Stormwater Management Engineering Report

Transcription

1 March 12, 2018 Stormwater Management Engineering Report for Brighton Oaks Subdivision Cato Road Bay County, Florida Prepared for: DR Horton PO Box 958 Lynn Haven, Florida, Ph Fax

2 Brighton Oaks Engineering Report 1. Project Introduction TABLE OF CONTENT 1.1. General Property Description Existing Site Conditions Proposed Site Conditions Site Data Bulk Regulations Stormwater Design Summary 2.1. Geotechnical Evaluation Elevation Datum Hydrologic Design Criteria Water Quality Standards Existing Stormwater Conditions Proposed Stormwater Design Stormwater Design Conclusions Base Flood Elevation Sedimentation & Erosion Control Measures 3.1. Erosion Controls/Sediment Barriers Pond Sediment Tracking Control.6 4. Operation and Maintenance 4.1. Maintenance Operation Responsible Party....6 ii

3 Brighton Oaks Engineering Report APPENDIX A Stormwater/Drainage Stage Storage Relationship Curve Number and Runoff Coefficient Worksheet Retention Calculations Basin Recovery Calculation Adicpr Pond Routing Storm Sewer/ Culvert Analysis SCS Soils Map iii

4 Brighton Oaks Engineering Report DR Horton 1. Project Introduction 1.1. General Property Description o The Developer intends to develop Brighton Oaks Subdivision as a single family residential development. The proposed roadways will be two lane urban section roadway with sidewalks and underground utilities. The project will connect onto Cato Road and onto E. 43 rd Street which are both Public Bay County roadways. The subject property is currently owned by Craig Freeman be purchased and developed by DR Horton. DR Horton is acting as agent and applicant on permits. This part of the county is mainly residentially developed. This development will be consistent with the surrounding developments within the area Existing Site Conditions o The site is currently developed with a single family residential structure and overall mixture of tree growth. o The topography slopes to the west ranging in elevation of 40 to Proposed Site Conditions o Site development of this parcel will consist of: the construction of new single family housing, roadways, utilities and on site stormwater management pond Site Data Zone..Residential R1 (currently under review) Future Land Use... Residential Size acres onsite Flood Zones X 1.5. Bulk Regulations o The setbacks, Impervious Surface Ratio and Floor Area Ratio Standards and criteria for residential zoning regulations are prescribed in Bay County Development Code. The summary chart is shown on Site Plan within construction plan set. 2. Stormwater Design Summary 2.1 Geotechnical Evaluation The subsurface exploration and geotechnical evaluation was performed by Magnum Engineering, Inc. to determine the any applicable infiltration rates and Seasonal High Water Level (SHWL) for this site. For information concerning building and pavement recommendations and for more details on stormwater recommendations, see the geotechnical exploration report performed by Magnum Engineering provided. Seasonal high and seasonal low water table elevations were taken from the Geotechnical report. The NRCS Web Soil Survey was used to identify soil types for each basin. The soil types and Hydrologic 1 SCR & Associates NWFL, Inc.

5 Brighton Oaks Engineering Report DR Horton Soil Group (HSG) found within this project are shown in Appendix for NRCS references. A weighted curve number was determined for the pre and post development conditions and used for pre and post runoff rate calculations Elevation Datum o All vertical values for this project refer to North American Vertical Datum 1988 (NAVD 88) 2.3. Hydrologic Design Criteria The land elevations range from elevation 40 to elevation 20 and provides adequate slope to drain. The majority of the developed land will be collected in the roadway storm sewer thence discharge to the onsite Pond for treatment and attenuation. The outskirts of the outer perimeter lots will overland flow towards the swale and pond areas. There are two distinct basins. West Basin The main basin for Brighton Oaks flows toward the west toward Mill Bayou Roadway culvert. This area eventually flows toward Mill Bayou tributary. This basin will be where the stormwate management pond will be constructed to detain to predevelopment rates. It will be a dry detention system North Basin The north basin flows towards Riverside Subdivision (privately maintained) area and has adequate outfall once it reaches the crown of the roadway. It appears from elevations and onsite verification, the north basin does not drain properly due to the existing storm inlet system not working properly. The storm sewer pipe crossing Indian Springs Road towards Mill Bayou tributary is laying on the ground through trees, preventing this area to drain north (backing up the system). This causes the overtopping of roadway during extreme events. Historically, this area flowed towards Mill Bayou tributary. To mimic existing conditions as best possible and adequately drain the site, the post conditions will not exceed the pre conditions flow rate for either basin. DESIGN METHODOLOGY As a guideline, the Bay County Land Development Code (referring to Florida Department of Transportation (FDOT)), and the Northwest Florida Water Management District (NWFWMD) have established criteria for the design of stormwater management facilities for projects that increase runoff due to construction of impervious surfaces. The minimum design requirements for stormwater facilities in open drainage basins, as well as for water quality treatment and storm sewer design are discussed in this section. This project uses a dry detention pond which is designed to satisfy the appropriate combination of these criteria. 2 SCR & Associates NWFL, Inc.

6 Brighton Oaks Engineering Report DR Horton Lastly, the geotechnical findings and assumptions used in analyzing the various pond sites are presented. POND ANALYSIS Rate Control Bay County Land Development Code states criteria for stormwater design and requires that all projects located in watersheds with positive outlets shall comply with the discharge requirements of limit post developed discharge rates to the pre developed rates for the critical duration (1 hour to 24 hour) storms for return frequency of 25 year storms when discharging to areas subject to historical flooding. In areas not subject to historical flooding or discharging to open water bodies, all storm events cited will be analyzed to ensure that post development discharge rates will not cause an adverse impact on downstream property owners. NWFWMD For project serving areas over 40 acres, detention systems must be installed such that the peak rate of post development runoff will not exceed the pre development peakrate of runoff for the 25 year, 24 hour design storm event, utilizing a Natural Resources Conservation Service (NRCS) Type III distribution with an antecedent moisture condition II. ERP Applicant s Handbook Volume II Section states that for systems serving new construction that is greater than 50 percent impervious over the project area, the postdevelopment discharge rate must not exceed the pre development run off rate for the 2 year, 24 hour design storm event. The most stringent criteria of the above is used for rate control and has been determined independently for each basin. ICPR v3.10 program was used to develop pre and post runoff rates. Post runoff rates have been set to equal or less than pre runoff rates. Pond volumes and control structures were determined based on the aforementioned criteria. See Appendix for ICPR computations, summary of results, and for treatment volumes and final pond volumes. DRAINAGE DESIGN CRITERIA AND STANDARDS Drainage will be designed to Florida Department of Transportation (FDOT) criteria utilizing current criteria as found in the FDOT Drainage Manual, various Drainage Department Handbooks, and District preferences. Water quality treatment will be determined using the criteria as defined in the NWFWMD ERP Applicant s Handbook, Volume II. Section 2.2 Design Frequency (Open Channel) Roadside ditches 10 year Outfall ditches 25 year Section Manning s N (Channels) Table 2.1, Table 2.2 Section Minimum Slope (Channel) ft/ft Section Velocity (Channel) (Grass and sod based on Shear Stress) 3 SCR & Associates NWFL, Inc.

7 Brighton Oaks Engineering Report DR Horton Section 3.3 Design Frequency (Storm Sewer) General Design = 3 year, Roadside Ditch = 10 year Section 3.4 Design Tailwater for system Stormwater Ponds=Peak stage in the pond during the storm drain design event, Ditches: Free flowing=normal depth flow in the ditch at the storm drain outlet for the storm drain design storm event. (may differ from ditch design storm event.) Section Time of Concentration Minimum = 10 minutes Section Outlet Velocity Less than 4 fps (w/o ditch lining) Section Manning s n (pipe) Concrete = Metal = 0.02 Section 3.9 Spread Standards Design speed < 45 mph Keep ½ of lane clear Section Cross Drain Analysis Design Frequency High use or essential facility 50 years Section Regulatory Requirements= Bay County, NWFWMD/FDEP Section Hydrologic Methods: one of the following Modified rational for basins having Tc of <15 minutes SCS Unit Hydrograph Method (UH 323 used) Bay County Sec Maintenance Berm Minimum 10 feet. Bay County Sec.2407(4) Detention Pond freeboard 10% volume or 3 above the maximum design stage NWFWMD Sec Detention Pond fencing Ponds having more than 2 foot of water at control elevation must have side slopes 4:1 to two feet below permanent pool otherwise fencing or protective barrier is required. Storm drains are sized using the rational method for a 3 year design storm and analyzed with Streamline Technologies Networx Program. The maximum 3 year pond stage elevation was used to set the tailwater elevation for storm sewers discharging to pond facilities. The maximum stage in pond for the critical duration was cross checked to assure if inlets overtop, there will be minimal flooding/spread Water Quality Standards To meet the requirements of the Bay County Land Development Code (LDC) and Chapter of the Florida Administrative Code for water quality, the stormwater management facility for this project must provide for the treatment of the first 1 inch of runoff with the full volume being available again in 72 hours for any dry retention/detention ponds. As per Bay County Land Development Regulations, this site is within the North Bay Ecosystem Management Area. Therefore, 1.5 treatment is required and provided. 4 SCR & Associates NWFL, Inc.

8 Brighton Oaks Engineering Report DR Horton 2.5. Existing Stormwater Conditions o Currently the site is developed and drains to the west with low elevation of approx.. 14 at culvert invert. The site also drains to the North with the existing top of inlet at 23.5, roadway crown at 24. Most of the stormwater run off from the site currently flows to this wesst Proposed Stormwater Design o The portion of the site draining towards the pond will be treated as a single drainage basin with the run off being directed to, stored and treated in an on site stormwater management facility. Run off from the housing will be captured by overland flow, gutters, downspouts and piped to the stormwater conveyance system where feasible. The street run off will sheet flow to adjacent gutters thence to pond via storm sewer. o The on site stormwater management facility consists of one detention pond, and is designed in accordance with above stated detention criteria. See Appendix for stormwater management facility summary. o The outfall structure will be via type E inlet overflow weir built within the Inlet box with overflow downstream to the low lying area along the western property line. The overall discharge for the site will not exceed the predevelopment rate of the basin as a whole. o The tailwater condition at the boundary node was set based on the low elevation of the existing adjacent land. The model was extended to include the existing culvert along Mill Bayou and overland roadway weir characteristics were built into model. The groundwater table and percolation rate for the site indicated no limitations to the pond with regards to tailwater effects for the discharge weir. o 2.7. Stormwater Design Conclusions o o o The requirements for water quality standards were met, providing for the first 1 inch of runoff plus the 1.5 Northbay EMA criteria over the basin area The requirements for water quantity were met, as is shown in Appendix, with postdevelopment run off not exceeding the pre development run off rate. The requirement for peak discharge attenuation of the 2 year, 24 hour SCS storm event was met. 2.8 Base Flood Elevation o The site is within a FEMA Flood Hazard Zone X ; The minimum Finished Floor is set above the high water of stormwater management area and/or crown of roadway plus SCR & Associates NWFL, Inc.

9 Brighton Oaks Engineering Report DR Horton 3. Sedimentation & Erosion Control Measures 3.1. Erosion Controls/Sediment Barriers o Type III silt fencing is to be installed around the entire perimeter of the project site, stormwater facility site and extended around the perimeter of any off site grading. It is to be installed in compliance with the standards set forth by the Florida Department of Environment Protection Agency (FDEP) and the Florida Department of Transportation (FDOT) Design Standards Index no Regular inspection and maintenance of the fence will be performed during construction and after a storm event as required by FDEP regulations Pond o The retention pond will be excavated or filled, as necessary, to within 6 inches of the final grade to act as a temporary sedimentation basin. Site grading and construction stock piling will be maintained so that run off during construction will be directed to this basin. Upon significant completion of construction, the stormwater system will be flushed out to remove accumulated debris and sediment. The bottom shall be scarified and stabilized according to these plans. Once completed, no heavy machinery shall be allowed within the stormwater pond Sediment Tracking Control o A gravel pad at any exit points from the site shall be provided as a buffer where vehicles can drop their mud and sediment to avoid transporting it onto paved streets, to control erosion from surface run off, and to help control dust. 4. Operation and Maintenance 4.1. Maintenance o Applicant shall perform the following maintenance functions monthly or after each significant rainfall event: inspection of pond for erosion or sediment build up and removal of any trash within pond, inspections of the stormwater inlets and piping for blockage and remove any blockage or accumulated sediments Operation o Applicant shall plant, sod, and seed as necessary to prevent sediment from reaching the stormwater conveyances and stormwater pond Responsible Party: o Applicant is responsible for operating and maintaining the stormwater facilities. 6 SCR & Associates NWFL, Inc.

10 Brighton Oaks Engineering Report APPENDIX A iv

11 PROJECT: Brighton Oaks SYSTEM: Pond Impervious Area Calculation RESIDENTIAL LOTS DRAINING TO POND AREA TOTAL ASSUMED TOTAL IMP. TOTAL IMP. NUMBER OF LOTS pad area IMPERVIOUS AREA AREA (SF) AREA (Ac) % 2, TOTAL RESIDENTIAL IMPERVIOUS = 345, ROADWAY LENGTH OF ROAD R/W ROAD NAME IMPERVIOUS AREA/LF TOTAL IMP. TOTAL IMP. AREA (SF) AREA (Ac) 5,800 Main Road , ,800 sidewalk 10 58, TOTAL ROADWAY IMPERVIOUS = 197, OTHER IMPERVIOUS AREAS AREA IMPERVIOUS TOTAL IMP. TOTAL IMP. STORMWATER POND AREA AREA (SF) AREA (Ac) 81, , OVERALL IMPERVIOUS AREA TOTAL IMPERVIOUS = 81, OVERALL IMP OVERALL IMP AREA AREA (Sf) (Ac) LOTS 345, ROADWAY and SIDEWALK 197, Pond 81, , % impervious percent

12 PROJECT: Brighton Oaks SYSTEM: Pond Outfall Watershed: Mill Bayou tributary DETENTION POND DESIGN Basin Area(acres) = Impervious Area (acres) = % Pervious area (acres) = % Pond Area at NWL(acres) = % 100% REQUIRED TREATMENT VOLUME average C= " of Runoff = [(Basin Area)(1)/12"= 1.42 Ac-Ft northbay EMA=1.5 times= 2.13 TOTAL REQUIRED TREATMENT VOLUME = 2.13 Ac-Ft STAGE-STORAGE POND (POND A) WEIR ELEV. = Ft NWL ELEV = Ft TREATMENT VOLUME PROVIDED= 2.16 Ac-Ft COEFFICIENT CALCULATION C= 0.95 * IMPERVIOUS (INCLUDING POND) * PERVIOUS C= 0.54

13 STAGE-STORAGE POND A Above Control Elevation POND A Elev. Area Area Avg Area Avg Area Volume Vol. Sum Volume 4.5 IN/HR (Ft.) (Ac) (SF) (SF) (Ac) (CF) (CF) (Ac-Ft) FT/SEC , CF/S , CF/S \ , , , DRAINAGE SUMMARY overall site development west West North Total outfall pond Boundary North ACRES ACRES STORM PRE PRE PRE POST POST POST PEAK ELEV. EVENT Q Q TOTAL Q Q TOTAL POND 25 YR 1HR YR 2HR YR 4HR YR 8HR YR 24 HR yr 24 hr yr 24 hr 10 yr 24 hr 100 yr 24 hr bottom pond 21 weir width 30 inches 22.5 E Inlet 36x emergency spill 50' total

14 POND 1 - DRY RETENTION BASIN RECOVERY Fillable Porosity (f) = Unsaturated Vertical Infiltration Rate (K vu ) = in/hr 8.912E-05 ft/s **Avg. Horiz. Hydraulic Conductivity (K H ) = Factor of Safety = Basin Bottom Elev. = Groundwater Table Elev.= ft/day Ft Ft this puts worst case 1' Impervious Layer Elev. = Avg. Basin Bottom Width (W) = Avg. Basin Bottom Length (L) = 4.00 Ft 100 Ft 500 Ft REQUIRED TREATMENT VOLUME 1" of Runoff = [(Basin Area) (1.0")]/12"= Ac-ft HEIGHT OF TREATMENT VOLUME IN BASIN Weir Elev. = Ft Treatment volume depth (h v ) = Weir Elev. - Basin Bottom Elev. h v = 1.50 Ft if greater than Hu go to bottom ca Height of water to saturate soil (h u ) = Fillable Porosity x (Basin Bottom Elev. - SHGWT) h u = 0.50 Ft (EQUATION 13-4)* Does Saturated Flow Occur? or Is Hv> Hu? yes Per ERP Volume II, section , If recovery of the treatment storage occurs entirely under vertical unsaturated conditions, analysis of the system for saturated lateral flow conditions will not be necessary. VOLUME OF WATER INFILTRATED IN VERTICAL STAGE Area of basin bottom (A b ) = 56,700 sf Volume of water infiltrated (V u ) = Area of basin bottom x height of water to sat. soil V u = cf (13 3)* 0.65 AF Unsaturated Vertical Infiltration Rate K vu = 7.70 ft/day (13-11)* *DRI done therefore testing gives Kvu directly if permeameter test then Kvu=0.67Kvs Design Infiltration Rate (I d ) = (Unsaturated Vertical Infiltration Rate) / (Factor of Safety) I d = 3.85 ft/day (13 1)* Time to saturate soil beneath the basin (t sat ) = (Height of water to saturate soil) / (Design Infiltration Rate) t sat = 3.12 hrs (13 2)* * Methodology based on Volume II, Section 13 of the Environmental Resource Permit Applicants' Handbook ** Average horizontal hydraulic conductivity is assumed to be twice the vertical rate (MODRET) VOLUME OF WATER TO BE RECOVERED UNDER SATURATED LATERAL FLOW CONDITIONS Remaining volume to be infiltrated under saturated lateral flow = cf D:\KB Projects\00 market\dr horton\cato road\cato retention.xls

15 Treatment volume elev. at start of saturated lateral flow = ft CALCULATE Fx AND Fy Height of basin bottom above SHGWT (h b = h c ) h b = 2.00 ft Height of water in the basin at the start of sat. lateral flow (h 2 ) = (Treat. vol. elev. at start of sat. lat. flow) - (Basin bottom elev.) h 2 = 1.06 ft Height of water above groundwater table at the start of sat. lateral flow (H t ) = h b + h 2 H t = 3.06 ft (13 8)* F y = h c / H t = 0.65 (13 6)* Basin length to width ratio (L/W) = 1.0 From figure 13-7 F x = 2.5 TIME TO RECOVER THE REMAINING TREATMENT VOLUME UNDER SAT. LATERAL FLOW Average saturated thickness (D) = (SHGWT - Impervious Layer Elev.) + (Height of water above SHGWT) / 2 D = ft (13 7)* Time to recover the remaining treatment volume under lateral sat. flow conditions (t) = (W) 2 / 4 (K H )(D)(F x ) 2 t = 2.16 days (13 9)* t = hours Total time to recover treatment volume (t total ) = (vertical flow time) + (lateral sat. flow time) t total = 55.1 hours < 72 hours okay D:\KB Projects\00 market\dr horton\cato road\cato retention.xls

16 CURVE NUMBER WORKSHEET SCS Soils Basin Area = acres PREDEVELOPMENT albany sands 6 20 in/hr AREA SCS SOIL COVER TYPE AND CONDITIONS CURVE SUB TYPE NUMBER TOTAL A brush weed mixture poor C brush weed mixture poor D woods-grass combo poor PREVIOUSLY DEVELOPED WEIGHTED CURVE NUMBER = 52 WEIGHTED CURVE NUMBER = SUM (CN*AREA) / TOTAL AREA Basin Area = acres POST DEVELOPMENT AREA SCS SOIL COVER TYPE AND CONDITIONS CURVE SUB TYPE NUMBER TOTAL A grass Cover > 75% C grass Cover > 75% pond Impervious (Pavmt,Conc.) WEIGHTED CURVE NUMBER = 66 WEIGHTED CURVE NUMBER = SUM (CN*AREA) / TOTAL AREA WT acres albany C pond area blanton A development area WT >6' foxworth A development area pamlico dorovan D 0.27

17 Time of Concentration (T c ) or travel time (T t ) By KBB Date 3/26/2018 Basin Pre North Pre West Post Sheet flow (Applicable to Tc only) Segment ID 1. Surface Description (Table 3-1) WOODS/GRASS WOODS/GRASS grass sod 2. Manning's Roughness coeff., n (Table 3-1) Flow Length, L (total L 300 ft) ft Yr 24-Hr rainfall, P 2 in Land slope, s ft/ft T t = 0.007(nL) 0.8 / P s 0.4 hr Shallow Concentrated Flow Segment ID 7. Surface Description (Paved or Unpaved) unpaved unpaved paved 8. Flow Length, L ft Watercourse slope, s ft/ft Average Velocity, V (figure F-2) ft/s T t = L / 3600V hr Channel Flow Segment ID swale,pipe,pond 12. Flow Length, L ft T t = L / 3600V (V is assumed at 2 ft/s) hr Watershed or subarea T c or T t (Adding T t in Steps 6,11,and 19) hr or min min.for post is 10 (210-VI-TR-55, Second Ed., June 1986)

18 2/26/2018 BORINNG EXIST DEPTH ELEV MIN road HA ELEV SHWT SHWT ROADBED station not found not found not found not found 7 38 not found not found not found not found not found not found pond pond not found

19 Brighton Oaks Nodes A Stage/Area V Stage/Volume T Time/Stage M Manhole T: PRE north U: Pre North T: bndy North U: backyard north Basins O Overland Flow U SCS Unit CN S SBUH CN Y SCS Unit GA Z SBUH GA Links P Pipe W Weir C Channel D Drop Structure B Bridge R Rating Curve H Breach E Percolation F Filter X Exfil Trench T: PRE West U: Pre West T: bndy West P: culvert W: road weir M: culvert up U: Mill Bayou East D: outfall pond P: Pipe North A: pond 1 U: Post All R: perc T: ground Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc.

20 Brighton Oaks ==== Basins ============================================================================== Name: backyard north Node: bndy North Status: Onsite Group: BASE Type: SCS Unit Hydrograph CN Unit Hydrograph: Uh323 Peaking Factor: Rainfall File: Storm Duration(hrs): 0.00 Rainfall Amount(in): Time of Conc(min): Area(ac): Time Shift(hrs): 0.00 Curve Number: Max Allowable Q(cfs): DCIA(%): 0.00 Name: Mill Bayou East Node: culvert up Status: Onsite Group: BASE Type: SCS Unit Hydrograph CN Unit Hydrograph: Uh323 Peaking Factor: Rainfall File: Storm Duration(hrs): 0.00 Rainfall Amount(in): Time of Conc(min): Area(ac): Time Shift(hrs): 0.00 Curve Number: Max Allowable Q(cfs): DCIA(%): 0.00 Name: Post All Node: pond 1 Status: Onsite Group: BASE Type: SCS Unit Hydrograph CN Unit Hydrograph: Uh323 Peaking Factor: Rainfall File: Storm Duration(hrs): 0.00 Rainfall Amount(in): Time of Conc(min): Area(ac): Time Shift(hrs): 0.00 Curve Number: Max Allowable Q(cfs): DCIA(%): 0.00 Name: Pre North Node: PRE north Status: Onsite Group: BASE Type: SCS Unit Hydrograph CN Unit Hydrograph: Uh323 Peaking Factor: Rainfall File: Storm Duration(hrs): 0.00 Rainfall Amount(in): Time of Conc(min): Area(ac): Time Shift(hrs): 0.00 Curve Number: Max Allowable Q(cfs): DCIA(%): 0.00 Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 1 of 12

21 Brighton Oaks Name: Pre West Node: Pre West Status: Onsite Group: BASE Type: SCS Unit Hydrograph CN Unit Hydrograph: Uh323 Peaking Factor: Rainfall File: Storm Duration(hrs): 0.00 Rainfall Amount(in): Time of Conc(min): Area(ac): Time Shift(hrs): 0.00 Curve Number: Max Allowable Q(cfs): DCIA(%): 0.00 ==== Nodes =============================================================================== Name: bndy North Base Flow(cfs): Init Stage(ft): Group: BASE Warn Stage(ft): Type: Time/Stage Time(hrs) Stage(ft) Name: bndy West Base Flow(cfs): Init Stage(ft): Group: BASE Warn Stage(ft): Type: Time/Stage Time(hrs) Stage(ft) Name: culvert up Base Flow(cfs): Init Stage(ft): Group: BASE Plunge Factor: 1.00 Warn Stage(ft): Type: Manhole, Flat Floor Stage(ft) Area(ac) Name: ground Base Flow(cfs): Init Stage(ft): Group: BASE Warn Stage(ft): Type: Time/Stage Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 2 of 12

22 Brighton Oaks Time(hrs) Stage(ft) Name: pond 1 Base Flow(cfs): Init Stage(ft): Group: BASE Warn Stage(ft): Type: Stage/Area Stage(ft) Area(ac) Name: PRE north Base Flow(cfs): Init Stage(ft): Group: BASE Warn Stage(ft): Type: Time/Stage top of inlet inv=20.17 Time(hrs) Stage(ft) Name: PRE West Base Flow(cfs): Init Stage(ft): Group: BASE Warn Stage(ft): Type: Time/Stage Time(hrs) Stage(ft) ==== Operating Tables ==================================================================== Name: perc Group: BASE Type: Rating Curve Function: US Stage vs. Discharge Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 3 of 12

23 Brighton Oaks US Stage(ft) Discharge(cfs) ==== Pipes =============================================================================== Name: culvert From Node: culvert up Length(ft): Group: BASE To Node: bndy West Count: 1 Friction Equation: Automatic UPSTREAM DOWNSTREAM Solution Algorithm: Most Restrictive Geometry: Circular Circular Flow: Both Span(in): Entrance Loss Coef: 0.00 Rise(in): Exit Loss Coef: 1.00 Invert(ft): Bend Loss Coef: 0.00 Manning's N: Outlet Ctrl Spec: Use dc or tw Top Clip(in): Inlet Ctrl Spec: Use dc Bot Clip(in): Stabilizer Option: None Upstream FHWA Inlet Edge Description: Circular Concrete: Square edge w/ headwall Downstream FHWA Inlet Edge Description: Circular Concrete: Square edge w/ headwall Name: Pipe North From Node: pond 1 Length(ft): Group: BASE To Node: bndy North Count: 1 Friction Equation: Automatic UPSTREAM DOWNSTREAM Solution Algorithm: Most Restrictive Geometry: Circular Circular Flow: Both Span(in): Entrance Loss Coef: 0.00 Rise(in): Exit Loss Coef: 1.00 Invert(ft): Bend Loss Coef: 0.00 Manning's N: Outlet Ctrl Spec: Use dc or tw Top Clip(in): Inlet Ctrl Spec: Use dc Bot Clip(in): Stabilizer Option: None Upstream FHWA Inlet Edge Description: Circular Concrete: Square edge w/ headwall Downstream FHWA Inlet Edge Description: Circular Concrete: Square edge w/ headwall Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 4 of 12

24 Brighton Oaks ==== Channels ============================================================================ Name: From Node: Length(ft): 0.00 Group: BASE To Node: Count: 1 UPSTREAM DOWNSTREAM Friction Equation: Automatic Geometry: Trapezoidal Trapezoidal Solution Algorithm: Automatic Invert(ft): Flow: Both TClpInitZ(ft): Contraction Coef: Manning's N: Expansion Coef: Top Clip(ft): Entrance Loss Coef: Bot Clip(ft): Exit Loss Coef: Main XSec: Outlet Ctrl Spec: Use dc or tw AuxElev1(ft): Inlet Ctrl Spec: Use dc Aux XSec1: Stabilizer Option: None AuxElev2(ft): Aux XSec2: Top Width(ft): Depth(ft): Bot Width(ft): LtSdSlp(h/v): RtSdSlp(h/v): ==== Drop Structures ===================================================================== Name: outfall pond From Node: pond 1 Length(ft): Group: BASE To Node: culvert up Count: 1 UPSTREAM DOWNSTREAM Friction Equation: Automatic Geometry: Circular Circular Solution Algorithm: Most Restrictive Span(in): Flow: Both Rise(in): Entrance Loss Coef: Invert(ft): Exit Loss Coef: Manning's N: Outlet Ctrl Spec: Use dc or tw Top Clip(in): Inlet Ctrl Spec: Use dc Bot Clip(in): Solution Incs: 10 Upstream FHWA Inlet Edge Description: Circular Concrete: Square edge w/ headwall Downstream FHWA Inlet Edge Description: Circular Concrete: Square edge w/ headwall E inlet 36 by54 *** Weir 1 of 3 for Drop Structure outfall pond *** Count: 1 Bottom Clip(in): Type: Vertical: Mavis Top Clip(in): TABLE Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 5 of 12

25 Brighton Oaks Flow: Both Weir Disc Coef: Geometry: Rectangular Orifice Disc Coef: Span(in): Invert(ft): Rise(in): Control Elev(ft): *** Weir 2 of 3 for Drop Structure outfall pond *** Count: 1 Bottom Clip(in): Type: Horizontal Top Clip(in): Flow: Both Weir Disc Coef: Geometry: Rectangular Orifice Disc Coef: TABLE Span(in): Invert(ft): Rise(in): Control Elev(ft): *** Weir 3 of 3 for Drop Structure outfall pond *** Count: 1 Bottom Clip(ft): Type: Vertical: Mavis Top Clip(ft): Flow: Both Weir Disc Coef: Geometry: Trapezoidal Orifice Disc Coef: TABLE Bottom Width(ft): Invert(ft): Left Sd Slp(h/v): Control Elev(ft): Right Sd Slp(h/v): Struct Opening Dim(ft): ==== Weirs =============================================================================== Name: road weir From Node: culvert up Group: BASE To Node: bndy West Flow: Both Count: 1 Type: Vertical: Paved Geometry: Trapezoidal Bottom Width(ft): Left Side Slope(h/v): Right Side Slope(h/v): Invert(ft): Control Elevation(ft): Struct Opening Dim(ft): Bottom Clip(ft): Top Clip(ft): Weir Discharge Coef: Orifice Discharge Coef: TABLE ==== Rating Curves ======================================================================= Name: perc From Node: pond 1 Count: 1 Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 6 of 12

26 Brighton Oaks Group: BASE To Node: ground Flow: Both TABLE ELEV ON(ft) ELEV OFF(ft) #1: perc #2: #3: #4: ==== Percolation Links =================================================================== Name: From Node: Flow: Both Group: BASE To Node: Count: 1 Surface Area Option: Use 1st Point in Stage/Area Table Vertical Flow Termination: Horizontal Flow Algorithm Aquifer Base Elev(ft): Perimeter 1(ft): Water Table Elev(ft): Perimeter 2(ft): Ann Recharge Rate(in/year): Perimeter 3(ft): Horiz Conductivity(ft/day): Distance 1 to 2(ft): Vert Conductivity(ft/day): Distance 2 to 3(ft): Effective Porosity(dec): Num Cells 1 to 2: 0 Suction Head(in): Num Cells 2 to 3: 0 Layer Thickness(ft): ==== Hydrology Simulations =============================================================== Name: 002Y024H Filename: D:\KB Projects\icpr\icpr DATA\002Y024H.R32 Override Defaults: Yes Storm Duration(hrs): Rainfall File: Scsiii Rainfall Amount(in): 6.00 Time(hrs) Print Inc(min) Name: 025Y001H Filename: D:\KB Projects\icpr\icpr DATA\025Y001H.R32 Override Defaults: Yes Storm Duration(hrs): 1.00 Rainfall File: Scsiii Rainfall Amount(in): 3.70 Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 7 of 12

27 Brighton Oaks Time(hrs) Print Inc(min) Name: 025Y002H Filename: D:\KB Projects\icpr\icpr DATA\025Y002H.R32 Override Defaults: Yes Storm Duration(hrs): 2.00 Rainfall File: Scsiii Rainfall Amount(in): 4.80 Time(hrs) Print Inc(min) Name: 025Y004H Filename: D:\KB Projects\icpr\icpr DATA\025Y004H.R32 Override Defaults: Yes Storm Duration(hrs): 4.00 Rainfall File: Scsiii Rainfall Amount(in): 6.00 Time(hrs) Print Inc(min) Name: 025Y008H Filename: D:\KB Projects\icpr\icpr DATA\025Y008H.R32 Override Defaults: Yes Storm Duration(hrs): 8.00 Rainfall File: Scsiii Rainfall Amount(in): 7.40 Time(hrs) Print Inc(min) Name: 025Y024H Filename: D:\KB Projects\icpr\icpr DATA\025Y024H.R32 Override Defaults: Yes Storm Duration(hrs): Rainfall File: Scsiii Rainfall Amount(in): Time(hrs) Print Inc(min) Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 8 of 12

28 Brighton Oaks Name: 100yr24hr Filename: D:\KB Projects\icpr\icpr DATA\100YR24HR.R32 Override Defaults: Yes Storm Duration(hrs): Rainfall File: Scsiii Rainfall Amount(in): Time(hrs) Print Inc(min) ==== Routing Simulations ================================================================= Name: 02yr24hr Hydrology Sim: 002Y024H Filename: D:\KB Projects\icpr\icpr DATA\02yr24hr.I32 Execute: Yes Restart: No Patch: No Alternative: No Max Delta Z(ft): 1.00 Delta Z Factor: Time Step Optimizer: Start Time(hrs): End Time(hrs): Min Calc Time(sec): Max Calc Time(sec): Boundary Stages: Boundary Flows: Time(hrs) Print Inc(min) Group Run BASE Yes Name: 100yr24hr Hydrology Sim: 100yr24hr Filename: D:\KB Projects\icpr\icpr DATA\100YR24HR.I32 Execute: Yes Restart: No Patch: No Alternative: No Max Delta Z(ft): 1.00 Delta Z Factor: Time Step Optimizer: Start Time(hrs): End Time(hrs): Min Calc Time(sec): Max Calc Time(sec): Boundary Stages: Boundary Flows: Time(hrs) Print Inc(min) Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 9 of 12

29 Brighton Oaks Group Run BASE Yes Name: 25yr1hr Hydrology Sim: 025Y001H Filename: D:\KB Projects\icpr\icpr DATA\25yr1hr.I32 Execute: Yes Restart: No Patch: No Alternative: No Max Delta Z(ft): 1.00 Delta Z Factor: Time Step Optimizer: Start Time(hrs): End Time(hrs): 2.00 Min Calc Time(sec): Max Calc Time(sec): Boundary Stages: Boundary Flows: Time(hrs) Print Inc(min) Group Run BASE Yes Name: 25yr24hr Hydrology Sim: 025Y024H Filename: D:\KB Projects\icpr\icpr DATA\25yr24hr.I32 Execute: Yes Restart: No Patch: No Alternative: No Max Delta Z(ft): 1.00 Delta Z Factor: Time Step Optimizer: Start Time(hrs): End Time(hrs): Min Calc Time(sec): Max Calc Time(sec): Boundary Stages: Boundary Flows: Time(hrs) Print Inc(min) Group Run BASE Yes Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 10 of 12

30 Brighton Oaks Name: 25yr2hr Hydrology Sim: 025Y002H Filename: D:\KB Projects\icpr\icpr DATA\25yr2hr.I32 Execute: Yes Restart: No Patch: No Alternative: No Max Delta Z(ft): 1.00 Delta Z Factor: Time Step Optimizer: Start Time(hrs): End Time(hrs): 3.00 Min Calc Time(sec): Max Calc Time(sec): Boundary Stages: Boundary Flows: Time(hrs) Print Inc(min) Group Run BASE Yes Name: 25yr4hr Hydrology Sim: 025Y004H Filename: D:\KB Projects\icpr\icpr DATA\25yr4hr.I32 Execute: Yes Restart: No Patch: No Alternative: No Max Delta Z(ft): 1.00 Delta Z Factor: Time Step Optimizer: Start Time(hrs): End Time(hrs): 6.00 Min Calc Time(sec): Max Calc Time(sec): Boundary Stages: Boundary Flows: Time(hrs) Print Inc(min) Group Run BASE Yes Name: 25yr8hr Hydrology Sim: 025Y008H Filename: D:\KB Projects\icpr\icpr DATA\25yr8hr.I32 Execute: Yes Restart: No Patch: No Alternative: No Max Delta Z(ft): 1.00 Delta Z Factor: Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 11 of 12

31 Brighton Oaks Time Step Optimizer: Start Time(hrs): End Time(hrs): Min Calc Time(sec): Max Calc Time(sec): Boundary Stages: Boundary Flows: Time(hrs) Print Inc(min) Group Run BASE Yes Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 12 of 12

32 Brighton Oaks Max Time Max Max Max Time Max Max Time Max Name Group Simulation Flow Flow Delta Q US Stage US Stage DS Stage DS Stage hrs cfs cfs hrs ft hrs ft culvert BASE 02yr24hr outfall pond BASE 02yr24hr perc BASE 02yr24hr Pipe North BASE 02yr24hr road weir BASE 02yr24hr culvert BASE 100yr24hr outfall pond BASE 100yr24hr perc BASE 100yr24hr Pipe North BASE 100yr24hr road weir BASE 100yr24hr culvert BASE 25yr1hr outfall pond BASE 25yr1hr perc BASE 25yr1hr Pipe North BASE 25yr1hr road weir BASE 25yr1hr culvert BASE 25yr24hr outfall pond BASE 25yr24hr perc BASE 25yr24hr Pipe North BASE 25yr24hr road weir BASE 25yr24hr culvert BASE 25yr2hr outfall pond BASE 25yr2hr perc BASE 25yr2hr Pipe North BASE 25yr2hr road weir BASE 25yr2hr culvert BASE 25yr4hr outfall pond BASE 25yr4hr perc BASE 25yr4hr Pipe North BASE 25yr4hr road weir BASE 25yr4hr culvert BASE 25yr8hr outfall pond BASE 25yr8hr perc BASE 25yr8hr Pipe North BASE 25yr8hr road weir BASE 25yr8hr Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 1 of 1

33 Brighton Oaks Max Time Max Warning Max Delta Max Surf Max Time Max Max Time Max Name Group Simulation Stage Stage Stage Stage Area Inflow Inflow Outflow Outflow hrs ft ft ft ft2 hrs cfs hrs cfs bndy North BASE 02yr24hr bndy West BASE 02yr24hr culvert up BASE 02yr24hr ground BASE 02yr24hr pond 1 BASE 02yr24hr PRE north BASE 02yr24hr PRE West BASE 02yr24hr bndy North BASE 100yr24hr bndy West BASE 100yr24hr culvert up BASE 100yr24hr ground BASE 100yr24hr pond 1 BASE 100yr24hr PRE north BASE 100yr24hr PRE West BASE 100yr24hr bndy North BASE 25yr1hr bndy West BASE 25yr1hr culvert up BASE 25yr1hr ground BASE 25yr1hr pond 1 BASE 25yr1hr PRE north BASE 25yr1hr PRE West BASE 25yr1hr bndy North BASE 25yr24hr bndy West BASE 25yr24hr culvert up BASE 25yr24hr ground BASE 25yr24hr pond 1 BASE 25yr24hr PRE north BASE 25yr24hr PRE West BASE 25yr24hr bndy North BASE 25yr2hr bndy West BASE 25yr2hr culvert up BASE 25yr2hr ground BASE 25yr2hr pond 1 BASE 25yr2hr PRE north BASE 25yr2hr PRE West BASE 25yr2hr bndy North BASE 25yr4hr bndy West BASE 25yr4hr culvert up BASE 25yr4hr ground BASE 25yr4hr pond 1 BASE 25yr4hr PRE north BASE 25yr4hr PRE West BASE 25yr4hr bndy North BASE 25yr8hr bndy West BASE 25yr8hr culvert up BASE 25yr8hr ground BASE 25yr8hr pond 1 BASE 25yr8hr PRE north BASE 25yr8hr PRE West BASE 25yr8hr Interconnected Channel and Pond Routing Model (ICPR) 2002 Streamline Technologies, Inc. Page 1 of 1