Group ponders grand possibilities for canal


The High Line Canal Working Group is contemplating converting the entire 66-mile system into a rain garden, a concept that is gaining popularity as municipalities struggle with water issues.

“It’s a major rethinking outside of the box,” Littleton City Councilor Bruce Beckman told the rest of the council during a Nov. 12 study session.

The Rain Garden Network’s website defines a rain garden as a shallow, constructed depression that is planted with deep-rooted native plants and grasses. It collects runoff from hard surfaces such as a driveway, slows it down and then allows it to naturally infiltrate into the ground.

“A rain garden can be thought of as a personal water-quality system, because it filters the runoff from your roof and lawn and recharges the groundwater,” says the network. “A rain garden also conserves municipal water resources by reducing the need for irrigation.”

The city of Aurora plans to install 28 rain gardens next spring, and Littleton already has one on the Mary Carter Greenway behind the Carson Nature Center.

Such a project would fulfill the HCWG’s first major goal, which is to find ways to repurpose the canal. While Denver Water is committed to keeping it flowing whenever possible, drought years have taken a toll. Most recently, the canal suffered damage in the September downpours, though Denver Water says it will be repaired by spring.

Lack of water has contributed to the downfall of the cottonwood canopy along the banks of the canal, many of which are more than 100 years old.

“The cottonwoods are going to go,” said Beckman. “They’re going to go due to old age, but it’s being accelerated by the lack of water running through the canal.”

He said Cherry Hills Village is testing a drip irrigation system on its stretch, but ultimately the goal is to replace the cottonwoods with native, drought-tolerant trees.

The working group’s second major goal is to improve the safety of the trail. Beckman notes it was not designed for recreational use.

“More than 120 years ago, the High Line Canal was constructed to deliver irrigation water,” reads the working group’s report. “Since then, the corridor has evolved into a different resource — the High Line Canal Trail. Quietly tucked away in one of America’s greatest metropolitan areas, the trail has become an inspiring recreation destination.”

As traffic continues to increase throughout the metro area, there are places where trail crossings are becoming more dangerous. Broadway and Arapahoe Road is a prime example, notes Beckman. But installing either a culvert or an overpass for pedestrian use would cost about $4 million.

While the group continues to study these grand-scale plans, it decided to narrow down some smaller projects to take back to the member communities.

“We said we can’t sit and wait,” said Beckman. “We didn’t want to lose the synergy and the movement we had.”

Council agreed to consider going forward with improvements to bridges on Ridge Road and Elati Street, at a cost of about $200,000 each, and widening the sidewalk on Broadway from Ridge Road to Arapahoe.

“This is not going to be ideal, but it could be, perhaps, safer,” said Beckman.

Money for the bridge projects could be allocated from the city’s dedicated open-space fund, which is granted by Arapahoe County from voter-approved property taxes. The sidewalk improvements wouldn’t cost the city anything more than what was already in the public-works budget.