DESIGN SERVICES FOR GOLDEN GATE CITY OUTFALLS

As requested by the Transportation Engineering Division (hereinafter, the “Division or Department”), the Collier County Board of County Commissioners Procurement Services Division (hereinafter, “County”) has issued this Request for Professional Services (hereinafter, “RPS”) with the intent of obtaining proposals from interested and qualified Consultants in accordance with the terms, conditions and specifications stated or attached. The Consultants, at a minimum, must achieve the requirements of the Specifications or Scope of Work stated.

The selected consultant shall perform a comprehensive design of the County-owned inlets and outfall pipping and structures, identified within the Golden Gate City area to construct system renovations to improve the stormwater drainage system and minimize flooding events in Golden Gate City. The selected Consultant will perform preliminary design, construction phasing, final design, permitting, bidding packages, opinion of probable costs, public involvement services, construction-related support services, and construction warranty services.

The Collier County Transportation Engineering Division is undertaking a comprehensive program to replace Golden Gate City outdated stormwater infrastructure, specifically targeting the inlet and outfall systems, which have been in operation for over fifty (50) years. This upgrade aims to improve stormwater drainage and mitigate flood risks across the area. The Florida Department of Environmental Protection (FDEP) has allocated $2,810,500 for this project through the FY23-FY24 Appropriation, with no match required.

In 2020, AIM Engineering & Surveying, Inc., completed a survey of the stormwater infrastructure in Golden Gate City finding that the system is approximately fifty (50) years old and at the end of its useful life (Attachment 1: Golden Gate City Outfall Summary Report). The system includes a total of one-hundred and thirty-seven (137) outfalls that were surveyed, comprising of pillbox type structures and corrugated metal pipe in poor and occasionally hazardous conditions. Maintenance access is restricted to a 12-foot easement (6 feet on either side of the lot line). Concrete structures are frequently cracked or broken, and the pipes are corroded or collapsing, compromising both the structural integrity of the system and its ability to effectively convey stormwater. This condition results in a diminished level of service for stormwater management.

In 2020 Collier County replaced outfall/inlet system SMOF-1968 and SMIL-11786, identified as the most critical/failing. Subsequently, in 2022, AIM Engineering & Survey, Inc. developed initial plans to replace fifteen (15) outfalls that were determined to be the most critical infrastructures that needed to be replaced (see Attachment 2: Golden Gate City Outfall Pipe Replacement, Final Construction Plans). The design considerations included open trench replacement of the existing corrugated metal pipes with Corrugated Plastic Pipes (CPP). Headwall outfalls were preferred, with new precast inlets. The plans also considered private improvements within the drainage easements, such as vegetation and fencing, which may require restoration. The plans are being provided as a reference only.

The FDEP funding will support the replacement of fifteen (15) stormwater outfalls. The selected firm will be responsible for updating bid documents, technical specifications, and cost estimates for the fifteen (15) outfall pipe replacement plans, and to ensure alignment with current industry standards. Additionally, services will include construction bidding support and post-design services through construction to ensure effective stormwater conveyance and functionality.