Californians have fundamentally altered many of the state’s rivers and streams with dams, pipes, and diversions, and the State is home to some of the world’s most complex water delivery projects. As an unfortunate consequence, habitat for many freshwater species has been degraded or destroyed.

But, is it necessary to tradeoff the freshwater needs of birds, fish, and other species against the needs of farms and cities? Could freshwater flows be managed to better mimic the dynamics of their unimpaired past, dynamics to which native species have adapted and need to persist? And how should climate change considerations be incorporated into water management, to enhance the resilience of freshwater systems for both people and nature?

Our science is focused on tackling these questions.

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 | Science

Not Leaving it to Beaver

Can we restore meadows by mimicking beavers?

2014 | Freshwater | Science | Publications & Reports

Low-Cost Restoration Techniques for Rapidly Increasing Wood Cover in Coastal Coho Salmon Streams

Jennifer K. Carah, Christopher C. Blencowe, David W. Wright

Coho salmon in California are critically imperiled so there is strong impetus to achieve as much habitat restoration as possible in priority watersheds quickly and with limited resources. This paper discusses a proven low-cost restoration technique for salmon streams. Adding fallen trees and pieces…

2014 | Freshwater | Maps & Webmaps

Hope Runs Deep: Conservation Solutions for Salmon in Shasta Valley

Jeanette Howard, Megan Webb, Katie Andrews

Using maps, images, and video, this interactive StoryMap illustrates how The Nature Conservancy works with partners in Shasta Valley, California to find conservation solutions that work for salmon and people. 

2013 | Freshwater | Terrestrial | Planning | Science | Publications & Reports

Successes, Failures and Suggested Future Directions for Ecosystem Restoration of the Middle Sacramento River, CA

Golet G.H., D.L. Brown, M. Carlson, T. Gardali, A. Henderson, K.D. Holl, C.A. Howell, M. Holyoak, J. Hunt, G.M. Kondolf, E.W. Larsen, R.A. Luster, C. McClain, C. Nelson, S. Paine, W. Rainey, Z. Rubin, F. Shilling, J.G. Silveira, H. Swagerty, N.M. Williams, D.M. Wood

Large-scale ecosystem restoration projects seldom undergo comprehensive evaluation to determine project effectiveness. Consequently, there are missed opportunities for learning and strategy refinement. In their synthesis of 36 ecological indicators of Sacramento River riparian restoration, the authors found steady progress in the restoration of riparian habitats and…

2013 | Freshwater | Planning | Science | Publications & Reports

Below the Surface: California’s Freshwater Diversity

Jeanette Howard, Kirk Klausmeyer, Kurt Fesenmyer

Californians face profound decisions regarding the management of their state’s increasingly limited water supply. Critical for decision-making is information about the plants and animals that also rely on California’s freshwater resources to survive. This report includes an atlas of the freshwater biodiversity patterns in California,…

2013 | Freshwater | Terrestrial | Science | Publications & Reports

Decline and Recovery of Small Mammals after Flooding: Implications for Pest Management and Floodplain Community Dynamics

Golet G.H., J. Hunt, D. Koenig

Floodplains often are managed both for agriculture and as habitat for native species. On the Sacramento River, farmers have expressed concern that natural areas may be sources of pests to adjoining farmlands, generating opposition to riparian restoration. This study examined this question by studying small…

2012 | Freshwater | Terrestrial | Marine | Science | Publications & Reports

Restoring Salmon Habitat: Garcia River Forest

Jennifer Carah, Jason Pelletier

A two-page summary of salmon restoration efforts at the Garcia River Forest on the North Cost of California focusing on the reintroduction of wood in streams as a strategy.

2012 | Freshwater | Maps & Webmaps

California's Flood Risk: Green Solutions for an Uncertain Future

Kirk Klausmeyer, Megan Webb

Almost 9 million acres of California are at risk from flooding. These flood zones cover 16% of the state’s urban and suburban development, and 36% of the state’s land dedicated to cultivated crops. As the climate changes, flooding is likely to be more frequent and…

2012 | Freshwater | Terrestrial | Marine | Science | Video

Saving Salmon One Log at a Time

The Nature Conservancy, Jennifer Carah

Salmon and trout thrive in streams with cool water, low levels of sand and silt, and deep, shaded pools. Intensive forest management in California over the last 150 years led to the removal of these streamside trees, eliminating the cover that salmon depend upon. Restoration…

2011 | Freshwater | Marine | Planning | Publications & Reports

SalmonScape: Priorities for Conserving California’s Salmon and Steelhead Diversity

Jeanette Howard, Kirk Klausmeyer, Sally Liu

This report analyzed Chinook, coho salmon, and steelhead trout population and habitat data across California to identify a portfolio of places called the SalmonScape. SalmonScape identifies areas in California with the greatest potential for habitat restoration and protection, and where wild salmon also have the best…

2011 | Freshwater | Marine | Planning | Maps & Webmaps

SalmonScape map

Megan Webb, Jeanette Howard , Kirk Klausmeyer, Sally Liu

The Conservancy's SalmonScape is an analysis and map that analyzed and ranked the watersheds that support or contribute to salmon habitat in California based on where conservation efforts would have the best return-on-investment. The analysis helped coordinate and direct salmon conservation efforts across the state.

2011 | Freshwater | Science | Publications & Reports

Identifying habitat conservation priorities and gaps for migratory shorebirds and waterfowl in California

Stralberg, D., D. Cameron, M. Reynolds, C. Hickey, K. Klausmeyer, S. Busby, L. Stenzel, W. Shuford, G. Page

This analysis provides the first comprehensive overview of the specific habitats used by 42 different migratory waterbird species throughout California. The authors reveal important gaps in protection for wintering habitat for shorebirds and waterfowl and highlight the importance of agricultural lands in migratory bird conservation. They advocate…

2008 | Freshwater | Terrestrial | Science | Publications & Reports

Wildlife Response to Restoration on the Sacramento River

Golet G.H., T. Gardali, C. Howell, J. Hunt, R. Luster, B. Rainey, M. Roberts, H. Swagerty, N. Williams

Studies that assess the success of riparian restoration projects seldom focus on wildlife. More often, vegetation is studied, with the assumption that animal populations will recover once adequate habitats are established. Authors of this paper present an exception: findings of a suite of studies that…

2006 | Freshwater | Terrestrial | Science | Publications & Reports

Abundance Patterns of Landbirds in Restored and Remnant Riparian Forests on the Sacramento River, California, U.S.A.

Gardali T. , A.L. Holmes, S.L. Small, N. Nur, G.R. Geupel, G.H. Golet

Restoration efforts on the Sacramento River are focusing on revegetating the land with native plants and restoring natural river processes in an attempt to recover wildlife populations. To evaluate the success of these efforts, surveys were conducted of landbirds on revegetated and remnant riparian plots.…

2006 | Freshwater | Terrestrial | Planning | Economics | Science | Publications & Reports

Assessing societal impacts when planning restoration on large alluvial rivers: A case study of the Sacramento River Project, CA

Golet G.H., M.D. Roberts , E.W. Larsen, R.A. Luster, R. Unger, G. Werner, G.G. White.

River restoration projects have the potential to influence many of the services that rivers provide to people, yet rarely is this studied in a comprehensive manner. This paper reports on a set of coordinated studies that were conducted to evaluate the effects of alternative restoration…