Oklahoma City's ability to keep water flowing through the drought could take a hit if the U.S. Supreme Court sides with a Texas water district in a fight over southeast Oklahoma water.
The nation's highest court is to hear oral arguments in the case next week.
The Tarrant Regional Water District claims that a 1980 congressionally approved agreement, the Red River Compact, authorizes it to draw water from within Oklahoma.
Oklahoma says it has sole authority over use of water from streams within its borders.
In legal arguments filed with the Supreme Court, lawyers for Oklahoma City say the Texas water district wants to upend the basis of regional water management “because of Tarrant's opinion that North Texas needs the water more than Oklahoma.”
The compact allocates water from the Red River and its tributaries among Louisiana, Arkansas, Texas and Oklahoma.
Tarrant says on its website that it provides water for 1.7 million people in cities including Fort Worth and Arlington. Oklahoma City provides primary or backup water supplies to cities in central Oklahoma, with the potential to serve up to 1.3 million people.
In their brief, Oklahoma City's lawyers — from a Denver law firm — note the city's projected need for more water and its efforts to conserve through outdoor watering restrictions.
Oklahoma City has long-standing permits for water from the Kiamichi and Muddy Boggy rivers. The water is pumped from southeast Oklahoma through the 50-year-old Atoka pipeline.
An application for more water from the Kiamichi would provide nearly enough to meet city needs for 2060, as projected in a 2009 study. That application is tied up in a separate lawsuit over tribal water rights.
Oklahoma City's lawyers say the water from southeastern Oklahoma “is a critical component of (Oklahoma City's) municipal water supply.”
Contrary to the Texas Regional Water District's claims, the lawyers say, reservoirs that store water for Oklahoma City were funded and authorized by Congress “for the express purpose of providing OKC with a municipal water supply.”
The case is Tarrant Regional Water District, A Texas State Agency v. Rudolph John Herrmann, et. al., No. 11-889.