Aug 31, 2007

Stormy Summer Testing Colorado Drainage Devices

Damaged weirs postpone Glen Cove wetland restoration project

Heavy rainfall turning the Glen Cove wetland in Colorado Springs, Colo., into a sprawling sandbox was supposed to be a thing of the past. Crews planned to restore the area by rescuing plants, hauling away gravel and sand, then replanting and reseeding. An August storm, however, changed those plans.The storm resulted in a surge of storm water over a detention weir along nearby Pikes Peak Highway. Runoff from the storm carried sand more than 20 ft into a previously undamaged area of the wetland, and buckets used to carry plants away were nearly buried in fresh sediment."In any job you have good days and bad days," said Eric Billmeyer, assistant director for the Rocky Mountain Field Institute, who is leading highway runoff restoration efforts. "That was a bad day."After years of drought, this summer's heavy rainfall has tested paving and erosion control efforts along the peak. The city of Colorado Springs, which operates the road under a lease with the U.S. Forest Service, has paved the majority of the highway's erosion prone sections, lined a number of drainage ditches with concrete and installed 17 detention weirs.Having recently toured a newly paved section of road running from Glen Cove Lodge to Devil's Playground at about 13,000 ft, Billmeyer said he has discovered signs of new erosion and fresh damage to detention weirs and healthy trees. "I think the city has some really big challenges ahead of it," he said.The Sierra Club sued the city of Colorado Springs and the U.S. Forest Service in 1998, saying the gravel heaped on 12 unpaved miles leading to the top of the highway was pushing down the mountain, creating a possible Clean Water Act violation.The city settled the lawsuit one year later by agreeing to invest $17 to $20 million in paving the upper 12 miles and installing drainage structures, such as weirs. In 2001, the Forest Service agreed to sink money into mountain cleanup and water quality monitoring efforts.Colorado Springs began paving in 2001, and six miles have been completed since. The project's completion is scheduled for 2012.Today two of the 17 weirs appear to be "breaking out" due to this story summer, said city capital projects manager Jack Glavan. Colorado Springs officials are considering repair and redesign options for the damaged structures. Other devices, Glavan said, are functioning as intended. And the $6.8 million revegetation, paving and drainage project, he added, is "going pretty well."The damage is the result of intense storms, the most recent of which struck on Aug. 7 and dumped nearly 2 in. of rain on the peak over a one-hour period.If the rain fell over an entire hour, it would be classified as a two-year storm; the weirs are designed as such that they should be able to handle such a rainfall level. If the rains came, however, in about 15 minutes, the water naturally would have overwhelmed them, as this type of storm is a 25-year event. Regardless of which situation occurred, Billmeyer sees signs of trouble at each weir above Glen Cove Lodge.Billmeyer, who led a volunteer team this summer to stabilize peak drains, said he plans to postpone the Glen Cove wetland restoration project until next year, when the weird protecting it from uncontrolled runoff will, he hopes, function. "If you were to build a road anywhere on Earth," he said, "this would not be the place to do it."