Colorado Springs Utilities hosted a media tour Friday to spotlight projects addressing one of its ugliest problems — sewage spills.

The city has embarked on a 25-year, $250 million program to prevent spills such as the one in 1999 that sent 71 million gallons of untreated sewage down Fountain Creek.

Since then, the city has been fined several times for chronic spills and has vowed to clean up its record.

One project involves stabilizing the west bank of Fountain Creek, where it intersects with Sand Creek.

Crews are arranging 2,400 tons of boulders along a 1,200-foot-long embankment. The stone wall, or riprap, will protect a 54-inch sewer main from busting open under erosive pressure. The project started in mid-April and wraps up within a month.

The bigger job, though, is the $10.5 million Fountain Creek recovery facility, a huge catch basin into which sewage-laced water can flow.

Designed to save those downstream from Colorado Springs’ sewage, the project began in October and was completed in mid-May. It passed a battery of tests and is ready for what Utilities officials hope never comes.

“I hope we never use it,” Springs Utilities water services chief Bruce McCormick said.

But that’s not likely, given that floods can prompt spills from the best sewage systems.

Here’s how it works:

When a spill sends sewage into a creek or tributary in Colorado Springs, officials will go to the recovery project and open the gates of a canal that borders the creek. (Officials know when to open the gate because utilities put dye into streams all over the city and then gauged how long it took the colored water to flow to the diversion point.)

Gravity will feed the polluted water through a concrete channel into an 18.5-million-gallon holding pond. The pond can hold the equivalent of four hours of normal creek flows.

From there, the tainted water will be pumped north to the Las Vegas Street sewage treatment plant.

Another 20-million-gallon pond filled with normal creek water will siphon water back into Fountain Creek, so those downstream won’t have their water use interrupted.

McCormick said the project represents the city’s third line of defense against sewage spills. The first is the improvement program and the second, a quick response team that contains spills before sewage reaches a waterway.

“This is really insurance,” he said. “To me, this is a pretty strong commitment for stewardship. Doing something like this is above and beyond, in my opinion.”

Designed by CH2M Hill, Mc-Cormick said the project is unlike any other diversion project in the country.