Four specialists in water and forest management came together to talk about the connection at the quarterly meeting of Mountain Counties Water Resources Association recently. The meeting was held at EID headquarters in Placerville.
The panel members were:
• Jim Branham, Sierra Nevada Conservancy Executive Officer. The Sierra Nevada Conservancy is a state agency under the Natural Resources Agency. Previously, Branham served as Chief Deputy Director of California Department of Forestry and Fire Protection.
• Roger Bales, Ph.D Environmental Engineering Science; Director of Sierra Nevada Research Institute, UC Merced.
• Susie Kocher, MS Forestry; UC Davis Natural Resources Advisor.
• Barry Hill, Hydrologist, Pacific Southwest Region, U.S. Department of Agriculture Forest Service.
Tuolumne Utilities District’s Ditch System Sustainability Project
As a prelude to the panel, Barbara Balen, a Tuolumne Utilities District director, and also on the board of Mountain Counties, described Tuolumne’s Ditch System Sustainability Project. Balen is an archeologist with the U.S. Forest Service.
The system is a consolidation of 13 ditches between 1,400 and 4,000 feet elevation that Balen depicted as being “knitted together.” Like many conveyance systems in northern Sierra Nevada water districts, it has its roots in the Gold Rush era.
The ditch system is Tuolumne’s primary water conveyance from the water reservoirs to the treatment plants and agricultural and irrigation customers. The water district’s investment in maintenance and improvements has not been enough to take care of high water loss and increasing maintenance costs. In addition, land development projects have been intruding on the ditches.
The district was faced with competing pressures: 1) public and regulatory agency push to convert the open ditches to a piped system; 2) local sentiment to preserve the ditch system and its historic, recreation and ecologic values.
The district received a $350,000 grant from the Sierra Nevada Conservancy, a state agency, to help fund a Ditch Optimization Study, withthe goal of developing a comprehensive plan for management of the system that will support its multiple values.
A Public Outreach Plan was completed in December 2011, an Historic Resource Evaluation Report came out in January, and a Ditch System Sustainability Project Case Study was finished in February. These reports are available on the district Website at tudwater.com.
The Forest Water Connection in the Sierra Nevada Region
Jim Branham, Sierra Nevada Conservancy Executive Director, said the 2002 Denver Hayman fire that burned 215 square miles resulted in more than $70 million in direct costs to the Denver Water Agency. Through a five-year equal partnership with the U.S. Forest Service, 38,000 acres were restored.
“Catastrophic fire presents the greatest threat to our water,” he said. It affects water quantity and quality.
“Forest health and upper watershed issues should get more attention,” he said, and mentioned some of the work being done by communities working together to reduce the risk and consequences of large fires while at the same time improving their economic situations.
Examples are the 15 Integrated Regional Water Management planning efforts. One of them combines the Cosumnes, American, Bear and Yuba watersheds.
Looking at the tasks at hand, Branham said, “We need to have quantification of the impacts of catastrophic fire on water infrastructure here in California, and we need to have better answers to the question of how does forest management relate to water yield and the timing of runoff.”
As to the flow of funding, Branham said, “We have to openly address the need for downstream beneficiaries to share in the investment required for these activities.”
Forests and Water in the High Sierra
Roger Bales, Ph.D, reported on work being done by the Sierra Nevada Research Institute at UC Merced.
He said that some of their motivating points are: 1) Water is the highest-value ecosystem service associated with Sierra Nevada conifer forests: 2) precipitation and temperature trends are changing the timing and amount of runoff; and 3) many second-growth forests have dense canopies and growing fire risks. One of the areas the researchers are working on is the American River Basin, which includes the North, South and Middle forks. Sensors are strategically placed to get spatial estimates of snow cover, soil moisture and other water-balance elements.
“We are building a knowledge base to enhance forest and water management,” said Bales. “We need a statewide water accounting system.”
Sierra Watershed Ecosystem Enhancement Project (SWEEP)
The vision of SWEEP is to quantify the effect of forest management on water yields in the Sierra Nevada forests. UC Davis Natural Resources Advisor Susie Kocher is enlisting involvement by agencies, landowners and other stakeholders in this project. The Website is ucanr.org/sweep.
Sierra Nevada Conservancy and the Bella Vista Foundation funded the planning phase. Bella Vista is a northern California foundation that funds ecosystem restoration.
Phase 2 pays for the team to design the research and obtain permits to allow experiments. The UC Competitive Grants program awarded SWEEP $600,000 over four years for this purpose. It integrates the research and extension services into one team.
Forest silviculturist Kevin O’Hara, UC Berkeley, is the principal investigator. Bales is a member of the team. Funding and hiring of a project coordinator is underway.
Kocher said that thinning and fuels reduction, including biomass, is expected to affect multiple ecosystem services. Increased water runoff, or water yield, is most valuable if it can also be used to produce hydroelectric power during periods of high prices. Water is least valuable if it is spilled early in the season from already full reservoirs.
Phase 3, the actual monitoring and evaluation, has not been funded.
The research includes a technical advisory committee that will look at pricing and allocating ecosystem services in the American River Basin.
National Forest Management and Water Yield in the Sierra Nevada
U.S. Forest Service hydrologist for the Pacific Southwest Region Barry Hill said, “The Forest Service is working with stakeholders, tribes, researchers, and regulatory agencies to improve water quantity and quality on National Forests in California.”
The 18 national forests in California are the locations for the headwaters of most major rivers and responsible for 50 percent of the water runoff in the state.
Forests affect water yield in three ways:
1) Transpiration, the process by which water is transferred from the soil through the trees to the atmosphere by evaporation.
2) Interception and snow accumulation. Dense treetop canopies intercept about 25 percent of the total rainfall in the Coast Range and 20-30 percent of total snowfall in the mountains.
3) Infiltration. Forest soils generally have much higher infiltration rates than agricultural fields and pastures. In the Sierra Nevada, the soils tend to soak up water faster than rains fall, so less water flows downhill. Mechanical removal of vegetation tends to compact the soils, reducing infiltration and increasing runoff.
Hill said significant adverse impacts to water resources on forests are expected if wildfire risk is not reduced. “About 45 percent of National Forest Service lands are high priorities for treatment.” Treatments, such as tree thinning and vegetation management need to be repeated every 20 years. As a result of fire treatments, water yield is likely to increase, he said.
One way to make up for reduced snowpack storage is to restore the depleted meadows in the Sierra Nevada.
Hill said, “Limited improvements in water delivery from forests are possible through forest and meadow management. More information is needed.”