HR: 0800h
AN: H31D-0642    [Abstracts]
TI: Mountain Meadows and their contribution to Sierra Nevada Water Resources
AU: Cornwell, K
EM: cornwell@csus.edu
AF: Department of Geology, California State University, Sacramento, 6000 J Street, Sacramento, CA 95819-6043, United States
AU: * Brown, K
EM: kamala@californiaalpineguides.com
AF: Department of Geology, California State University, Sacramento, 6000 J Street, Sacramento, CA 95819-6043, United States
AU: Monohan, C
EM: carriem@n-h-i.org
AF: Natural Heritage Institute, 409 Spring St., Nevada City, CA 95959, United States
AB: Human alterations of California's waterscape have exploited rivers, wetlands and meadows of the Sierra Nevada. A century of intensive logging, mining, railroad building, development, fire suppression, and grazing by sheep and cattle has left only 25 percent "intact" natural habitat in the Sierra Nevada (SNEP 1995). Much of this intact habitat occurs at higher elevations, often in non-forested alpine or in less productive forests and woodlands where mountain meadows exist. Mountain meadows serve many ecological functions including habitat for threatened and endangered terrestrial and aquatic species, and are considered to be essential physical components to watershed function and hydrology with significant water storage, filtration and flood attenuation properties. This study evaluates the physical characteristics and hydrologic function of Clarks Meadow located in northern Sierra Nevada, Plumas County, California. In 2001, Clarks Meadow received significant restoration work in the upstream half of the meadow which diverted the stream from an incised channel to a shallow remnant channel, creating a stable channel and reconnecting the groundwater table to the stream. No restoration work was done in the lower half of Clarks Meadow where the stream still flows through an incised channel. Clarks Meadow offers a unique opportunity to study both a restored, hydrologically functional meadow and an incised, hydrologically disconnected stretch of the same stream and meadow. The physical characteristics of Clarks Meadows that were measured include surface area, subsurface thickness, porosity and permeability of subsurface materials, potential water storage volume, and surface infiltration rates. The goal of this study is to refine hydrologic characterization methods, quantify water storage potential of a healthy, non-incised meadow and assess its role in attenuating flood flows during high discharge times. Initial results suggest that significant subsurface storage volume is available in the meadow. Incising conditions in the unstable lower channel tends to dewater the lower portion of the meadow which encourages bank erosion through piping and corrasion. This study addresses questions that have broad implications for water management throughout the state because much of California gets water from Sierra high elevation watersheds in which meadows are thought to play a critical role in sustained long-term hydrologic function. The results of this study will be used to inform Integrated Regional Water Management Plans throughout Northern California.
DE: 1830 Groundwater/surface water interaction
DE: 1879 Watershed
DE: 1890 Wetlands (0497)
SC: Hydrology [H]
MN: 2007 Fall Meeting