In the 1980s, through collaboration between the DNR and several Trout Unlimited Chapters, including Mershon-Neumann Heritage Chapter, a system was implemented for adding cold water to the Rifle River, just south of Devoe Lake. A pipe was sunk to the bottom of the very deep and very cold Devoe Lake, located within the Rifle River Recreation Area. Water is diverted from the bottom of the lake into the river, lowering temperatures significantly.
This pipe is still working today, more than 40 years later. At this time the water goes through a pond before making its way into the river. It was questioned whether this warms the water before it gets to the river, making the pipe obsolete. To gather data, useful in deciding if the rechannelization of this pond would be a project for our chapter, four temperature loggers were placed at the pipe, the exit of the pond, and up and down stream.
Data shows that the water does not warm significantly as it goes through the pond. In fact, water entering the river is only 1-2 degrees warmer than it is as it leaves the diversion pipe.
In a recent forum post, this October 25, 2023 science News article was mentioned, giving more details about the efficiency of such projects.