How Much Water Is Available for Groundwater Recharge?
From
“The wet winter of 2017 brought an opportunity to test groundwater recharge—the intentional spreading of water on fields to percolate into the aquifer—as a tool for restoring groundwater levels and helping basins comply with the Sustainable Groundwater Management Act (SGMA). This is especially important in the San Joaquin Valley, which has the biggest imbalance between groundwater pumping and replenishment in the state.
A key question for many valley water managers is how much water will be available for recharge in the long term. By law, only river flows in excess of what is required for environmental purposes and to supply existing water-right holders are available for recharge. A recent report by the PPIC Water Policy Center estimated how much water would be available in the San Joaquin Valley over the long term. Two earlier studies—one by two scientists at UC Davis and the other by the Department of Water Resources—estimated a maximum of about half a million acre-feet on average, which is about a quarter of the valley’s estimated deficit. The PPIC study updated these estimates in the context of current conditions and concluded that an average of more than a million acre-feet of San Joaquin River flows may be available. … “
Toxic Trap: Groundwater Overpumping Boosts Arsenic in California Aquifer
From Water Deeply:
“In California’s agricultural heartland, the San Joaquin Valley, excessive pumping of groundwater has resulted in subsidence, damaging crucial infrastructure, including roads, bridges and water conveyance. A study last year from NASA’s Jet Propulsion Laboratory in Pasadena, California, found overpumping of groundwater since the 1920s had caused parts of the San Joaquin Valley to sink as much as 28ft.
But groundwater overpumping may have another serious side effect, according to a study published June 5 in the journal Nature Communications. Researchers found that recent groundwater pumping caused an increase in the concentrations of arsenic in the aquifer. … “
Read more from Water Deeply here: Toxic Trap: Groundwater Overpumping Boosts Arsenic in California Aquifer
Three Water Challenges for Almonds
From Ellen Hanak at the PPIC Blog:
“California is a force of nature when it comes to almonds. The state’s farmers produce virtually the entire US almond crop and dominate the international market. As the market has grown, almonds have become California’s largest single crop—now accounting for about 12% of irrigated acreage, with more than 1.2 million acres harvested in 2016. Availability of water is clearly a major issue for the industry, since the trees must be irrigated throughout the long spring and summer dry season. At a May event on water issues organized by the Almond Board of California, I was asked for some thoughts on the water realities almond growers must grapple with in coming years. Here are three key takeaways. … “
Expanding Groundwater Recharge in San Joaquin Valley Cities
From at the PPIC Blog:
“The San Joaquin Valley is ground zero for groundwater management challenges. While agriculture is the region’s predominant water user, its cities are more likely to rely on groundwater as their primary source of water. For this reason, the urban sector will need to play a bigger role in the regional effort to balance groundwater use and replenishment.
Our recent research indicates that cities in the valley lag behind agricultural districts in the intentional recharge of groundwater. That’s primarily because most have limited access to two things necessary for storing more water underground: extra surface water and unpaved land on which to spread it so it can percolate into the ground. But some cities have had success with recharge activities. Here are three methods that can serve as models. … “
The Yuba Accord: A Model for Water Management
From Ellen Hanak at the PPIC Blog:
“Last week a diverse group of stakeholders celebrated the tenth anniversary of the Lower Yuba River Accord—a historic agreement to improve conditions for the river’s endangered fishes, maintain water supplies for cities and farms, and reduce conflict over competing uses for water. Here at the PPIC Water Policy Center we frequently refer to the Yuba Accord as a model for modern water management in California. Here are three reasons why. … “
How “Weather Whiplash” Could Change California
From Lori Pottinger at the PPIC Blog:
“First came the drought, then the floods: California has long bounced between the two weather extremes―most recently when the latest drought segued into 2017’s record-breaking rain and snow. Such “weather whiplash” could become much more common as the climate changes, according to a new study. We talked to Daniel Swain, a climate scientist at UCLA—and the study’s lead author—about what to expect.
PPIC: California already has a highly variable climate. How will this be different? … ”
Can California’s groundwater basins be managed collaboratively?
From Stanford’s Water in the West:
“For local communities, complying with the Sustainable Groundwater Management Act (SGMA), the law passed in 2014 that was California’s first statewide framework for managing groundwater, has been no easy task.
A recent study in the journal California Agriculture examined some of the challenges rising to the surface in large, agriculturally-oriented basins as local governments form groundwater sustainability agencies (GSAs), particularly for agricultural water users who have been pumping groundwater with private rights for decades. These GSAs are required to develop groundwater sustainability plans (GSPs) by 2020 in critically overdrafted basins, or by 2022 in other high and medium priority basins.
The analysis highlights that creating effective governance at the basin scale, while still accounting for the interests of agricultural water users, is best pursued through multi-level governance structures that include nongovernmental entities, such as nonprofits, farmers, and ranchers. … “
Read more from Water in the West here: Can California’s groundwater basins be managed collaboratively?
Ecosystems Need Groundwater Too
From Lori Pottinger at the PPIC Blog:
“Groundwater is a critical resource for most living things in California. But while human communities can increase groundwater pumping when surface supplies diminish during droughts, ecological systems often have no backup supply. We talked to Sandi Matsumoto, associate director of the Nature Conservancy’s California Water Program, about determining which ecosystems are particularly dependent on groundwater and what can be done to help them cope with dropping water levels.
PPIC: What are “groundwater-dependent ecosystems”? … “
Why we can’t just suck it up: The challenges of groundwater recharge in California
From Stanford’s Water in the West:
“California is on track to have the wettest water year in the 122-year period of record and replenishing our drought-stricken groundwater basins is a critical part of California’s vision for a sustainable water future. However, the state’s ability to take full advantage of this precipitation to recharge our depleted aquifers remains limited.
One of the many tools designed to help agencies and water managers comply with the Sustainable Groundwater Management Act (SGMA) is groundwater banking or any effort to retain or place water in an aquifer that would not otherwise occur. This effort can take various forms including: conjunctive use—the substitution of surface water for groundwater to reduce pumping); in-lieu recharge—the supply of surface water to users who otherwise rely on groundwater; and managed aquifer recharge (MAR)—the active recharge of groundwater with surface water through dedicated infiltration basins or injection wells. Maximizing these tools, however, will require rethinking both water management and infrastructure. … “
Continue reading at Stanford’s Water in the West here: Why we can’t just suck it up: The challenges of groundwater recharge in California
GROUNDWATER RIGHTS PRIMER: What Agencies & Project Developers Need to Know
From Maven’s Notebook:
“California depends on groundwater for a major portion of its annual water supply, and sustainable groundwater management is essential to a reliable and resilient water system. In recognition of this, the legislature passed a three-bill package known as the Sustainable Groundwater Management Act in 2014 that set in motion a plan to sustainably manage the state’s groundwater basins. The centerpiece of the legislation is recognition that groundwater management is best accomplished at the local level, and so SGMA requires the creation of groundwater sustainability agencies to develop and implement locally-developed groundwater sustainability plans, allowing 20 years to achieve sustainability.
The legislation explicitly states that it does not alter any water rights: the legislation adds Water Code section 10720.5(b) that states that nothing in the legislation “determines or alters surface water rights or groundwater rights under common law or any provision of law that determines or grants surface water rights.” However, Groundwater Sustainability Agencies and project proponents must address such rights in groundwater sustainability plan development, projects to increase yield such as recharge projects, and reducing pumping to reach sustainability.
California’s structure of groundwater rights is notoriously complex, directly related to hydrologic conditions, and complicates the goal of sustainable groundwater management. At the McGeorge School of Law’s Executive Training on Water Rights in Groundwater: A Deep Dive into California Groundwater Rights, Professor Jennifer Harder and Hydrogeologist Derrik Williams discussed the convoluted world of groundwater rights as it exists in California. … “