The Rocky Mountain Arsenal site has had a connection to Denver Water for more than a century.
In the late 1800s, farmers and ranchers in the Manhattan-sized swath of land northeast of Denver diverted water from the High Line Canal to fill their newly constructed reservoirs with water for irrigation and livestock.
During World War II, after the U.S. Army had converted the area to a chemical arms manufacturing facility, Denver Water installed a 3-foot-diameter conduit to provide the Army with nearly unlimited amounts of potable water in support of the war effort.
And now, after nearly three decades of environmental cleanup efforts, Denver Water will begin supplying the Rocky Mountain Arsenal National Wildlife Refuge with recycled water — filling lakes and wetlands and coaxing hundreds of wildlife and vegetation species to the rehabilitated area.
"Recycled water is our assurance that for the majority of the time, the lakes and wetlands will have water,” said Tom Jackson, the refuge’s cleanup coordinator. “That’s a critical feature.”
The Rocky Mountain Arsenal site has had a unique, variegated history. In the 1870s, settlers moved to the area for dryland farming and ranching. When the High Line Canal was completed in 1883, they began irrigating their crops and selling the food to people in Denver.
In 1941, after the United States was attacked by Japan, the military began searching for places to manufacture chemical arms to guard against the use of similar weapons by Germany and Japan. The 27 square miles of farmland northeast of Denver seemed like the perfect place. It was close to a major city, had railroad access and utility service, and was far from the range of enemy attacks. Construction began almost immediately, and by 1943, the $50 million Rocky Mountain Arsenal was producing mustard gas, napalm, incendiary bombs and other chemical arms.
After World War II ended, the U.S. Army leased a portion of the facility to Shell Oil Company to produce pesticides and herbicides, as well as the household staple Shell No-Pest Strips. During the Cold War, the Rocky Mountain Arsenal continued to produce chemical arms and began manufacturing rocket fuel, which powered Apollo 11 on its 1969 flight to the moon.
But as chemical production wound down, major environmental cleanup efforts began. In the 1980s, the Army, Shell and the U.S. Fish and Wildlife Service began a joint venture to safely clean the area, tear down the buildings and turn it into a protected site for wildlife.
Thirty years and more than $2 billion later, the site’s cleanup program is officially complete, and the Rocky Mountain Arsenal National Wildlife Refuge is one of the largest urban wildlife refuges in the country.
“It provides a wildlife experience for people in the Denver-metro area and along the Front Range who don’t often have the opportunity to experience the wild,” Jackson said.
The site no longer receives raw water from the dirt-lined High Line Canal — doing so caused tremendous water loss from seepage and often washed sediment, pesky weed seeds and nonnative fish larvae into the lakes.
Instead, Denver Water will start delivering recycled water to this site, expected by late 2011, where it will be dechlorinated and sent to three lakes — Lake Ladora, Lower Derby Lake and Lake Mary — as well as to four wetlands. The refuge also plans to send recycled water through 30 miles of cast-iron pipelines, which the Army installed in the 1950s, to irrigate newly planted short-grass prairie, helping the native grassland establish and fend off noxious weeds.
“We’re essentially bringing this area back to the way it was in the 1850s,” Jackson said.
The refuge plans to supplement recycled water with its well water, but recycled water is crucial to re-creating that stable ecosystem.
“It’ll provide a major habitat for all sorts of wildlife,” Jackson said. “Recycled water is part of that assurance that we’ll have that habitat going forward.”
The refuge is already bustling with migratory songbirds, dozens of wintering bald eagles, mule and white-tailed deer, burrowing owls, American bison, raccoons, toads, fish — all sorts of critters. And once the four wetlands have been established, they’ll lure even more wildlife and vegetation to the refuge.
“Absent the recycled water,” Jackson said, “we’d be in a world of hurt.”