This article was written by Matt Hildner for the Rio Grande Basin Roundtable.
While Colorado remains largely an observer in the ongoing federal court case over the Rio Grande Compact, the issues that could increase its involvement have become clearer since Texas filed its initial complaint eight years ago.
Texas originally made no claims against Colorado as its arguments focused on New Mexico’s delivery obligations and the use of groundwater below Elephant Butte Reservoir. Colorado was named a party to the initial complaint simply because it is a signatory to the 1938 compact. But the state’s role in the proceedings could change, depending on whether the case impacts Colorado’s ability to manage Platoro Reservoir, the Upper Rio Grande Basin’s largest post-compact reservoir, and the debits the state is allowed to accrue under the compact. Likewise, decisions by the court that might change how federal water compacts are interpreted could also spur greater involvement by Colorado.
In August, Special Master Michael J. Melloy ordered Texas to file a supplemental complaint with the U.S. Supreme Court because it raised issues distinct from the original complaint and had the potential to greatly expand the scope of the lawsuit. That supplemental complaint claimed, among other issues, that New Mexico violated the compact by not keeping a pool of water equal to the delivery debits its allowed to accrue in reservoir storage.
While Colorado was not named directly in the complaint, Colorado sees that claim as an attack on how the state manages its reservoirs and the 100,000 acre-feet of debits it is allowed to accrue against its downstream delivery obligation. “It is a bigger concern because it directly affects us,” Division Engineer Craig Cotten said earlier this month.
Water users in Colorado’s section of the Rio Grande have also informed Attorney General Phil Weiser that they would seek amicus status to join the case should Texas prevail with its claim. “If Texas were to prevail on its claimed interpretation of Arts. VI-VIII, Platoro Reservoir would be rendered effectively useless to the Conejos District because it would be the only reservoir where Colorado could store debit water,” stated the memorandum signed by the Rio Grande Water Conservation District, the Conejos Water Conservancy District and the Rio Grande Water Users Association.
Platoro Reservoir has a storage capacity of only 53,571 acre-feet, which would put Colorado in the position of losing roughly half of its allowable debits under the compact. Those debits, as the memorandum noted, were intended to recognize that variations in stream flow would impact Colorado’s ability to strictly adhere to the delivery obligations laid out by the compact.
Colorado is also leery of the proceedings giving the Rio Grande Project, which is made up mainly of Elephant Butte and Caballo reservoirs in New Mexico, an authority not called for by the compact. Both the United States, which operates the reservoirs under the Bureau of Reclamation, and New Mexico have argued that the project and its contracts with downstream irrigation districts are silently incorporated into the compact. “They’re really trying to add a lot to the compact,” Cotten said. A brief by Colorado has asked the special master to rule as a matter of law that the Rio Grande Project is not incorporated into the compact and does not impose obligations to the states under the compact. The issue of obligations under those contracts should be addressed outside the compact, Colorado argued.
Cotten said the special master has set an October, 4 trial date. The proceedings will take place in Cedar Rapids, Iowa. Both Cotten and Deputy State Engineer Mike Sullivan are expected to testify as fact witnesses, although they may not take the stand until a second phase of the trial in spring.
“It’s a fluid situation,” Cotten said.