- Dam breach analyses
- Hydraulic modeling
- Outlet works design
- Construction documents
- Wetland and riparian plantings
- Landscape architecture coordination
- Emergency Action Plan
- Construction engineering
Niver Creek Detention Dam is a high-hazard dam that is owned and maintained by the City of Thornton (Thornton). The dam was constructed in the late 1970s to provide flood control along the Niver Creek drainageway. The dam is located in the Niver Creek Open Space, which consists of 120 acres of open space and multi-use trails surrounded by dense commercial and residential developments.
Thornton and Mile High Flood District (MHFD) desired to rehabilitate the outlet works to address the following issues:
- The approach channel frequently collected trash, debris, and vegetation. Also, the approach channel was narrow and shallow, which made maintenance difficult.
- The riser structure frequently collected trash, debris, and vegetation, which can reduce the capacity of the outlet works.
- An orifice plate mounted to the inlet of the reinforced concrete pipe (RCP) had caused significant cavitation damage to the RCP immediately downstream.
RJH worked closely with a landscape architect to develop a design concept that integrated with the surrounding open space. The project included wetland and riparian plantings along the Niver Creek corridor. The selected design concept included:
- Widening the approach channel and installing a forebay with low-flow crossing and grasscrete pavers.
- Installing a new intake structure with sloping steel trashrack. A new orifice plate was mounted to an interior wall 5 feet upstream of the reinforced concrete pipe (RCP) conduit to mitigate hydraulic issues that were previously causing cavitation.
- Demolishing and replacing damaged portions of RCP.
RJH led the engineering work from initial evaluation and assessment of the original outlet works through identification of preferred rehabilitation concept, state permitting, final design, and construction engineering.