For a state whose name has become synonymous with drought, California never seemed that dry during my youth. The creek near my childhood home always held water – even flooding on occasion – nurturing neighboring vineyards in my wine country community. My college stomping grounds on California’s northern coast were so saturated with maritime moisture that my dorm room walls would grow mold if left unchecked. And while summer days were hot, a nearby creek or river always offered plenty of water for a refreshing dip.

My brief forays into seasonal work during my college years provided a whirlwind tour of California’s diverse geography. Stationed on the Eldorado National Forest working for the Forest Service, I took advantage of quiet days in the visitor center to follow twisting trails and streams on a forest map and read countless books about public lands.

California is fortunate to be endowed with topography so unique that the state’s mountains and valleys function like a giant sink. The high elevation Sierra Nevada mountain range, running nearly the entire length of the state, acts like a giant squeegee that extracts rain and snow from storms that roll in from the Pacific Ocean. The mountains accumulate a large snowpack that serves as a giant freshwater reservoir for the state throughout the year. As snow melts, the conifer forests that flank the mountains filter it through their vegetation and soil. Water flows from the forested headwaters downhill into the Central Valley, where it is largely utilized for agriculture on its way toward the San Francisco Delta.

On those quiet down days, I learned that the Sierra Nevada mountains contain an impressive matrix of public lands, including eight National Forests and two National Parks. These and the state’s other National Forests play a disproportionately large role in providing water to the state. Although they collectively cover only 20 percent of California, they supply a whopping 65 percent of the state’s water. Tracing tributaries with my pointer fingers, I learned that the snow and rain that fell on the visitor center would eventually end up flowing through California’s capital as the American River.

Water Dependent, Water Scarce

California’s National Forest headwaters have supported one of the richest and varied histories in the United States. Not long ago, California’s numerous Native American groups relied on the state’s vast forests to nurture abundant pacific salmon runs. In the 19th century, gold miners seeking a better fortune depended on Sierra Nevada watersheds for their mining operations. The 20th century saw the proliferation of agriculture across California and an increased reliance on water for new crops. Now in the 21st century, the Silicon Valley tech industry and a growing recreational and tourism industry count on the same forested watersheds. California’s prominence as the eighth largest economy in the world is due in no small part to its unique geography’s role in providing water.

As of August 2015, farmers had pulled more than 542,000 acres of farmland out of production with an estimated annual economic impact of $2.7 billion.

Unfortunately, as time progresses, the state is beginning to understand just how dependent it is on its water resources. California’s record five-year drought has parched the state, slowing rivers to a trickle, challenging water supply and forcing many farmers to abandon their fields. In 2014, Governor Jerry Brown declared a state of emergency, requiring industries and citizens to conserve water. While it’s hard to measure, the economic impact of the drought in a state that leads the nation in agriculture, technology and innovation is immense. As of August 2015, farmers had pulled more than 542,000 acres of farmland out of production with an estimated annual economic impact of $2.7 billion.

A New Normal

To make matters worse, climate scientists warn that this is just the beginning. Climate models show that the reduced precipitation and increased temperatures we’ve seen in the 2012-2015 drought are representative of a startling long-term trend. As the years progress, there will be less snow accumulating in the mountains and the snowpack will melt earlier in the year. This climatic trend will not only challenge the state’s economy, but it will threaten the very National Forests that helped California flourish.

Long-term drought not only means less water in streams and reservoirs, but it means that entire watersheds are affected. Drought often coincides with hot temperatures that increase the evaporative stress on trees, meaning that trees have to work harder for less water. Hot and dry conditions lead to “drought stress” in trees, a condition that has been sufficient to kill thousands of acres of forest on the western flank of the Sierras in the last few years. As drought stress weakens forest health, trees become more susceptible to insect infestations and diseases. Perhaps more frightening is the simple fact that hot temperatures and abnormally low precipitation create the ideal conditions for severe wildfires.

While the threat of wildfire looms over much of the western U.S., fire’s impact is particularly pronounced in California where so many towns and cities lie in the shadows of forested mountains. The East Bay Area of Oakland relies on the Mokelumne River watershed on the Stanislaus and Eldorado National Forests for more than 90 percent of its water. The City of San Francisco relies on snowmelt and rainfall captured by the Tuolumne River watershed on the Stanislaus National Forest and a portion of Yosemite National Park. And, while the average Los Angeles resident may not realize it, the San Gabriel Mountains that make up much of the Angeles National Forest supply a critical 30 percent of water for Los Angeles County.

The Rim Fire of 2013 gave Californians an idea of what fire conditions will look like if drought persists. Over a nine week period, firefighters struggled to get control of the intense blaze as it burned across more than 250,000 acres of the Stanislaus National Forest and Yosemite National Park. Fires like the Rim Fire are problematic not only because they are so difficult to control, but also because they are increasingly damaging to area water supplies. When severe fires burn through a forest, they often eliminate all vegetation and literally change the top layer of soil. This “hydrophobic” soil surface repels water rather than absorbing it, causing faster flows, erosion and sedimentation downstream. This in turn degrades water supplies and requires significant and expensive treatment practices. Had the Rim Fire occurred farther east, it would have burned through the high-elevation watershed that supplies San Francisco with water.

A Different State

Vast forests, abundant wildlife, mineral riches, a friendly climate and reliable water drew early Californians to the Golden State. A century and a half later our entire nation depends on California’s forested watersheds to help grow our food, manufacture our computers and provide life long memories. As important as these are to us, humans aren’t the only species that depend on California’s forests. Threatened pacific salmon and steelhead need clean, abundant water to spawn, and rare amphibians rely on wet mountain meadows to survive.

California’s water future is only as good as its headwaters are healthy.

It’s only been 15 years since my childhood, but California has changed in so many ways. The creek near my childhood home only flows in winter and spring now and many of the hillsides near my old home are brown when they used to be green. The impact of California’s drought goes well beyond browning lawns and intermittently flowing creeks. The drought has caused significant damage to the very ecosystems that are so crucial to its water supply, and these forests may take decades to recover.

As California breathes a sigh of relief following the first “normal” winter in years, managers are looking at what’s to come. While the water conservation measures proposed by Governor Brown will certainly help reduce demand at the tap, California’s water future is only as good as its headwaters are healthy. The problems facing California’s forests are not unique to the Golden State, but it’s hard to imagine a place where the stakes are higher.

National Forest Foundation