Prospect Lake has leaked massive amounts of water for more than 50 years, and a new water source must be found to save it, according to a report to be released this week.
The dire situation and potential expense of repairs has led at least one council member to ask whether the Memorial Park lake should be emptied for good. After watching the 31-acre hole lose about half its water during the past two summers, Colorado Springs commissioned a $50,000 study to determine why. Associated Design Professionals of Colorado Springs worked on to answer the question for four months. Its conclusions, which will be presented to the parks and recreation advisory board Thursday, have elicited surprise. The standing theory was the bentonite clay lining at the bottom of the lake cracked when it was exposed to the sun and dried out in 2002. After the lake was refilled in 2003, water leaked through the cracks and into an underground aquifer, many thought. Exposure to the sun seems to have had little effect on a problem dating to when the clay liner was installed on half of the lake bottom in 1953. The study concluded water leaked through porous ground soil at the same pace throughout the years. It also said evaporation accounts for almost half of the lost water every year. There is no way to offset that, short of pumping more water into the lake, parks and recreation director Paul Butcher said. “It’s a birdbath with a crack in it,” Butcher said. “We’d like to, if possible, seal the crack, but that only solves half the problem.” Built in 1890 as a reservoir for overflow irrigation water, Prospect Lake opened to swimmers 42 years later. Since then, it’s been a hot spot for boating and fishing. Colorado Springs Utilities pumped potable water into the lake, but when the 2002 drought hit, city leaders stopped the practice. The lake receded severely that summer. It was refilled in early 2003 by water from a nearby non-potable line, but by mid-April the lake level had dropped so swiftly the city banned swimming for the summer. Trying that again would result in similar scenarios where in which the lake shrinks quickly and becomes unusable, department analyst Mike McCauley said. The ADP study found the lake loses 392 acre-feet, or about 128 million gallons, of water each year, 54 percent through leakage and 46 percent from evaporation. The study said Prospect Lake can’t be opened to the public again unless the city resumes pumping water or finds a way to retain or get water from a new source. Several council members said they can’t support dumping in fresh water at a time when supplies are short and the public is being asked to conserve. There is no guarantee the utility will supply free water, Butcher said. Buying 400 acre-feet of water would cost the city $389,000. The city could drain the lake and install a bentonite liner over the other half of the bottom. That would cost several hundred thousand dollars and would not cure the evaporation problem. A more likely scenario would have the city building a well north of the lake in the aquifer that takes much of the seepage. It could pump that water and water from another nearby aquifer into the lake, McCauley said. Money will be hard to find in a parks and recreation department that took a $1.7 million cut in the 2004 budget. Still, Butcher and Vice Mayor Richard Skorman said last week they are committed to restoring the lake, even if the solution takes several years. “It’s just a major recreation area,” Skorman said. “We’ll put hundreds of thousands of dollars into ball fields ... and when you think about Prospect Lake, it has that same kind of benefit.” Councilman Jerry Heimlicher does not share the optimism that water will ever flow back into the lake. Heimlicher, who represents the district that includes Memorial Park, said the study gives the city an opportunity to evaluate whether fixing the lake is worth the cost. The money it would take to repair the area may be better spent on roads or public safety, he said. “It’s an unnatural feature of a park that’s very, very popular,” Heimlicher said. “But I think we have to look at reality. ... The cost and magnitude of this thing is something we can’t continue to do forever.” Several other council members contacted last week said they had not read about the study and declined comment. Heimlicher’s ideas did not sit well with the neighborhood around the lake, though. Phil McCaffrey, president of the East Lake Homeowners Association, was shocked when told Heimlicher’s view. The lake draws tens of thousands of people every summer for meeting, recreating or just admiring the view, McCaffrey said. Birds migrate to it, and it is arguably the highlight of one of the city’s most visited parks, he said. “You have people that have been swimming there for years,” McCaffrey said. “They walk their dogs there. They exercise there. They congregate there. This lake is very important to the people of this town, especially on the south side.” The matter may not reach the City Council agenda for several months.