Sable Outfall

The Sable Boulevard Regional Stormwater Drainage Outfall – Phase B project is a major regional drainage and flood resiliency initiative led by the Mile High Flood District (MHFD) and the City of Brighton. Naranjo Civil Constructors (NCC) is serving as the prime contractor, with JR Engineering as the design engineer, Western States Reclamation (WSR) performing storm drainage utility installation, revegetation, and ecological restoration, and CORVUS Environmental supporting environmental compliance and coordination.

Located along the Sable Boulevard corridor in Brighton, Colorado, the project will improve stormwater conveyance capacity, stabilize drainage infrastructure, and restore disturbed areas with native vegetation and long-term erosion protection. The work includes construction of a new regional outfall system, installation of precast concrete box culverts beneath Sable Boulevard and 144th Avenue, concrete trickle channels, headwalls, maintenance access paths, grading, and channel stabilization improvements extending through multiple crossings and drainage reaches.

WSR’s utility scope includes installation of the concrete box culvert systems at the Sable Boulevard and 144th Avenue crossings, helping deliver critical stormwater conveyance improvements throughout the project corridor. WSR is also completing native revegetation, erosion control, and reclamation work to stabilize disturbed soils, restore ecological function, and support pollinator habitat and overall watershed health.

A key component of the project is balancing regional infrastructure improvements with environmental stewardship. Revegetation and bank protection efforts are integrated throughout construction to improve long-term resilience along the corridor. Construction activities are carefully phased to minimize disruption while maintaining access and coordinating around existing utilities, roadways, agricultural properties, and drainage infrastructure.

The phased construction schedule includes excavation and haul-off operations, installation of stormwater conveyance structures, roadway and culvert reconstruction, grading, revegetation, and final stabilization extending from spring through fall 2026. Major improvements include new outfall conveyance infrastructure along Sable Boulevard, crossings at 144th Avenue, maintenance access improvements, sedimentation basin enhancements, and channel restoration features designed to improve system reliability and long-term maintainability.

By combining NCC’s heavy civil construction capabilities with WSR’s storm drainage utility installation and ecological restoration expertise, the Sable Outfall Phase B project strengthens regional flood protection while improving the long-term sustainability and functionality of the surrounding drainage corridor.