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 number jumps to 60… >>

Surface Flows

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

Science in Action

Freshwater | Science

Restoring California’s Largest River

How can we restore large rivers and floodplains to benefit nature and people?

Freshwater | Terrestrial | Technology | Economics | Science

Dynamic Conservation

In an era of rapid global change, how can conservationists provide habitat where and when nature needs it most?

2019 | Freshwater | Terrestrial | Planning | Technology | Science | Publications & Reports

Biodiversity Analysis in Los Angeles (BAILA) Report

Parker SS, Randall JM, Pauly GB, Li E, Brown BV, Cohen BS

This report is a product of the Biodiversity Analysis in Los Angeles (BAILA) project. It provides details on why we conducted our analysis, how the partnership between the Museum and the Conservancy was formed, how our Core Team, Scientific Advisory Group, and Stakeholder Group…


2019 | Freshwater | Terrestrial | Planning | Technology | Science | Data

Biodiversity Analysis in Los Angeles (BAILA) data

Enjie Li, Sophie S. Parker, Gregory B. Pauly, John M. Randall, Brian V. Brown, Brian S. Cohen

This dataset is a product of the Biodiversity Analysis in Los Angeles (BAILA) project, and demonstrates a new way to evaluate urban biogeography—patterns in the distribution of species across urban areas. The authors developed a hierarchical, quantitative method for classifying urban lands into different…


2019 | Freshwater | Terrestrial | Planning | Technology | Science | Publications & Reports

An urban biodiversity assessment framework that combines an urban habitat classification scheme and citizen science data

Enjie Li, Sophie S. Parker, Gregory B. Pauly, John M. Randall, Brian V. Brown, Brian S. Cohen

This paper presents a new way to evaluate urban biogeography—patterns in the distribution of species across urban areas. The authors developed a hierarchical, quantitative method for classifying urban lands into different habitat types, and then used citizen-science data to assess each type’s biodiversity. This approach…


2019 | Freshwater | Technology | Science | Maps & Webmaps

GDE Pulse: Monitoring Groundwater Dependent Ecosystems with Satellites

Kirk Klausmeyer, Falk Schuetzenmeister, Nathaniel Rindlaub, Tanushree Biswas, Melissa M. Rohde, Jeanette Howard

94,333 unique ecosystems depend on groundwater in California. GDE Pulse lets you see how they have changed over the last 30 years.  Groundwater managers and environmental stakeholders often lack information about the health of critical groundwater dependent ecosystems (GDEs). To fill this information gap, we…


2019 | Freshwater | Economics | Publications & Reports

SGMA's First Groundwater Market: An Early Case Study from Fox Canyon

Sarah Heard, E.J. Remson, Matthew Fienup, Siobhan King

In 2014, California passed the Sustainable Groundwater Management Act (SGMA) which regulates groundwater at scale for the first time, requiring the state’s largest source of stored water to be managed for long-term resilience. SGMA delegates the responsibility of achieving sustainable groundwater management by 2040 to…


2019 | Freshwater | Planning | Science | Publications & Reports

Conservation Planning Foundation for Restoring Chinook Salmon (Oncorhynchus tshawytscha) and O. mykiss in the Stanislaus River

Prepared by Anchor QEA, LLC (John Ferguson, Elizabeth Greene, and Michelle L. Ratliff), Contributors and Participants: John Cain, Jon Rosenfield, Alison Weber-Stover, Stephen Louie, John Shelton, Tim Heyne, Brian Ellrott, Sierra Franks, Monica Gutierrez, Rhonda Reed, David Swank, Steve Edmundson, Katie Schmidt, Rachel Johnson, Jeanette Howard, Julie Zimmerman, Chris Carr, Daniel Worth, Rene Henery, Ron Yoshiyama, Joshua Israel, Paul Cadrett, Ramon Martin, and J.D. Wikert

Also view Appendix A: Stanislaus Survival Model and and other report Appendices.  


2019 | Freshwater | Terrestrial | Science | Publications & Reports

The dark side of facilitation: native shrubs facilitate exotic annuals more strongly than native annuals

Jacob E. Lucero, Taylor Noble, Stephanie Haas, Michael Westphal, H. Scott Butterfield, Christopher J. Lortie

Previous work at the Carrizo Plain by this team in 2018 showed that native shrubs facilitated endangered blunt-nosed leopard lizard populations, and should be considered part of plans for habitat restoration in the San Joaquin Valley. This paper shows that shrubs have a dark…


2019 | Freshwater | Terrestrial | Science | Publications & Reports

Clarifying Effects of Environmental Protections on Freshwater Flows to—and Water Exports from—the San Francisco Bay Estuary

Gregory J. Reis, Jeanette K. Howard, Jonathan A. Rosenfield

For years the narrative of the San Francisco Bay Delta has been driven by the contention that water use by agriculture was being limited by environmental regulation. Analyzing long-term trends regarding factors governing water exports in the Delta, researchers from The Bay Institute, The Nature…


2019 | Freshwater | Science | Publications & Reports

Stream flow modeling tools inform environmental water policy in California

Theodore E. Grantham, Julie K. H. Zimmerman, Jennifer K. Carah, Jeanette K. Howard

Management of California’s vast water distribution network, involving hundreds of dams and diversions from rivers and streams, provides water to 40 million people and supports a globally prominent agricultural sector, but it has come at a price to local freshwater ecosystems. An essential first step…


2019 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

Habitat restoration opportunities, climatic niche contraction, and conservation biogeography in California's San Joaquin Desert

Joseph A. E. Stewart, H. Scott Butterfield, Jonathan Q. Richmond, David J. Germano, Michael F. Westphal, Erin N. Tennant, Barry Sinervo

Due to limited water resources, there is a global trend toward the retirement of farmland, especially in the San Joaquin Valley in California where the Sustainable Groundwater Management Act could necessitate the retirement of more than 500,000 acres. This paper helps identify where, across the…


2019 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

San Diego County Ecosystems: Ecological Impacts of Climate Change on a Biodiversity Hotspot

Megan Jennings, Dan Cayan, Julie Kalansky, Amber Pairis, Alexandra Syphard, Rachel Clemesha, Alexander Gershunov, Kristen Guirguis, John Randall, Eric Stein, Sula Vanderplank, Shasta Gaughen


2018 | Freshwater | Terrestrial | Marine | Science | Publications & Reports

Conservation Science Catalyst Fund - 2018 Annual Report

Brynn Pewtherer

The Nature Conservancy deploys science to help overcome major challenges facing people and nature. In today’s fast-paced world, turning threats to nature into opportunities for conservation requires agility. The Conservation Science Catalyst Fund enables our science team to mobilize quickly — and produce the information…


2018 | Freshwater | Terrestrial | Science | Blogs

The Promise of eDNA: A New Kind of Fieldwork to Guide Conservation

Sophie Parker

This blog post discusses how environmental DNA or “eDNA” methods can be used by conservation biologists. These methods rely on the premise that DNA is shed by organisms through normal, everyday activity. DNA collected in the field is compared with known specimens to determine what…


2018 | Freshwater | Terrestrial | Science | Publications & Reports

The emergence of cannabis agricultural frontiers as environmental threats

Van Butsic, Jennifer K. Carah, Matthias Baumann, Connor Stephens, Jacob C. Brenner

While cannabis cultivation in California is known to sometimes have serious collateral impacts on the environment, those impacts and their extent are not well understood or described. In this paper, the authors quantify growth in the footprint of cannabis cultivation between 2012 and 2016 in…


2018 | Freshwater | Terrestrial | Science | Publications & Reports

Wetland Bird Conservation in California Rice Fields

Chris Elphick, T. Rodd Kelsey, Catherine Hickey, Khara Strum, Paul Buttner, Monica Iglecia

Wetland birds, especially Sandhill Cranes, are heavily dependent on irrigated farmlands in the Central Valley of California after widespread conversion of natural habitats. TNC and its partners have had great success working with farmers to design and implement compatible management practices that make sure farms,…


2018 | Freshwater | Terrestrial | Science | Publications & Reports

Waterbird response to variable-timing of drawdown in rice fields after winter-flooding

Kristen Sesser, Monica Iglecia, Matthew Reiter, Khara Strum, Catherine Hickey, Rodd Kelsey, Daniel Skalos

Over 50% of waterbird habitat in the Central Valley of California is provided by flooded agricultural land. Each year non-breeding waterbird habitat decreases in the late winter as flooded agricultural fields are drained after waterfowl hunting season in late-January to prepare for the next crop.…


2018 | Freshwater | Terrestrial | Planning | Economics | Science | Publications & Reports

Groundwater sustainability in the San Joaquin Valley: Multiple benefits if agricultural lands are retired and restored strategically

Rodd Kelsey, Abby Hart, H. Scott Butterfield, Dan Vink

Restoring habitat in retired farmland could reduce water demand and provide ecosystem services for farmers and local communities. In some areas of California, as a result of the Sustainable Groundwater Management Act (SGMA), it is likely that large amounts of agricultural land will need to…


2018 | Freshwater | Planning | Science | Maps & Webmaps

Rearing habitat objectives to support salmon in the Central Valley

Travis M. Hinkelman, Myfanwy Johnston, Joseph E. Merz, Julie Zimmerman

To restore degraded stream corridors and develop large-scale, sustainable watershed conservation strategies, it is essential for managers to consider—in order to ultimately re-establish—the habitat requirements of keystone species. For example, in order to restore salmon in the Central Valley of California, we need a clear…