A state commission that sets water quality standards in Colorado is declining for now to wade into a debate over murky water in Grand Lake.
The Colorado Water Quality Control Commission will instead continue to monitor concerns about the popular tourist destination as federal and state authorities pursue solutions, the commission said at its regularly scheduled meeting Monday.
The lake is considered a prime jewel in Colorado’s scenic landscapes. Located on the western edge of Rocky Mountain National Park, it has been a tourist haven since the late 1800s.
But clarity deteriorated when the federal government began construction on the Colorado-Big Thompson Project, or C-BT, in the late 1930s.
The system gathers water from streams and rivers in Rocky Mountain National Park and Grand County, and stores it in Lake Granby and Shadow Mountain Reservoir.
From there it is pumped, eventually reaching Grand Lake where it is delivered under the Continental Divide via the Alva B. Adams Tunnel to Carter Lake and Horsetooth Reservoir on the Front Range to serve more than 1 million residents and hundreds of farms.
The pumping creates turbidity that clouds the lake during the resort area’s prime tourist season in the summer. Before the C-BT was built, the lake was clear to a depth of 9.2 meters, or roughly 30 feet. Now it is far less.
The U.S. Bureau of Reclamation plans to re-examine several options to fix the problem, including harvesting weeds and introducing aeration at Shadow Mountain, said Jeff Reiker, who manages the agency’s Eastern Colorado Area office. Reclamation owns the C-BT system, which is operated by Northern Water.
“We don’t have any major structural alternatives that have been identified as viable,” Rieker said. Some ideas considered previously involved things such as building a tunnel that would transport murky water from Shadow Mountain through Grand Lake, preventing the murkier water from mixing with Grand Lake’s.
“However, we are continuing our efforts to see if any structural alternatives need to be reconsidered. We want to focus on what can be done with our existing funding and authorities.”
The situation is complicated because it involves federal and state agencies, and any effort to redesign the massive system would cost hundreds of millions of dollars.
Early on locals had hoped the lake would be protected from damage caused by the giant water system. A 1937 federal law, U.S. Senate Document 80, was approved in part to protect Grand Lake’s recreational and scenic values, and a 15-year-old state standard was designed to improve water clarity, setting a goal for clarity of 3.8 meters, or about 12.5 feet.
During the pumping process, algae and sediment from Shadow Mountain are carried into Grand Lake, clouding its formerly clear waters and causing algae blooms and weed growth, and harming recreation.
In 2008, the state water quality commission moved to set a clarity standard, but it has since been replaced with a clarity goal and the aim of achieving “the highest level of clarity attainable.”
Northern Water doing better, but still can’t meet clarity standard
Northern Water and others have implemented different management techniques, including changing pumping patterns, to find ways to improve water quality. In some years, Northern has been able to improve clarity, but not to historical levels.
The utility is getting better at managing clarity, meeting the 3.8 meter standard 50% of the time in recent years, up from 27% historically, said Esther Vincent, Northern Water’s manager of environmental services.
“We have made notable progress,” she said.
Grand Lake advocates did not object to the commission’s decision, but urged it to bolster efforts to improve water quality.
Despite the progress, major improvements remain elusive, said Jeff Metzger, a volunteer advocate who has been trying to solve the problem for roughly 30 years.
“There are numerous documents related to efforts to improve Grand Lake clarity,” he said. “And we have seen some improvements. But none of these agreements have moved the needle.”
During the next several months, Reclamation and Northern Water will continue leading efforts to find a fix and the commission could revisit the issue again after 2024.
At the same time, advocates hope to involve Colorado legislators in their efforts to restore the lake and plan to introduce a resolution next year asking lawmakers to endorse their efforts.
This Fresh Water News story was produced as part of a collaboration between the Colorado Sun and Water Education Colorado.