Wetlands stormwater filtration project near Aspen park nears completion
July 15, 2014
Aspen city officials say the new wetlands area at the John Denver Sanctuary just north of Rio Grande Park is doing what it’s designed to do: filter stormwater runoff from the downtown area before it flows back into the Roaring Fork River, and lure locals and visitors to the beauty of the man-made wetlands system.
The project, which has been separated into sections over the past few years, is headed for an August completion. Sometime next month, volunteers will be asked to plant vegetation in and around a newly constructed pond on the western side of the wetlands system. That pond, a 30-second walk from North Mill Street, currently is under construction, as is the stream bed that runs parallel to North Mill Street, which will feed stormwater to the pond.
The western section of the project that’s currently under construction is designed to collect water from the central part of the city’s core, filter the sediment and deposit it back into the river. The eastern section of the project, completed in the summer of 2012, is already functioning. It filters stormwater from the eastern side of the city’s core.
Taken as a whole, the project will end up with a cost of around $2.5 million — far less than the $5 million-plus estimate when it was envisioned nearly a decade ago, according to Scott Chism, a project manager with the city’s Parks and Recreation Department. The city utilized in-house labor and took in partners, including Theatre Aspen and the county’s Healthy Rivers and Streams fund, to save money.
The $2.5 million price includes the completed eastern portion of the wetlands; the new bathroom facility near the park; the pump station that garners gray water to irrigate the Rio Grande playing field, the John Denver Song Garden and other grassy areas of the sanctuary; the underground vaults that filter solid materials from the stormwater and move it into the series of streams and ponds that make up the wetlands area, which provide enhanced filtration; pathways that wind around the entire sanctuary; utility-line relocations and replacements; and other costs.
Tricia Aragon, who heads the city’s Engineering Department, said the difference between the water that is transported to the eastern section of the wetlands area and what ends up in the river is like night and day, courtesy of the natural filtration system.
“When it’s really dirty (at the top end), you can definitely tell the difference (at the bottom end),” Aragon said of the eastern-side wetlands. “It goes from chocolate milk to almost clear spring water. We’re removing about 90 percent of the total suspended solids that’s coming into the sanctuary.”
Prior to the wetlands project, stormwater flowed through drainage systems downward from the city and into the river with no filtration, a practice deemed environmentally unsound.
Chism provided a private tour Monday of the finished areas and the section of the stormwater-wetlands project that has yet to be completed. Since the eastern section of the wetlands was completed in 2012, a few finishing touches have been added, including new bridges, picnic tables at overlooks and boulders that feature quotes from renowned environmentalists, poets and thinkers, including Rachel Carson, Ralph Waldo Emerson and Albert Einstein.
A finished pond on the west side of the bridge nearest the Theatre Aspen tent includes a “Kids Play” area with a small beach. An overlook and grass roof mask the pump station on the west side of the theater facility.
Chism pointed out that the parks and engineering departments worked hand in hand “to make the area feel like a park,” as opposed to building what engineers call “a stormwater facility.”
He added that the area also is intended to serve as a quiet zone for people seeking a change of pace from the numerous activities and crowds in the downtown area.
On Monday, several adults and children wandered through the paths in finished portions of the wetlands area as well as the John Denver Song Garden, taking photographs, reading quotes and admiring the native plant rushes, wildflowers and riparian trees and shrubs planted over the past two years.