Middle Rio Grande Water Supply Study

New Mexico

New Mexico

For this water supply planning study, SSP&A quantified the inter-related groundwater and surface water supply and its variability, and provided a common basis for regional and New Mexico water planning activities.

This study integrated vast quantities of existing data, models and investigations conducted over the past 100 years over a 150-mile reach of the Rio Grande and the adjacent basins to develop a water budget for the linked groundwater/surface-water system. To characterize the water budget elements and their variability, descriptive statistics and probability density functions were developed for each water budget inflow and outflow term using data recorded over a 50-year period. Groundwater inflow/outflow to the river system was characterized through MODFLOW simulation. Monte Carlo simulation of the river system water budget was conducted to characterize the probabilistic nature of the overall water supply and likelihood of meeting Rio Grande Compact obligations under several potential future development conditions.

The probabilistic water supply, based on surface-water and groundwater supplies, was quantified as probability density functions under various scenarios. The source data, methodologies and results were presented in a final report, through oral presentation at several public meetings, and in an interactive website.  In a follow-on project, SSP&A provided technical support to regional planning groups and state water planners in assessing the impact of proposed conservation measures on basin water supplies.