From The Colorado Springs Gazette (Matt Steiner):
The diminishing water level in the 280-acre lake south of the Colorado Springs Airport is intentional. Gary Steen, manager of the Fountain Mutual Irrigation Company that owns the Big Johnson, said Tuesday morning that his company has been draining the reservoir since the summer of 2016 and preparing to repair three outlet gates…
The irrigation company typically fills the reservoir in the fall and winter months before the irrigation season begins in early April. Steen said crews have been building a bypass pipeline for the last few weeks and will finish the work prior to April 1.
When Fountain Mutual built the reservoir in 1910, it took control of a water storage decree that dates back to 1903, Steen said. That decree allows the company to store up to 10,000-acre feet of water in the lake. But, according to Steen, sediment in the reservoir has diminished its capacity over the years to about 5,000-acre feet.