Urban development transforms the natural hydrologic regime and has significant effects on baseflow and storm runoff. Colorado’s population is expected to increase to 7.48 million by 2050. 85% of the population is projected to reside along the Front Range with the Denver Metro area hosting about 45% of this population. Previous studies have analyzed changes in streamflow driven by urban development in the Denver Metro area and have found considerable effects on the magnitude and duration of streamflow and baseflow. We aim to build on this work by developing predictive models for changes in streamflow considering different watershed characteristics. For this, 21 gauged watersheds with different extent of urbanization located in the Denver Metro area will be analyzed. The studied watersheds range in size from 0.73 km2 to 89.61 km2, and in imperviousness from 0.8% to 47.3%. So far, the analysis suggests that the lower values of imperviousness have a linear relationship with the median discharge, but other watershed characteristics should be explored for a better fit in the higher end of imperviousness. These predictive models will help us determine what most affects the streamflow change from an undeveloped watershed to traditionally developed watershed. The results of this project will help decision makers in the urban planning process by providing a tool to explore the potential effects of different future urban development scenarios on streamflow.
Graduate Student Civil, Environmental, and Architectural Engineering, CU Boulder