Hydrologic and Environmental Systems Modeling

Transcription

1 Hydrologic and Environmental Systems Modeling Model Documentation Report (DRAFT) RSM Glades-LECSA Pre-CERP Baseline (PCB) July 6, Overview Identification This report documents key inputs and assumptions used in the RSM Glades-LECSA Pre- CERP Baseline (hereafter referred to as PCB in this document). The simulation period is from 1/1/1965 to 12/31/2000. Boundary flows along the northern boundary of the model domain were extracted from the SFWMM PCB simulation (PCB1_V5.4.2_111604_out). These include structure flows, and overland and groundwater flows applied at the model s upper boundary (SFWMM flow tags used as external boundary flows are specified in the water budget reports). No SFWMM simulated results were used as internal boundary flows in the Glades-LECSA model. Scope and Objectives The Glades-LECSA modeling team, as part of the Modeling Service Request 333, was asked to produce a simulation of the Pre-CERP Baseline utilizing the Regional Simulation Model (RSM). Operational Intent The intent of this model run is to represent the hydrologic conditions in the South Florida ecosystem on the date of enactment of WRDA 2000 (December 11, 2000) using a multi-year period of record based on assumptions such as land use, population, water demand, water quality, and assumed operation of the Central and Southern Florida Project. Intended Use of Results The results of this simulation are intended to be used in the WCA-3 Decompartmentalization and Sheetflow Enhancement (DECOMP) Project.

2 2.0 Basis Inputs and Assumptions The inputs and assumptions for the RSM PCB are noted in the table provided below. Pre-CERP Baseline Meteorological Data Rainfall file used: rain_v3.0_beta_tin_14_05.bin Reference Evapotranspiration (RET) file used: RET_48_05_MULTIQUAD_v1.0.bin (ARCADIS, 2008) Topography See Figure 1. Same as calibration topography except where S332B Reservoir is introduced. Tidal Data Tidal data from two primary (Naples and Virginia Key) and five secondary NOAA stations (Flamingo, Everglades, Palm Beach, Delray Beach and Hollywood Beach) were used to generate a historic record to be used as sea level boundary conditions for the entire simulation period. Land Use and Land Cover Water Conservation Area 1 (Arthur R. Marshall Loxahatchee National Wildlife Refuge) Water Conservation Area 2A & 2B See Figure 2. All land use has been updated using most recent FLUCCS data (1995), modified in the Lower East Coast using 2000 aerial photography. Vegetation classes and their spatial distribution in the natural areas comes from the following data: o Welch et al. (1995) aerial photography in Everglades National Park o Rutchey and Vilchek (1995) classification in WCA-3B, WCA-3A north of Alligator Alley and the Miami Canal, WCA-2A & WCA-2B o Richardson et al. (1990) data for Loxahatchee National Wildlife o Refuge FLUCCS (1995) for Big Cypress National Preserve, Holey Land & Rotenberger Wildlife Management Areas & WCA-3A south of Alligator Alley and Miami Canal Modified at locations where reservoirs are introduced (Lakebelt Lakes and S332B Reservoir). Current C&SF Regulation Schedule. Includes regulatory releases to tide through LEC canals. No net outflow to maintain minimum stages in the LEC Service Area canals (salinity control), if water levels are less than minimum operating criteria of 14 ft. The bottom floor of the schedule (Zone C) is the area below 14 ft. Any water supply releases below the floor will be matched by an equivalent volume of inflow. Current C&SF regulation schedule. Includes regulatory releases to tide through LEC canals. No net outflow to maintain minimum stages in the LEC Service Area canals (salinity control), if water levels in WCA-2A are less than minimum operating criteria of 10.5 ft. Any water supply releases below the floor will be matched by an equivalent volume of inflow. Page 2 of 39

3 Water Conservation Area 3A & 3B Pre-CERP Baseline Current C&SF regulation schedule. Includes regulatory releases to tide through LEC canals. No net outflow to maintain minimum stages in the LEC Service Area canals (salinity control), if water levels are less than minimum operating criteria of 7.5 ft in WCA-3A. Any water supply releases below the floor will be matched by an equivalent volume of inflow. Everglades National Water deliveries to Everglades National Park are based on the Interim Park Structural Operating Plan (ISOP) Other Natural Areas Flows to Biscayne Bay are simulated through Snake Creek, North Bay, the Miami River, Central Bay and South Bay. Public Water Supply and Irrigation Public water supply well field pumpage and locations are based on actual pumpage data for calendar year 2000 from the surficial aquifer (see Figures 3-5). Irrigation demands for the six irrigation land use types are calculated internally by the model. Acreages for the six irrigation land use types are depicted in Figures 6 through 11 and fractions of water from wastewater and public water supply wells used are shown in figures 12 through 14. Canal Operations C&SF system and operating rules in effect in Includes operations to meet control elevations in the primary coastal canals for the prevention of saltwater intrusion. Includes existing secondary drainage/water supply system. Lower East Coast Service Area Water Shortage Management Model Limitations Lower east coast water restriction zones and trigger cell locations are equivalent to SFWMM ECB implementation (Dabral, 2006). Thus, this implementation deviates from SFWMM PCB which has fewer number of water restriction zones. The trigger zones and trigger cells are depicted on Figure 15. Periods where the Lower East Coast is under water restriction due to low Lake Okeechobee stages were extracted from the corresponding SFWMM PCB simulation. The RSM is a robust and complex sub-regional scale model. Due to the scale of the model, it is frequently necessary to implement abstractions of system infrastructure and operations that will, in general, mimic the intent and result of the desired project features while not matching the exact mechanism by which these results would be obtained in the real world. Additionally, it is sometimes necessary to work within established paradigms and foundations within the model code (e.g. use available input-driven options to represent more complex project operations). Page 3 of 39

4 3.0 Simulation Modeling Tools Used Regional Simulation Model o Model Release: o Release Date: 06/17/2010 Glades-LECSA Pre-CERP Model Input Dataset SVN Version #: 6187 Operational Additions/Modifications Table of special operations is compiled as Appendix A. References ARCADIS Generation of the Expanded Coverage Reference Evapotranspiration Dataset for Hydrologic Modeling. Dabral, S South Florida Water Management Model (SFWMM) V5.5x Trigger Module Modifications. South Florida Water Management District. Richardson, J.R., Bryant, W.L., Kitchens, W.M., Mattson, J.E. and Pope, K.R., An Evaluation of Refuge Habitats and Relationship to Water Quality, Quantity and Hydroperiod. A Synthesis Report. Arthur R Marshall Loxahatchee National Wildlife Refuge. Rutchey, K., and L. Vilchek, Development of an Everglades Vegetation Map Using a SPOT Image and the Global Positioning System, Journal of Photogrammetric Engineering and Remote Sensing, 60(6): United States Army Corps of Engineers (USACE) Modified Water Deliveries to Everglades National Park. Welch, R., M. Remillard, and R. Doren, GIS database development for South Florida s National Parks and Preserves, Photogrammetric Engineering & Remote Sensing, 61(11): Page 4 of 39

5 - Topography Ü Miles Topography (ft NGVD 29) Figure 1: Topography Page 5 of 39

6 - Landuse/Landcover (LULC) WCA-1 Palm Beach Feeder Canal L28 Interceptor WCA-2A WCA-2B L28 Gap Broward Big Cypress WCA-3A Everglades National Park WCA-3B Miami Dade LULC Code CAT CIT FUP FWT GLF HDU IRR LDU MAN MAR MDU MEL ROW SAW SHR SUG WAT WET Miles Ü Figure 2: Landuse/Landcover code distribution Page 6 of 39

7 Table 1: Landuse/Landcover Codes and their Descriptions LULC Code CAT CIT FUP FWT GLF HDU IRR LDU MAN MAR MDU MEL ROW SAW SHR SUG WAT WET Description Cattail Citrus Forested Upland Freshwater Wetland Golf Course High Density Urban Irrigated Pasture Low Density Urban Mangrove Marsh Medium Density Urban Melaleuca Row Crop Sawgrass Shrub Land Sugar Cane Open Water Wet Prairie Page 7 of 39

8 - PWS Pumpage Ü Miles Average PWS Pumpage (MGD) Figure 3: Average public water supply pumpage Page 8 of 39

9 - RSS Pumpage Average RSS Pumpage (MGD) Miles Ü Figure 4: Average residential self-supplied (RSS) pumpage Page 9 of 39

10 - IND Pumpage Ü Average IND Pumpage (MGD) Miles Figure 5: Average industrial pumpage Page 10 of 39

11 Figure 6: Agriculture low volume (ALV) irrigation acreages Page 11 of 39

12 Figure 7: Agriculture other (AOT) irrigation acreages Page 12 of 39

13 Figure 8: Agriculture overhead (AOV) irrigation acreages Page 13 of 39

14 Figure 9: Golf course (GLF) irrigation acreages Page 14 of 39

15 Figure 10: Landscape (LSC) irrigation acreages Page 15 of 39

16 Figure 11: Nursery (NUR) irrigation acreages Page 16 of 39

17 Figure 12: Fraction of Golf course irrigation from wastewater reuse (FGI) Page 17 of 39

18 Figure 13: Fraction of Landscape irrigation receiving water from PWS wells (FLI) Page 18 of 39

19 Figure 14: Fraction of Landscape irrigation from wastewater reuse (FLR) Page 19 of 39

20 - LEC Trigger Cells & Zones Legend Trigger Cells Canal/River LECsR Water Restriction Zone GL Water Restriction Zone Broward Central Broward NE Broward SE Broward W. Broward-Dade E. Broward-Dade W. S. Dade/Homestead S. Dade/Kendal Lakes S. Dade/Kendall S. Palm 3 S. Palm 4 S. Palm 5 S. Palm 6 S. Palm7 S. Palm8 SD/Miami Miles Ü Figure 15: Water restriction zones and trigger cells Page 20 of 39

21 - Lakebelt Cells Lakebelt Cells Miles Ü Figure 16: Lakebelt cells Page 21 of 39

22 - Water Control Districts (WCDs) Legend PCB WCDs Broward WCDs Palm Beach WCDs Western Basins WCDs Miles Ü Figure 17: Water control districts (WCD) Page 22 of 39

23 Appendix A Special Structure Operations Structure S197 Descriptions Purpose: The S-197 structure consists of 13 corrugated metal pipe culvert located near the mouth of the C-111 canal, 750 feet east of the US Highway 1 in Miami-Dade County. The purpose of the structure is to maintain an optimum stage in the upper reaches of the C-111 canal, prevent saline intrusion during high tides, divert discharges from S-18C upstream to the pan handle of the Everglades National Park, and release water during major flood events based on guidelines. Structure Info: Structure Name: S-197 culvert Function: Flood Control Structure Type: Culvert with thirteen barrels with upstream control and risers for some of the barrels Upstream waterbody: C-111 Canal downstream of S-18C. Downstream waterbody: C-111 Canal Tidal. Discharge Coefficient: Power in discharge equation: 0.5 Design Capacity: 6000 cfs. Description of Structure Operation: The structure is normally closed except during a storm and when conditions are described as below: Open Culverts: The culverts open when water levels exceed the specified levels at the structures described below. S-177 HW > 4.10 after gates have been opened full or S-18C HW > 2.80: open 3 culverts S-177 HW > 4.20 for 24 hours or S-18C HW > 3.10: open 7 culverts S-177 HW > 4.30 or S-18C HW > 3.30: open 13 culverts Close Culverts: The culverts close when the specified levels at upstream structures are as follow: S-176 HW < 5.2 ft NGVD and S-177 HW has declined below 4.2 ft NGVD and a declining trend indicating the peak of the storm has passed and storm has passed away from the basin. Once these conditions are matched, only the number of culverts required to match the residual discharge flowing through S-176 will remain open. The culverts will be closed when the S-177 HW stage declines below 4.1 ft NGVD and the above conditions are satisfied. Page 23 of 39

24 S331 Purpose: The S-331 structure consists of three vertical axial flow pumps, located on the L-31N borrow canal, about 9 miles north of Homestead in Miami-Dade County. The purpose of the structure is to function as a component of the South Dade Conveyance System to deliver water supply to South Dade County and to provide a continuous supply to the Everglades National Park at Taylor Slough and to the Panhandle Area. The purpose has been further augmented by the Iteration 7 agreement between the Corps of Engineers, the Everglades National Park and the District. As per this agreement the structure serves the purpose of controlling the water level in L-31N north of S-331 as a function of the water levels in the Rocky Glades residential area. For the 2015FWO conditions the operation rules are based on Iteration 7. Structure Info: Structure Name: S-331 pump Function: Flood Control and Water Supply. Structure Type: Three vertical axial flow pumps. Upstream waterbody: L31N Borrow Canal. Downstream waterbody: L31N Borrow Canal. Pump Rating Coefficient: 387 cfs per pump Power in discharge equation: 1.0 Design Capacity: 1161 for 3 pumps. Description of Structure Operation: The structures operates in both flood control and water supply modes, and in both cases the discharge, depending on the quantity required, is achieved by siphoning through the pumps, by operation of the adjacent culvert (S-173), or by use of pumping. Flood Control: The structure operations are tied to the stage at Angels well located near the western boundary of the Rocky Glades residential area. Discharges through S-331 can be made if the S-331 tailwater stage is below 6.0 feet and the S-176 headwater stage is below 5.5 feet. If either of those water levels of S-331 and S-176 were exceeded, discharges at S-331 would be terminated until the S-176 headwater state recedes to 5.0 feet. S-331 discharges would be terminated when the S-176 headwater stage is between 5.0 and 5.5 feet if heavy rainfall is forecast. If the stage at Angels well is less than 5.5 feet, the L31N borrow canal system is operated with complete flexibility within the design limits specified by the Corps. If the stage at Angels well is between 5.5 and 6.0 feet, the operations are performed such that the average daily water level upstream of the S-331 will be maintained between 5.0 ft., and 4.5 ft. if permitted by downstream conditions. If the level at Angels well is above 6.0 ft., the average daily water Page 24 of 39

25 level upstream of S-331 will be maintained between 4.5 ft. and 4.0 ft. until the water level at Angel's well recedes below 5.7 ft. if permitted by downstream conditions. Water Supply In the water supply mode, discharge through the structure is performed when the stage at any downstream canal drops below their maintenance level. S343A Purpose: This structure permits discharge from Water Conservation Area 3A during period of excessively high stages. Structure Info: Function: Flood Control Structure Type: Culvert Upstream waterbody: WCA-3A Downstream waterbody: BCNP Discharge Coefficient: Power in discharge equation: 0.5 Design Capacity: Seasonal (200 cfs between July 16 and October 31 and 0 otherwise). Description of Structure Operation: Normally, this structure is closed. It is operated when average stage in WCA-3A is either in Zone A, B or C and LOOP1 Rd Gauge is below 8.5 ft. S343A flow is computed as its flow capacity subject to LOOP1 stage. That is, if LOOP1 stage is greater than 8.5 ft, S343A flow is zero; otherwise, flow is increased linearly from 0 to structure capacities when LOOP1 stage ranges from 8.5 ft to 8.3 ft, respectively. Flow remains at structure capacity when LOOP1 stage is below 8.3 ft. Further, flow adjustments are made based on average stage in WCA- 3A as described below for each WCA-3A regulation Zone. Zone A: No adjustment; flow adjustment factor is 1. Zone B: Flow adjustment factor for S343A is 1 when average stage in WCA-3A is greater than that of bottom elevation of Zone B by 0.2 ft; otherwise, the flow adjustment factor is increased linearly from 0 to 1 as the average stage in WCA-3A ranges between bottom elevation of Zone B to that of bottom elevation of Zone B plus 0.2 ft, respectively. Zone C: Flow adjustment factor for S343A is 1 when average stage in WCA-3A is greater than that of bottom elevation of Zone C by 0.2 ft; otherwise, the flow adjustment factor is increased linearly from 0 to 1 as the average stage in WCA-3A ranges between bottom elevation of Zone C to that of bottom elevation of Zone C plus 0.2 ft, respectively. Page 25 of 39

26 Finally, S343A flow is computed as computed flow multiplied by flow adjustment factor. S343B Purpose: This structure permits discharge from Water Conservation Area 3A during period of excessively high stages. Structure Info: Function: Flood Control Structure Type: Culvert Upstream waterbody: WCA-3A Downstream waterbody: BCNP Discharge Coefficient: Power in discharge equation: 0.5 Design Capacity: Seasonal (200 cfs between July 16 and October 31 and 0 otherwise). Description of Structure Operation: Normally, this structure is closed. It is operated when average stage in WCA-3A is either in Zone A, B or C and LOOP1 Rd Gauge is below 8.5 ft. S343B flow is computed as its flow capacity subject to LOOP1 stage. That is, if LOOP1 stage is greater than 8.5 ft, S343B flow is zero; otherwise, flow is increased linearly from 0 to structure capacities when LOOP1 stage ranges from 8.5 ft to 8.3 ft, respectively. Flow remains at structure capacity when LOOP1 stage is below 8.3 ft. Further, flow adjustments are made based on average stage in WCA- 3A as described below for each WCA-3A regulation Zone. Zone A: No adjustment; flow adjustment factor is 1. Zone B: Flow adjustment factor for S343B is 1 when average stage in WCA-3A is greater than that of bottom elevation of Zone B by 0.2 ft; otherwise, the flow adjustment factor is increased linearly from 0 to 1 as the average stage in WCA-3A ranges between bottom elevation of Zone B to that of bottom elevation of Zone B plus 0.2 ft, respectively. Zone C: Flow adjustment factor for S343B is 1 when average stage in WCA-3A is greater than that of bottom elevation of Zone C by 0.2 ft; otherwise, the flow adjustment factor is increased linearly from 0 to 1 as the average stage in WCA-3A ranges between bottom elevation of Zone C to that of bottom elevation of Zone C plus 0.2 ft, respectively. Finally, S343B flow is computed as computed flow multiplied by flow adjustment factor. Page 26 of 39

27 S344 Purpose: This structure permits discharge from Water Conservation Area 3A during periods of excessively high stages, and extends the hydroperiod in the Big Cypress National reserve during dry periods. Structure Info: Function: Flood Control Structure Type: Culvert Upstream waterbody: WCA-3A Downstream waterbody: BCNP Discharge Coefficient: Power in discharge equation: 0.5 Design Capacity: Seasonal (300 cfs between July 16 and October 31 and 0 otherwise). Description of Structure Operation: Normally, this structure is closed. It is operated when average stage in WCA-3A is either in Zone A, B or C and LOOP1 Rd Gauge is below 8.5 ft. S344 flow is computed as its flow capacity subject to LOOP1 stage. That is, if LOOP1 stage is greater than 8.5 ft, S344 flow is zero; otherwise, flow is increased linearly from 0 to structure capacities when LOOP1 stage ranges from 8.5 ft to 8.3 ft, respectively. Flow remains at structure capacity when LOOP1 stage is below 8.3 ft. Further, flow adjustments are made based on average stage in WCA- 3A as described below for each WCA-3A regulation Zone. Zone A: No adjustment; flow adjustment factor is 1. Zone B: Flow adjustment factor for S344 is 1 when average stage in WCA-3A is greater than that of bottom elevation of Zone B by 0.2 ft; otherwise, the flow adjustment factor is increased linearly from 0 to 1 as the average stage in WCA-3A ranges between bottom elevation of Zone B to that of bottom elevation of Zone B plus 0.2 ft, respectively. Zone C: Flow adjustment factor for S344 is 1 when average stage in WCA-3A is greater than that of bottom elevation of Zone C by 0.2 ft; otherwise, the flow adjustment factor is increased linearly from 0 to 1 as the average stage in WCA-3A ranges between bottom elevation of Zone C to that of bottom elevation of Zone C plus 0.2 ft, respectively. Finally, S344 flow is computed as computed flow multiplied by flow adjustment factor. BR-CS39 Purpose: The control structure BR-CS39 is a gated culvert with a vertical lift Page 27 of 39

28 gate and is located south of Sample Road in eastern Broward County. The structure allows discharges from WCD2_SB5 to WCD3_SB2 for flood control operations. Structure Info: Structure Name: BR-CS39 gated culvert Function: Flood Control and Water Supply Structure Type: Gated culvert with vertical lift gate Upstream waterbody: WCD2_SB5. Downstream waterbody: WCD3_SB2 Discharge Coefficient: 2.0. Power in discharge equation: 1.5. Design Capacity: Not applicable for a weir. Description of Structure Operation The BR-CS39 culvert and vertical lift gates are operated manually. The structure is operated when water levels in the WCD2_SB5 rises above 9.5 feet NGVD and discharges are made to the receiving WCD WCD3_SB2. The operations are normally for flood control and in some cases for water supply to the lower basin. The source of water for water supply is the Hillsboro canal to the north. Flow Equations: The structure is modeled using the Genxweir equation and the weir parameters are summarized in the table below. Genxweir equation: a Q = CL H z) ( H H ) ( where, Q = discharge C = user defined coefficient b a = user defined exponent for upstream water level b= user defined exponent for water level difference H = upstream or downstream water level L = crest length Structure (Name) Crest Elevation (ft NGVD 29) L (ft) a b C (forward) C (reverse) BR-S6S38 BR- CS Purpose: The control structure BR-S6S38 is a gated culvert with a vertical lift gate and is located south of Sample Road and east of the Florida Turnpike in eastern Broward County. The structure allows discharges from WCD2_SB1 to WCD3_SB2 for water supply operations. Page 28 of 39

29 Structure Info: Structure Name: BR-S6S38 gated culvert Function: Water Supply Structure Type: Gated culvert with vertical lift gate Upstream waterbody: WCD2_SB1. Downstream waterbody: WCD3_SB2 Discharge Coefficient: 2.0. Power in discharge equation: 1.5. Design Capacity: Not applicable for a weir. Description of Structure Operation The BR-CS39 culvert and vertical lift gates are operated manually. The structure is operated when water levels in the WCD2_SB1 rises above 9.5 feet NGVD and discharges are made to the receiving WCD WCD3_SB2. The operations are normally for water supply to the lower basin. The water supply source is Hillsboro canal to the north via the Turnpike borrow canal. Flow Equations: The structure is modeled using the Genxweir equation and the weir parameters are summarized in the table below. Genxweir equation: a Q = CL H z) ( H H ) ( where, Q = discharge C = user defined coefficient b a = user defined exponent for upstream water level b= user defined exponent for water level difference H = upstream or downstream water level L = crest length S151 Structure (Name) Crest Elevation (ft NGVD 29) L (ft) a b C (forward) C (reverse) BR- S6S Purpose: This structure permits release of water from Conservation Area 3A to supply water needs to South Dade County and along the Miami Canal (C-6), C-7 and C-8 during the dry season. It also can be used to discharge excess water from Conservation Area 3A into 3B, when capacity is available in the Miami Canal, to seaboard. Structure Info: Function: Water Supply and Flood Control Structure Type: Culvert Page 29 of 39

30 Upstream waterbody: WCA-3A Downstream waterbody: C-304 Discharge Coefficient: Power in discharge equation: 0.5 Design Capacity: 1800 Description of Structure Operation: Flow computation depends on water release Zones (i.e., Zone A, B, C, D, E or E1) and the Interim Structural Operating Plan (ISOP). Water release zones are determined by comparing the average WCA- 3A stage to that of each zones top and bottom elevations. Under ISOP when there is WCA-3A regulatory release to South Dade Conveyance System (SDCS), both the fraction of target S12s flow (i.e., S12A, S12B, S12C and S12D combined target flows) going to S12A and S12B are zero and the average WCA-3A stage is not in Zone E. Target Flow: Under ISOP when there is WCA-3A regulatory release to SDCS: Zone A: Zone B: Zone C: S151 target flow is 1000 cfs if the average stage in WCA- 3A is greater than or equal to the bottom elevation of Zone A by a threshold value of 0.2 ft. Otherwise, the 500 cfs portion of S151 target flow is reduced linearly to zero when the Average stage in WCA-3A ranges from 0.2 ft above Zone A bottom elevation and Zone A bottom elevation, respectively. Target Flow = * (Average stage in WCA-3A Bottom Elevation of Zone A) / 0.2 S151 target flow linearly increases from zero to a maximum of 500 cfs when the average stage in WCA-3A ranges between bottom elevation for Zone B to bottom elevation for Zone A, respectively. Target Flow = 500 * (Average stage in WCA-3A Bottom Elevation of Zone B) / (Bottom Elevation of Zone A Bottom Elevation of Zone B) S151 target flow linearly increases from zero to a maximum of 500 cfs when the average stage in WCA-3A ranges between bottom elevation for Zone C to bottom elevation for Zone A, respectively. Target Flow = 500 * (Average stage in WCA-3A Bottom Elevation of Zone C) / (Bottom Elevation of Zone A Page 30 of 39

31 Bottom Elevation of Zone C) Zone D, E and E1: S151 target flow is 0. Under ISOP when there is no WCA-3A regulatory release to SDCS or Shark Slough: S151 target flow is equal to S151 maximum flow (i.e., minimum of S151 design capacity (1800 cfs) or S151 capacity calculated from headwater and tailwater conditions) Simulated Flow First, S151 flow is calculated as minimum of S151 target flow and S151 maximum flow subject to G3B71 stage. That is, if G3B71 stage is greater than 8.5 ft, S151 flow is zero; otherwise, S151 flow is increased linearly from 0 to S151 maximum flow when G3B71 stage ranges from 8.5 ft to 8.3 ft, respectively. S151 flow remains at its maximum when G3B71 stage is below 8.3 ft. The remaining portion of S151 target flow is passed through S31 subject to S31 tailwater (i.e., if S31TW stage is greater than 4 ft, S31 flow is zero; otherwise, S31 flow is increased linearly from 0 to S31 maximum flow when S31TW stage ranges from 4 ft to 3.8 ft and remains at its maximum when S31TW stage is below 3.8 ft). Further, under ISOP when there is WCA-3A regulatory release to South Dade Conveyance System (SDCS), S337 is operated to pass the remaining S151 target flow after meeting S31 capacity. S337 flow is the minimum of the remaining portion of S151 target flow and S337 maximum flow subject to L31N stage (i.e., if L31N or S334TW stage is greater than 6 ft, S337 flow is zero; otherwise, S337 flow is increased linearly from 0 to S337 maximum flow when L31N stage ranges from 6 ft to 5.8 ft, respectively and remains at its maximum when G3B71 stage is below 5.8 ft). Thus, the total S151 flow will be the sum of S151 initial flow, S31 flow and S337 flow. Finally, S151 flow is reduced linearly from S151 total flow to 0 when S151 HW ranges between 0.2 ft above S151TW and S151 TW, respectively. S12A-D Purpose: These structures provide the principal means of discharge from Conservation Area #3A to the Everglades National Park. Structure Info: Function: Flood Control Structure Type: Gated Spillway Upstream waterbody: WCA-3A Downstream waterbody: ENP Discharge Coefficient: 9206 Power in discharge equation: 0.5 Design Capacity: 8000 cfs Page 31 of 39

32 Description of Structure Operation: These structures are operated by the South Florida Water Management District for the U.S. Corps of Engineers, in accordance with the "Rain-driven Water Deliveries to Everglades National Park," the Regulation Schedule of Conservation Area 3A and the operation plan for protection of the Cape Sable Seaside Sparrow. The steps involved in determining flows at these structures are described below. Rainfall Plan Targets: Total rainfall plan target has two components; namely, rainfall component and regulatory component. The rainfall component is determined by a statistical formula that relates flow to current and antecedent upstream weather conditions (Neidrauer and Cooper, 1989). A pre-processed rainfall component time series is used. The regulatory component is 2500 cfs for each foot increase in average stage of WCA-3A from bottom elevation of Zone D (See Figure A1). The total target flow is the sum of rainfall and regulatory components Water Level in WCA 3A (ft NGVD) C E1 A B D E C 8.5 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure A1. WCA-3A regulation zones S12s Targets: Rainfall and regulatory target for S12s structures is calculated from total rainfall and regulatory targets (i.e., target flow from WCA-3A) and pre-defined seasonal factors (see Table 1). S12s Target = Total Target * Seasonal Factor Where, Total Target is the sum of rainfall and regulatory target flows from WCA-3A. Page 32 of 39

33 Table 1: Seasonal Factors for S12s Structures Structure Dry Season Wet Season S12s Zone A: Zone B or C: S12As target flow is calculated based on stage at G3A28 as follows: S12s Target flow = 2666 * (G3A28 9.5) for G3A28 stage > 9.5 ft = 1100 * (G3A28 8.5) for G3A28 stage less than or equal to 9.5ft and greater than 8.5ft = 500 * (G3A28 7.5) for G3A28 stage between less than or equal to 8.5ft and greater than 7.5ft = 0; otherwise. S12s target flow is calculated as the sum of S12s total target flow (i.e., rainfall component and regulatory component) and S333/S355 total target flow unmet by S333 and S355 structures. Zone D, E1 or E: S12As target flow is calculated the same as that in Zone B or C. S12A, S12B, S12C and S12D Flow Computations: Prior computing flows for S12A, S12B, S12C and S12D, target flow for S12s is adjusted for all Zones except Zone A. First, the maximum fraction of total target flow passed through S12s structures is computed by multiplying the total target flow by a seasonal factor set for each Zones (see Table 2). Finally, the adjusted target flow for S12s is computed as the minimum of S12s target flow computed in previous steps and that of maximum fraction of the total target flow that is allowed pass through S12s structures. Table 2: Maximum Fraction of Target Flows Allowed through S12s Zone Dry Season Wet Season B C D E E Page 33 of 39

34 Flow at S12A, S12B, S12C and S12D is computed as fraction of S12s structural flows (see Table 3) multiplied by the S12s total target flow. Table 3: Fraction of S12A, S12B, S12C and S12D flows as S12s Target Flow Date S12A S12B S12C S12D 1-Jan Jan Feb Jul Jul Oct Nov Dec The computed flows at S12 structures are adjusted if the head water is greater than tail water and their difference is less than 0.1ft. The adjustment is to reduce S12s structural flows linearly from computed flow to 0 when head water ranges between 0.1 ft above the tail water and tail water, respectively. S12(A/B/C/D) adjusted = S12(A/B/C/D) * (head water tail water) / 0.1 ft Reference Neidrauer, C.J. and Cooper, R.M A two-year Field Test of the Rainfall Plan: A management Plan for Water Deliveries to Everglades National Park. Technical Publication 89-3, South Florida Water Management District, West Palm Beach, FL. S31 Purpose: This structure, together with S-151, permits release of water from Conservation Area 3 to supply water needs along the Miami Canal during the dry season. It also can be used to discharge excess water from Conservation area 3B when capacity is available in the Miami Canal. Structure Info: Function: Water Supply and Flood Control Structure Type: Culvert Upstream waterbody: WCA-3B Downstream waterbody: C6 Discharge Coefficient: 521 Power in discharge equation: 0.5 Design Capacity: 700 Page 34 of 39

35 Description of Structure Operation: S31 is operated to pass S151 target flow not met due to G3B71 stage constraint. S333 First, S151 flow is calculated as minimum of S151 target flow and S151 maximum flow subject to G3B71 stage. That is, if G3B71 stage is greater than 8.5 ft, S151 flow is zero; otherwise, S151 flow is increased linearly from 0 to S151 maximum flow when G3B71 stage ranges from 8.5 ft to 8.3 ft, respectively. S151 flow remains at its maximum when G3B71 stage is below 8.3 ft. The remaining portion of S151 target flow is passed through S31 subject to S31 tailwater (i.e., if S31TW stage is greater than 4 ft, S31 flow is zero; otherwise, S31 flow is increased linearly from 0 to S31 maximum flow when S31TW stage ranges from 4 ft to 3.8 ft and remains at its maximum when S31TW stage is below 3.8 ft). For detail description of S151 flow computation, readers are referred to S151 documentation. Purpose: This structure functions principally to make water deliveries from Conservation Area 3A to Shark River Slough in Everglades National Park Band to make regulatory releases from Conservation Area 3A. Structure Info: Function: Flood Control Structure Type: Gated Spillway Upstream waterbody: WCA-3A Downstream waterbody: L29 Discharge Coefficient: 2548 Power in discharge equation: 0.5 Design Capacity: 1350 cfs Description of Structure Operation: When S-333 is used in conjunction with S-12 to make regulatory releases to the Everglades National Park at Shark River Slough, the structure will be operated in accordance with ISOP. (1) When water levels at G-3273 have been above 6.8 feet, NGVD for 24 hours, S- 333 will be closed; (2) Discharges to Shark River Slough of the Everglades National Park are a function of a rain driven model. For the rainfall plan operation description readers are referred to documentation for S12A-D. The steps involved in determining flow at this structure are described below. S333/S355 Targets: Rainfall and regulatory targets for S333/S355 (i.e., S333, S355A and S355B) structures are calculated from total rainfall and regulatory targets (i.e., target flow from WCA-3A) and pre-defined seasonal factors (see Table 1). Page 35 of 39

36 S333/S355 Target = Total Target * Seasonal Factor Where, Total Target is the sum of rainfall and regulatory target flows from WCA-3A. Zone A: Table 1: Seasonal Factors for S333/S355 Structures Structures Dry Season Wet Season S333/S S333 flow is computed as maximum S333 flow subjected to minimum of G3273 or L29 stages. If G3273 stage is greater than 6.8 ft, G3273 constraint factor is zero; otherwise, the factor is increased linearly from 0 to 1 when G3273 stage ranges from 6.8 ft to 6.6 ft, respectively and it remains at 1 when G327 stage is below 6.6 ft. Similarly, if L29 stage is greater than 9.0 ft, L29 constraint factor is zero; otherwise, the factor is increased linearly from 0 to 1 when L29 stage ranges from 9.0 ft to 8.8 ft, respectively. The factor remains 1 when L29 stage is below 8.8 ft. Under the Interim Structural Operating Plan (ISOP) when there is WCA-3A regulatory release to South Dade Conveyance System (SDCS), S334 flow is added to computed-s333 flow to arrive at the final S333 flow. Zone B, C, D, E1 or E: S334 Under ISOP when there is no WCA-3A regulatory release to SDCS or Shark Slough: S333 flow is computed as minimum of S333/S355 target flow unmet by S355 structures (i.e., S355A and S355B) and that of maximum S333 flow subject to minimum of G3273 or L29 stages. If G3273 stage is greater than 6.8 ft, G3273 constraint factor is zero; otherwise, the factor is increased linearly from 0 to 1 when G3273 stage ranges from 6.8 ft to 6.6 ft, respectively and it remains at 1 when G327 stage is below 6.6 ft. Similarly, if L29 stage is greater than 9.0 ft, L29 constraint factor is zero; otherwise, the factor is increased linearly from 0 to 1 when L29 stage ranges from 9.0 ft to 8.8 ft, respectively. The factor remains 1 when L29 stage is below 8.8 ft. Under ISOP when there is WCA-3A regulatory release to SDCS: S333 flow is computed the same as that in Zone A. Purpose: This structure functions when regulatory releases from Conservation Area 3A are being made. Page 36 of 39

37 Structure Info: Function: Flood Control Structure Type: Gated Spillway Upstream waterbody: ENP Downstream waterbody: L31NC Discharge Coefficient: 2841 Power in discharge equation: 0.5 Design Capacity: 1230 cfs Description of Structure Operation: When regulatory releases are being made from WCA 3A, this structure is operated in conjunction with S-333. For the rainfall plan operation description readers are referred to documentation for S12A- D. The steps involved in determining flows at this structure are described below. Zone A, B or C: Zone E or E1: S334 is operated under Interim Structural Operating Plan (ISOP) when there is WCA-3A regulatory release to South Dade Conveyance System (SDCS) to pass the remaining portion of S333 capacity. S334 flow is computed as the remaining portion of S333 capacity subject to S334 capacity and L31N stage. If L31N or S334TW stage is greater than 6 ft, S334 flow is zero; otherwise, S334 flow is increased from 0 to S334 maximum flow when L31N stage ranges from 6 ft to 5.8 ft, respectively. S334 flow remains at its maximum when L31N stage is below 5.8 ft. S337 No flow. Purpose: This structure, together with S-31 and S-151, permits release of water from Conservation Area 3 to supply water needs in East and South Dade County. It also can be used to discharge excess water from Conservation Area 3B when downstream capacity is available. Structure Info: Function: Water Supply and Flood Control Structure Type: Culvert Upstream waterbody: WCA-3B Downstream waterbody: L30 Discharge Coefficient: 1053 Power in discharge equation: 0.5 Design Capacity: 1100 Page 37 of 39

38 Description of Structure Operation: S337 is operated under Interim Structural Operating Plan (ISOP) when there is WCA-3A regulatory release to South Dade Conveyance System (SDCS), to pass S151 target flow not met after flow to S31 is allocated. First, S151 flow is calculated as minimum of S151 target flow and S151 maximum flow subject to G3B71 stage. That is, if G3B71 stage is greater than 8.5 ft, S151 flow is zero; otherwise, S151 flow is increased linearly from 0 to S151 maximum flow when G3B71 stage ranges from 8.5 ft to 8.3 ft, respectively and remains at its maximum when G3B71 stage is below 8.3 ft. The remaining portion of S151 target flow is passed through S31 subject to S31 tailwater (i.e., if S31TW stage is greater than 4 ft, S31 flow is zero; otherwise, S31 flow is increased linearly from 0 to S31 maximum flow when S31TW stage ranges from 4 ft to 3.8 ft and remains at its maximum when G3B71 stage is below 3.8 ft). Further, under ISOP when there is WCA-3A regulatory release to SDCS, S337 flow is computed as the minimum of the remaining portion of S151 target flow (i.e., after meeting S31 capacity) and S337 maximum flow subject to L31N stage. If L31N or S334TW stage is greater than 6 ft, S337 flow is zero; otherwise, S337 flow is increased linearly from 0 to S337 maximum flow when L31N stage ranges from 6 ft to 5.8 ft, respectively and remains at its maximum when G3B71 stage is below 5.8 ft. SR-29 For detail description of S151 flow computation, readers are referred to S151 documentation. Purpose: The SR-29 structure consists of 9 weirs located in the SR-29 canal, immediately east of the State Road (SR) 29, in the western portion (Big Cypress Basin) of the Glades-LECSA model domain. The orientation of the SR-29 canal is north-south and surface flows are oriented in the north to south direction. The 9 weirs are located at different points in the SR-29 canal (inline structures) and the purpose of the weirs is to provide flood protection during the wet season, and maintain water levels to prevent over drainage during the dry season for different sections of the north-south SR-29 canal. Simplifications were made to the number of structures simulated by the Glades- LECSA model to account for instances in which up to two or more SR-29 structures are contained in a single mesh cell. The actual number of weirs used in the model was five and the locations were SR-29-1, SR-29-3, SR-29-4, SR-29-6, and SR Structure Info: Structure Name: SR-29 weirs (1-9) Function: Flood Control and Water Supply Structure Type: Fixed crest weir with removable steel sheet pile stop logs. Upstream waterbody: SR-29 Canal depending on the weir (1-9) location. Page 38 of 39

39 Downstream waterbody: SR-29 Canal depending on the weir (1-9) location. Discharge Coefficient: Refer to the table below. Power in discharge equation: Refer to the table below. Design Capacity: Not applicable for a weir. Description of Structure Operation: The SR-29 weirs are operated in such a way that they are closed during the dry season and opened during the wet season. Flow Equations: Genxweir equation: a Q = CL H z) ( H H ) ( where, Q = discharge C = user defined coefficient b a = user defined exponent for upstream water level b= user defined exponent for water level difference H = upstream or downstream water level L = crest length Structure Crest L a b C C (Name) Elevation (ft) (forward) (reverse) (ft NGVD 29) SR SR SR SR SR Each of the structures is simulated with a user controller to capture the simple management. The controller assigned to each structure checks to determine if the current simulation date falls within the dry season. The dry season is defined as November through the end of May. If simulation date is during the dry season, the controller fully closes the weir, and no flow is simulated. Conversely, during the wet season, the weir is fully opened, and flow is allowed with no management constraints. Page 39 of 39