Joaquin Valley groundwater managers must find and implement a fix. The state’s Sustainable Groundwater Management Act mandates balancing the region’s pumping with replenishment by 2040.

Managed aquifer recharge — diverting excess flood water so it can soak into the ground — is an obvious remedy. But accelerating recharge in the San Joaquin Valley is easier said than done. “Recharge is slow in silt and clay, and these are ubiquitous across the Central Valley,” explains Graham Fogg, an emeritus hydrogeologist at UC Davis.

Fogg and colleagues have found a new way to speed recharge in the Central Valley: ancient river channels where water can shoot underground.

Click here to continue reading this article at Estuary News.

Click here to visit the Groundwater Exchange’s news page.

Stanford scientists offer a new way to identify ‘sweet spots’ for managed aquifer recharge

Amid a rapidly worsening drought and a California mandate to bring aquifer withdrawals and deposits into balance by 2040, there’s now growing urgency to better understand the hidden structures of groundwater basins.

One possible solution to balancing the aquifer water budget involves strategically flooding a field, orchard or dedicated recharge pond and letting the water seep down through sandy channels. In research published earlier this month in Vadose Zone Journal, Knight and postdoctoral scholar Meredith Goebel demonstrate a new way to assess sites for this type of managed aquifer recharge using soil measurements and a geophysical system towed by an all-terrain vehicle.

Click here to read this article from Stanford News.

Advancing Flood-MAR: What are the possibilities?

Dr. Graham Fogg and DWR’s Jenny Marr discuss the efforts underway to assess the potential for Flood Managed Aquifer Recharge (or Flood MAR)

At the April meeting of the California Water Commission, the Commission continued examining the state’s role in conveyance projects by hearing from two experts on flood-managed aquifer recharge, or Flood MAR.  First, Dr. Graham Fogg, UC David professor emeritus of Hydrogeology, discussed scaling up Flood MAR and how that will likely present new conveyance needs.  Then, Jenny Marr, Supervising Engineer at the Department of Water Resources, outlined the state’s approach to flood Mar.

GRAHAM FOGG: Flood-MAR Perspective: American-Cosumnes Basin Experience

Dr. Graham Fogg’s presentation gave the big picture perspective on Flood MAR and highlighted a case study underway in the American-Cosumnes basin as part of a UC Water initiative since 2014.

He began by pointing out California is not alone in having groundwater problems.  Groundwater depletion is a global problem. Depleted aquifers are being increasingly written about all over the world. In some cases, it’s becoming an existential crisis in water security.

Why is that? Dr. Fogg noted that since we’ve been developing groundwater, which has only in the last 50-70 years at high amounts, we’ve concentrated mainly on pumping it.

Typically, we pump the groundwater and hope for the best,” he said.  “The alternative in terms of managing it, now we can pump groundwater, is that we can also do things that increase the groundwater storage; we can replenish the groundwater. So one way to look at it is we’ve worked a lot harder in the last 50 years or so in pumping groundwater than we have in replenishing it.”

Click here to continue reading at Maven’s Notebook.