I had occasion this evening to revisit “Sensitivity of Streamflow in the Colorado Basin to Climatic Changes,” by Linda Nash and Peter Gleick, circa 1991:

Water availability, quality, and demand may be affected by higher temperatures, new precipitation patterns, rising sea level, and changes in storm frequency and intensity. Water supply and water management in the Colorado Basin, already contested issues, are likely to be aggravated by these changes.

Of course, as they pointed out in 1993 (and as remains true today), “large uncertainties remain”. But their central point is well taken.