Willow Creek Detention Pond, Colorado
This roller compacted concrete (RCC) project was for improvements to the Willow Creek channel for the Rampart Range Metropolitan District #1, Lonetree, Colorado. The work consisted of 39,000 cy of grading, 6000 cy of borrow, an extension of a 7’ X 5’ CBC to a single pre-cast 7’ X 5’ CBC including new headwalls and wingwalls, 3 concrete box flow control structures, 3,570 sf of sheet piling and cap for the weir structure and 3,000 cy of RCC for 3 drop structures and access roads.
The design of the RCC drop structures created several challenging construction problems. The geometry of the stepped facing for the drop structures was not straight line as is typical. The stepped faces were all curved with radii as short as 50’. Access points to the placement sites were difficult to access by traditional means. Also the existing drainage channel was highly susceptible to flooding.
In order to meet the 120-day schedule, preventative measures to protect the site against flooding were critical. Even with flood protection in-place the project was ravaged by a 100-year storm when the project was only 30% complete. IHC was able to repair the damage and still complete the project on time.