Paper No. J05214 of the Journal of the American Water Resources Association (JAWRA). Discussions are open until February 1, 2008.
Modeling Hydrology in a Small Rocky Mountain Watershed Serving Large Urban Populations1
Version of Record online: 25 JUN 2007
JAWRA Journal of the American Water Resources Association
Volume 43, Issue 4, pages 875–887, August 2007
How to Cite
Lemonds, P. J. and McCray, J. E. (2007), Modeling Hydrology in a Small Rocky Mountain Watershed Serving Large Urban Populations. JAWRA Journal of the American Water Resources Association, 43: 875–887. doi: 10.1111/j.1752-1688.2007.00069.x
- Issue online: 28 JUN 2007
- Version of Record online: 25 JUN 2007
- Received December 30, 2005; accepted June 26, 2006.
- snow hydrology;
- surface water hydrology;
- watershed management;
- Dillon Reservoir;
- mountain watersheds;
- hydrologic modeling.
Abstract: This article describes the development of a calibrated hydrologic model for the Blue River watershed (867 km2) in Summit County, Colorado. This watershed provides drinking water to over a third of Colorado’s population. However, more research on model calibration and development for small mountain watersheds is needed. This work required integration of subsurface and surface hydrology using GIS data, and included aspects unique to mountain watersheds such as snow hydrology, high ground-water gradients, and large differences in climate between the headwaters and outlet. Given the importance of this particular watershed as a major urban drinking-water source, the rapid development occurring in small mountain watersheds, and the importance of Rocky Mountain water in the arid and semiarid West, it is useful to describe calibrated watershed modeling efforts in this watershed. The model used was Soil and Water Assessment Tool (SWAT). An accurate model of the hydrologic cycle required incorporation of mountain hydrology-specific processes. Snowmelt and snow formation parameters, as well as several ground-water parameters, were the most important calibration factors. Comparison of simulated and observed streamflow hydrographs at two U.S. Geological Survey gaging stations resulted in good fits to average monthly values (0.71 Nash-Sutcliffe coefficient). With this capability, future assessments of point-source and nonpoint-source pollutant transport are possible.