Risk Study Reaches Phase IV

The original Colorado River Risk Study (“Risk Study”) was initiated almost ten years ago as an outgrowth of previous ‘Colorado River Compact Water Bank’ efforts. Beginning with Phase I in 2016, the project aimed to better understand risks of potential, involuntary curtailment for Colorado and the other Upper Basin states related to the 1922 Colorado River Compact and different hydrological scenarios. Phase IV of the Risk Study is now almost complete, the project having evolved to include the continued changes in hydrology, water demand patterns, modeling tools, and technological advances in the last decade.

Since Phase III was completed in 2019, the back-to-back years of severe drought drained Colorado River system reservoirs, while development and growth has increased water demands despite snowpack and rainfall becoming more uncertain. Also since 2019, the seven basin states and Reclamation have approved a new set of Drought Contingency Program (DCP) rules and Drought Response Operations and Storage Agreements, all of which needed to be factored in to this new phase of the Risk Study.

On July 18, Dr. John Carron of Hydros Consulting joined the Colorado River District’s Board of Directors and provided an update on these Phase IV findings. In short, a few of the final takeaways included:

  • Hydrology is still the #1 indicator of system health in the Colorado River Basin.
  • Increasing demands means an increasing risk and volume of curtailment.
  • Under the existing 2007 Interim Guidelines operating policy (alongside aridification), maintaining a 3500-foot elevation at Lake Powell puts the entire burden on the Upper Basin.

View the Hydros Presentation from the July 18, 2023 Board Meeting here.
Dave Kanzer, the River District’s Director of Science and Interstate Matters, also presented a summary of the Risk Study findings to the Southwest Basin Roundtable on July 27, 2023. You can find his Risk Study presentation slide deck here.

Read more about the Risk Study and view previous reports for Phases I-III on the District’s website here.