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.
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