The Middle Rio Grande Conservancy District Board this afternoon (Monday Oct. 14, 2024) approved an agreement among the District, the Albuquerque Bernalillo County Water Utility Authority, and the Bureau of Reclamation for temporary storage of District water in Abiquiu Reservoir on the Rio Chama while El Vado Reservoir is out of comission.

This is a huge deal. Without it, we could expect low river flows and lousy irrigation supplies through New Mexico’s Middle Rio Grande Valley in late summer for years to come. Even with it, there are still obstacles to good late summer flows – most notably New Mexico’s current Rio Grande Compact debt to Texas. But it’s a huge step.

All of this is necessary because El Vado Dam, where the 1930s relic built to store water during high spring flows for late summer use, is sorta broken. “Temporary” here seems to be as much as ten years.

It’s a hairball of an agreement. (You can read it here, it starts on page 44 of the pdf of today’s MRGCD board packet.)

Abiquiu, built by the U.S. Army Corps of Engineers in the 1950s, began its life as a flood control dam. But its role as a water storage facility has been expanding ever since, with Congress in the early 1980s approving the storage of San Juan-Chama Project water imported from the Colorado River Basin. It is that San Juan-Chama space, under the control of the Albuquerque Bernalillo County Water Utility Authority, that can be used under the new agreement to store native Rio Grande water for MRGCD.

You also get – Heron storage waivers!

The accounting will be tricky. The first water stored will be the top-priority water for the Six Middle Rio Grande Pueblos – a priority granted in the 1920s as part of a deal that provided the necessary up-front funding, via the federal Indian Irrigation Service, to kick-start the creation of the MRGCD. (Bob Berrens and I tell that story in our new book Ribbons of Green, which you’ll be able to read at some point once we finish the revisions currently underway.) The Pueblo water goes by the name “prior and paramount”. Once the P&P water is in, the next layer of stored water has to be equivalent to our New Mexico’s total Rio Grande Compact debt to southern New Mexico and Texas, currently 121,500 acre feet. (But maybe shrinking this year, based on early numbers?)

But wait, there’s more!

After those two accounts are filled, MRGCD will be able to begin storing water for farmers and environmental flows. But there’s a neat twist here to the agreement. Once this last account rises above 10,000 acre feet (it’s called “MRGCD usable water”), the District agrees to keep river flows high enough through the Middle Rio Grande Valley for ABCWUA to operate its drinking water plant.

But wait, there’s more!

In addition to all the above, if you act now (the ABCWUA board will take this up in a couple of weeks), you also get, at no additional charge, storage waivers in Heron (I’m sorry, this is already too complicated for more background, Heron’s another reservoir, it’s on Willow Creek, JFGI, it’s late and I’m tired.) for San Juan-Chama water that would have otherwise been parked in Abiquiu!