March 1 runoff forecasts are solid

With a solid snowpack in all of my rivers, we’ve got a pair of solid March 1 forecasts for 2023 runoff.

Rio Grande

102 percent at Otowi, the main forecast point for water entering New Mexico’s Middle Rio Grande Valley.

Implications: While we don’t have a formal Annual Operating Plan for the Albuquerque Bernalillo County Water Utility Authority yet, the army wavy Fleck assessment is that this means Albuquerque will be able to use river diversions all year this year, and won’t need to fall back on groundwater. +1

Note (see below) that the numbers also are good for the San Juan-Chama Project headwaters, which feed the transbasin diversion for Albuquerque, Santa Fe, and the Middle Rio Grande Conservancy District.

(The New Mexico outlook reports are here, but it March isn’t posted yet. Probably somewhere on the web where I can’t find it, drop it in the comments if you know a link, I got the numbers from the NRCS email blast).

Colorado River

April-July unregulated inflow forecasts for some of the major reservoirs in the UCRB include Fontenelle 620 KAF (84% average), Flaming Gorge 880 KAF (91%), Green Mountain 255 KAF (91%), Blue Mesa 665 KAF (105%), McPhee 345 KAF (135%), and Navajo 735 KAF (117%). The Lake Powell inflow forecast is 8.0 MAF (125% of average), which is a 500 KAF increase from February

Implications: The Powell numbers reduce the pressure for crisis actions, create an opportunity to hold water back in Flaming Gorge and the other Upper Basin reservoirs that have been somewhat depleted by Drought Response Operations Agreement actions, maybe make the paper move of water held back last year in Powell down to Mead. Combined with the cabin-crushing snowpack in the Sierra Nevada, this also could give the Metropolitan Water District of Southern California some breathing room to leave more water in Mead, though the politics are complicated right now around all of this because of all the pissed off-ness and dysfunction in the basin.

Source: CBRFC

3 Comments

  1. I’ll bet this is a big disappointment to all those who are shouting “the house is on fire.” As you know John, I have been steadfastly opposed to those who deny the variability of climate and precipitation.. Long run, the book is yet to be written. No need to push panic. Short term, will funding for more and more research dry up?

  2. Breathing room, indeed. Let’s hope that the Metropolitan Water District of SoCal, Reclamation, and the seven basin states use it wisely by taking real steps to equitably and methodically reduce water consumption to levels that the basin — with characteristically high inter-annual hydrologic variability yet inexorably declining supplies — can sustain.

  3. Bill – That – “those who deny the variability of climate and precipitation” – is a weirdly unhelpful strawman. To whom are you referring? Because I’ve not heard anyone make that argument.

    Speaking for myself, I would argue that our challenge with respect to variability is twofold. First, we have a need to adapt to variability around a new, lower, greenhouse altered mean. The science on this point is robust. Second, we need to abandon our current response to variability, which has been to use the extra water when flows are above the mean, and drain the reservoirs when flows are below the mean. That’s a one-way ratchet, which has led to emptying reservoirs. We’ve burned through our buffer of resilience.

    This year on the Colorado River is a good case in point. Last year, unregulated inflows into Lake Powell were 3 million acre feet below the long term median. This year, they’re forecast to be 2 million acre feet above. To simply balance last year’s low side of variability and this year’s high side, we need to cut a million acre feet of use.

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