Waterton Canyon will close on Monday so that crews can dredge Strontia Springs Reservoir.Denver Water will be dredging thousands of cubic yards of sediment that has built up following the 1996 Buffalo Creek wildfire and 2002 Hayman wildfire that stripped away vegetation and triggered erosion.The canyon will be off limits to hundreds of people who hike, bike and fish there every day."I wish there was a way they didn't have to close it, because everybody loves to use it. I mean, you can see all the people here," said Heidi Peterson, who came to ride her horse.The parking lot was overflowing with outdoor enthusiasts on Saturday. On high-use days, there are more than 2,000 visitors to Waterton Canyon, according to Denver Water."I like going up the canyon and seeing the big-horn sheep and just watching the river," said cyclist Tobin Kern."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 Joanna Masloski, who went for a hike in the canyon on Saturday.Denver Water worried the construction work would compromise safety."The canyon road essentially will be a six 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.Chesney said at least 625,000 cubic yards of sand, silt and gravel will be 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.Waterton Canyon will be closed for nearly a year and a half to complete the project. The first part of the closure will be from Aug. 2, 2010 to Dec. 3, 2010. The canyon will close again from Feb. 28, 2011 to Dec. 31, 2011.Neither the parking lot at the canyon's entrance nor the canyon will be accessible during the closure. Access to The Colorado Trail (CT) from Waterton Canyon will also be closed during these times. The next closest access to the CT Segment 1 is via the Indian Creek Trailhead on Colorado 67, 10.5 miles west of Sedalia.The project will cost more than $30 million. 7NEWS asked if water rates would go up as a result."Our water rates very likely will continue to go up based on a lot of other big capital projects that we have going on. This particular project has already been accounted for in the rates people are currently paying," said Chesney.