California is one of the most hydrologically altered landscapes in the world. As water becomes ever more scarce and the human population continues to grow, that vast engineered system strains to meet the needs of people let alone the needs of nature. 

Water rights allocations far exceed actual surface water supply, and millions of wells tap groundwater to meet the increasing demands of farms and communities. As groundwater reservoirs are depleted they can in turn reduce surface flows – exacerbating a vicious cycle in which people and nature both lose. Rivers, wetlands and groundwater-dependent ecosystems are caught in this struggle for an increasingly limited resource. Nearly half of California’s roughly 4,000 freshwater species are considered vulnerable to extinction. Of the taxa that are found nowhere but California – our endemic freshwater biodiversity – 90 percent are at risk.

But there is hope. While it is impossible to return natural flows to most of California’s rivers and streams, we can – through science, technology, and innovative market tools – endeavor to deliver water when and where nature needs it most.

Groundwater

In a normal year, groundwater accounts for 40 percent of California’s water supply. That…>>

Surface Flows

Californians have fundamentally altered many of the state’s rivers and streams with dams,…>>

Science in Action

Freshwater | Terrestrial | Science

Rewilding the San Joaquin Valley

40 years of science sets the course for the largest recovery of species in U.S. history

Freshwater | Terrestrial | Marine | Science

Research for Impact

How do we design scientific research to have impact in the world?

2017 | Freshwater | Terrestrial | Publications & Reports

Market-Based Mechanisms For Securing Environmental Water In California

Sarah Heard, Siobhan King, Eric Hallstein

California’s water supply is becoming increasingly unreliable. During dry times, consumptive use often outstrips supplies. As a result, people and nature suffer. This imbalance of supply and…

2017 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

Population and habitat objectives for avian conservation in California’s Central Valley riparian ecosystems

Kristen E. Dybala, Neil Clipperton, Thomas Gardali, Gregory H. Golet, Rodd Kelsey, Stefan Lorenzato, Ron Melcer, Jr., Nathaniel E. Seavy, Joseph G. Silveira

The Conservancy and partners are working to establish riparian ecosystems that provide sufficient habitat to support genetically robust, self-sustaining, and resilient bird populations in…

2017 | Freshwater | Terrestrial | Planning | Publications & Reports

Informing watershed planning and policy in the Truckee River basin through stakeholder engagement, scenario development, and impact evaluation

Kristen Wilson, Erik Lowe, Stacey Wolny, Barry Nickel , Rodd Kelsey

This study demonstrates how science-based planning with stakeholder input can improve and direct conservation investments across existing state and jurisdictional boundaries. The authors set out to…

2017 | Freshwater | Planning | Publications & Reports

Water for nature: What we can do today to help California’s rivers, streams and wetlands

Burns, C.E., A. Hoss, N. Smith, K. Klausmeyer, K. Fesenmeyer, A. Campbell, J. Carah, E. Forsburg, S. Heard, J.K. Howard, L. Hulette, S. Liu, P. Spraycar, B. Stranko, G. Werner, D. Wordham

This report identifies a set of strategies that will have the greatest impact on environmental flows, and to provide a resource for conservation organizations, resource agencies, and other…

2016 | Freshwater | Science | Publications & Reports

Benefits and Economic Costs of Managed Aquifer Recharge in California

Debra Perrone, Melissa M. Rohde

Managed aquifer recharge (MAR) projects can play an important role in ensuring California manages its groundwater sustainably. This study, the first to investigate the benefits and economic costs…

2016 | Freshwater | Terrestrial | Technology | Science | Publications & Reports

Pop-up wetland habitats benefit migrating birds and farmers

Christopher J. McColl, Katie Andrews, Mark Reynolds, Gregory H. Golet

In response to the decline of wetland habitats for migrating and wintering water birds in California, the Conservancy developed a program called BirdReturns that creates “pop-up”…

2016 | Freshwater | Terrestrial | Planning | Publications & Reports

Future land-use related water demand in California

Tamara S Wilson, Benjamin M Sleeter, D Richard Cameron

This publication discusses how land use changes in Mediterranean California will drive changes in water use between urban uses and annual vs. perennial crops. The authors used a state-and-transition…

2016 | Freshwater | Maps & Webmaps

How and Where Nature Uses Groundwater

Kirk Klausmeyer, Jeanette Howard, Sandi Matsumoto, Sally Liu, Melissa Rohde

Groundwater is essential to the health and viability of plants, animals and ecosystems. Many tree species, like willows and cottonwoods, rely on groundwater to survive seasonal and annual dry spells.…

2016 | Freshwater | Terrestrial | Marine | Planning | Publications & Reports

Designing virtuous socio-ecological cycles for biodiversity conservation

Scott A. Morrison

Conservationists should assume that people don’t care about biodiversity. By doing so, they would be especially motivated to figure out what people do care about, and how conservation might be…

2016 | Freshwater | Science | Publications & Reports

Sustainable Groundwater Management: What We Can Learn from California's Central Valley Streams

The Nature Conservancy, RMC Consultants, Inc.

Groundwater is intimately connected to surface water, which has profound implications for sustainable water resource management. California has historically overlooked this important interaction and…

2016 | Freshwater | Science | Publications & Reports

Groundwater and Stream Interaction in California’s Central Valley: Insights for Sustainable Groundwater Management

The Nature Conservancy, RMC Consultants, Inc.

Groundwater is intimately connected to surface water, which has profound implications for sustainable water resource management. California has historically overlooked this important interaction and…