The Sacramento-San Joaquin

Standing on the edge of Shasta Lake in northern California, an eagle-eyed observer can trace the path of the Sacramento River for 400 miles, down volcanic ridges, fanning out into the fertile Sacramento–San Joaquin River Delta and finally reaching the bustle of the San Francisco Bay. This river has withstood centuries of activity, from volcanic events to gold mining, forest fires to engineered levees and tunnels. Harder to see, yet no less critical, is the water contained deep underground in aquifers even older than the river.

Five years have passed since we opened our first office in California. During that time, we have built a network of monitoring sites, of scientific data and of strong partnerships throughout the Sacramento Valley in the quest to meld compliance with state regulations to cost-effective, tangible results for freshwater ecosystems.

In 2019, we cemented major partnerships with Microsoft and American Farmland Trust. Projects with each entity kicked off in 2020 to meet replenishment and groundwater sustainability targets.

We continued to make strides on projects already underway. In the Solano Subbasin, we installed 10 monitoring sites on agricultural wells and connected them to the first iteration of a unique groundwater trading tool built on a secure blockchain platform. We refined our measurement method for surface water irrigators in the Sacramento-San Joaquin Delta and secured the support of the region’s Watermaster. For the Sacramento Regional County Sanitation District, our team completed the first draft of an extensive Ecological Program with a roadmap for securing, protecting, and enhancing 8,400 acres of important habitat in the southern Sacramento Valley over the next 80 years.

The Sacramento has run full and strong for three million years and the region’s farmers need it to remain vibrant for decades to come, particularly in the face of recent prolonged droughts.

“Our work here is underpinned by relationships with more than 80 agricultural landowners alongside community partners and robust technologies,” said Anna Swenson, community outreach coordinator for TFT. “These relationships allow us to assess the entire Sacramento Valley, and move us toward prioritizing and funding the conservation actions that will drive groundwater sustainability and protecting freshwater ecosystems. It’s a win-win for everyone.”

Building resilience for the region extends beyond our food supply. The burgeoning urban populations of the Bay Area get their drinking water in part from snowmelt delivered from the Sacramento River watershed. And many rural communities rely on groundwater wells as their only source of drinking water.

The Solano Subbasin is also the center of TFT’s work with severely disadvantaged communities, where incomes in several areas are less than 80% of the state’s median household income. A grant from the California Department of Water Resources allowed TFT to bring in a fellow through CivicSpark, an AmeriCorps program. In 2019, Jacqueline Garcia focused on engaging with local communities around groundwater sustainability. Garcia led the charge on a community-wide assessment with the Local Government Commission to characterize and map how communities rely on groundwater throughout the subbasin and develop strategies for engagement.

“Many folks don’t know where their water comes from,” said Garcia. “Nor do they think they have a meaningful stake in water management. The truth is, however, local water management has big implications for the health of their communities for present and future generations. Many of these communities are often entirely dependent on groundwater and, therefore, most significantly impacted by unsustainable practices.”

Moving toward coordinated actions for sustainable groundwater and surface water management is our vision.

“The water we see on the surface is related to the water we don’t see underground,” said Becky Rittenburg, conservation programs manager. “Rivers and groundwater are actually connected. Pumping too much groundwater lowers the water table and dries up, which, in turn, dries up the small creeks and streams that are sustained by groundwater. Tree roots can’t reach the water they need during the dry season. Seasonal pools and wetlands can’t support wildlife and fish.”

“It’s all interrelated. By focusing on groundwater in California, we are at the heart of systems change for many impacted basins.”

Want to help The Freshwater Trust and the Sacramento-San Joaquin River Basin Partners keep working on the Sacramento-San Joaquin? Make a gift today.

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In 2015 California passed Senate Bill 88, which made it mandatory for those diverting more than 10 acre-feet of surface water per year to accurately measure the amount of water used. In most cases, SB 88 requires meters for surface water diversions. However, in the Northern Delta, it is technically and logistically challenging to meter the diversions. Instead, most people use gravity-fed siphons, which are unpowered pipes that bring water from the rivers that are at higher elevations to the farms on the Delta islands. TFT is a partner in a scientific consortium to find more accurate and cost-effective methods of measuring water use.

In many locations, groundwater mixes with water in a river channel through the porous sediment surrounding a river. This is a natural process called hyporheic exchange. Rivers recharge the groundwater and, in some cases, rivers are depleted by declining groundwater. While many streams can naturally "lose" water, it is particularly the over-pumping of groundwater in much of California that has led to stream flows being significantly depleted.

For example, in south Sacramento County, a drop in the groundwater table of 30 feet in one area has jeopardized multiple other surrounding water resources – from irrigation wells to wetlands and forests to rivers that support migrating salmon.

TFT is working on several initiatives related to groundwater sustainability in northern California. It is working with the Northern Delta Groundwater Sustainability Agency (NDGSA) and its 17 member agencies to provide administrative support, analytical services, and grant-writing assistance as the NDGSA prepares their Groundwater Sustainability Plans (GSPs).

On a broader scale, TFT is developing user-friendly tools that provide information about water savings, the costs to implement savings, and, most importantly, how to add more water through conservation practices such as cover cropping and winter recharge with surface and stormwater.

In lieu recharge is where surface water is used as a substitute for pumping from a groundwater source. The substituted water is a renewable supply, such as excess surface water or treated wastewater. In lieu recharge allows for "conjunctive use," where surface water is used by persons that could otherwise extract groundwater in order to leave groundwater in the basin. This practice can help improve water reliability in California.

Groundwater is important to everyone, from farmers growing crops to local communities that rely on groundwater as their source of drinking water. Therefore, regional Groundwater Sustainability Plans (GSPs) need to consider the needs and concerns of all water users. In eastern Solano County, TFT is working with local partners to reach out to disadvantaged communities (where incomes are less than 80% of the state’s median household income) to actively engage them in the decision-making process about the future of the resource.