San Joaquin Basin Flood‑MAR Watershed Studies Calaveras Watershed Study Area Report

California Department of Water Resources (DWR) | December 3rd, 2025

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Jo

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Joaquin watersheds and a Basinwide Summary — deliver data‑driven assessments of climate change vulnerabilities and adaptation that reveal risks and consequences and call for bold, coordinated solutions. In the San Joaquin Basin, the effects of climate change will exacerbate long-standing water management challenges. As these reports quantify, every water management sector — flood, water supply (surface and groundwater), and ecosystems — is vulnerable. Without bold action, the basin and its watersheds face mounting threats to communities, economies, and ecosystems. Although each watershed has unique characteristics, all confront a future climate that is hotter and characterized by more extreme weather. For flood management, the 2022 Central Valley Flood Protection Plan states clearly: Catastrophic flooding in the San Joaquin Basin is not a question of if, but when. Meanwhile, the reliability of water supplies is expected to worsen, and ecosystems face degradation. Click here to be taken to the California Department of Water Resources Watershed Studies home page

San Joaquin Basin Flood‑MAR Watershed Studies Merced Watershed Study Area Report

California Department of Water Resources (DWR) | December 3rd, 2025

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Jo

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Joaquin watersheds and a Basin-wide Summary — deliver data‑driven assessments of climate change vulnerabilities and adaptation that reveal risks and consequences and call for bold, coordinated solutions. In the San Joaquin Basin, the effects of climate change will exacerbate long-standing water management challenges. As these reports quantify, every water management sector — flood, water supply (surface and groundwater), and ecosystems — is vulnerable. Without bold action, the basin and its watersheds face mounting threats to communities, economies, and ecosystems. Although each watershed has unique characteristics, all confront a future climate that is hotter and characterized by more extreme weather. For flood management, the 2022 Central Valley Flood Protection Plan states clearly: Catastrophic flooding in the San Joaquin Basin is not a question of if, but when. Meanwhile, the reliability of water supplies is expected to worsen, and ecosystems face degradation. Click here for the California Department of Water Resources Watershed Studies homepage

San Joaquin Basin Flood‑MAR Watershed Studies Stanislaus Watershed Study Area Report

California Department of Water Resources (DWR) | December 3rd, 2025

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Jo

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Joaquin watersheds and a Basin-wide Summary — deliver data‑driven assessments of climate change vulnerabilities and adaptation that reveal risks and consequences and call for bold, coordinated solutions. In the San Joaquin Basin, the effects of climate change will exacerbate long-standing water management challenges. As these reports quantify, every water management sector — flood, water supply (surface and groundwater), and ecosystems — is vulnerable. Without bold action, the basin and its watersheds face mounting threats to communities, economies, and ecosystems. Although each watershed has unique characteristics, all confront a future climate that is hotter and characterized by more extreme weather. For flood management, the 2022 Central Valley Flood Protection Plan states clearly: Catastrophic flooding in the San Joaquin Basin is not a question of if, but when. Meanwhile, the reliability of water supplies is expected to worsen, and ecosystems face degradation. Click here to be taken to the California Department of Water Resources Watershed Studies homepage

San Joaquin Basin Flood‑MAR Watershed Studies Tuolumne Watershed Study Area Report

California Department of Water Resources (DWR) | December 3rd, 2025

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Jo

The San Joaquin Basin Flood‑MAR Watershed Studies (Watershed Studies) — comprising five watershed reports for Calaveras, Stanislaus, Tuolumne, Merced and Upper San Joaquin watersheds and a Basin-wide Summary — deliver data‑driven assessments of climate change vulnerabilities and adaptation that reveal risks and consequences and call for bold, coordinated solutions. In the San Joaquin Basin, the effects of climate change will exacerbate long-standing water management challenges. As these reports quantify, every water management sector — flood, water supply (surface and groundwater), and ecosystems — is vulnerable. Without bold action, the basin and its watersheds face mounting threats to communities, economies, and ecosystems. Although each watershed has unique characteristics, all confront a future climate that is hotter and characterized by more extreme weather. For flood management, the 2022 Central Valley Flood Protection Plan states clearly: Catastrophic flooding in the San Joaquin Basin is not a question of if, but when. Meanwhile, the reliability of water supplies is expected to worsen, and ecosystems face degradation. Click here for the California Department of Water Resources Watershed Studies home page

San Mateo Plain Groundwater Basin Assessment

San Mateo County | July 12th, 2018

On behalf of the County of San Mateo, EKI Environment & Water, Inc., Todd Groundwater, and HydroFocus, Inc. (the Project Team) have prepared this report to summarize

On behalf of the County of San Mateo, EKI Environment & Water, Inc., Todd Groundwater, and HydroFocus, Inc. (the Project Team) have prepared this report to summarize the efforts and results of the San Mateo Plain Groundwater Basin Assessment (Project). The Project was conducted by the County, with the support of the Project Team, to comprehensively evaluate the San Mateo Plain Groundwater Subbasin as defined by the Department of Water Resources (DWR).

Santa Ana Winds of Southern California: Their climatology, extremes, and behavior spanning six and a half decades

American Geophysical Union (AGU) | March 24th, 2016

Santa Ana Winds (SAWs) are an integral feature of the regional climate of Southern California/Northern Baja California region, but their climate-scale behavior is poorly

Santa Ana Winds (SAWs) are an integral feature of the regional climate of Southern California/Northern Baja California region, but their climate-scale behavior is poorly understood. In the present work,we identify SAWs in mesoscale dynamical downscaling of a global reanalysis from 1948 to 2012. Model windsare validated with anemometer observations. SAWs exhibit an organized pattern with strongest easterlywinds on westward facing downwind slopes and muted magnitudes at sea and over desert lowlands. Weconstruct hourly local and regional SAW indices and analyze elements of their behavior on daily, annual, andmultidecadal timescales. SAWs occurrences peak in winter, but some of the strongest winds have occurred infall. Finally, we observe that SAW intensity is influenced by prominent large-scale low-frequency modes ofclimate variability rooted in the tropical and north Pacific ocean-atmosphere system.

Satellite observations indicate that chia uses less water than other crops in warm climates

Nature Portfolio (Springer Nature) | September 30th, 2024

Scaling protection and restoration of natural infrastructure to reduce flood impacts and enhance resilience

Shore & Beach (American Shore and Beach Preservation Association) | October 1st, 2019

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction strategies. Interest increased in flood risk reduction methods using natural and nature- based features, in part, because of increased recognition that such could provide both flood risk reduction and other benefits, such as water quality uplift, community recreational space, and fish and wildlife habitat. Recent flood disasters and the rising costs of disaster response and recovery have triggered policy shifts toward economi- cally efficient investments that enhance greater community resilience. While natural infrastructure is becoming more widely recognized as a tactic for building community and ecological resilience to erosion and flooding, it remains underutilized. Actions to aid consideration of natural infrastructure and scale up its use are presented.

Scattered tree death contributes to substantial forest loss in California

Nature Portfolio (Springer Nature) | January 20th, 2024

In recent years, large-scale tree mortality events linked to global change have occurred around the world. Current forest monitoring methods are crucial for identifying m

In recent years, large-scale tree mortality events linked to global change have occurred around the world. Current forest monitoring methods are crucial for identifying mortality hotspots, but systematic assessments of isolated or scattered dead trees over large areas are needed to reduce uncertainty on the actual extent of tree mortality. Here, we mapped individual dead trees in California using sub-meter resolution aerial photographs from 2020 and deep learning-based dead tree detection. We identified 91.4 million dead trees over 27.8 million hectares of vegetated areas (16.7-24.7% underestimation bias when compared to field data). Among these, a total of 19.5 million dead trees appeared isolated, and 60% of all dead trees occurred in small groups ( ≤ 3 dead trees within a 30 × 30 m grid), which is largely undetected by other state-level monitoring methods. The widespread mortality of individual trees impacts the carbon budget and sequestration capacity of California forests and can be considered a threat to forest health and a fuel source for future wildfires.

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

Environmental Research Letters (IOP) | September 30th, 2019

Management of protected lands may enhance ecosystem services that conservation programs were designed to protect. Practices that build soil organic matter on agri

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 (CWD), increasing actual evapotranspiration (AET) and increasing groundwater recharge (RCH). We developed nine spatially-explicit land use and conservation scenarios (2001–2100) in the LUCAS land use change model to address two questions for California working lands (cropland and rangeland): How does land use change limit opportunities to manage soils for hydrologic climate adaptation benefits? To what extent and where can soil management practices increase climate adaptation on protected working lands? Hydrologic benefits [Σ(ΔCWD, ΔAET, ΔRCH)] due to soil management were simulated in the Basin Characterization Model (a state-wide water balance model) for two Representative Concentration Pathway 8.5 climate models. LUCAS simulated land conversion and new conservation easements with potential for maximum hydrologic benefits. Climate drove differences in lost potential for water benefits due to urbanization (33.9–87.6 m3 × 106) in 2050. Conflict between development pressure and potential hydrologic benefits occurred most in Santa Clara County in the San Francisco Bay Area and Shasta County in Northern Sacramento Valley. Hydrologic benefits on easements were similar in magnitude to losses from development. Water savings from management of California Land Conservation (a.k.a. Williamson) Act contract lands were an order of magnitude greater, totaling over 460 m3 × 106 annually in a drier climate by 2050. Few counties provide most benefits because of soil properties, climate and land area protected. The increase in hydrologic benefits varies by agricultural practice and adoption rate, land use type and configuration, and terms of conservation agreements. The effectiveness of programs designed to improve climate adaptation at county to state scales will likely increase by taking this variability into consideration.