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.

Freshwater Systems

California is one of the most hydrologically altered landscapes in the world. As water becomes…>>

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,…>>

Terrestrial Systems

In California, a day’s drive can take a visitor from record-setting desert heat to glaciated…>>

Wildlands

Nearly half of California is protected in some land status that prevents most kinds of intensive…>>

Harvested Landscapes

A third of California is privately-owned forestland, woodland or grassland. From redwood forests on…>>

Cultivated Landscapes

California is the leading agricultural state in the country and it’s agriculture generates…>>

Urban Areas and Infrastructure

With California’s population on track to reach 50 million people, the demand for energy,…>>

Fisheries

Wild capture fisheries supply food and jobs for hundreds of millions of people across the globe. Yet…>>

Coastal Conservation

Almost half of the world’s human population lives in coastal areas, and associated coastal…>>

Science in Action

Terrestrial | Planning | Technology | Economics

Wildfire and Communities

How can land protection and restoration help protect communities from wildfire?

Terrestrial | Marine | Economics | Science

TNC and FEMA

How do we increase climate resilience in ways that work for people and nature?

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

Harnessing cross-border resources to confront climate change

Aburto-Oropeza, O., M. Edwards, S. Butterfield, and 93 additional authors

The U.S. and Mexico face many shared ecological changes due to the increased frequency and severity of droughts and rising energy demands; trends that entail economic costs for both nations and…

2018 | Terrestrial | Planning | Science | Publications & Reports

Adapting the bioblitz to meet conservation needs

Parker, S.S., B.V. Brown, B.S. Cohen, N.S. Fraga, J.J. Knapp, Z. Principe, J. Moore, G.B. Pauly, J.M. Randall, T.A. Wake

A bioblitz is a collaborative, rapid field assessment that takes place in a given location over a short period of time. This paper discusses how bioblitz events involving experts are being used to…

2018 | Marine | Science | Publications & Reports

Partnerships in Fisheries Management

Wilson J. , McGonigal, H., Dempsey, T., Gleason, M., Rienecke, S.

Fisheries management in California is a complex, resource intensive process that is limited by funding and staff capacity. In this report, Conservancy scientists and colleagues identify ways in which…

2018 | Freshwater | Science | Publications & Reports

Groundwater Dependent Ecosystems under the Sustainable Groundwater Management Act: Guidance for Preparing Groundwater Sustainability Plans

Rohde, M.M., S. Matsumoto, J. Howard, S. Liu, L. Riege, E.J. Remson

California's Sustainable Groundwater Management Act (SGMA) of 2014 is landmark legislation that empowers local agencies, known as groundwater sustainability agencies, to sustainably manage…

2018 | Freshwater | Terrestrial | Science | Publications & Reports

Using ricelands to provide temporary shorebird habitat during migration

Gregory H. Golet, Candace Low, Simon Avery, Katie Andrews, Christopher J. McColl, Rheyna Laney, Mark D. Reynolds

Migratory birds face great challenges due to the climate change, conversion of historical stopover sites, and other factors. To help address these challenges, the Conservancy launched a dynamic…

2018 | Terrestrial | Science | Publications & Reports

Introduction to the Special Issue on the Flora and Vegetation of the Islands of the Californias

John J. Knapp, John M. Randall

The islands off the Pacific coast of California and Baja California, from the Farallones in the north to Isla Natividad in the south, are within the California Floristic Province. Their shared flora…

2017 | Freshwater | Terrestrial | Planning | Publications & Reports

Identification of potentially suitable habitat for strategic land retirement and restoration in the San Joaquin Desert

H. Scott Butterfield, Rodd Kelsey, Abigail Hart, Tanushree Biswas, Mark Kramer, Dick Cameron, Laura Crane, Erica Brand

California's Sustainable Groundwater Management Act (SGMA) established a framework for sustainable, local groundwater management. SGMA requires groundwater-dependent regions to…

2017 | Terrestrial | Science | Publications & Reports

Amargosa River Expert BioBlitz 2017 Final Report

Parker, S.S., B.S. Cohen, N. Fraga, B. Brown, J. Cole, W. Chatfield-Taylor, K. Guadalupe, G.B. Pauly, D. Cooper, M. Ordeñana

In 2017, The Nature Conservancy co-organized an “Expert BioBlitz” to explore a 26-mile stretch of the Wild and Scenic Amargosa River, located in the heart of the Mojave Desert. The event…

2017 | Freshwater | Terrestrial | Planning | Publications & Reports

Rethinking the Grid: Optimizing California’s Transmission System For Renewable Energy

Energy+Environmental Economics for The Nature Conservancy, Arne Olson, Doug Allen, Vivian Li, Emily Leslie

California leads the nation in the transition to a clean energy economy. However, current transmission planning processes limit development of new renewable resources. This report (slide deck),…

2017 | Freshwater | Science | Publications & Reports

Managing diversions in unregulated streams using a modified percent-of-flow approach

Darren W. Mierau, William J. Trush, Gabriel J. Rossi, Jennifer K. Carah, Matthew O. Clifford, Jeanette K. Howard

The California water rights system often dis-incentivizes water management that benefits both nature and people by directing the timing of diversions to the summer when water is the most scarce. It…

2017 | Freshwater | Science | Publications & Reports

Patterns and magnitude of flow alteration in California, USA

Julie K H Zimmerman, Daren M. Carlisle, Jason T. May, Kirk R. Klausmeyer, Theodore E. Grantham, Larry R. Brown, Jeanette K. Howard

The importance of the natural flow regime to stream and river health has received growing attention in recent years. Understanding natural flows and patterns of flow alteration is an important first…

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

Conservation Science Catalyst Fund - 2017 Annual Report

Brynn Pewtherer, Scott Morrison

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…

2017 | Terrestrial | Science | Publications & Reports

Ecosystem management and land conservation can substantially contribute to California’s climate mitigation goals

D. Richard Cameron, David C. Marvin, Jonathan M. Remucal, Michelle C. Passero

Combatting climate change will require using all available tools, especially those that contribute to other societal and economic goals, such as natural resource protection and energy security.…

2017 | Terrestrial | Planning | Publications & Reports

Regional Prioritization for Forest Restoration across California's Sierra Nevada

Rodd Kelsey, Edward Smith, Tanushree Biswas, Chris McColl, Kristen Wilson, Dick Cameron

This report provides a systematic regional-scale assessment of biodiversity, fire regime change, and fire risk to infrastructure of forested watersheds across the Sierra Nevada and prioritizes…

2017 | Terrestrial | Technology | Science | Publications & Reports

Testing a Remote Sensing-Based Interactive System for Monitoring Grazed Conservation Lands

Lawrence D. Ford, H. Scott Butterfield, Pete A. Van Hoorn, Kasey B. Allen, Ethan Inlander, Carrie Schloss, Falk Schuetzenmeister, Miriam Tsalyuk

The Nature Conservancy developed RDMapper, a web-based tool that uses satellite-based productivity estimates, rainfall records, and compliance history to identify easement properties at risk of being…

2017 | Marine | Technology | Science | Video

Aquaculture by Design, Tomales Bay

Serena Lomonico, Robert Jones, Torrey Johnson, Sarah Newkirk, Sarah Lummis, Kirk Klausmeyer, John Finger, Terry Sawyer, Richard James

Aquaculture is becoming an increasingly important global food source. With this growth comes urgent, unanswered questions about the interactions of aquaculture operations—both positive and…

2017 | Terrestrial | Technology | Science | Publications & Reports

Novel fine-scale aerial mapping approach quantifies grassland weed cover dynamics and response to management

Carolyn M. Malmstrom, H. Scott Butterfield, Laura Planck, Christopher W. Long, Valerie T. Eviner

Invasive weeds threaten the biodiversity and forage productivity of grasslands worldwide. However, management of these weeds is constrained by the practical difficulty of detecting small-scale…

2017 | Freshwater | Terrestrial | Marine | Technology | Economics | Science | Publications & Reports

Dynamic conservation for migratory species

Mark D. Reynolds, Brian L. Sullivan, Eric Hallstein, Sandra Matsumoto, Steve Kelling, Matthew Merrifield, Daniel Fink, Alison Johnston, Wesley M. Hochachka, Nicholas E. Bruns, Matthew E. Reiter, Sam Veloz, Catherine Hickey, Nathan Elliott, Leslie Martin, John W. Fitzpatrick, Paul Spraycar, Gregory H. Golet, Christopher McColl, Scott A. Morrison

What if instead of buying habitat, conservationists could rent it when and where nature needs it most? The Conservancy is using predictive models of shorebird movements, data from the citizen science…