Effect of Drought on Urban Water Supplies. I: Drought Analysis

Abstract

This paper summarizes studies conducted for the City of Fort Collins, Colorado, to determine the effects of prolonged droughts on the city's water supplies. As a result of the analysis, various water‐supply strategies were developed to be used by the city for handling the problems associated with extreme droughts. This study utilized stochastic modeling coupled with water‐resource‐system modeling to evaluate drought effects on the water supplies of the city. A stochastic model was developed for the five river basins that account for the city's water supplies. The stochastic model was verified with 400 years of tree‐ring data obtained for the area. Periods of records were then generated to determine potential droughts that could occur. Representative l‐in‐20‐, l‐in‐50‐, l‐in‐100‐, and 1‐in‐500‐year droughts were selected for the analysis.