Developing Tools for Improved Water Supply Forecasting in the Rio Grande Headwaters Completed

The Rio Grande River is a critical source of freshwater for 13 million people in Colorado, Texas, New Mexico, and Mexico. More than half of the Rio Grande’s streamflow originates as snowmelt in Colorado’s mountains, meaning that changes in the amount of snowmelt can impact the water supply for communities along the entire river. Snowmelt runoff is therefore an important component of water supply outlooks for the region, which are used by a variety of stakeholders to anticipate water availability in the springtime.

 

It is critical that these water supply outlooks be as accurate as possible. Errors can cost states millions of dollars due to mis-allocation of water and lost agricultural productivity. There is a perception that runoff forecast accuracy has declined over the last several decades in Colorado and New Mexico, making water supply outlooks less reliable. Declines in accuracy could be related to changes in climate and land cover; however, potential sources of error have not yet been examined in the upper Rio Grande basin.

 

This study aims to improve runoff forecast models for the upper Rio Grande. Researchers will identify potential sources of error in existing models, improve the representation of snowpack in models of the watershed, develop a new hydrologic model for the basin, and test this model’s ability to forecast runoff. The end product of this study will be a tool for making improved runoff forecasts for the upper Rio Grande basin. The tool will be transferable to other snowmelt-dominated basins in the region that have similar characteristics. These improved runoff forecasts, in turn, can be used to develop more accurate water supply outlooks in the region, empowering stakeholders in the basin to plan their water use more effectively.