The Impact of Extreme Precipitation on Reservoir Inflow at the Taylor Park Dam

Michael J Mueller(1),Kelly Mahoney(1),Jamie Scott(1)

Abstract
The United States Bureau of Reclamation is responsible for the safety of the Taylor Park dam, located in central Colorado at an elevation of 9300 feet. A key aspect of dam safety is anticipating extreme precipitation, runoff and the associated inflow of water to the reservoir. In the case of the Taylor Park dam, developing a climatology of extreme precipitation can be challenging due to the heterogeneity of the surrounding mountainous terrain and relative lack of nearby observation sites. Further complications occur due to lack of radar coverage in the high terrain of central Colorado. This study leverages a gridded dataset generated primarily by NOAA Cooperative Observer (COOP) data (Livneh et al. 2013) to construct a precipitation climatology for the Taylor Park drainage basin. The dataset is used to determine precipitation magnitude, type and seasonal dependence of the most extreme events. Cases of large reservoir inflow are cross referenced with the resulting climatology. Results clearly show seasonal dependence both in extreme precipitation (October-March) and large reservoir inflow events (May-July). The impact of the most extreme precipitation events was muted at the reservoir due to precipitation falling as snow. Precipitation events of lesser magnitude had much larger impacts at the reservoir due to the combination of snowmelt and enhanced runoff as events became more rain-dominant as late spring arrived.