Xcel Energy Centre Point Facility
Roseville, MN

Reconstruction of the employee parking lot, installing stormwater treatment systems and drainage improvements for compliance with the City of Roseville and Rice Creek Watershed District requirements.

Filtration systems were deemed the preferred best management practice based on site conditions and coordination with local permitting agencies. Two bio-filtration basins were implemented to collect roof rainwater and an underground storage chamber arrangement was designed to collect parking lot runoff. The underground treatment system consisted of 20 prefabricated chambers embedded in an aggregate trench, overlaying a sand section with an outlet drain. Each system provides stormwater treatment, detention, and rate control.

Reconstruction of the pavement section included removing and recycling the existing degraded asphalt pavement and replacing with new bituminous over the recycled aggregate base material. After reclaiming and stockpiling the salvaged material, a new granular sub-base section was installed over a drain tile system atop soil separation fabric. The drain tile configuration was designed to efficiently collect and route water to the existing catch basins and ultimately the underground chambers.

Larson Engineering assisted facility managers with preliminary design and coordination of construction staging.  Construction phasing exhibits were prepared and communicated to site staff and contractors to mitigate the disruption to facility operations and provide cost savings by re-using on site materials.