L-8 FLOW EQUALIZATION BASIN PROJECT - CONVERTING RETIRED ROCK QUARRIES FOR ENVIRONMENTAL RESTORATION

摘要

The South Florida Water Management District (SFWMD) is responsible for implementing projects to improve water quality and water flow into the Everglades. The L-8 Flow Equalization Basin (FEB) Project involves improvements to an existing, retired rock quarry in Western Palm Beach County. The FEB will improve water quality in the Everglades by capturing stormwater flows, storing and attenuating the water to the local stormwater treatment areas (STAs) for phosphorus removal prior to delivery to the Arthur R. Marshall Loxahatchee National Wildlife Refuge. The accelerated Design/Build project is being executed by Archer-Western Contractors, Inc. and Jacobs Engineering Group, Inc. (Jacobs). Project features include: 1. Approximately 46,000 acre-feet (15 billion gallons) of storage with perimeter embankment improvements, cell modifications and a new boat ramp facility. 2. An extension of the inflow-outflow canal connecting the FEB to the existing L-8 Canal, as well as the installation of a new access road bridge across the canal. 3. G-538 Spillway - A new gated control structure, with a maximum flow capacity of 3,000 cfs, connecting the FEB to the existing L-8 Canal, including a concrete outfall channel that extends to the bottom of the L-8 FEB with a USBR Type Ⅲ stilling basin. 4. G-539 Pump Station - A new 2-stage pumping facility, with a maximum pumping capacity of 450 cfs, connecting the L-8 FEB to the existing L-8 Canal. 5. A sustainable project designed to capture stormwater flows and store them for use for dry season hydration of the STAs. The project converts a 1,000 acre retired rock mine to a below-ground FEB/storage reservoir. No new lands are impacted by the construction of the L-8 FEB. The unique geology at this particular site consists of dense rock and sand minimizing the loss through seepage outflows. This paper will provide an overview of the project and present some of the design and construction features and challenges for the L-8 Flow Equalization Basin Project in the South Florida environment.