From the Sky-Hi Daily News (Reid Tulley):
Some of the alternatives for improving the clarity of Grand Lake that are discussed in the report include: Stopping pumping at the Farr Pumping Plant in July, August, and September; modify pumping at the plant during these three months; bypass Grand Lake with a buried pipeline and pump flows directly to Adams Tunnel; or bypass both Grand Lake and Shadow Mountain Reservoir with a buried pipeline and pump flows directly to Adams Tunnel…
Two standards for the clarity of Grand Lake were adopted by the Colorado Water Quality Control Commission in 2008.
The first standard is a narrative clarity standard requiring “the highest level of clarity attainable, consistent with the exercise of established water rights and the protection of aquatic life,” according to the report.
The second standard is a numerical clarity standard of a 4 meter Secchi disk depth that will be assessed by comparing 85 percent of available recordings from the months of July, August, and September. That means at least 85 percent of the measurements taken during those three months must meet the 4 meter Secchi disk depth standard, while 15 percent can be below the minimum requirement.