Water Conservation Area 3
Decompartmentalization & Sheet Flow
Enhancement (Decomp)

 

28 Sep 2012 | Documentation Report for WCA 3
Decomp Project

A documentation report has been prepared for the Water Conservation Area 3 - Part 1 Decomp Project, which will be integrated into the Central Everglades Planning Project (CEPP).

30 Jan 2012 | Decomp Physical Model Receives Final Permit

The U.S. Army Corps of Engineers (USACE) Jacksonville District received the final permit for the construction and interim operations of the Water Conservation Area 3 (WCA-3) Decompartmentalization (Decomp) and Sheetflow Enhancement Physical Model Jan.9 from the Florida Department of Environmental Protection.


The Decomp Physical Model (DPM) is a field-scale test that will be conducted along a 3,000-foot stretch of the L-67A and L-67C levees and canals in WCA- 3A and 3B to determine how best to design and formulate plans for future decompartmentalization of WCA-3, as visualized in the Comprehensive Everglades Restoration Plan (CERP).


The DPM is designed to address scientific, hydrologic and water management uncertainties that require clarification prior to future planning and construction of Everglades restoration projects, authorized in the Water Resources Development Act of 2000.


Installation of the DPM was completed in October 2013. The first operational testing period began Nov. 5, 2013. Access through the L-67A canal will remain open during and after installation. Access through the northern portion of L-67C will be blocked until the model is decommissioned.


It is the natural flow of water – volume, direction, speed and depth – that help create the unique characteristics of the Everglades ecosystem. Decompartmentalization entails removing constructed canals, levees and other barriers that impede the natural sheetflow of water into and through the historic Everglades and restoring a more natural water flow. The primary impediment to the natural flow of water through WCA-3A is the Miami Canal, which separates WCA-3A north from WCA-3A south. The initial area of investigation will look into removing barriers to sheet flow through WCA-3A.


Because of scientific and ecological uncertainties, and dependence (WRDA 2000) upon the Modified Water Deliveries Project, the DECOMP Project Delivery Team is utilizing a multiple PIR phased approach for implementation that uses adaptive management, construction of a first phase, monitoring of component performance, and additional construction to achieve the desired results.

  • PIR 1 (Miami Canal portion of QQ P1 and SS) focuses on options to backfill the Miami Canal, and on any North New River improvements needed to offset conveyance lost in the Miami Canal. Alternatives being examined include complete backfill, partial backfill, plugging of the canal and removal of existing canal spoil mounds.

Concurrent with PIR #1, a temporary field test, or Physical Model, will be implemented. The Decomp Physical Model (DPM) consists of culverts in the L67A levee, a gap in the L67C levee, and the complete and partial backfilling of segments of the L67-C canal. These features will provide a controllable hydrologic connection between WCA-3A and WCA-3B that delivers pulsed flows at velocities of at least 31 cm/sec over a period of days. The DPM will assess the effects of pulsed flows on hydrology, sediment transport, vegetation and wildlife. Results will guide planning, design and operational guidance for alternatives for both PIRs #2 and #3. The project is tentatively located in northern Miami-Dade County, along the southern 10 to 15 miles of the L-67A and L-67C canals.

  • PIR 2 (Tamiami Trail portion QQ - P1 and AA) focuses on modifying eastern sections of Tamiami Trail.

  • PIR 3 (QQ - P2, ZZ) includes backfilling the southern 7.5 miles of L-67A borrow canal, removal of the L-68A, L-67C; degradation of western portions of L-29 below WCA 3A, L-28, and L-28 Tieback Levees and Borrow Canals; and elevating the western portion of Tamiami Trail south of WCA 3A.

An adaptive management strategy will be developed for the overall project, including formation of an interagency adaptive management team. Sequencing with the Modified Water Deliveries, C-111 South Dade, and CERP projects (e.g., L-31N Seepage Management Pilot, ENP Seepage Management, Broward County Water Preserve Areas, and Everglades Agricultural Area) is critical because of inter-relationships.


Project Details:

Project Sponsor:

South Florida Water Management District

Project Schedule:

For scheduling information regarding this project, please see the Master Implementation Sequencing Plan (MISP).

Project Phase:

Pre-Construction, Engineering and Design

Design Agreement:

12 May 2000

CERP Component Designation:

QQ (Part 1 and 2), SS and AA and ZZ

Project Cooperation Agreement:

 

Authorization:

WRDA 2000 (Initially Authorized QQ P1 and SS);
Other components are not currently authorized

 

 

 

Project Contacts:

Stephen Baisden
U.S. Army Corps of Engineers
Stephen.A.Baisden@usace.army.mil


Matthew Morrison
South Florida Water Management District mjmorris@sfwmd.gov


Related Links & Project Documents: