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Brevard County US 192 Solid Waste Management FacilityContinuous Simulation Wetland Modeling April 23, 2013
Seth M. Nehrke, P.E., D.WRE
APWA Florida State Conference
Agenda
• Project Overview• Selection of Keystone Indicator Wetlands• Model Updates• Model Results• Next Steps
Proposed Brevard County Solid Waste Management Facility
Why Do We Model?
• Guide wetland mitigation decisions
• Aid in the design & permitting process
• Enhance the rate of wetlands survivability
• Optimize system operation and performance protocols
Existing WetlandsSystems: 581 Ac
Effect of Shutting Off Wells: Groundwater Drops 0.5 Feet
Notes: 1) Potential groundwater effects on wetlands are based on an anticipated 0.5' drop from a wells‐on to a wells‐off condition
2) Anticipated Minor Affect (loss of minor amount of fringing wet prairie component of polygon and/or minor shift in vegetative cover to include reduced cover by obligate/facultative wet species)
3) Anticipated Moderate Affect (loss of significant portion of herbaceous component of polygon and/or moderate shift of vegetative cover from obligate and facultative wet species to species less tolerant of inundation/saturation)
4) Anticipated Significant Affect (anticipated that the majority of the polygon to shift to cover by facultative and upland species and/or significant loss of other wetland indicators ‐ i.e., reduction in hydric soils, loss of expected hydrologic regime, etc.)
KeystoneWetlands
Wetlands Distribution
Wet Freshwater Mixed Prairie Marsh Cypress Hardwood
Adjacent to Proposed Development D‐O; F‐O D‐O; F‐M F‐O F‐M
Adjacent to Ex/Prop DitchE‐H; F‐D; F‐O; G‐E
A‐T; C‐M; C‐P/Q; E‐H; F‐D; G‐E; I‐N
A‐T; C‐A; C‐M; C‐P/Q; E‐H; F‐O; G‐B; I‐N
C‐A; E‐H; G‐B
In or Adjacent to Proposed PondA‐J; D‐O; F‐D; F‐O;
G‐E
A‐J; B‐Q; C‐M; C‐P/Q; D‐H; D‐O; F‐D;
F‐M; G‐E; I‐N,
A‐J; B‐Q; C‐A; C‐M; C‐P/Q; D‐H, F‐O; G‐B;
I‐N
C‐A; F‐M; G‐B
Removed from Proposed Development E‐H; I‐F E‐H; I‐F E‐H E‐HNote: 16 Systems and all 8 community types are represented
Herbaceous Wooded
Geographic Location
Indicator Wetlands Distribution
Development of a Comprehensive Survey Plan
Update Hydrology
• Refine basins• Dynamic soil storage• Existing calibrated HSPF
Representative Hydrologic Year
Update Hydraulics
• Connectivity• Evaporation• Infiltration• Use site‐specific information
when available
Multiple Community Systems
LABEL ACRES Community TypeI‐N 9.70 621 ‐ CypressI‐N 2.45 641 ‐ Freshwater MarshI‐N 3.79 641 ‐ Freshwater Marsh
Surface Water Driven
KeystoneWetlands
Groundwater/Evaporation Driven
Reduced Stages
KeystoneWetlands
Elevated Stages
Summary Results and Recommendations
WETLAND ID Phase I Conceptual RecommendationA-J +0.5' to +1.5' +0.5' - 1.5' Construct connection to eastA-T Good Match Good Match N/AB-Q Good Match Good Match N/AC-A -1.0' to +0.5' -1.0' to +0.5' Modify proposed control structure from BP1C-M +0.5' to +1.5' +0.5' to +1.5' Divert water to create wetlands
C-P/Q Good Match Good Match N/AD-H Good Match Good Match N/AD-O match to +0.5' match to +0.75' Divert water to create wetlandsE-H -0.5' -0.5' Construct ditch block in proposed ditches
F-D(N) Good Match N/A N/AF-D(S) Good Match match to +/-0.25' N/A
F-M match to -0.5' match to +0.5' Could Connect to SWM4 in Phase I F-O Good Match Good Match N/AG-B +0.5' to +1.0' +0.5' to +1.0' Divert flow into adjacent ditchG-E Good Match Good Match N/AI-F Good Match Good Match N/AI-N Good Match Good Match N/A
Next Steps
• Continuous simulation• Design storm simulation• Development of wetland
creation plan
Special Thanks to