Here’s a background piece on the Arkansas River flow program, from Chris Woodka writing for the Pueblo Chieftain. From the article:
Since the program was set up under a 2004 intergovernmental agreement, nearly 30,000 acre-feet of water has been released through Pueblo that might not have been otherwise. More than half of that came in 2005, when water providers were figuring out how the program would work. About 56 percent of the water released under the flow program came from mandatory curtailment of exchanges – out-of-priority diversions that are accompanied by an equivalent release of water downstream to satisfy other water rights. Those primarily affected Colorado Springs and Aurora. The remainder were releases of water, primarily by the Pueblo Board of Water Works and Colorado Springs, for special events like kayak races. About 71 percent of the water has been recovered downstream and used in later exchanges. In the process of running the program, the water users have learned how to keep water in the river and still make the numbers work, said Alan Ward, water resources administrator for the Pueblo water board…
For the past two years, the partners in the flow program have agreed to keep 100 cfs in the river and rebalance the accounts with paper trades at the end of the winter water storage season after March 15. That has meant less water lost to program participants while preserving the benchmark flows, Ward said.
In recent weeks, the program has surfaced as a core issue in Pueblo County conditions for SDS. Pueblo West filed a lawsuit for exemption for the program, because it could reduce their future water supplies. Pueblo County officials say the Pueblo West claims of losses are exaggerated. Pueblo City Council President Vera Ortegon last week said preservation of the Pueblo flow program was the main reason council voted to reaffirm parts of the 2004 IGA, including Aurora’s right to use the Fryingpan-Arkansas Project, a disputed point in a federal lawsuit. The Pueblo water board and Colorado Springs have signed an agreement that would put water into the Arkansas River – something they were never required to do under the 2004 IGA – if flows reach below 50 cfs. The cities would maintain a 3,000 acre-foot pool for that purpose, but would not be required to contribute in the driest of years.