New steps to manage runoff | AspenTimes.com

New steps to manage runoff

Charles Agar

The city of Aspen is taking charge of its storm runoff, thanks to a comprehensive plan that not only improves what pours into the Roaring Fork River but increases local wildlife habitat, wetlands and open spaces.Aspen residents were forward-thinking in their early efforts to manage storm runoff, and ’70s-era holding basins and wooded buffer zones dot the city. But the system is now out of date, Stephen Ellsperman, parks department and open spaces director, said Wednesday during a citizens advisory committee tour of the city’s water outfall sites.Large silt deposits from road sand and construction, as well as petrochemical foam from oil and auto emissions, still flow directly into the Roaring Fork in many spots. However, the city has taken important first steps to do something about it.Two water filtration areas, the Rio Grande and the Jenny Adair areas, funnel nearly all the town water into the Roaring Fork, and both areas are being redesigned.Updates to the Rio Grande outfall site, which consists of the Rio Grande water outfall and the sports fields of Rio Grande Park, started with a new mechanical water filtration system that went online in July. Located under the town recycling center, the filtration system is a large holding tank with a maze of 90-degree baffles that help settle sediments and chemicals. The system has been a huge success, transforming water loaded with 1,280 parts per million of silt and pollutants, into clear water with just in excess of 100 parts per million.The filter is just the first step in the Rio Grande site, where the parks department and open spaces are proposing the creation of wetlands to filter town water further. The project is awaiting support and funding.Voters did provide support and funding last year to the tune of $1.4 million for a water project at the Jenny Adair site near the Aspen Center for Environmental Studies. The holding pond, which requires periodic dredging, soon will be transformed into picturesque wetlands. Work begins in September at the Jenny Adair site, and when the job is complete in the fall of 2007 more than half of the town’s runoff will flow first through a mechanical filtration system like the one at the Rio Grande outfall before passing through natural filters.”These wetlands are a finishing touch,” Ellsperman said of the Jenny Adair site. Water passing through the planned mechanical filtration system will already be clean and the wetlands serve as a secondary filter.”The message here,” Ellsperman said, “is that stormwater management can be ecologically beneficial.” In addition, the new wetlands expand the riparian zone, or wooded buffer of a riverside, which means increased wildlife habitat and improved views for local residents and visitors. “We’re taking something that is a perceived negative, and turning it into a positive,” Ellsperman said. Most people associate water treatment with industrial procession plants, but this project improves local ecology and open spaces.John Emerick, professor emeritus of the Colorado School of Mines and a member of the citizens advisory committee, said the Roaring Fork is “generally very clean.” But the river is choked with algae growth, a sign of increased nitrates. “A lot of this pollution is out of our control,” Emerick said, “but what we can control is town sewage and stormwater discharge.” The city of Aspen is on the case.Charles Agar’s e-mail address is cagar@aspentimes.com.