Total storage on New Mexico’s Upper Rio Grande reservoirs right now is the lowest it’s been at this point in the spring in over four decades of records

No sooner did my spring break begin a week ago (quite literally within a couple of hours of the end of my last class before break) than I got sick. This has led to much laying around, and resting, which I think was the point?

I’m finally on the mend, and a friend got me out of the house yesterday morning for a walk down by the river. Which was nice, except I have the sort of friends who have the latest Rio Grande gossip. Like about how we could see the river go dry by June, stuff like that.

Sigh.

Rio Grande at Albuquerque’s Central Avenue Bridge, March 19, 2021

To be honest, the river looks pretty good right now. There were a few buds to be seen, but mostly the river’s still wearing its winter colors, the quiet tans and browns that I’ve always thought were one of its best looks. With the gauge at the Central Avenue Bridge reading a bit less than 600 cubic feet per second, it was enough water to barely fill the channel from bank to bank, which as you can see from the picture also is a nice look. It’s only 25th percentile flow for this time of year, but not awful.

The awful is the thing we expect to come next.

The March 1 forecast called for 54 percent of the long term mean flow in the river into New Mexico’s “Middle Rio Grande Valley” – the part of the river where I live, the “Albuquerque reach”. That’s the mid-point, the one-in-ten best chance (90th percentile) is 93 percent of average, the one-in-ten worst (10th percentile) is 26 percent.

That’s bad, but the situation is made far worse by the graph at the top of the page. Mid-March total storage in the three upstream reservoirs was just 140,300 acre feet, which is just 29 percent of average and, more importantly, the worst in the dataset that I have access to, which goes back to 1980.

We’ve limped by in recent years by draining storage, keeping the river wet for the cultural and environmental benefits that provides, and keeping the irrigation ditches wet as well. That’s not going to be possible this year. That’s why my gossipy friend, who is connected, pointed to the possibility of river drying by June.

A note on data sources and methods: The data comes from the USBR Upper Colorado Region’s historical datasets, to be found here. I grabbed the data for Heron, Abiquiu, and El Vado reservoirs, summing up total storage for March 15 every year for which we had data on all three, which goes back to 1980. There’s probably longer datasets available somewhere, but I’m just an unpaid blogger with a few spare hours on a spring weekend, so you get what you pay for, eh?