All the the Snow Promises…

Although water year 2023 is off to a relatively good start, it’s too early to make solid projections for water managers and users. Snapshot data of current conditions indicate that the snowpack across the Upper Colorado River Headwaters is 133% of average, which is almost identical to the conditions we experienced this time last year (see picture). Mid-January 2022 was the beginning of an exceptionally dry period for the basin, resulting in a total snowpack of less than 90%. The mid-winter dry spell, coupled with early and warm spring temperatures, brought a runoff season with only about 60% of average flows to rivers throughout the basin.

Atmospheric moisture is expected to continue to deliver the rain and snow we need throughout the rest of this month, hopefully avoiding a repeat of last year’s bait-and-switch conditions. The misalignment of expectations, however, has serious ramifications.

Long-term predictions estimating runoff flows have significantly underperformed during the past three years of intense drought conditions. This kind of January prognosticating is meant to inform water managers throughout the Upper Basin (CO, WY, UT, NV) as well as Lower Basin (AZ, NM, CA) on how to make room in downstream reservoirs for the incoming spring flows. But when these early models promise average flows only to have the real flows be far less, reservoir levels do not recover as expected. With record low reservoir conditions across much of the west, this uncertainty leaves water managers nervously watching weather patterns for indicators as the annual snowpack slowly grows in the headwaters of the system.

However, due to the continuing storm cycle, which had produced above-average snowpack in nearly every basin within the state, the outlook for inflows into Powell have improved significantly. The 24-month study provided by the Bureau of Reclamation in December, 2022, forecasted only 78% of average inflow into Lake Powell. The January 24-month study forecasted an inflow of 105%.