HR: 09:00h
AN: H31M-05    [Abstracts]
TI: A Hydrologic Study of High Creek Fen: Groundwater Dynamics and Sources
AU: * Legg, T M
EM: teresa.legg@colorado.edu
AF: University of Colorado Department of Geography, Guggenheim 110; 260 UCB, Boulder, CO 80309-0260, United States
AU: Blanken, P
EM: Blanken@colorado.edu
AF: University of Colorado Department of Geography, Guggenheim 110; 260 UCB, Boulder, CO 80309-0260, United States
AU: Anderson, S P
EM: Suzanne.Anderson@colorado.edu
AF: University of Colorado Department of Geography, Guggenheim 110; 260 UCB, Boulder, CO 80309-0260, United States
AB: High Creek Fen is a groundwater-fed wetland located in South Park, Colorado. Although the ecology and hydrology of the fen have been studied, the groundwater sources to the fen have not been identified. In addition, the spatial and temporal variation in the physical and chemical properties of groundwater at High Creek Fen are not well understood. This research has become a priority because land use changes in the South Park are exacerbating groundwater resource issues. Hydrologic modifications to High Creek Fen could have dramatic ecological effects that threaten globally rare plants and invertebrates. In addition, the Nature Conservancy is interested in identifying additional preservation lands to protect the hydrologic and ecologic integrity of High Creek fen. To characterize the physical properties of groundwater, a regional groundwater contour map was created to establish the regional groundwater flowpaths. Next, the local physical dynamics of groundwater was characterized using hydraulic head and groundwater level measurements at bi-weekly intervals from June 2007 to October 2007. These measurements were paired with stream discharge measurements at High Creek, the outlet of the fen, in order to determine the relationship between spatial and temporal groundwater dynamics and the surface water discharge. Water samples were collected from possible groundwater sources for chemical and isotopic characterization. These potential sources include groundwater in the piezometers throughout the fen, and surface water in the fen and in High Creek. This data supports the existence of multiple, relatively shallow, groundwater sources to High Creek Fen. Additionally, the data highlights the spatial and temporal variation of physical and chemical groundwater dynamics at High Creek Fen. Since it is a groundwater-fed system, understanding the hydrology of High Creek Fen is dependent on our understanding of groundwater dynamics. This research provides the foundation for studying other aspects of this unique and diverse ecosystem.
DE: 0454 Isotopic composition and chemistry (1041, 4870)
DE: 1829 Groundwater hydrology
DE: 1830 Groundwater/surface water interaction
DE: 1890 Wetlands (0497)
SC: Hydrology [H]
MN: 2007 Fall Meeting