Thinning Sierra forest may help water supply
By Edward Ortiz, Sacramento Bee
With the state entering its fourth year of drought, some conservationists are looking at thinning Sierra forests to increase the amount of water that flows into area rivers.
The Nature Conservancy issued a report Friday that argues that thinning forests on public lands can reduce wildfire risk in the Northern Sierra. The report also found that such action brings a bonus: water conservation.
Thinning dense forests may lead to a 3 percent to 6 percent increase in mean annual stream flow to some watersheds, according to the report.
The conservancy based its estimates of stream flow on gauge records across 11 watersheds from 1980 to 2000 and found that the Feather River watershed would show the greatest increased water flow due to thinning.
This not the first time tree thinning has been examined for water conservation. However, the conservancy report is one of the first to look into the effect that ecologically based forest thinning would have on water yields in the Sierra Nevada and the economic benefit that could come from it.