The preliminary March 1 runoff forecast from Karl Wetlaufer, the federal government employee at the USDA’s Natural Resource Conservation Service who provides vital information to help us make informed water management decisions, is yikes:

February brought another month of well below median precipitation across the entire Rio Grande basin. As one would anticipate this generally led to lowered forecast volumes over a month ago. It is worth noting that similar to last month there remains a broad gap between current percent of median snowpack and water year precipitation. This is a result of a wet October and early November followed by several months of dry conditions. These persistent dry conditions have led to record lowest or otherwise very low rankings of snowpack compared to the period of record for March 1^st.

As Wetlaufer noted in the email discussion he distributes each month to New Mexico water managers, it’s a bit tricky this year, because early precipitation last fall fell as rain, not snow. That helps the runoff by wetting soils in the high watersheds, but doesn’t show up in the snowpack numbers. So yes it’s bad, but not quite as bad as it appears if you only look at the snowpack.

The midpoint flow estimate for Otowi on the Rio Grande is 205,000 acre feet, 36 percent of the long term average. It could be higher or lower, depending on what happens in the next few months. But as Friend of Inkstain Rolf Schmidt-Petersen pointed out in the comments last month:

The median assumes near average conditions going forward but that sure hasn’t been the case for several months and no one I know is predicting a turnaround to wet this Spring.

With that in mind, I give you the four-week Evaporative Drought Demand Index, which federal scientists at NOAA and the National Integrated Drought Information System provide to help us make good decisions about water management:

Thanks, federal workforce!