The forest is thinned at the Valentine Camp research center in the Sierra Nevada to reduce wildfire risk. Such efforts can enhance forest resiliency, benefit wildlife and increase water supplies. Photo/University of California Natural Reserve Center

COMMENTARY: Logging can protect forests, increase water supplies

By Edward Ring, Ag Alert

Practical solutions to California’s energy and water shortages will always have a better chance of being implemented if they adhere to the limitations placed upon them by those concerned about climate change. A solution that should work for everyone is forest thinning. It will save our forests, with the added benefit of increasing our water supply.

Wildfires have become catastrophic because the California Legislature funds fire suppression at the same time as it has regulated timber harvesting nearly out of existence. We are very good at squelching wildfires before they get started. But if ignited, our overgrown forests can now fuel infernos that were once unfathomable.

California’s forests today have tree densities that are many times what is historically normal, and conditions are more dangerous because we’ve reduced our annual timber harvest from 6 billion board feet per year in the 1990s to around 1.5 billion board feet today.

In past millennia, fires caused by lightning strikes routinely burned off undergrowth and a high percentage of small trees, leaving the larger trees to survive. Today, trees and undergrowth are so crowded that everything is stressed. Light, soil nutrients and water are shared by anywhere between two and six times as many trees and plants as these ecosystems naturally evolved to support. Observations of excessive tree density are corroborated by numerous studies, testimony and journalistic investigations.

This is why fires have gotten so bad. Anyone concerned about climate resiliency who cares about the health of our forests should be demanding forest thinning.

Examples of success with forest thinning are readily available. When the Creek Fire tore through the forests of Fresno, Madera, and Mariposa counties in 2020, 20,000 acres around Shaver Lake were spared. The fire engulfed an estimated 380,000 acres but inflicted almost no damage in these 20,000 acres of managed forests. For decades, Southern California Edison protected the watershed feeding into the 135,000 acre-foot Shaver Lake reservoir by forest thinning via selective logging and controlled burns. Significantly, the wildlife counts in these managed forests were consistently higher than average.

That forests subject to responsible logging actually report more robust populations of wildlife, including the endangered spotted owl, is rarely acknowledged. But comparisons between commercially managed forests in California’s Northern Sierra and adjacent national forests that are off limits to logging confirm this assertion. Even clear cuts, when implemented on a multi-decade rotation and with each cut limited in area, are beneficial to wildlife. They temporarily create meadows that create forage for deer, in turn creating food for mountain lions. These open areas also help owls and other raptors spot prey. When the slash is furrowed along level contours, runoff is contained and percolates.

Logging has come a long way. It’s time to bring it back to save the forests. But what about water? It turns out that forest thinning also reduces the amount of water that is immediately taken up by the roots of overcrowded trees and undergrowth and transpired into the atmosphere. Instead, more of this water can run off into tributaries or percolate to recharge springs. How much water?

A 2011 study by experts from the University of California, Merced, and UC Berkeley provides enough data to begin to answer that question. It reports that 60% of the state’s consumptive water comes in the form of Sierra runoff, and when forest cover is reduced by 40%, total runoff increases by an estimated 9%. California’s consumptive use of water, including urban and agricultural use but not including diversions for ecosystem health, is around 40 million acre-feet per year. That means if California’s forests were thinned appropriately, 2.2 million acre-feet of water would be added to California’s water supply in an average year.

This is not a trivial increase, particularly because it could be realized at no expense to taxpayers. In fact, reviving California’s timber industry would create thousands of jobs and industry profits, which would increase state tax revenues.

Another benefit would be the obvious upside of having an additional 2 million acre-feet of water to deliver to California farmers. That’s enough to irrigate at least a half-million acres, with all the jobs, food and tax revenues this productive farmland would contribute to California.

Restoring California’s forests to a healthy density is a win for everyone. It will restore wildlife habitat at the same time as it revitalizes California’s logging industry. It will sequester carbon in lumber products, generate fuel for biomass energy and prevent super fires. By transforming California’s forested watersheds, it will increase California’s water supply, boost hydroelectric power generation and, most importantly, help maintain California’s status as America’s food basket.

What are we waiting for? If you harvest more timber, you can harvest more water.

(Edward Ring is a senior fellow with the California Policy Center and author of the “The Abundance Choice: Our Fight for More Water in California.” He may be contacted at ed@edwardring.com.)