In a normal year, groundwater accounts for 40 percent of California’s water supply. That number jumps to 60 percent during a drought. It’s also critically important for sustaining certain types of aquatic, terrestrial and coastal ecosystems.
Yet decades of unregulated groundwater withdrawal has compromised that ability to provide for people and nature. Wells dry up, water quality declines, and rivers, wetlands, and springs disappear.
To address this problem, California passed legislation requiring that groundwater basins be managed sustainably. We still face gaps, however, in our understanding of how to manage these basins to ensure the health of the ecosystems they support. Conservancy scientists are working with water managers and state agencies to close those gaps.
Adam H. Love, Andy Zdon, Naomi S. Fraga, Brian Cohen, Maura Palacios Mejia, Rachel Maxwell, Sophie Parker
This paper presents results from the Mojave Desert Springs research project. The authors present a comprehensive statistical analysis of similarities between California desert springs. An observed lack of correlation between the springs’ hydrologic and ecological parameters suggests that each spring represents a somewhat unique…
Kristen Wilson, Dale W. Johnson, Douglas F. Ryan, ed.
Authored by TNC staff and colleague, Chapter 8 of this report synthesizes environmental monitoring and studies performed at Sagehen Experimental Forest that are relevant to water quality regulatory agencies. Water quality in the basin is mainly controlled by groundwater emerging in springs, but wildland fires,…
Naomi S. Fraga, Brian S. Cohen, Andy Zdon, Maura Palacios Mejia, Sophie S. Parker
This paper presents novel botanical inventories of 48 desert springs as part of the Mojave Springs Research Project. The authors assess plant species composition and richness within and between springs and evaluate how botanical diversity relates to physical and hydrological parameters. The results of…
Sophie S. Parker, Bradley Franklin, Brian S. Cohen, Melissa M. Rohde, Michael Clifford, Andrew Williams
Climate change will cause severe financial, social, and environmental upheaval if a massive reduction in carbon emissions is not achieved by 2030. To address this challenge, rechargeable lithium-ion batteries will play a key role in transitioning the energy and transportation sectors away from fossil fuel…
Melissa M. Rohde, Tanushree Biswas, Ian W. Housman, Leah S. Campbell, Kirk R. Klausmeyer, Jeanette Howard
Groundwater dependent ecosystems (GDEs) are increasingly threatened worldwide, but the shallow groundwater resources that they are reliant upon are seldom monitored. In this study, the researchers used satellite-based remote sensing, climate data, and machine learning to predict groundwater levels over a 35 year period (1985…
Melissa M. Rohde, Tanushree Biswas, Ian W. Housman, Leah S. Campbell, Kirk R. Klausmeyer, Jeanette Howard
Groundwater dependent ecosystems (GDEs) are critical habitats throughout California that rely on shallow groundwater. Unfortunately, only a small subset of wells provide monitoring data for shallow groundwater. This tool, developed for a publication in Frontiers in Earth Science, uses satellite data and machine learning tools to…
Melissa M. Rohde, John C. Stella, Dar A. Roberts, Michael Bliss Singer
This study combines satellite, groundwater, and streamflow data over a 5 year period (2015-2020) to understand the impacts of groundwater depth and streamflow alteration on groundwater-dependent vegetation across California. The study shows that deeper groundwater levels resulted in poor vegetation health, but that current water management…
Sarah M. Yarnell, Ann Willis, Alyssa Obester, Ryan A. Peek, Robert A. Lusardi, Julie Zimmerman, Theodore E. Grantham, Eric D. Stein
Very few rivers have protections to protect flow for species and ecosystems, in part because of the complexity and resources required to develop ecological flow criteria - the amount of water needed in rivers to protect ecosystems. The authors applied the California Environmental Flows Framework,…
Kelsey Jessup, Sophie S. Parker, John M. Randall, Brian S. Cohen, Rowan Roderick-Jones, Shona Ganguly, Jill Sourial
This paper presents results from Planting Stormwater Solutions, part of TNC’s Urban Conservation work in Los Angeles. The authors develop a methodology to prioritize siting of vegetated nature-based solutions for stormwater capture so that these projects maximize benefits to biological diversity, social and public…
Christopher Dillis, Van Butsic, Jennifer Carah, Samuel Zipper, Theodore Grantham
Water management practices for cannabis farming in California are not well understood. This study examined permit reporting data and found that the vast majority (>75%) of permitted cannabis farms use groundwater wells to source water, with many wells located outside regulated groundwater basins. Groundwater pumping…
Barton H. Thompson, Jr., Melissa M. Rohde, Jeanette K. Howard, Sandi Matsumoto
In 2014, California’s landmark Sustainable Groundwater Management Act (SGMA) promised comprehensive management of California’s groundwater. This report, Mind the Gaps: The Case for Truly Comprehensive Sustainable Groundwater Management, based on joint analysis by Water in the West at Stanford University and The Nature Conservancy, finds…
Kirk Klausmeyer, Jeanette Howard, Melissa Rohde, Charlotte Stanley
The first step to sustainably manage groundwater dependent ecosystems (GDEs) is to identify where they are. The Nature Conservancy developed a statewide spatial database that provides locations of seeps and springs, wetlands, and vegetation likely to depend on groundwater. This database (version 2.0) is an…
Charlotte Stanley, Kirk Klausmeyer
This dataset categorizes the rivers and streams in the Central Valley on the likelihood that they are interconnected surface water (ISW) -- surface water hydraulically connected to groundwater. The dataset includes information on the average, maximum, and minimum depth to groundwater, using groundwater elevation…
Laurel Saito, Bill Christian, Jennifer Diffley, Holly Richter, Melissa M. Rohde, Scott A. Morrison
In this paper, we describe minimum provisions for planning, managing, and monitoring groundwater in a manner that collectively can lower the risk of harm to groundwater-dependent ecosystems and species, as well as providing sustainable groundwater resources for communities. The paper has a special emphasis on…
H. Scott Butterfield, T. Rodd Kelsey, and Abigail K. Hart, Editors
As the world population grows, so does the demand for food, putting unprecedented pressure on agricultural lands. At the same time, climate change, soil degradation, and water scarcity mean that productivity of many of these lands is deteriorating. In many desert dryland regions, drinking wells…
Mary Kang, Debra Perrone, Ziming Wang, Scott Jasechko, Melissa M. Rohde
To ensure that California’s groundwater is sustainably managed in the future and over the long-term, current state definitions of what constitutes groundwater may need to be revised, according to this research published in PNAS. A research collaboration between McGill University, University of California Santa…
Sophie S. Parker, Andy Zdon, William T. Christian, Brian S. Cohen, Maura Palacios Mejia, Naomi S. Fraga, Emily E. Curd, Kiumars Edalati, Mark A. Renshaw
This paper presents results from the Mojave Desert Springs research project, and discusses why the conservation of these groundwater-dependent ecosystems is so critical to biodiversity. The authors present results of a comprehensive survey of Mojave Desert springs including hydrological and ecological observations, and an…
M. Florencia Miguel, H. Scott Butterfield, Christopher J. Lortie
This meta-analysis provides a global synthesis of the which restoration practices – active vs. passive – are most successful at restoring plants, animals, and other ecosystem functions to dryland agricultural (grazing and farmlands) ecosystems, including the San Joaquin Valley of California where The Nature Conservancy…
Maura Palacios Mejia, Emily Curd, Kiumars Edalati, Mark A. Renshaw, Roy Dunn, Daniel Potter, Naomi Fraga, Jenna Moore, Justin Saiz, Robert Wayne, Sophie S. Parker
This paper presents results from the Mojave Desert Springs research project. The authors used an environmental DNA (eDNA) technique to assess biodiversity at four naturally occurring springs. They compared the effectiveness of detecting DNA in water and sediment with conventional field survey and…
