The Town of Cherry Hills Village and the Urban Drainage and Flood Control District collaborated on this maintenance project to address bank erosion through Woodie Hollow Park. This master planned reach of Little Dry Creek is located just downstream of a previous bank stabilization project. Unrestricted flows out of the stabilized channel, combined with high velocity flows from a tributary storm sewer outfall, directed hydraulic energy into the unprotected north bank of Little Dry Creek and began undercutting trees. The resulting meander into the south bank threatened stability of a sanitary sewer manhole and soft surface park trail.
The stabilization solution preserved the meander of the creek but reinforced the outside bends with buried riprap. The inside bends were stabilized with soil lifts. The channel was restored to proposed master plan grades by implementing channel fill and a 18-inch boulder grade control structure at the downstream limit. A “no rise” floodplain permit was achieved by laying back the northern channel bank to counteract the fill. The channel design also minimized tree removals during construction, and where tree removals were necessary, noxious species were targeted and replaced with native species in locations determined by Cherry Hills Village staff. The trail alignment was lowered adjacent to the soil lifts, reducing the bank height and bringing trail users closer to stream environment and away from private properties. The City will assist UDFCD in maintaining the soil lifts through the first few seasons by irrigating the seed plugs and vegetation.
Naranjo Civil Constructors and Arrowhead Landscaping built this project per plan, on schedule, and at budget.