250 likes | 353 Views
Everglades Agricultural Area Storage Reservoir A-1 30% Earthworks Design Phase. WRAC April 6, 2006 Shawn Waldeck, P.E. Acceler8 Project Manager. Project Purpose. EAA Reservoir A-1 is an important part of the Comprehensive Everglades Restoration Plan (CERP). As part of CERP it will:.
E N D
Everglades Agricultural AreaStorage Reservoir A-130% Earthworks Design Phase WRAC April 6, 2006 Shawn Waldeck, P.E. Acceler8 Project Manager
Project Purpose EAA Reservoir A-1 is an important part of the Comprehensive Everglades Restoration Plan (CERP). As part of CERP it will: • Allow SFWMD to better manage water to the environment • Allow SFWMD to manage water deliveries to agricultural community
Project Purpose • Capture, store, and make use of EAA Basin runoff and releases from Lake Okeechobee • Reduce Lake Okeechobee regulatory releases to the estuaries • Restoration of Everglades’ hydropatterns • Balancing inflow into STA-3/4 • Preserve existing agricultural water uses • Ancillary improvement in flood protection in EAA A-1
US Highway 27 Future A-2 Reservoir Miami Canal North New River Canal Proposed A-1 Reservoir Pump Station G-372 Supply Canal Holey Land Wildlife Management Area Pump Station G-370 STA-3/4
Overall Plan Connector Canal • 190,000 ac-ft of storage • Seepage canals • New pump station from North New River Canal • Gated discharge structures • STA-3/4 Supply Canal Northeast Pump Station North New River Canal Gate Structure Seepage Canal EAA Reservoir A-1 Embankment Internal Borrow Canal From G-372 Pump Station Gate Structures G-370 Pump Station G-383 STA-3/4 Supply Canal
S T R I P P I N G Stripping berm Seepage canal Borrow canal Cut-off wall
Downstream slope maintenance generally not required if defect free. Risk of piping in dam eliminated. Minor overtopping may be acceptable without damage. Avoids the need to use moisture sensitive Fort Thompson Formation material Occupies less area than an embankment, so EAA Reservoir A‑1 storage can be maximized. Advantages of Roller Compacted Concrete RCC
Higher cost Supply risk because a large volume of cement must be imported. Special foundation treatment required where caprock thin or absent Predicting the magnitude of cracking and control of crack location with certainty is difficult due to the variable foundation conditions. Seepage is expected to occur through cracks. Foundation preparation by air/water blasting Settlement of the cutoff must be compatible with the rigidity of the RCC structure. Temperature control of the RCC components difficult in hot temperatures. Moisture control in stockpiled aggregates difficult during wet season. An RCC structure does not fit aesthetically with the surroundings. Vertical upstream face creates a safety hazard; means for escape required Disadvantages of Roller Compacted Concrete RCC
Design Safety • Dam Design Criteria – DCM (Design Criteria Memorandum) coordination • Superiority • Stability • Regular Inspections/Monitoring
Project Assurance Requirements WRDA (Water Resources Development Act) 2000 and Florida Statute requirements addressed: • Identify water for the natural system • Identify water for other water-related needs • Confirm quantify water available to existing legal users has not been diminished • Determine that existing levels of service for flood protection will not be diminished outside geographic area of the project
Documentation of Project Assurances • Documentation of Project Assurances for A8 Reservoir will be included in the Preliminary Design Documents (30% Design for both the earthworks and pump station phases) • Acceler8 system wide benefits, ascribable to the EAA Project, will be identified in the Final Supplemental Environmental Impact Statement (SEIS) • Corps Project Implementation Report (PIR) documents project assurances for Compartment A in its entirety
Surface Water Flood Protection • Inherent flood protection due to reservoir • Additional capacity created in the existing canal system • Additional pumping station(s) in system
Permitting/Environmental • 1502 Water Quality Certificate • USACE 404 • 1501 Assurances • Environmental Site Assessment and Clean Up • Protected Species • Manatee • Florida Panther • Wading Birds • Other • Environmental Enhancements • Construction Permits • Air/Noise
Stakeholder Presentations • Agricultural • Environmental • 298 Districts • Belle Glade • Pahokee • South Bay • Palm Beach County • Tribes • FPL/FDOT • Recreational • WRAC Issues Workshop • Full WRAC
Stakeholder Comments • Safety • Flood Protection • Local Economic Development • Recreational Use(s) • Assurances • Consider other “less – engineered” alternatives • Wetland impact and mitigation • Holey Land seepage
Degradation in the EAA HISTORICAL Lake Okeechobee Sheetflow over the sawgrass plains to the Everglades PRESENT EAA Lake Okeechobee S7 Loss of muck in the EAA through subsidence, compaction, and oxidation
2005 Schedule for EAA Reservoir A-1 2006 2007 2008 2009 Design Construction
Base Cost from Yellow Book Embankment Pump Station Control Structures U.S. 27 Bridges Subtotal Structures Total Yellow Book Prorated to 190,000 AF $M 437 243.3 Costs adjusted to 2006 A-1 (acres) Total A (acres) 364 16,700 30,000
Base Cost from BODR for EAA Reservoir A-1 Embankment Pump Station Control Structures U.S. 27 Bridges Subtotal Structures Total BODR Costs adjusted to 2006 310.4 70.4 14.6 5.3 90.3 400.7 412.7 • Added cutoff wall • Increase water depth to 12 feet • Modified pump station and added pump station
Preliminary Design Report Embankment Structures Total PDR Costs adjusted to 2006 349.7 90.3 440.0 440.0 • Added concrete to slurry wall • Added mechanical mixing of slurry wall • Embankment volume increased