Client
Location
Services Provided
- Geotechnical investigations
- Floodplain permitting
- Alternatives evaluation
- Spillway design
- Pipeline and pump station design
- Slope modifications
- Surface water collection facilities
- Construction documents
- Resident engineering
- Construction administration services
Challenges
The City of Thornton (Thornton), located about 10 miles northeast of Denver, is one of the fastest growing areas in the state of Colorado. Like many other providers, development of a reliable raw water storage system requires several decades of planning and implementation. In the 1980s, Thornton began acquiring gravel pits along the South Platte River with the intention of converting them into water storage reservoirs. Thornton continued to acquire gravel pit reservoirs over the next 20 years.
In 1995, key RJH staff began providing engineering services for select gravel pit facilities. Shortly after, RJH staff and Thornton identified the need to manage development of the reservoirs as a collective system rather than as a series of independent projects.
Solution
The Southern Raw Water System (System) is Thornton’s primary raw water supply and consists of a series of twelve reservoirs with interconnect pipelines between the reservoirs, in addition to diversion structures, spillways, groundwater wells, pipelines, and pump stations to convey the stored water to water treatment plants. The reservoirs consist of both below-grade reservoirs and above-grade dams, and are located adjacent to the South Platte River over a distance of about 7 miles. When completed, the System will provide a combined storage of over 30,000 acre-feet with total project costs exceeding $200 million.
For more than 25 years, RJH has provided a leadership role for technical issues, permitting, master planning, cash flow, site acquisition, and negotiations and have been instrumental in the development and implementation of the System. As part of this on-going work, RJH has developed planning and final designs, bid documents, and cost estimates for numerous reservoir facilities for over 20 discrete projects. Project components have included embankment dams, clay and soil-bentonite liners, spillways, outlet pipes, river diversions, interconnects, gates, hydraulic control systems, pump stations, multi-use trails, security features, and access roads. Several of the reservoir sites are highly visible and required public involvement in the planning and design phases.