an institutional hydrograph

We’re entering the end-of-year water accounting phase of the Rio Grande hydrograph in central New Mexico, with big flows coming out of the Rio Chama, the largest tributary in this stretch of our “big” river.

As I’ve written before, relatively higher December flows are a weird artifact of water management rules, which do accounting on an annual basis. In this case, it’s water the federal government stored in spring for use by New Mexico’s indigenous Pueblo farmers that was not used. The rules require the feds to send that water down to Elephant Butte reservoir before the end of the year. They’ve got about 14,000 acre feet to move.

This is also part of a plan to lower the levels at El Vado enough to begin some major dam repairs there next year.

This year, Reclamation is managing the flows for sediment and habitat along the Chama, blasting a big pulse Sunday out of El Vado Dam – an unusual 3,000 cfs down the stretch between El Vado and Abiquiu Dam. That’ll quickly taper this week, with the water released more slow out of Abiquiu.

The first of the pulse passed the Otowi gauge overnight, my friends at the state tell me we should expect to see higher flows through Albuquerque by the end of the week.