Decompartmentalization and Sheetflow Enhancement of Water Conservation Area 3, Hydrologic Field Test, Miami-Dade County, Florida

The Decomp Physical Model (DPM), also known as the Decomp hydrologic field test, is a large field-scale design test that will address scientific, hydrologic, and water management uncertainties specific to the CERP project Decomp. The goal of the design test is to obtain information to reduce uncertainties involved in the planning of later phases of the Decomp Project and CERP overall. The fundamental uncertainties the design test will address are related to the effects associated with canal backfilling, effects associated with levee removal, and the magnitudes and directions of sheetflow necessary to restore and maintain the landscape characteristics of the Everglades. The design test will be extensively monitored and will adhere to operational constraints described in the Draft Operational Guidance in the April 2010 Final Decomp Physical Model Environmental Assessment & Design Test Documentation Report.

The work for this contract includes installing a new water conveyance structure (Structure 152) on the L-67A levee to convey water from WCA 3A to WCA 3B. S-152 is ten controllable gated 60" diameter culverts with a combined minimum flow of 750 cubic feet per second (cfs). In addition, a 3000 ft gap will be created in the L-67C levee downstream of the S-152 structure. Material from the L-67C gap will be used to construct backfill treatments in the L-67C Canal. 1,000-feet of canal will be backfilled to grade, 1,000-feet will be partially backfilled, and the final 1,000-feet will have no backfill. An additional feature for the contract includes a walkway for the S-152 structure. Contractor shall complete L-67C degrade and backfilling a minimum of 30 calendar days prior to completion of L-67A (S-152). INSTALLATION OF THE STRUCTURE AND BACKFILL PLACEMENT HAS ENVIRONMENTAL SENSITIVITY AS THE WORK IS PREDOMINATELY IN WETLANDS. WORK MAY REQUIRE PLACEMENT OF MATERIALS IN SURFACE WATER. Access to the project site is from US 41 (Tamiami Trail) by S-333 along L-67A and L-67C levees. The period of performance is 180 days from Notice to Proceed. Work is located in Miami-Dade County, Florida.