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 | 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?

2020 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

Shaping land use change and ecosystem restoration in a water-stressed agricultural landscape to achieve multiple benefits

Benjamin P. Bryant, T R. Kelsey, Adrian L. Vogl, Stacey A. Wolny, Duncan J. MacEwan, Paul C. Selmants, Tanushree Biswas, H S. Butterfield

Irrigated agriculture has grown rapidly over the last 50 years, helping food production keep pace with population growth, but also leading to significant habitat and biodiversity loss globally. Now, in some regions, land degradation and overtaxed water resources mean historical production levels may need to…


2020 | Freshwater | Science | Publications & Reports

Evaluating and Protecting Environmental Water Assets: A Guide for Land Conservation Practitioners

Author: Chris Alford, Editors and Reviewers: Amy Campbell, Monty Schmitt, Sara Press, Wendy Eliot, Bob Neale

Evaluating and Protecting Environmental Water Assets: A Guide for Land Conservation Practitioners, a publication by TNC and the Sonoma Land Trust (SLT), provides provides easy to understand guidance, resources, and tools that California land trusts, open space districts, resource conservation districts, and others can…


2020 | Freshwater | Science | Publications & Reports

Characterizing benthic macroinvertebrate and algal biological condition gradient models for California wadeable Streams, USA

Michael J. Paul, Ben Jessup, Larry R. Brown, James L. Carter, Marco Cantonatie, Donald F. Charles, Jeroen Gerritsena, David B. Herbst, Rosalina Stancheva, Jeanette Howard, Bill Isham, Rex Lowe, Raphael D. Mazor, Patina K. Mendez, Peter R. Ode, Alison O'Dowd, John Olson, Yangdong Pan, Andrew C. Rehn, Sarah Spaulding, Martha Sutula, Susanna Theroux

Water resource agencies assess stream water quality by determining the bugs and algae present to develop biotic indices. Yet translating these technical measures into meaningful language is difficult. This study finds that by placing technical numerical measures/indices into categories of condition allows resource manages to…


2020 | Freshwater | Terrestrial | Technology | Science | Publications & Reports

Mojave Desert Springs: setting an ecological baseline

Sophie S. Parker

This article appears in the Desert Report, a news publication of the Sierra Club California/Nevada Desert Committee. The article introduces the Mojave Springs Research Project, led by The Nature Conservancy, that involves a research collaboration with UCLA, the California Botanic Garden, and Partner Engineering and…


2020 | Freshwater | Terrestrial | Marine | Planning | Technology | Science | Publications & Reports

Jack and Laura Dangermond Preserve Integrated Resources Management Plan

Butterfield, H.S., M. Reynolds , M.G. Gleason, M. Merrifield, B.S. Cohen, W.N. Heady, D. Cameron, T. Rick, E. Inlander, M. Katkowski, L. Riege, J. Knapp, S. Gennet, G. Gorga, K. Lin, K. Easterday, B. Leahy, M. Bell

This Plan frames the biological and cultural significance and provides the short- and long-term goals, objectives, and priority actions for the Jack and Laura Dangermond Preserve.


2020 | Freshwater | Marine | Science | Microsite

State of Salmon in California

Sally Liu, Megan Webb, Jeanette Howard, Jennifer Carah

Chinook, coho and steelhead were once tremendously abundant in most of California’s major rivers and streams. As recently as the 1960s, salmon and steelhead were so plentiful in streams that horses would get spooked trying to cross. Due to water damming and diversions, habitat degradation and…


2020 | Freshwater | Terrestrial | Marine | Technology | Publications & Reports

Technology Catalyst Fund - 2019 Annual Report

Matt Merrifield, Sue Pollock

Conservation needs to harness technology to meet the complex challenges of today’s world. The Technology Catalyst Fund provides early stage resources to investigate and prototype technologies that have high potential for impact and have effectively disrupted the status quo in other sectors. The Fund empowers…


2020 | Freshwater | Terrestrial | Marine | Science | Publications & Reports

Conservation Science Catalyst Fund - 2019 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 requires agility. The Conservation Science Catalyst Fund enables our science team to mobilize quickly — and produce the information…


2020 | Freshwater | Science | Publications & Reports

A functional flows approach to selecting ecologically relevant flow metrics for environmental flow applications

Sarah M. Yarnell, Eric D. Stein, J. Angus Webb, Theodore Grantham, Rob A. Lusardi, Julie Zimmerman, Ryan A. Peek, Belize A. Lane, Jeanette Howard, Samuel Sandoval-Solis

The authors of this paper are engaged in developing flow criteria for California Streams through California Environmental Flows Framework (CEFF) collaboration. The effort is funded by the State Water Resources Control Board. This collaboration is a working group within the California Water Quality Monitoring Council. This…


2019 | Freshwater | Planning | Science | Publications & Reports

Dynamic multibenefit solutions for global water challenges

Melissa M. Rohde, Mark Reynolds, Jeanette Howard

In this article, the authors provide an example of how dynamic multi-benefit solutions used to provide “pop-up” wetland habitat for migratory birds also replenishing depleted aquifers to create environmental and water supply benefits and broadens it to the global scale. Additionally, this article outlines six…


2019 | Freshwater | Science | Publications & Reports

Cannabis and residential groundwater pumping impacts on streamflow and ecosystems in Northern California

Samuel C. Zipper, Jennifer K. Carah, Christopher Dillis, Tom Gleeson, Ben Kerr, Melissa M. Rohde, Jeanette K. Howard, Julie K.H. Zimmerman

Using a newly developed tool for estimating streamflow depletion from groundwater pumping, this study examined the impacts of ongoing groundwater pumping on streamflow and aquatic ecosystems in the Navarro watershed in rural, coastal California. The study found that common uses of groundwater in the watershed,…


2019 | Freshwater | Terrestrial | Science | Publications & Reports

Scenarios of climate adaptation potential on protected working lands from management of soils

Kristin B Byrd, Pelayo Alvarez, Benjamin Sleeter, Lorraine Flint, Alan Flint, Richard Cameron, Jeffrey Creque

Management of protected lands may enhance ecosystem services that conservation programs were designed to protect. Practices that build soil organic matter on agricultural lands also increase soil water holding capacity, potentially reducing climatic water deficit, increasing actual evapotranspiration and increasing groundwater recharge. The authors of this…


2019 | Freshwater | Science | Publications & Reports

A Transdisciplinary Approach to Characterize Hydrological Controls on Groundwater-Dependent Ecosystem Health

Melissa M. Rohde, Sara B. Sweet, Craig Ulrich, Jeanette Howard

Groundwater plays an essential role in supporting freshwater species, riparian habitats, and migratory birds. These ecological communities, commonly referred to as groundwater-dependent ecosystems (GDEs), can suffer undesirable impacts from unsustainable pumping practices. This study assessed whether ecosystem health varied with groundwater availability in riparian forests in California’s…


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

Evidence Synthesis as the Basis for Decision Analysis: A Method of Selecting the Best Agricultural Practices for Multiple Ecosystem Services

Gorm E. Shackelford, Rodd Kelsey, William J. Sutherland, Christina M. Kennedy, Stephen A. Wood, Sasha Gennet, Daniel S. Karp, Claire Kremen, Nathaniel E. Seavy, Julie A. Jedlicka, Kelly Gravuer, Sara M. Kross, Deborah A. Bossio, Andrés Muñoz-Sáez, Deirdre G. LaHue, Kelly Garbach, Lawrence D. Ford, Mark Felice, Mark D. Reynolds, Devii R. Rao, Kathleen Boomer, Gretchen LeBuhn, Lynn V. Dicks

Agricultural management practices impacts not only on crops and livestock, but also soil health, water quality, wildlife, and ecosystem services. There is abundant, but disconnected, scientific evidence for the impacts of different practice. But this evidence is often not used in decision making by farmers or…


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

Aligning evidence generation and use across health, development, and environment

Heather Tallis, Katharine Kreis, Lydia Olander, Claudia Ringler, David Ameyaw, Mark E Borsuk, Diana Fletschner, Edward Game,, Daniel O Gilligan, Marc Jeuland, Gina Kennedy, Yuta J Masuda, Sumi Mehta, Nicholas Miller, Megan Parker, Carmel Pollino, Julie Rajaratnam, David Wilkie, Wei Zhang, Selena Ahmed, Oluyede C Ajayi, Harold Alderman, George Arhonditsis, Ines Azevedo, Ruchi Badola, Rob Bailis, Patricia Balvanera, Emily Barbour, Mark Bardini, David N Barton, Jill Baumgartner, Tim G Benton, Emily Bobrow, Deborah Bossio, Ann Bostrom, Ademola Braimoh, Eduardo Brondizio, Joe Brown, Benjamin P Bryant, Ryan SD Calder, Becky Chaplin-Kramer, Alison Cullen, Nicole DeMello, Katherine L Dickinson, Kristie L Ebi, Heather E Eves, Jessica Fanzo, Paul J Ferraro, Brendan Fisher, Edward A Frongillo, Gillian Galford, Dennis Garrity, Lydiah Gatere, Andrew P Grieshop, Nicola J Grigg, Craig Groves, Mary Kay Gugerty, Michael Hamm, Xiaoyue Hou, Cindy Huang, Marc Imhoff, Darby Jack, Andrew D Jones, Rodd Kelsey, Monica Kothari, Ritesh Kumar, Carl Lachat, Ashley Larsen, Mark Lawrence, Fabrice DeClerck, Phillip S Levin, Edward Mabaya, Jacqueline MacDonald Gibson, Robert I McDonald, Georgina Mace, Ricardo Maertens, Dorothy I Mangale, Robin Martino, Sara Mason, Lyla Mehta, Ruth Meinzen-Dick, Barbara Merz, Siwa Msangi, Grant Murray, Kris A Murray, Celeste E Naude, Nathaniel K Newlands, Ephraim Nkonya, Amber Peterman, Tricia Petruney, Hugh Possingham, Jyotsna Puri, Roseline Remans, Lisa Remlinger, Taylor H Ricketts, Bedilu Reta, Brian E Robinson, Dilys Roe, Joshua Rosenthal, Guofeng Shen, Drew Shindell, Ben Stewart-Koster, Terry Sunderland, William J Sutherland, Josh Tewksbury, Heather Wasser, Stephanie Wear, Chris Webb, Dale Whittington, Marit Wilkerson, Heidi Wittmer, Benjamin DK Wood, Stephen Wood,, Joyce Wu, Gautam Yadama and Stephanie Zobrist

Although environmental conservation, human health, and sustainable development challenges are interconnected, approaches to these challenges and the evidence used remain disconnected. Creating integrated solutions across these sectors will require better alignment of the methods used to assess the problems and quantifying success. In this review,…


2019 | Freshwater | Terrestrial | Marine | Economics | Publications & Reports

MarketLab: Where Economics and Finance Meet Conservation

Sarah Heard

We have an opportunity to apply the principles of economics and finance to demonstrate the value of conservation and create systems that incentivize the protection of nature at scale. In a changing climate, natural landscapes are extremely valuable for the benefits they provide to both…


2019 | Freshwater | Terrestrial | Science | Publications & Reports

Effects of cover crops on multiple ecosystem services: Ten meta-analyses of data from arable farmland in California and the Mediterranean

Gorm E. Shackelford, Rodd Kelsey, Lynn V. Dicks

As California and other major agricultural regions around the world tackle the challenge of increasing the sustainability of agriculture to improve environmental health, cover crops are increasingly viewed as an important practice to protect soils and contribute to climate change mitigation. In this analysis, the authors…