Trends Summer 2013 | Page 12

finding a viable project. Hollingsworth’s “tenacity and creative vision brought together all the project elements to provide the City of Longmont a project that everyone can be proud of,” he said. Lykins Gulch is a perennial stream in the St. Vrain Creek watershed. It generally flows easterly from the Rocky Mountain foothills west of the City. Decades ago, the natural Lykins Gulch drainageway was filled in and diverted to a series of irrigation ditches to maximize the agricultural use of the land. These ditches overflowed frequently, and approximately 150 acres at the lower end of the watershed were in the floodplain, meaning during a 100-year flood event the entire area was under water, creating a hazard to property owners. To exacerbate the problem, all land between the busy Airport Road on the far west side of the project and the St. Vrain Creek was privately owned. Additionally, preservation of the St. Vrain habitat and water quality was a critical component to any modifications to the area. St. Vrain Creek is recognized as a significant riparian corridor and fishery. The stream’s reach in the area supports a significant population of rare native fish. The original solution proposed routing water from the channel into a private lake and conveying the water into a City-owned pond before discharging into St. Vrain Creek, Pennington said. When this solution was deemed too costly because of land acquisition costs and coordination and regulatory issues, other alternative solutions were explored. The ultimate solution took an innovative approach: constructing the flood channel through the middle of the private lake, requiring less land acquisition and earthwork removal. During construction the lake was drained, and flood control berms were built on either side of the channel to hold back the water from the remaining lakes. It was paramount that the design not hamper the Carter Lake pipeline, Pennington said, which runs along the east side of Airport Road and provides a critical water supply for a neighboring city. “Years earlier when the pipeline was being built, the City had the forethought to lower this pipeline that now crosses the Lykins Gulch channel with a vision that a natural channel would eventually go through the area,” Pennington said. “If the pipeline had not been lowered at this juncture, the project would have been too costly.” Left: The muli-use greenway path along the channel provides a critical link to the St. Vrain Greenway trail system. 12│TRENDS TRENDS │13