HR: 15:05h
AN: H33J-06    [Abstracts]
TI: Quantifying the Hydrological Effects of Stream Restoration in A Mountain Meadow
AU: * Hammersmark, C T
EM: chammersmark@ucdavis.edu
AF: Center for Watershed Sciences - University of California, One Shields Ave, Davis, CA 95616, United States
AU: Rains, M C
EM: mrains@cas.usf.edu
AF: Department of Geology, University of South Florida, 4202 E. Fowler Ave. SCA 528, Tampa, FL 33620, United States
AU: Mount, J F
EM: mount@geology.ucdavis.edu
AF: Center for Watershed Sciences - University of California, One Shields Ave, Davis, CA 95616, United States
AB: Stream restoration activities are increasingly abundant. Particularly common are "pond and plug" type stream restoration projects, in which (a) alluvial materials are excavated from the floodplain, forming ponds; (b) excavated alluvial materials are used to plug incised channels; and (c) channels are restored to the floodplain surface. A commonly stated objective of these efforts is to restore hydrological processes to the riparian systems. However, little research has been conducted to quantify the restoration of these hydrological processes. Direct comparisons of pre- and post-project hydrological observations are often misleading due to inter-annual climate variability. To overcome this issue and accurately quantify the hydrological effects of restoration, we developed, calibrated and validated a MIKE SHE hydrological model of a 230 ha mountain meadow along a 3.6 km restored reach of Bear Creek in northeastern California. We then applied the model to simulate the pre- and post-restoration scenarios by altering the floodplain topography and stream channel networks. A comparison of model results indicate that channel and floodplain topographic modifications associated with stream restoration activities (a) raise groundwater levels, (b) reduce the magnitude of flood peaks, (c) increase floodplain inundation through increased channel-floodplain connectivity, (d) increase recharge and subsurface storage, (e) increase evapotranspiration and (f) reduce total runoff. This study supports and quantifies the hypothesis that "pond and plug" type stream restorations restore hydrological processes to riparian systems. In addition, this study can be used to improve quantitative objectives for "pond and plug" type stream restoration activities in similar environments.
DE: 1830 Groundwater/surface water interaction
DE: 1847 Modeling
DE: 1850 Overland flow
DE: 1856 River channels (0483, 0744)
DE: 1876 Water budgets
SC: Hydrology [H]
MN: 2007 Fall Meeting