Wetland geomorphology and tidal hydrodynamics drive fine‑scale fish community composition and abundance

Environmental Biology of Fishes (Springer) | January 19th, 2024

What If California’s Drought Continues?

Public Policy Institute of California (PPIC) | August 20th, 2015

California is in the fourth year of a severe, hot drought—the kind that is increasingly likely as the climate warms. Although no sector has been untouched, impacts so

California is in the fourth year of a severe, hot drought—the kind that is increasingly likely as the climate warms. Although no sector has been untouched, impacts so far have varied greatly, reflecting different levels of drought preparedness. Urban areas are in the best shape, thanks to sustained investments in diversified water portfolios and conservation. Farmers are more vulnerable, but they are also adapting. The greatest vulnerabilities are in some low-income rural communities where wells are running dry and in California’s wetlands, rivers, and forests, where the state’s iconic biodiversity is under extreme threat. Two to three more years of drought will increase challenges in all areas and require continued—and likely increasingly difficult—adaptations. Emergency programs will need to be significantly expanded to get drinking water to rural residents and to prevent major losses of waterbirds and extinctions of numerous native fish species, including most salmon runs. California also needs to start a longer-term effort to build drought resilience in the most vulnerable areas.

What the US Supreme Court decision means for wetlands

Nature Portfolio (Springer Nature) | June 5th, 2023

When the River Meets the Sea

Pacific Institute | June 7th, 2019

Where the Wild Things Aren't: Making the Delta a Better Place for Native Species

Public Policy Institute of California (PPIC) | April 5th, 2012

This report proposes a reconciliation approach for addressing 160 years of accumulated problems and for managing the Delta’s ecosystem in the future. Reconciliation eco

This report proposes a reconciliation approach for addressing 160 years of accumulated problems and for managing the Delta’s ecosystem in the future. Reconciliation ecology seeks to improve conditions for native species while recognizing that most ecosystems have been altered irrevocably by human use and will continue to be used to support human goals. Improving ecosystem conditions for native species must, therefore, happen in a context of continuing use of land and water by humans and continuing physical and biological change.

Widespread aquifer depressurization after a century of intensive groundwater use in USA

American Association for the Advancement of Science (AAAS) | September 15th, 2023

Widespread potential loss of streamflow into underlying aquifers across the USA

Nature Portfolio (Springer Nature) | March 17th, 2021

Most rivers exchange water with surrounding aquifers. Where groundwater levels lie below nearby streams, streamwater can infiltrate through the streambed, reducing stream

Most rivers exchange water with surrounding aquifers. Where groundwater levels lie below nearby streams, streamwater can infiltrate through the streambed, reducing streamflow and recharging the aquifer. These ‘losing’ streams have important implications for water availability, riparian ecosystems and environmental flows, but the prevalence of losing streams remains poorly constrained by continent-wide in situ observations. Here we analyse water levels in 4.2 million wells across the contiguous USA and show that nearly two-thirds (64 per cent) of them lie below nearby stream surfaces, implying that these streamwaters will seep into the subsurface if it is sufficiently permeable. A lack of adequate permeability data prevents us from quantifying the magnitudes of these subsurface flows, but our analysis nonetheless demonstrates widespread potential for streamwater losses into underlying aquifers. These potentially losing rivers are more common in drier climates, flatter landscapes and regions with extensive groundwater pumping. Our results thus imply that climatic factors, geological conditions and historic groundwater pumping jointly contribute to the widespread risk of streams losing flow into surrounding aquifers instead of gaining flow from them. Recent modelling studies have suggested that losing streams could become common in future decades, but our direct observations show that many rivers across the USA are already potentially losing flow, highlighting the importance of coordinating groundwater and surface water policy.

Wildfire Impacts on Snowpack Phenology in a Changing Climate Within the Western U.S.

American Geophysical Union (AGU) | July 8th, 2022

Snowpack accumulation and melt are critical for water supply in the western United States. As the number and size of wildfires have increased, it is important to understa

Snowpack accumulation and melt are critical for water supply in the western United States. As the number and size of wildfires have increased, it is important to understand how these events impact the seasonal snowpack. Using data from the Snow Telemetery monitoring network, we quantify the impacts of wildfires on snowpack for various regions across the western U.S. and Alaska. The results indicate that decreases in snowpack tend to occur following fires. Also, the snowmelt period usually begins and finishes earlier in the spring due to the conditions in the burned forests. In regions of the western U.S. that are already experiencing earlier snowmelt due to climate changes, wildfires are further shifting the melt earlier, which could have substantial consequences for water supply and flood risks.

Wildfire smoke reduces lake ecosystem metabolic rates unequally across a trophic gradient

Nature Portfolio (Springer Nature) | May 22nd, 2024

Wildfires drive multi-year water quality degradation over the western United States

Nature Portfolio (Springer Nature) | June 23rd, 2025

Wildfires can dramatically alter water quality, resulting in severe implications for human and freshwater systems. However, regional-scale assessments of these impacts ar

Wildfires can dramatically alter water quality, resulting in severe implications for human and freshwater systems. However, regional-scale assessments of these impacts are often limited by data scarcity. Here, we unify observations from 1984–2021 in 245 burned watersheds across the western United States, comparing post-fire signals to baseline levels from 293 unburned basins. Organic carbon and phosphorus exhibit significantly elevated levels (p ≤ 0.05) in the first 1–5 years post-fire, while nitrogen and sediment show significant increases up to 8 years post-fire. During peak post-fire response years, average carbon, nitrogen, and phosphorus concentrations are 3–103 times pre-fire levels, and sediment 19–286 times pre-fire concentrations. Higher responses are linked with greater forested and developed areas, which respectively explain up to 31 and 33% of inter-basin response variability. Overall, this analysis provides strong evidence of multi-year water quality degradation following wildfires in the western United States and highlights the influence of basin and wildfire features. These insights may aid water managers in preparation efforts, increasing resilience of water systems to wildfire impacts.