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 | 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…

2015 | Freshwater | Marine | Publications & Reports

Assessing California’s bar-built estuaries using the California Rapid Assessment Method

Walter Heady, Ross P. Clark, Kevin O’Connor, Cara Clark, Charles Endris, Sierra Ryan, Sara Stoner-Duncan

Connecting marine, freshwater and terrestrial ecosystems, bar-built estuaries are complex and dynamic coastal confluences that provide a great diversity of habitat and ecosystem services. The wetland…

2015 | Freshwater | Terrestrial | Publications & Reports

The benefits of crops and field management practices to wintering waterbirds in the Sacramento-San Joaquin River Delta of California

W. David Shuford , Matthew E. Reiter, Khara M. Strum, Michelle M. Gilbert , Catherine M. Hickey, Greg Golet

Although agricultural intensification is one of the largest contributors to the loss of global biodiversity, agricultural landscapes can provide valuable habitat for birds. Recognizing this, wildlife…

2015 | Freshwater | Planning | Maps & Webmaps

California’s Freshwater Conservation Blueprint map

Megan Webb, Kirk Klausmeyer, Jeanette Howard

The transformation of California into one of the most productive agricultural and urban landscapes in the world and a growing population have put unprecedented pressure on freshwater habitats,…

2015 | Freshwater | Science | Publications & Reports

California Freshwater Blueprint: Phase I Overview

Jeanette K. Howard, Kirk R. Klausmeyer, Kurt A. Fesenmyer

California is one of the most productive agricultural and urban landscapes in the world with a growing population. These pressures have reduced aquatic and wetland habitats to a small fraction of…

2015 | Freshwater | Terrestrial | Technology | Publications & Reports

Abundance models improve spatial and temporal prioritization of conservation resources

Johnston, A., D. Fink, M. D. Reynolds, W. M. Hochachka, B. L. Sullivan, N. E. Bruns, E. Hallstein, M. S. Merrifield, S. Matsumoto, S. Kelling

Global declines in migratory species in response to accelerating habitat destruction and climate change challenge the scope and scale of conservation efforts. The ability to pinpoint where and when…

2015 | Freshwater | Marine | Publications & Reports

Aligning Natural Resource Conservation and Flood Hazard Mitigation in California

Juliano Calil, Michael W. Beck, Mary Gleason, Matthew Merrifield, Kirk Klausmeyer, Sarah Newkirk

The U.S. National Flood Insurance Program has paid out more than $38 billion in claims since its inception in 1968, more than a third of which has gone to the 1% of policies that experienced multiple,…

2015 | Freshwater | Planning | Data

California Freshwater Species Database v2

Jeanette Howard, Kirk Klausmeyer, Kurt Fesenmyer

The California Freshwater Species Database is the first comprehensive geospatial database of California’s freshwater species compiled and standardized into single format from nearly 500 sources.…