There is good news for hikers, walkers, fishermen and cyclists who enjoy Waterton Canyon.The canyon reopened Thursday after a 19-month closure.The canyon closed in July 2010 so crews could dredge Strontia Springs Reservoir. Denver Water said it needed to remove thousands of cubic yards of sediment that had built up following the 1996 Buffalo Creek wildfire and 2002 Hayman wildfire.The fires stripped away vegetation and triggered erosion. That debris makes it much more expensive and much more difficult to treat water.The plan had been to reopen last December. However, Denver Water said the reopening was delayed until March 1 while the majority of heavy machinery and equipment was moved, officials said.A 75-ton dredge will remain in the reservoir until the ice melts, meaning the canyon will need to be closed for three weeks in the spring for the contractor to remove the dredge.
On high-use days, there were more than 2,000 visitors to Waterton Canyon, according to Denver Water."I like going up the canyon and seeing the bighorn sheep and just watching the river," said cyclist Tobin Kern before the canyon closed in 2010."This is a beautiful trail, and it's close enough to our house where we can enjoy it, and it's not too hilly," said hiker Joanna Masloski."The canyon road is essentially a 6-mile-long construction site during this project," said Denver Water spokeswoman Stacy Chesney. "We considered other alternatives to the dredging project, as well as ways to keep the canyon open during construction, but in the end, we determined it is in the best interest of public safety to close the road."
Chesney said the dredging is necessary to maintain water quality and avoid operational problems that could impact service to Denver Water's 1.3 million customers."I called it the giant straw," said project manager Doug Raitt.At least 625,000 cubic yards of sand, silt, gravel and debris was piped down the canyon. That's enough to fill Invesco Field at Mile High to a depth of about 200 feet. It will be stockpiled for later use as fill."This kind of dredging project has never really been done before," Raitt said.Work crews used a 150,000-pound dredge to drill into and vacuum the sediment and then sent it down a high-pressure slurry pipe to the mouth of Waterton Canyon."Were trying to get the sediment load back to where it was before the fires," Raitt said. "Burnt needles and burnt pine trees have a high load of manganese. Manganese is the black stuff in your pipes that nobody wants."By removing the sediment and debris from Strontia Springs, the utility hoped to lower the cost of treating water.Work crews dredged 24 hours a day, six days a week during the project.Strontia Springs Reservoir holds 7,863 acre feet of water.It is 6 1/2 miles upstream from the mouth of Waterton Canyon.The project is expected to cost more than $30 million.