The effect of climate change in the natural hydrology cycle is becoming more prominent in the recent years. The urban stormwater systems are more vulnerable to the magnified effects of the hydrology because of climate change. This study used the Climate information from the North American Regional Climate Change Assessment Program and North American Regional Reanalysis climate model data for the Las Vegas Valley. The Generalized Extreme Value method with the aid of L-Moment was used for the determination of change in design storm in the climate model predicted future climate. Gridded reanalysis data were used to assess the performance of the climate models. An existing HEC-HMS model with 100-yr, 6-hr design storm information was implemented using the projected climate change information. Hydrological simulation showed exceedances of existing stormwater facilities that were designed under the assumption of stationarity in design depth. There was a variation in the future climate among the different climate models that ranges from 1.06 to 1.86 in the delta change factor using the L-Moment approach. The hydrological simulation resulted in a potential exceedances in the selected existing stormwater facilities that were designed as per the current design standard. The findings will be helpful for water managers in strategizing the future development plans within the Las Vegas valley under changing climatic conditions.