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Honor Award - Planning

Feasibility and Routing Study for Phase 2B/2C Regional Integrated Loop Pipeline Project

Entrant: Kimley-Horn and Associates, Inc., and the Peace River Manasota Regional Water Supply Authority
Engineer in Charge: Douglas H. Eckmann, P.E., BCEE, BC.WRE, F.ASCE
Location: Fort Myers, Florida
Media Contact: Douglas H. Eckmann, P.E., BCEE, BC.WRE, F.ASCE

Entrant Profile

The Peace River Manasota Regional Water Supply Authority (Authority) Five-Year Capital Improvement Plan (CIP) identified two pipeline projects related to advancing their Regional Integrated Loop System. These are large diameter potable water transmission mains connecting the Authority’s 54-mgd surface water treatment plant in DeSoto County to the Authority’s members and customers while interconnecting regional water treatment plants. The Phase 2B pipeline begins at the terminus of the existing Phase 2A pipeline that extends from the Authority’s water treatment plant complex westward toward North Port’s 3.0 mgd Myakkahatchee Creek Surface WTP, terminating with a storage tank and booster pumping station in Charlotte County. The Phase 2C pipeline continues westward passing North Port’s new SWWTP (an RO brackish groundwater facility) and northward connecting to Sarasota County’s T. Mabry Carlton WTP (a 15-mgd EDR brackish groundwater plant). This effectively drought proofs the southwest coast of Florida from Manatee County to Charlotte County by interconnecting both surface water and groundwater facilities.

The Authority selected Kimley-Horn to perform a feasibility and routing study for the proposed Phase 2B and 2C pipelines. The feasibility and routing study identified and evaluated feasible alternative routing alignments for these two phases of the Authority’s regional pipeline interconnect system.

Kimley-Horn is a multidisciplined professional design firm ranked 9th in Engineering News-Record’s 2023 Top 500 Design Firms.

Project Description

Introduction

The Peace River Manasota Regional Water Supply Authority (PRMRWSA) is expanding its regional interconnecting pipelines to serve the growing needs of its member utilities, customers, and partners. As acomponent of this program, Kimley-Horn was authorized to perform a Feasibility and Routing Study for the Regional Integrated Loop Phase 2B and 2C Pipelines Project.

In performing this routing study, the goal was to make the evaluation and priority ranking of route alternativesas objective and quantitative as possible. The key to this was to establish non-direct cost criteria (factors thathave a hard-to-define cost that is not directly related to construction). The team collected, combined, andevaluated GIS data from multiple sources (Sarasota County, Charlotte County, the City of North Port, the FloridaDepartment of Transportation (FDOT), the Southwest Florida Water Management District (SWFWMD), theFlorida Department of Environmental Protection (FDEP), and property appraisers) into a custom GIS database.Field reconnaissance was performed to augment the GIS data with additional information not available inagency GIS. The possible route alternatives were prescreened and broken down into manageable routesegments for detailed analysis. Each segment was analyzed for intersections with pertinent GIS informationand a calculated score for non-direct cost factors and the comparative direct cost was determined for eachsegment. The individual segments were then combined into feasible routes providing maximum regional benefit. The shortlisted routes were then ranked by the resulting score for regional benefit, non-direct cost, anddirect cost, resulting in a robust and defensible quantitative analysis and ranking of alternatives.

The development of a GIS total model and a quantitative method of route alternative analysis allowed for an efficient and objective segment analysis, and the subsequent final ranking and selection of the most beneficial route for the new 42-inch potable water regional transmission main that runs through a 32-mile urban alignment spanning two counties.

Integration

The PRMRWSA was established to provide an integrated, environmentally responsible, and sustainable regionalwater supply from the Peace River, a surface water source with extreme variations in flow, in response to concerns for over pumping groundwater in SW Florida. The companion regional interconnecting transmission mains provide connectivity to the region’s brackish groundwater facilities and amajor surface water treatment in Manatee County on the Manatee River, a similar highly variable surface watersource. Cooperation between the four member counties, customers, and partners has created a robust interconnected regional water supply addressing unprecedented population growth with a sustainable extremely reliable and sustainable water supply system.

Quality

The resulting route study received a unanimous vote of approval by the Authority Board and member utilities,with $82,000,000 of funding being finalized for the Phase 2B project (13 miles of 42-inch steel potable watertransmission main). The project is currently under design by the Design-Build team of Woodruff and Sons, Inc.and Kimley-Horn and Associates, Inc. with completion scheduled for June 2025.

Innovation

Previous pipeline routing studies review by the engineering team relied heavily on subjective weighing factors for preference ranking. The goal of the Phase 2B/2C routing study was to make the evaluation andpriority ranking of route alternatives as objective and quantitative as possible. This defensible analysis facilitated buy-in from the many participants contributing to the $200 million program to complete the Authority’s Phase 2 interconnect between the T. Mabry Carlton EDR WTP and the Peace River SurfaceWater Facility.

The key was to establish non-direct cost criteria for factors that do have hard-to-define costs that are notdirectly related to construction costs. The team collected, combined, and evaluated GIS data from multiple sources (Sarasota County, Charlotte County, the City of North Port, FDOT, SWFWMD, FDEP, and property appraisers) into a custom GIS database. Field reconnaissance was performed to augment the GIS data with additional information not available in agency GIS. The possible route alternatives were prescreened and broken down into manageable route segments for detailed analysis. Each segment was analyzed for intersections with pertinent GIS information and a calculated score for non-direct cost factors and comparative direct cost was determined for each segment. The individual segments were then combined into feasible routesproviding maximum regional benefit. The shortlisted routes were then ranked by the resulting score for regional benefit, non-direct cost, and direct cost. The result was a robust and defensible quantitative analysis and ranking of alternatives.

Complexity

The Phase 2B and 2C interconnect pipelines are components in a regional system representing over $2 billion in capital investment by the Authority members (DeSoto, Charlotte, Sarasota, and Manatee counties)and SWFWMD. Complex interlocal agreements and negotiations involving SWFWMD, FDEP, environmental advocates, elected officials, member, and customer utility management have avoided “water wars” and fostered one of the most robust and reliable regional water supply systems in the US

Social and Economic Benefit

A sustainable and highly reliable water supply system made possible by a regional water supply authority supports the unprecedented population growth in coastal Southwest Florida, while protecting the marine environment and reducing saltwater intrusion to existing groundwater supplies.

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