What would a San Juan-Chama 2013 water shortage look like?

As I wrote last month, federal officials have begun preparing for a possible shortage. It would be the first in the 40-year history of the project, which brings water beneath the continental divide in a series of tunnels, moving Colorado River Basin into the Chama and Rio Grande drainages for use over here. Albuquerque, Santa Fe and the Middle Rio Grande Conservancy District (valley farmers) are the biggest users.

After a meeting two weeks ago, water officials are contemplating setting a starting benchmark of 80 percent allocation for the San Juan-Chama water users, with the possibility of raising the allocation depending on how much snow there is. Some of the contractors seem to be holding out for a full allocation, though, while others would like to take less water this year to leave a hedge of stored water for next year.

Lela Hunt, spokeswoman for the New Mexico Interstate Stream Commission, told me today that if there is a 20 percent shortage, effects would be most noticeable for the Conservancy District and the Bureau of Reclamation. For the District, according to Hunt, it might mean a 3 to 5 day shorter irrigation season. For the Bureau, it would mean less water for endangered species flows for the Rio Grande silvery minnow.

Albuquerque has a surplus of water it has faithfully squirreled away in Abiquiu Reservoir, so it should be OK this year.

The details of how a shortage might be handled remain uncertain, however, because of complexities int the water users’ contract language, and the fact that officials have never had to do this before.