RES delivered design-build services for four bioretention areas at Ameren corporate headquarters, the electric utility provider for most of eastern Missouri. Ameren entered a landowner agreement with RES, and RES fronted all project costs including surveying, design, permitting, bonding, and construction, which the Metropolitan St Louis Sewer District (MSD) then reimbursed via the Rainscaping Large Scale Grants program established following the U.S. EPA consent decree.

The design-build approach provided an opportunity to establish a project team that included Ameren, RES, engineers, and contractors at the project’s inception. The team’s delivery process optimized the design and reduced construction risks. This improved the project schedule and safeguarded the project budget. Once potential green stormwater infrastructure areas were identified, the team conducted a walk-through to investigate ways to increase the stormwater drainage area managed, identify construction risks, develop strategies to mitigate risks, reduce construction costs, simplify engineering and design, and meet Ameren’s expectations.

At 30-percent design, the contractors performed site investigation and provided the engineers with information needed to avoid utility conflicts. RES continually updated estimates, had contractor agreements in place before the construction documents were completed, and began construction immediately after MSD approved the plans. The project was constructed efficiently and enhanced the sustainable functionality of Ameren’s corporate headquarters.

Client Benefits
• Flood reduction: Bioretention areas help manage stormwater runoff
• Cleaner water: Green stormwater infrastructure improves water quality
• Healthier environment: Native plantings support biodiversity and habitat
• Community resilience: Infrastructure reduces strain on local sewer systems
• Shared investment: Grant-funded project maximized community resources