Deal preserves Sierra Nevada land, helps with drought.
Thinning its overgrown treesmay increase California’s water supply
More than 10,000 acres of scenic meadows, forests and trout streams in the Sierra Nevada 10 miles west of Lake Tahoe are to be preserved in a deal in which environmentalists hope to prove that thinning out overgrown forests can increase California’s water supply.
The Northern Sierra Partnership, an environmental group in Palo Alto and founded by longtime Silicon Valley leaders Jim and Becky Morgan, joined with the Nature Conservancy and the American River Conservancy to buy the land for $10.1 million from Simorg West Forests, a timber company based in Atlanta.
The deal, which closed Aug. 5, preserves a landscape south of Interstate 80 in Placer County adjacent to Granite Chief Wilderness in the Tahoe National Forest. The land contains more than 20 miles of blue ribbon trout streams.
Home to black bears, mountain lions, deer, songbirds and
other wildlife, the remote property also includes the headwaters of two of California’s popular whitewater rafting rivers, the North and Middle forks of the American River.
“There are forests and meadows, and granite outcroppings,” said David Edelson, Sierra Nevada director for the Nature Conservancy. “There are terrific views looking down the American River watershed and toward the Granite Chief Wilderness.”
For years, loggers turned the property’s evergreen forests into wooden crates for Central Valley fruits and vegetables. Now the environmental groups plan to remove old logging roads and restore the landscape.
But more significantly, the purchase could change how California, now suffering through the fourth year of a historic drought, manages its Sierra Nevada forests in ways that might provide more water to cities, farms and the environment.
Many Sierra Nevada forests, including the ponderosa pine, white fir and Jeffrey pine forests on this property, burned roughly every 10 years in lightningsparked fires before California became a state in 1850. Those natural fires thinned out dead trees and brush.
But starting roughly 100 years ago, the U.S. Forest Service and other agencies began putting out the fires, often to protect communities that had sprung up through the mountains. As a result, the forests grew thicker. Now, across millions of acres of the Sierra, around Lake Tahoe and in other parts of the West, some evergreen forests have five ormore times the trees per acre they would naturally. Many of the trees are small, spindly and often prone to disease and beetles.
UC Merced and UC Berkeley scientists have done research indicating that if these forests are thinned it could increase the amount of water flowing from the Sierra Nevada into streams, rivers, the Sacramento-San Joaquin River Delta and San Francisco Bay.
“We’re trying to keep the trees in check so the forest is in a more sustainable condition,” said Roger Bales, a UC Merced engineering professor who directs the university’s Sierra Nevada Research Institute. “One of the benefits is that you get more water.”
The Sierra Nevada provides 40 percent or more of California’s water supply through snow and rain.
The trees in unnaturally dense forests drink up precipitation that falls in the mountains, allowing less to run off. And often snow stays on top of their tight forest canopy and evaporates, rather than naturally flowing into the soil and streams, researchers say.
Worse, dense forests increase the intensity of fires when they burn. The huge fires create erosion, which damages streams and lakes.
By thinning about 25 to 50 percent of the trees in many of these areas, Bales said, the amount of water flowing into streams could increase from 9 to 16 percent. Sierra-wide, that could increase the water running off by 500,000 to 1 million acre feet a year, enough for up to 5 million people for a year. Much of that would flow into rivers, where it could be stored behind existing dams.
But thinning forests isn’t cheap. It can cost $1,000 to $2,000 per acre. And spindly trees and brush have limited value as timber to offset costs.
The environmental groups who purchased the Sierra property, known as the American River Headwaters, have raised $3 million to work with scientists to measure the impact of thinning and controlled burns on water runoff.
“What we’re most excited about is the potential to use this as a living laboratory,” Edelson said. “This could be a game changer for the Sierra’s forests.”
If they can show that thinning forests generates more water, that could convince water districts and other agencies to invest water bond money and other funds into expanding Sierra forest thinning to boost water supplies and reduce fire risk.
To pay for the $10.1 million land purchase, the state provided $5 million, most of which came from Proposition 84, a parks and water bond act passed in 2006 by California voters. The other $5.1 million and the $3 million research fund came from private donations, including $1 million from the Morgan Family Foundation in Los Altos.
That foundation was established by Jim Morgan, the former CEO of Applied Materials, and his wife, Becky, a former Santa Clara County supervisor and Republican state senator.
In 2007, the Morgans were the driving force behind setting up the Northern Sierra Partnership, an alliance of conservation groups who set a goal of preserving 100,000 acres between Lake Tahoe and Mount Lassen. So far, the partnership has preserved 50,715 acres by purchasing land or development rights from willing sellers, much of it adjacent to national forests in checkerboard-patterns that originated with federal grants to railroads in the mid-1800s.
“This was the largest piece of unprotected land along the Sierra Crest south of Donner Summit,” Lucy Blake, president of the Northern Sierra Partnership, said of the recent purchase. “This is a big win for water quality, for wildlife and for everyone who loves the splendid landscapes of the Sierra Nevada.”