New Mexico Can’t Afford to Ignore the Compact

Failure to pull out all the stops to control MRG water users and avoid an imminent violation of the Rio Grande Compact would, at best, represent gross negligence on the part of New Mexico’s Executive and Legislative Branches.

New Mexico has been on a roll toward violating its Rio Grande Compact water delivery obligations through the Middle Rio Grande (MRG) to Elephant Butte Reservoir (EBR), largely due to overuse of water in the Middle Rio Grande. For all New Mexico taxpayers and ratepayers, such a violation would bring indefensible costs due to violations caused only by a single region of the state. 

The Impending Costs – We have comparable data to make a credible estimate of violation costs.  New Mexico, Colorado, and Texas (along with the United States because of treaty requirements with Mexico) have argued for the last eight years in still-continuing litigation. The lawsuit concerns alleged New Mexico violations of the Compact along the Lower Rio Grande (south of Elephant Butte), based on alleged excess pumping of groundwater for irrigation needs.

We have little idea how high the costs of an adverse judgement might prove to be.  Based on Inspection of Public Records Act requests (March 2022), we do know New Mexico taxpayers and ratepayers have already spent nearly $41,000,000 on the Lower Rio Grande litigation (about $46 million in inflation-adjusted 2022 dollars), and are still spending heavily:

Office of the Attorney General$18,477,100.96
Office of the State Engineer & Interstate Stream Commission$20,998,553.71
Elephant Butte Irrigation District$1,465,287.08

What did we gain from our $41 million? There is no obvious reason to expect dissimilar non-productive costs if New Mexico were, in fact, to violate its delivery obligations on MRG deliveries.  Further, the almost certain adverse judgment, besides costly, would be debilitating for New Mexico’s management of its future water supplies.

The Road to Violation – The Rio Grande Compact requires New Mexico to deliver a certain amount of water each year to EBR, which varies depending on the annual river inflow at the Otowi Gauge (at the Los Alamos highway bridge). The Compact allows for accumulating credits and debits in actual deliveries, but only up to a point. The violation threshold is an accrued debit of 200,000 acre-feet (one acre-foot is 326,000 gallons).

The delivery to EBR each year is the actual flow past Otowi, plus precipitation run-off in the region, less the amount of water consumed by users along the MRG, both natural users (mostly riparian evapotranspiration along the Rio Grande) and human users. 

In a decade, New Mexico has dropped over 170,000 acre-feet, from an accumulated credit of about 44,600 acre feet to a debit of 127,100 acre feet, with a fairly steady downward trend. Particularly noteworthy is an average of 44,000 acre-feet annual shortfall for the most recent three years. That rate would leave us about two years away from violation.

End of 201144,600 acre feet  Credit
End of 20123,000 acre feet  Credit
End of 201362,400 acre feet  Credit
End of 20140 acre feet  Credit
End of 2015400 acre feet  Credit
End of 201620,300 acre feet  Debit
End of 2017700 acre feet  Credit
End of 20185,400 acre feet  Credit
End of 201938,800 acre feet  Debit
End of 202096,300 acre feet  Debit
End of 2021127,100 acre feet  Debit

Better to prevent the compact violation rather than go through the expensive, years-long secretive litigation while nothing is done, only to have the U.S. Supreme Court require New Mexico to figure out and implement needed actions.

Action Is Needed Now! — To avoid the consequences of violation, especially in the environment of climate change and ongoing drought, it is obvious that New Mexico must cut its water uses in the Middle Rio Grande region, immediately and for the long term! Voluntary reductions haven’t worked well enough. We need equitable and enforceable mandates to reduce Middle Rio Grande’s excessive water uses. The ball is in the court of both the Executive Branch and the Legislative Branch.