With the development of the Solstice Subdivision at Chatfield Reservoir by Shea Homes, the Centennial Water and Sanitation District (CWSD) needed to provide timely sewer and water service that would allow Shea homes to take advantage of the accelerating housing market. In 2015, Muller was contracted to prepare a conceptual design study and report to determine the most cost-effective and resilient approach for CWSD to serve the new development.

Upon completion of the study, CWSD asked Muller to prepare plans and specifications for Phase I of the project. The initial phase of work consisted of an extension of water mains and parallel sewer force mains from the intersection of US 85 and Highlands Ranch Parkway, across the Plum Creek drainageway in a southwesterly direction to the development situated along the south side of Chatfield State Park. The force mains were later extended west to the low point of the development where a lift station pumps wastewater flows from the development to CWSD’s gravity system along US 85.

Due to the proximity of the lift station to the reservoir and the sensitive nature of the area, parallel (dual) sanitary sewer force mains were included in the design. To avoid environmental impacts and disturbance of endangered species in Chatfield State Park, Horizontal Directional Drilling (HDD) was utilized for a portion of the water line beneath the Plum Creek drainageway. The project consisted of approximately 15,300 feet of 10-inch dual sewer force main that included 24-inch casing pipe crossings under US 85 (Santa Fe Drive) and the Burlington Northern Santa Fe and Union Pacific Railroads (1,170 feet). Water line work included approximately 4,300 feet of 16-inch open cut water line construction and 2,230 feet of fused HDD 16-inch PVC construction.

The project was closely coordinated and permitted through the US Army Corps of Engineers (USACE), Colorado Parks and Wildlife, Colorado Department of Transportation (CDOT), and Douglas County.