Reservoir Interconnect Pipeline

GEI was retained by the City of Thornton to provide flexibility in storing and managing the City’s raw water supply while maximizing the effective capacity of two reservoirs.

GEI performed a field investigation program, evaluated design alternatives, recommended a preferred alternative, and designed a pipeline to connect two existing off-channel gravel pit reservoirs.

GEI’s field investigation program consisted of a site reconnaissance, geotechnical explorations, geophysical and civil surveys, laboratory testing, and utility research to gather information evaluating pipeline design and construction alternatives.

Different pipeline routes, materials and construction methods were evaluated based on constructability, time of construction and estimated project costs. Site constraints, easements, and construction sequencing alternatives were also evaluated. The preferred alternative recommended was a 42-inch diameter, butt-welded, steel pipeline, with cathodic protection using cut-and-cover construction methods.

Ancillary project features that were designed and constructed included impact stilling basins with 42-inch sluice gates and a reservoir gaging station to record water use. The pipeline crosses an arterial street, therefore, the project also included a temporary detour and associated traffic control.

GEI prepared contract documents, construction drawings and technical specifications for final design. GEI also provided bid assistance, construction observation and documentation services.