California’s Sierra-Cascade region plays a critical role in California’s water system. Snowpack in the region is a critical form of water storage, and forests and meadows play important roles in ensuring water quality and reliability.
More than 75% percent of Californians drink water that originates in the region, which has all the source watersheds for the Sacramento and San Joaquin rivers, and California’s developed water supply system. Percolating groundwater from the Sierra Nevada delivers an additional 4 million acre feet per year to central valley aquifers, accounting for about 10% of the water from all sources that reach this highly productive agricultural region.
The quantity and quality of water from Sierra-Cascade headwaters is threatened by overcrowded forests, degraded meadows, and a changing climate. Historically, Sierra-Cascade forests and meadows yielded more water, of a higher quality, and later in the summer than they do today. Although changing weather patterns play an important role, less crowded forests consumed less water per acre and allowed a deeper snowpack to develop.
Meadows characterized by meandering streams and floodplains acted like sponges, soaking up snowmelt, filtering it, and releasing it slowly—extending runoff into the dry California summer. Today, Sierra-Cascade forests have grown more dense and many meadow floodplains are channelized. As a result, our headwaters are less capable of providing these beneficial services to the state water system.
Overcrowded forests also threaten our water supply infrastructure. They are less resilient to drought, beetle infestation, and wildfire. The result is unprecedented tree mortality in the region—over 129 million killed by beetles and drought alone since 2010. Forests of dead trees create numerous challenges for water management, from an increase in flooding and landslides to a reduction in water quality and reservoir capacity.
Highlights From Our Newsroom
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![A few people wading in water use shovels and other tools. The water is flanked by long grass, bushes, and pine trees.](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2023/11/meadowRestoration_troy-SequoiaNF.jpg)
Meadow restoration in the Sierra-Cascade—keeping the momentum flowing
![hillside meadow looking out at a water body with a tree-covered mountain behind it](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2023/04/webberLake-littleTruckee.jpg)
Critical forest-restoration efforts help protect Little Truckee River headwaters
![aerial looking down across green pine trees with a building and open space behind them](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2022/12/earlyAction-quincyHospital-FI.jpg)
Historic state budget investments protect communities, watersheds, and hospital
![several people standing on a platform that faces a lake with a forest behind it](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2022/10/HazelCreek-boardwalk-FI.jpg)
Sly Park meadow restoration boosts water quality, recreation access
![low aerial looking out across a teal blue reservoir with green pine trees in the foreground and background.](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2022/07/ScottsFlatReservoir-FI-150x150.jpg)
Wildfire risk reduced near Scotts Flat Reservoir, Nevada City
![](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2022/07/sierraSnowpack-april2022-150x150.jpg)
California’s 2021-22 snowpack – prelude to a drought
![a large body of water surrounded by pine trees](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2022/06/LGVR-DroneLake-150x150.jpg)
Forestry project complete at Feather River reservoir
![](https://sierranevada.ca.gov/wp-content/uploads/sites/326/2022/03/22WIPsummit-postFI-150x150.jpg)
Leaders, scientists discuss wildfire recovery at WIP Summit
Regional Challenges, State Priorities
Forests in California's Sierra-Cascade region are unhealthy, vulnerable to damaging wildfires and an accelerating climate crisis. Local communities and economies are at risk. And it’s not just the Sierra-Cascade, California’s water security, outdoor access, biodiversity, and climate leadership all depend upon healthy, resilient forests.
Learn more about these challenges and priorities: