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HomeMy WebLinkAboutSW6221101_Stormwater Narrative_20221129US Army Corps of Engineers® Wilmington District STORMWATER MANAGEMENT PERMIT APPLICATION NARRATIVE PN 79439.2, SOF Technical Support Training Annex and HAZMAT Storage Building, Yarborough Complex, Fort Bragg, NC Volume 1 of 1 A-E Contract: W912PM22C0007 Task Order: W81 LJ821571676 Solicitation No. W912PM22R0012 eeZt ex P.federal 205 North Michigan Avenue, Suite 3800 Chicago, Illinois 60601-5941, USA 312.616.7500 1 www.expfederal.com A-E Project No.: CHI-00243079-AO ISSUED FOR PERMIT SEPTEMBER 2022 Q �aFess rod 9 �) SEAL o46S4� ,4�L B Ro IL1TA*JRAdW: A. Site Description Existing Site Conditions The existing site consists mainly of gravel surfaces, asphalt and dirt roadways, and open earth surfaces with vegetation. The surrounding sites are either established buildings or are currently under construction. The existing drainage pattern through the site consists mainly of runoff which drains from the northeast to southwest direction where it exits the site via an existing ditch system which ultimately discharges to an Unnamed Tributary to Bones Creek. Bones Creek is within the Cape Fear River basin and is a Class C waters, meaning it is protected for uses such as secondary recreation (swimmable), fishing, and wildlife. See Exhibit 1 for an overall USGS topography map of the project site and surrounding areas. Based on the USGS Web Soil Survey, the existing soils are hydrologic soil group B and are a mix of Blaney loamy sand and Faceville loamy sand. Refer to the Exhibit 2 - Soils Maps for HSG and saturated hydraulic conductivity information. The saturated hydraulic conductivity of 40 micrometers/second is approximately 5.5 inches/hour. A summary of the existing runoff and discharge information is below. Refer to the Exhibit 3 - Pre -Development Release Rates for supporting calculations. Existing Drainage Area = 17.17 Acres Existing CN = 70 Existing Release Rates: PRE -DEVELOPED PEAK FLOW RATES (cfs) OPEN IMPERVIOUS BASIN/OUTFALL ID AREA (ac) AREA Tc (hrs) CN 1-YR 2-YR 10-YR 25-YR 100-YR AREA (ac) (ac) ONSITE (A/13) 8.41 3.72 4.69 0.192 74 0.38 3.43 8.59 12.02 18.01 OFFSITE 5.17 0.00 5.17 0.232 65 1 0.07 0.73 2.40 3.68 6.05 EXISTING C 3.59 0.30 3.29 0.167 67 0.07 0.65 2.08 3.16 5.16 TOTAL 17.17 4.02 13.15 0.232 70 0.48 4.54 12.57 18.31 28.56 Proposed Site Conditions The proposed site will be developed with two buildings, container storage area, parking, and access roadways. The rainfall drains to inlets, which are routed to one of four bio-retention facilities. There are three storm sewer networks within the proposed site. Network A collects the drainage from the Technical Support Training Annex Building roof and the surrounding asphalt pavement and parking lot. This network drains directly to Pond A, which has both a retention component and a detention component. Before entering the pond, this stormwater is first routed through a forebay for pretreatment and sediment removal. Network B collects the drainage from the parking lot to the east of the Annex building. This system is routed through one of three bioretention facilities within the parking lot medians before discharging to Pond A. Network C collects the runoff from the access road south of the site before discharging to Pond A. This system outlets directly to a ditch and leaves the site draining west. Pond A ultimately outlets to the southwest of the site into an existing ditch system. All discharges ultimately drain to Bones Creek. A summary of the proposed runoff and discharge information is below. Refer to the Exhibit 4 — Post -Development Release Rates for supporting calculations. Proposed Drainage Area = 17.17 Acres Proposed CN = 81 Proposed Release Rates: POST -DEVELOPED PEAK FLOW RATES (cfs) SASINIOUTFALL 10 AREA (ac) IMPERVIOUS AREA (ac) OPEN AREA (ae) T. (hrs) CN 1 YR 2-YR 10•YR 25•YR 100-YR ONSITE (A/B/C) 14.26 8.21 6.05 0.167 89 0.43 3.06 8.54 12.07 19.97 OFF51TE 2.91 0.00 2.91 0.220 65 0.04 0.41 1.35 2.07 3.41 TOTAL 17.17 8.21 8.96 W20 81 1 0.47 3.47 9.89 14.14 23.38 In addition to the proposed conditions calculations, the Army LID Planning Tool forms have been included as well at the end of Exhibit 4. The Best Management Practices on site treat the required treatment volumes for the site from this planning analysis tool. B. Storm Drainage System Description The storm sewers were sized to have capacity for the 10-Year rainfall event. C. Criteria / Regulations Criteria and regulations utilized in the development of the design include but are not limited to the following: North Carolina Department of Environmental Quality Minimum Design Criteria (NCDEQ MDC) UFC 3-201-01, Civil Engineering UFC 3-210-10, Low Impact Development American Concrete Pipe Association (ACPA) Concrete Pipe Design Manual ASTM C 76 Standard Specification for Reinforced Concrete Culvert, Storm Drain and Sewer Pipe D. Summary of Design and Methodology 1. Detention and Retention The UFC 3-210-10, Low Impact Development requires that a site drainage system be designed so that the pre -development runoff conditions are maintained in the post - development design. This can be accomplished on site through interception, infiltration, storage or evapotranspiration processes. Due to the increase in impervious area on this site, the site drainage design required both infiltration and storage to bring the post -development runoff rates down to and below the existing, pre -development runoff rates. Storm Sewer Network A drains the Training Annex building and container storage area within the compound to the south. This stormwater is routed to Pond A. Pond A has both an infiltration component and a detention component. Network B drains the large parking area on the east side of the site. This stormwater is routed to one of 3 bioretention areas located within the parking lot medians. The water that is not infiltrated continues to Pond A. Pond A outlets to the existing ditch along the west side of the site. Network C drains Jedburgh Lane to the south. This stormwater is routed to Pond A. Pond A discharge ultimately ends up in the Unnamed Tributary to Bones Creek. A portion of the existing offsite area will be collected within the project site drainage network. The remainder of the offsite area will drain west of the site to the ditch that runs along the east side of Ammo Pointe Blvd where it will tie into the same ultimate outfall. The detention analysis was completed using SCS Curve Number Method and XPSTORM software. Refer to Exhibits 3 and 4 for calculations. 2. Inlet Capacity The capacity of the proposed frame and grates were checked for the 10-year event to ensure that the 10-year runoff from the site will be fully captured within the storm sewer system. The runoff to the inlet was calculated using the Rational Method. The capacity of the frame intake was determined using the weir and orifice equations. Refer to Exhibit 4 for calculations. 3. Storm Sewer Pipe The storm sewers were sized to carry the 10-year storm event per UFC 3-201-01, Civil Engineering. Since the drainage area to each inlet is less than 200 acres, the Rational Method was used to determine flow to the pipes. The hydraulic grade line is contained within the pipe for the 10-year event. The storm sewers were sized using the Manning's Equation, Hydraflow Drainage and XPSTORM software. An overview of the storm sewer pipe lengths and sizes proposed for the project can be seen in Part B of this Narrative. Refer to Exhibit 4 for calculations. Network C was originally designed to discharge to the ditch north of Urban Freedom, eventually flowing to the Unnamed Tributary to Bones Creek. Storm sewer pipe sizes were previously designed to convey flow in this direction. Following further discussion to reroute flow from Jedburgh Lane to Pond A, it was determined drainage areas to Network C remain unchanged. The only design element changing is the direction in which stormwater flow drains, which is to the north instead of the originally designed south direction. Essentially pipe sizes for the incoming laterals stay the same as drainage areas do not change, whereas previously designed pipes C-2 and C-3 are flipped in terms of sewer size to accommodate for the change in direction of flow being conveyed. These storm sewer sizes and subsequent slopes were confirmed utilizing XPSTORM. The peak 10-year HGL elevation is contained completely within the specified storm sewers at their respective size and slopes. Refer to Exhibit 4 for calculations. 4. Structural Design of Storm Drainage System Features The reinforced concrete pipe was designed in accordance with the American Concrete Pipe Association (ACPA) Concrete Pipe Design Manual and ASTM C76 Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe. In addition, the cover of the proposed storm sewer is in accordance with UFC 3-201-01. E. Hydrology Summary Refer to plan sheets CE601 and CE602 for area maps. The pre -development site consists of an offsite drainage area and an onsite drainage area. The post -development site consists of the below drainage areas: Network A + Network B + Network C + Offsite Treated = 14.26 Acres Bypass Offsite = 2.91 Acres Total = 17.17 Acres F. Other Submittal Materials The following additional submittal materials are included within this submittal as the following exhibits: • Exhibit 5: Signed Stormwater Management Permit Application Form • Exhibit 6: Signed Supplement Forms • Exhibit 7: Signed O&M agreements • Exhibit 8: Plan set with applicable soil boring reports o Two sets of plans will be submitted as well EXHIBIT 1- USGS TOPOGRAPHY MAP U.S. DEPARTMENTU S. GEOLOGICAL INTERIOR GIICAL SURVEY science for a changing world 79°07'30" 35°07'30" 672000-E 673 3888000m n 5' 388 � 388( 3886 388` 3882 3881 388( 2'30" 387E 387 E 387 460 000 FEET 3876 3875 35°00' 79°07'30" s72 s73 Produced by the United States Geological Survey North American Datum of 1983 (NAD83) World Geodetic System of 1984 (WGS84). Projection and 1 000-meter grid: Universal Transverse Mercator, Zone 17S 10 000-foot ticks: North Carolina Coordinate System of 1983 This map is not a legal document. Boundaries may be generalized for this map scale. Private Lands within government reservations may not be shown. Obtain permission before entering private Lands. Imagery ................................................... NAIP, May 2014 Roads ................................ U.S. Census Bureau, 2015 - 2016 Names .......................................................... GNIS, 2016 Hydrography .................... National Hydrography Dataset, 2014 Contours ............................ National Elevation Dataset, 2008 Boundaries ............ Multiple sources; see metadata file 1972 - 2016 Wetlands ......... FWS National Wetlands Inventory 1977 - 2014 5' 674 675 The National Map 1-USTopo 176 677 2'30" s78 s79 1 1 990 000 FEET 180 181 CLIFDALE QUADRANGLE NORTH CAROLINA 7.5-MINUTE SERIES 79°00' 35°07'30" hn GRUBER tD RD EET _ Vau 8- Hill LONGST -� � 300�- °so B 11eS l .,, . • .,, 4pp � C�Qi JSOn -�� < � - Ole o W Newton ° 0 � N o y � R ` P i 1 RT BRAGG p o � \_ - i DANDRIDGE-DR GODFREY DR `;y •� a � D MOR GANiON RD � - � \ _ - �L- m - PAXTON DR Ao 70 o \ l - �ry / 'Chaff Q OVE z BR _ L_ ake. 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CELfIC \ - AYE � - R I I U/U UUU rtt I °74 M. 8" 47- 156 MILS N 1" 7- 20 MILS UTM GRID AND 2016 MAGNETIC NORTH DECLINATION AT CENTER OF SHEET U.S. National Grid 100,000-m Square ID PU Grid Zone Designation 17S 5, °75 °76 °77 °78 SCALE 1:24 000 1 0.5 0 KILOMETERS 1 2 1000 500 0 METERS 1000 2000 1 0.5 0 1 MILES 1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 FEET CONTOUR INTERVAL 10 FEET NORTH AMERICAN VERTICAL DATUM OF 1988 This map was produced to conform with the National Geospatial Program US Topo Product Standard, 2011. A metadata file associated with this product is draft version 0.6.19 2'30" °79 °80 NORTH CAROLIN ■ QUADRANGLE LOCATION 1 Lobelia 1 2 3 2 Overhills 3 Manchester 4 5 4 Nicholson Creek 5 Fayetteville 6 Raeford 6 7 8 7 Parkton 8 Hope Mills ADJOINING QUADRANGLES -08 3887 3886 490 000 FEET 3885 5' 3884 3883 3882 3881 3880 2'30" 3879 3878 3877 3876 3875000m N �P SURREY RD 181 682000mE 35°00' 79°00' ROAD CLASSIFICATION Expressway Local Connector Secondary Hwy Local Road - Ramp 4WD • Interstate Route C3 US Route O State Route CLIFDALE, NC 2016 * I-- �N O LO LQ� rn Cl) N (C) X (0�O U co 0 � cY CY7co O Z � LL LQ w �Z Q z z EXHIBIT 2 -SOILS MAPS m 679080 35' 5' 20" N ' ,A Soil Map —Cumberland County, North Carolina (Technical Support Annex Soils Map) 679160 679240 679320 679400 Soil MaN may not he valiel at this scale. 35o 4' 58" N 679080 679160 679240 679320 679400 m Map Scale: 1:3,410 if printed on A portrait (8.5" x 11") sheet. Meters N 0 50 100 200 300 Feet 0 150 300 E00 900 Map projection: Web Mercator Conermordinates: WGS84 Edge tics: UTM Zone 17N WGS84 usoA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 679480 679480 a 679560 9 35o 520" N 1 ;ff 35o 4'58" N 679560 o 12/13/2017 Page 1 of 3 MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils 0 Soil Map Unit Polygons ,N Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit �i Gravelly Spot 0 Landfill A. Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Soil Map —Cumberland County, North Carolina (Technical Support Annex Soils Map) MAP INFORMATION Spoil Area The soil surveys that comprise your AOI were mapped at 1:24,000. Stony Spot Very Stony Spot Warning: Soil Map may not be valid at this scale. Wet Spot Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil 4� Other line placement. The maps do not show the small areas of Special Line Features contrasting soils that could have been shown at a more detailed scale. Water Features Streams and Canals Please rely on the bar scale on each map sheet for map measurements. Transportation Rails Source of Map: Natural Resources Conservation Service Web Soil Survey URL: . 0 Interstate Highways Coordinate System: Web Mercator (EPSG:3857) US Routes Maps from the Web Soil Survey are based on the Web Mercator Major Roads projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Local Roads Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. Background Aerial Photography This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Cumberland County, North Carolina Survey Area Data: Version 18, Sep 26, 2017 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 13, 2014—Feb 4, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. usoA Natural Resources Web Soil Survey 12/13/2017 Conservation Service National Cooperative Soil Survey Page 2 of 3 Soil Map —Cumberland County, North Carolina Technical Support Annex Soils Map Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI BaD Blaney loamy sand, 8 to 15 percent slopes 7.0 12.3% FaB Faceville loamy sand, 2 to 6 percent slopes 50.1 87.7% Totals for Area of Interest 67.2 100.0% USDA Natural Resources Web Soil Survey 12/13/2017 Conservation Service National Cooperative Soil Survey Page 3 of 3 Map Unit Description: Blaney loamy sand, 8 to 15 percent slopes ---Cumberland County, North Carolina Technical Support Annex Soils Map Cumberland County, North Carolina BaD—Blaney loamy sand, 8 to 15 percent slopes Map Unit Setting National map unit symbol: w6z3 Elevation: 160 to 660 feet Mean annual precipitation: 38 to 52 inches Mean annual air temperature: 61 to 70 degrees F Frost -free period: 210 to 245 days Farmland classification: Farmland of statewide importance Map Unit Composition Blaney and similar soils: 85 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Blaney Setting Landform: Low hills Landform position (two-dimensional): Shoulder Landform position (three-dimensional): Crest Down -slope shape: Convex Across -slope shape: Convex Parent material: Sandy and loamy marine deposits Typical profile A - 0 to 4 inches: loamy sand E - 4 to 25 inches: loamy sand Bt - 25 to 62 inches: sandy clay loam C - 62 to 80 inches: loamy coarse sand Properties and qualities Slope: 8 to 15 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.57 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 4.0 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: C Ecological site: Loamy Backslope Woodland - PROVISIONAL (F137XY006GA) USDANatural Resources Web Soil Survey 12/13/2017 am Conservation Service National Cooperative Soil Survey Pagel of 2 Map Unit Description: Blaney loamy sand, 8 to 15 percent slopes ---Cumberland County, North Carolina Technical Support Annex Soils Map Hydric soil rating: No Data Source Information Soil Survey Area: Cumberland County, North Carolina Survey Area Data: Version 18, Sep 26, 2017 USDANatural Resources Web Soil Survey 12/13/2017 am Conservation Service National Cooperative Soil Survey Page 2 of 2 Map Unit Description: Faceville loamy sand, 2 to 6 percent slopes ---Cumberland County, North Carolina Technical Support Annex Soils Map Cumberland County, North Carolina FaB—Faceville loamy sand, 2 to 6 percent slopes Map Unit Setting National map unit symbol: w70c Elevation: 80 to 330 feet Mean annual precipitation: 38 to 55 inches Mean annual air temperature: 59 to 70 degrees F Frost -free period: 210 to 265 days Farmland classification: All areas are prime farmland Map Unit Composition Faceville and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Faceville Setting Landform: Ridges on marine terraces, broad interstream divides on marine terraces Landform position (two-dimensional): Shoulder, summit Landform position (three-dimensional): Crest Down -slope shape: Convex Across -slope shape: Convex Parent material: Clayey marine deposits Typical profile Ap - 0 to 7 inches: loamy sand E - 7 to 17 inches: loamy sand Bt - 17 to 80 inches: clay Properties and qualities Slope: 2 to 6 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 7.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B USDANatural Resources Web Soil Survey 12/13/2017 am Conservation Service National Cooperative Soil Survey Pagel of 2 Map Unit Description: Faceville loamy sand, 2 to 6 percent slopes ---Cumberland County, North Carolina Technical Support Annex Soils Map Hydric soil rating: No Data Source Information Soil Survey Area: Cumberland County, North Carolina Survey Area Data: Version 18, Sep 26, 2017 USDANatural Resources Web Soil Survey 12/13/2017 am Conservation Service National Cooperative Soil Survey Page 2 of 2 679110 35o 5' 16" N 35o 5'0"N Saturated Hydraulic Conductivity (Ksat)—Cumberland County, North Carolina 679170 679230 679290 679350 679410 679110 679170 679230 679290 679350 Map Scale: 1:2,400 if printed on A portrait (8.5" x 11") sheet. � N Milers 0 35 70 140 210 Feet 0 100 200 400 E00 Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84 usoA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 679410 679470 35o 516" N I 35o 50" N 679470 o 8/30/2022 Page 1 of 3 Saturated Hydraulic Conductivity (Ksat)—Cumberland County, North Carolina MAP LEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons 0 = 40.0000 0 Not rated or not available Soil Rating Lines ,.yam = 40.0000 N 0 Not rated or not available Soil Rating Points = 40.0000 0 Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes r Major Roads Local Roads Background . Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Cumberland County, North Carolina Survey Area Data: Version 23, Jan 21, 2022 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 23, 2022—Apr 27, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. usoA Natural Resources Web Soil Survey 8/30/2022 Conservation Service National Cooperative Soil Survey Page 2 of 3 Saturated Hydraulic Conductivity (Ksat)—Cumberland County, North Carolina Saturated Hydraulic Conductivity (Ksat) Map unit symbol Map unit name Rating (micrometers persecond) Acres in AOI Percent of AOI FaB Faceville loamy sand, 2 to 6 percent slopes 40.0000 19.7 100.0% Totals for Area of Interest 19.7 100.0% Description Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a saturated soil transmit water. The estimates are expressed in terms of micrometers per second. They are based on soil characteristics observed in the field, particularly structure, porosity, and texture. Saturated hydraulic conductivity is considered in the design of soil drainage systems and septic tank absorption fields. For each soil layer, this attribute is actually recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For this soil property, only the representative value is used. The numeric Ksat values have been grouped according to standard Ksat class limits. Rating Options Units of Measure: micrometers per second Aggregation Method: Dominant Component Component Percent Cutoff. None Specified Tie -break Rule: Fastest Interpret Nulls as Zero: No Layer Options (Horizon Aggregation Method): Surface Layer (Not applicable) USDA Natural Resources Web Soil Survey 8/30/2022 Conservation Service National Cooperative Soil Survey Page 3 of 3 EXHIBIT 3 - PRE DEVELOPMENT ANALYSIS .MM 17 . �\ i OFFSITE 5.17 ac Tc = 13.9 min CN=65 \ l EXHIBIT 2-1 AREA MAP US Army Corps of Engineers& PRE -DEVELOPED PEAK FLOW RATES (c&; BA SI NIOUTFALL ID AREA Jac) IMPERVIOUS AREA lac) OPEN AREA ac Te (hrs) CH 1-YR 2-YR 10-YR 25-YR 100-YR ON SITE (A/B) 8.41 3.72 4.69 0.192 74 0.38 3.43 8.59 12.02 18.01 OFFSITE 5.17 0.00 5.17 0.232 65 0.07 0.73 2.40 3.69 6.05 EXISTING C 3.59 0.30 3.29 0.167 67 0.07 0.55 2.09 3.16 5.16 TOTAL 17.17 4.LF 13.15 0.231- 70 0.48 4.54 12.57 18.31 28.56 i { ONSITE (A/B) 8.41ac 'i Tc = 11.5 min I MITI F= T--\ i '-. --------- i♦, SHEET ID 95% DESIGN SUBMITTAL EXHIBIT 2-2 Pre Development - Time of Concentration Existing Offsite Existing Onsite Existing C 1) Sheet Flow 1) Sheet Flow 1) Sheet Flow Landuse Range, brush, grass, dirt Landuse Range, brush, grass, dirt Landuse Range, brush, grass, dirt n (Table 3-1) 0.08 n (Table 3-1) 0.08 n (Table 3-1) 0.08 Length (ft) 100 Length (ft) 100 Length (ft) 100 P2 (in) 2-yr 24-hr 3.73 P2 (in) 2-yr 24-hr 3.73 P2 (in) 2-yr 24-hr 5.45 El Up (ft) 268 El Up (ft) 273 El Up (ft) 265.5 El Down (ft) 267 El Down (ft) 271 El Down (ft) 264.5 Slope (ft/ft) 0.01 Slope (ft/ft) 0.02 Slope (ft/ft) 0.01 Tt (hr) 0.12 Tt (hr) 0.09 Tt (hr) 0.10 2) Shallow Concentrated Flow 2) Shallow Concentrated Flow 2) Shallow Concentrated Flow El Up (ft) 267 El Up (ft) 271 El Up (ft) 264.5 El Down (ft) 249 El Down (ft) 260 El Down (ft) 262.75 Length (ft) 900 Length (ft) 810 Length (ft) 170 Slope (ft/ft) 0.0200 Slope (ft/ft) 0.0136 Slope (ft/ft) 0.0103 V (ft/s) Figure 3-1 2.25 V (ft/s) Figure 3-1 2.25 V (ft/s) Figure 3-1 1.6 Tt (hr) 0.11 Tt (hr) 0.10 Tt (hr) 0.03 5) Open Channel Flow - n/a 5) Open Channel Flow - n/a 5) Open Channel Flow - n/a El Up (ft) El Up (ft) El Up (ft) El Down (ft) El Down (ft) El Down (ft) Length (ft) 0 Length (ft) 0 Length (ft) 0 Slope (ft/ft) Slope (ft/ft) Slope (ft/ft) n (for OCF) n (for OCF) n (for OCF) Area (sq ft) Area (sq ft) Area (sq ft) Pw (ft) Pw (ft) Pw (ft) R R R Velocity (ft/s) Velocity (ft/s) Velocity (ft/s) Tt (hr) 0.00 Tt (hr) 0.00 Tt (hr) 0.00 Tc (hr) 1 0.23 ITc (hr) 1 0.19 ITc (hr) 1 0.13 Tc (min) 1 13.9 ITc (min) 1 11.5 ITc (min) 1 10.0 PRE -DEVELOPMENT RELEASE RATES EXHIBIT 2-3 XP STORM HYDROGRAPHS O EXISTING OUTFALL Node - ONSITE (A/B) 18 16 14 12 CO LL U_ 10 0 U- 8 6 4 2 0 1 YR - 0.5 HR[Max 0.000] 1 YR - 6 HR[Max 0.233] 2 YR i - 1 HR[Max 3.433] 2 YR - �I �I 12 HR[Max 2.160] 10YR - 2HR[Max 7.418] 10YR - 24HR[Max 3.332] 25YR I J J - 3HR[Max 8.349] 100YR - 0.5HR[Max 14.518] 100YR - 6HR[Max 9.668] 1 YR - 1 HR[Max 0.201] 1 YR - i 12 HR[Max 0.315] 2 YR i - 2 HR[Max 2.981 ] 1 2 YR - 24 HR[Max 1.805] IJIJIJ ICJ 10YR - 3HR[Max 5.948] 25YR - 0.5HR[Max 9.974] 25YR - 6HR[Max 5.883] 100YR - 1 HR[Max 18.006] 100YR - 12HR[Max 8.366] 1 YR - 2 HR[Max 0.248] 1 YR - 24 HR[Max 0.378] 2 YR �I �I - 3 HR[Max 2.404] 10YR - 0.5HR[Max 7.185] M I J J 10YR - 6HR[Max 4.318] 25YR - 1 HR[Max 12.019] 25YR - 12HR[Max 5.841 ] 100YR I J J - 2HR[Max 15.392] 1 100YR - 24HR[Max 5.826] �i ;I ll AA Ili II � I 1 ;II lv 11 /l: 1 YR - 3 HR[Max 0.205] 2 YR - i 0.5 HR[Max 2.695] 2 YR - 6 HR[Max 1.989] 10YR I - 1 HR[Max 8.585] �IIJ �J 10YR - 12HR[Max 4.377] 25YR - 2HR[Max 10.369] 25YR - 24HR[Max 4.284] 100YR - 3HR[Max 12.460] 1 Wed 3AM 6AM 9AM 12PM 3PM Jan 2014 6PM 9PM 2 Thu Time (HR) UI11 •UM11 MUM LTA M I a' 11 Node - OFFSITE 6.0 5.5 5.0 4.5 4.0 U 3.5 0 3.0 2.5 2.0 1.5 1.0 0.5 0.0 1 YR - 0.5 HR[Max 0.000] 1 YR - 6 HR[Max 0.027] 2 YR - 1 HR[Max 0.651] 2 YR - • J J 12 HR[Max 0.727] 10YR - 2HR[Max 2.283] 10YR - 24HR[Max 1.574] 25YR - 3HR[Max 3.054] 100YR - 0.5HR[Max 3.927] 100YR 1 - 6HR[Max 3.887] 1 YR I� - 1 HR[Max 0.000] 1 YR - 12 HR[Max 0.044] 2 YR I� - 2 HR[Max 0.710] 2 YR - ' J 24 HR[Max 0.734] 10YR - 3HR[Max 1.919] 25YR - 0.5HR[Max 2.379] 25YR - 6HR[Max 2.441] 100YR - 1 HR[Max 6.050] 100YR - 12HR[Max 4.109] 1 YR - 2 HR[Max 0.000] 1 YR - i 24 HR[Max 0.069] 2 YR - 3 HR[Max 0.586] 10YR - 0.5HR[Max 1.583] 10YR - 6HR[Max 1.644] 25YR - 1 HR[Max 3.675] 25YR - 12HR[Max 2.667] 100YR - 2HR[Max 5.856] 100YR - 24HR[Max 3.042] 1 YR - 3 HR[Max 0.001] 2 YR - 0.5 HR[Max 0.376] 2 YR - 6 HR[Max 0.530] 10YR - 1 HR[Max 2.396] 10YR - 12HR[Max 1.865] Mj 25YR - 2HR[Max 3.535] a 25YR - 24HR[Max 2.124] J 100YR - 3HR[Max 5.139] �I I, I I I II\ I E I ;I •, 1 Wed 3AM 6AM 9AM 12PM 3PM 6PM 9PM 2 Thu 3AM 6AM 9AM 12PM Jan 2014 Time (HR) Node - EXISTING C 5.0 4.5 3.5 U) U 3.0 0 2.5 MCI 1.5 1.0 0.5 1 YR - 0.5 HR[Max 0.000] 1 YR - 6 HR[Max 0.031] 2 YR - 1 HR[Max 0.649] 2 YR - 12 HR[Max 0.602] 10YR - 2HR[Max 1.927] 10YR - 24HR[Max 1.173] 25YR - 3HR[Max 2.484] 100YR - 0.5HR[Max 3.722] 100YR J J J J - 6HR[Max 2.933] 1 YR I� - 1 HR[Max 0.000] 1 YR - 12 HR[Max 0.046] 2 YR I� - 2 HR[Max 0.624] 2 YR - ' J J 24 HR[Max 0.570] 10YR - 3HR[Max 1.623] 25YR - 0.5HR[Max 2.291] 25YR - 6HR[Max 1.894] 100YR - 1 HH�RR[Max 5.162] J 100YR - 12HR[Max 3.041] 1 YR - 2 HR[Max 0.006] 1 YR - i 24 HR[Max 0.067] � • J J 2 YR - 3 HR[Max 0.499] 10YR - 0.5HR[Max 1.469] 10YR - 6HR[Max 1.312] 25YR - 1 HR[Max 3.160] 25YR - • J 12HR[Max 2.014] 100YR - 2HR[Max 4.736] 100YR - 24HR[Max 2.208] r ; ; � � r -- ------- -------- 1 YR - 3 HR[Max 0.015] 2 YR - 0.5 HR[Max 0.447] 2 YR - 6 HR[Max 0.477] 10YR - 1 HR[Max 2.077] 10YR - 12HR[Max 1.435] 25YR - 2HR[Max 2.935] F, FM- 25YR - 24HR[Max 1.563] J 100YR - 3HR[Max 4.012] .1-1 11 MR,1 ' 11 1 Wed 3AM 6AM 9AM 12PM 3PM 6PM 9PM 2 Thu 3AM Jan 2014 Time (HR) Conduit TOTAL from JUNCTION to OUTFALL 25 20 LL U 6 15 U- 10 5 I 1 YR - 0.5 HR[Max 0.000] 1 YR - 6 HR[Max 0.245] 2 YR i - 1 HR[Max 4.540] 2 YR - 12 HR[Max 3.482] � I J 10YR - 2HR[Max 11.361] 10YR - 24HR[Max 6.075] 25YR 1 - 3HR[Max 13.815] 100YR - 0.5HR[Max 21.634] 100YR J J - 6HR[Max 15.433] 1 YR - 1 HR[Max 0.200] 1 YR - i 12 HR[Max 0.357] 2 YR i - 2 HR[Max 4.043] 2 YR - 24 HR[Max 3.105] IJIJ IJ IJ 10YR - 3HR[Max 9.405] 25YR - 0.5HR[Max 14.159] 25YR - 6HR[Max 10.174] 100YR - 1 HR[Max 28.557] 100YR F - 12HR[Max 15.505] 1 YR - 2 HR[Max 0.252] 1 YR - 24 HR[Max 0.483] 2 YR J - 3 HR[Max 3.258] 10YR - 0.5HR[Max 9.730] 10YR - 6HR[Max 7.259] 25YR J - 1 HR[Max 18.305] 25YR - 12HR[Max 10.518] 100YR - 2HR[Max 25.713] 100YR - 24HR[Max 11.074] 1 YR - 3 HR[Max 0.219] 2 YR - i 0.5 HR[Max 3.308] 2 YR - 6 HR[Max 2.978] 10YR I� - 1 HR[Max 12.568] 10YR - 12HR[Max 7.673] 25YR - 2HR[Max 16.570] �1IJ J 25YR - 24HR[Max 7.969] 100YR i - 3HR[Max 21.547] 1 Wed 3AM 6AM 9AM 12PM 3PM 6PM 9PM 2 Thu 3AM 6AM 9AM 12PM Jan 2014 Time (HR) EXHIBIT 4 - POST DEVELOPMENT ANALYSIS EXHIBIT 3-2 Post Development - Time of Concentration Offsite Network C - PCIa 1 j Sheet Flow 1 j Sheet Flow Landuse Range, brush, grass, dirt Landuse Range, brush, grass, dirt n (Table 3-1) 0.08 n (Table 3-1) 0.08 Length (ft) 100 Length (ft) 100 P2 (in) 2-yr 24-hr 4.69 P2 (in) 2-yr 24-hr 4.69 El Up (ft) 268 El Up (ft) 269.5 El Down (ft) 267 El Down (ft) 268.5 Slope (ft/ft) 0.01 Slope (ft/ft) 0.01 Tt (hr) 0.11 Tt (hr) 0.11 2] Shallow Concentrated Flow 2) Shallow Concentrated Flow El Up (ft) 267 El Up (ft) 268.5 El Down (ft) 249 El Down (ft) 260 Length (ft) 900 Length (ft) 400 Slope (ft/ft) 0.0200 Slope (ft/ft) 0.0213 V (ft/s) Figure 3-1 2.25 V (ft/s) Figure 3-1 2.25 Tt (hr) 0.11 Tt (hr) 0.05 5) Open Channel Flow - n/a 5) Open Channel Flow - n/a El Up (ft) El Up (ft) El Down (ft) El Down (ft) Length (ft) 0 Length (ft) 0 Slope (ft/ft) Slope (ft/ft) n (for OCF) n (for OCF) Area (sq ft) Area (sq ft) Pw (ft) Pw (ft) R R Velocity (ft/s) Velocity (ft/s) Tt (hr) 0.00 ITt (hr) 0.00 Tc (hr) 0.22 ITc (hr) 0.16 Tc (min) 13.2 ITc (min) 10.0 *Tc to all inlets within paved areas is less than 10 minutes. POST -DEVELOPMENT RELEASE RATES - XPSTORM HYDROGRAPHS OFFSITE Il ... eMial Ali LIM 535 � � 14NJOE iAM ff CJLWTIn" TaTX �auTY•,nL @SE= F •]R' Y CNLIiIi�An1 :4 F?...Ira1' ii•a e7• I. F___I_O�i�i�:•BI � i n7, :sscuehmeix i� Conduit ONSITE (AIB) from IN-1 to JUNCTION 111111� IYR-©.5 HR[Max 0000] 111111� 1YR-1 HRi .0.0711 1111111� 1YR-2 HR[Max 0.tl86} ,� 1YR-3HR[IAex0.0711 IYR-12HR[Maxu3W] 1YR-24HR[MW04251 2YR-0.6HR[Max11021 2YR-1HR[Max144M 2YR-3HR[Max11641 2YR-6HR[Max1 WA 2YR-12HR[Max2755] 2YR-2471Z306M 10YR-1H R[Max 5453) 10YR-2HRJMax 66751 10YR-3HR[Max 6815] 10YR-6HR[Max 66M 1 OYR - 24HR[Max 6.913] 25YR - 0.5HR[Max 3.9811 25YR - 1HR[Max 10.159] 25YR - 2HRRAm 11.951) 25YR • 6HR[Max 10.330j 25YR - 12HR[Max 12.074] 25YR • 24HR[Max 8.617] 50YR - 0.5HR[Max 4.898] 50YR-2HR[Max 16.068] 50YR-3HR[Max 14.952] 50YR-6HR[Max 13.9}4] 50YR-12HR[Ma 14.509] 100YR - 15.5HR[Max 7.791J 100YR - 7HR[Max 16.9441 f 00YR - 2HR[Max 19 9651 100VR - 3HR[Max 19.1751 100YR-12HR[Max 16 M41 111111111r 100YR - 24HR[Max 11.3851 20 18 16 14 12 3 M: 1 ❑ 8 6 4 2 0 1 Wed 3AM Jan 2014 111111� 1 YR -6 HR[Max 0.2761 2YR - 2 HR[Max 1.329] SOYR-0,5HR[Max 2.87 f [ 10YR - 12HR[Max 8.542] 25YR - 3HR[Max 11.1 B3] 50YR - 1 HR[Max 13.465] 50YR - 24HMMax 9.964] sft-ft 100YR - 6HR[Max 17.199] 6AM 9AM 12PM 3PM 6PM 9PM 2 Thu 3AM 6AM 9AM 12PM Time Conduit L1A125 from OFFSITE to JUNCTION 1 YR - 0.5 HR[Max O.D00) 1 YR - 1 HR[Max -0 0051 1 YR - 2 HR[Max -0 D061 1 YR - 3 HR[Max -0 0051 1 YR - 12 HR[Max 0.0251 1 YR - 24 HR[Max 0 0391 2 YR - 0.5 HRJMax 0..2131 2 YR - 1 HR[Max 0 3671 2 YR - 3 HR[Max 0.3301 2 YR - 6 HR[Max 0.2981 2 YR - 12 HR[Max 0.4D91 2 YR - 24 HR[Max 0.4121 10YR - 1 HR[Max 1.351] 10YR - 7HR[Max 1.2135) 10YR - 3HR[Max 1.D81J 10YR - 6HR17ax 0.921] 10YR - 24HR[Max 0.8861 25YR - 0.5HR[Max 1.3401 25YR - 1HR[Max 2.0611 25YR - 2HR[Max 1.9811 25YR - BHR[Max 1.3711 25YR - 12HR[Max 1.501J 25YR - 24HR[Max 1.196] 50YR - 0.5HR[Max 1.7701 a_ SOY - 2HR[Max 2.6131 SOYR - 3HR[Max 2.2711 50YR - 6HR(Max 1.763) 50YR - 12HR[Max 1.8901 100YR - 0.5HR[Max 2.2121 100YR - 1HR[Max 3.3931 1OOYR • 2HR[Max 3.2961 100YR - 3HR[Max 2.9961 7GOY R - 12HR[Max 2.3131 100YR - 24HR[Max 1.7121 3.5 3.0 2.5 2.0 3 0 1.5 1.0 0.5 0.0 �r 1 YR - 6 HR[Max D.0151 1_ 2 YR - 2 HR[Max D.4D01 1 DYR - D.SHRJMax 0.891 ] 10YR - 12HR[Max 1.0491 25YR - 3HR[Max 1.7121 50YR - 1HR[Max 2.7131 1♦ 50YR - 24HR[Max 1.4471 100YR - SH R[Max 2.1861 1 Wed 3AM 6AM 9AM 12PM 3PM 6PM 9PM 2 Thu 3AM 6AM 9AM 12PM Jan 2014 Time 1 YR - 0.5 HR[Max 0.000] 1 YR - 12 HR[Max 0.3881 2 YR - 3 HRjMax 1.492] ��r 10YR - 1HR[1 8.348] �a 10YR • 24HR[Max 7.7991 25YR - 6HR[Max 11.6021 rrrr 50YR - 2HR[Max 10-135] �rrr 1 OOYR - 0.5HR[Max 9.6491 rwww 100YR - 12HR[Max 19.2571 20 15 3 0 LL 10 5 0 Conduit TOTAL from JUNCTION to OUTFALL 1 YR - 1 HR[Max 0.0651 1 YR - 24 HR[Max 0 4591 2 YR - 6 HR[Max 1 989] 10YR - 2 HR[Max 7.4091 r 25YR - O.5HR[Max 5.047] 25YR-12HR[Max 13.5761 50YR - 3HR[Max ISM9] rwwr SOOYR - 1 HR[Max 19.9201 100YR - 24HR[Max 13.OM 1 YR - 2 HR[Max 0.086] 2 YR - 0.5 HR[Max 1296] 2 YR - 12 HR[Max 3.0431 rrww 10YR - 3HR[Max 7.6621 25YR - 1HR[Max 11.4581 25YR - 24H Rphbx 9.8131 50YR - 6=0.15.671] rrrw 100YR - 2HR[Max 22-6871 i YR - 3 HR[Max 0.0711 2 YR - 1 HR[Max 1.7491 2 YR - 24 HR[Max 3.4581 �r 10YR - SHR[Max 7.4291 25YR - 2HR[Max 13-5381 50YR - 0.5HR[Max 6.344] 50YR- 12HR[Max 16.397] 100YR - 3HR[Max 21.767] 1 YR - = 0.2921 2 YR - 2 HR[Max 1.7231 10YR - 0.5HR[Max 3.501] 1OYR - 12HR1Max 9.5621 25YR - 3HR[Max 12.487] 50YR -1 HR[Mw 15.087] 50YR - 24H R[Max 11 Al ] wrrr 100YR - 6HRIMax 19.384) 1 Wed 3AM 6AM 9AM 12PM 3PM 6PM 9PM 2 Thu 3AM 6AM 9AM 12PM Jan 2014 Time 1310-RETENTION VOLUME MEDIA D.A. PAVEMENT Ro WQV ICF: WGV ICFI INFILTRATION DRAWDOWN UNDERORAIN WQV OMPID iPE (AC IACRES) 1. I' R, IINi REQUIRED PROVIDED ORAWDOWN METHOD RATE DURATION DIAMETfR PONDING jrn� ri DEPTH DEPTH A 1340cell 9.40M 520 0.55 0.5479 1.00 1%95 19080 I nl l i tra l i on th ru media to u nderd rai n 1 12 hrs 6" 19" 93 &ocell 1.0" 0.75 0.75 0.7250 1.00 2632 6678 Inlitrarion thru media to underdrain 1 12 hrs A- 4- R4 8incOl 0-8000 0.65 0.81 0.7813 1.00 2259 6678 I nl l i tra I i on th ru media to underd rai n 1 12 hrs 4' 9- 85 &oeell I 1.0DD0 j 0.85 1 0.77 1 0.7455 1 1.00 1 2977 1 6678 1 1MIitraIionthrumedia tounderdrai n 1 12he$ 4' 9- Bio-Retention Basin Size Maximum WQV for Cells B3, B4 and B5 Depth (FT) 3 Length (FT) 265 Width (FT) 28 Voids (%j 30 Volume (CF) 6678 Simple Method for Runoff Volume Maximum WQV for Cell A Depth (FT) 3 Length(FT) 265 Width (FT) 30 Voids (%) 30 Ponding D (FT) 1.5 Volume (CF) 19080 Rv = 0.05 r 0.9 ' to Whefe R: - Runoff cOefNtrent turn ss) I. = Impervicxx frIactlon lunMess) DV = 3630, Ra ' R•. 'A Where DV = Deur vokime feu R1 R✓ Desm storm deM to I A Dramage area Iac I There afe two methods that are often used to determine the volume of runoff born a given design storm: the Simple Method (Schueler 1987) and the discrete MRCS Curve Number Method (NRCS 1986) The Simple Method was developed try measunng the runoff from marry watersheds with known impervious areas and curve -fitting a relationship between percent Imperviousness and the fraction of rainfall converted to runoff (the runoff coefficient) ft uses a minimal amount of information to estimate the volume of runoff A couple of notes on the variables In the Simple Method • The runoff coefficient. Rv. is the runoff depth in inches divided Iry the rainfall depth in Inches • The impervious fraction, IA, is the Impervious portion of drainage area in acres divided try the drainage area in acres • The design volume. DV, is the volume of runoff that must be controlled for the design storm • The design storm depth. Ro, is 1 5' in Coastal Counties and 1 0- elsewhere In SA waters, the OV is the difference between runoff volume pre- versus post -development for the 10-year storm • The drainage area. A. must include all of the surfaces that drain to the SCM regardless of whether they are on -site or off -site INLET CAPACITY Ftunof[ to Inlet Inlet Ca city Inlet Name Description Drainage Area I (in/hr) C a [cfs} F&G Capacity YES or NO? IN-A3 INLET 0.54 7.96 D.95 4.12 8.82 YES IN-A4 INLET 0.37 7,96 0.95 2.82 8.82 YES IN -AS INLET 0.61 7,96 0.95 4.60 8.82 YES IN-A6 INLET 0.30 7,96 0.95 2.24 &82 YES IN-A7 INLET Dk3 7.96 0195 4.77 8.82 YES IN-A8 INLET 0.27 7.96 0.95 2.03 8.82 YES IN-A9 INLET 0.53 7,96 D.72 1D5 8,82 YES IN-A10 INLET 0.13 7,96 0,95 0.99 F-82 YES 1N-83 INLET 1.04 7.96 0.83 6.85 �; 62 YES IN-94 INLET 0.77 7.96 0.83 5.03 &82 YES IN-B5 INLET 1.07 7,96 0,83 7.08 8.82 YES IN-B6 INLET GAS 7,96 0.35 2,65 8.82 YES IN-87 INLET 0,56 7.96 D-95 4.22 8.82 YES IN-B8 INLET D.67 7.96 DIS 5.06 8.82 YES IN•B9 INLET 0.29 7.96 D.95 2.16 8.82 YES IN-Cl ICATCH BASIN 0,11 7.96 0.95 0,80 1,34 YES IN-C2 CATCH BASIN 041 7.96 0.95 1 0.80 1.34 YES 1N•C3 CATCH BASIN US 7.96 0.95 0.59 1.34 YES IN-C4 CATCH BASIN 0.12 7.96 D.95 0.90 1.34 YES IN-05 CATCH BASIN 0,06 7,96 D.95 0,47 1 1.34 YES IN -CS CATCH BASIN 0,10 7,96 0.95 G.78 1.34 YES Note; All inlets are on a sag, and all catch basins are on grade. Frame and Grate Capacities Inlet Std. 840.16 Frame And Grate Open Perim. (ft) 33.92 Weir Coeff. 3 Max Depth (ft) 01 Orifice Coeff. 0.67 Opening (so 3.67 g;ft/s2) 32.2 Qweir [cfs) 9.10 Qorifice (cfs) 8.82 Catch Basin Std. 940.03 Frame and Grate 36" inlet Cox plus flat grate opening Open Perim. (ft) 5.00 Weir Coeff. 3 Avg Depth If[) 0.2 Qweir [cfsl 134 Hydraflow Storm Sewers Extension for Autodesk® AutoCAD® Civil 3D® Plan Exhibit 3-4 A-7 rA-6 Q w n d A-5 A-4 Pipe A-5 v Q aQ A-8 MH A-2 Pipe A-8 N Q N Q a 4utfall 0 Project File: A-Network.stm Number of lines: 6 Date: 9/5/2019 Storm Sewers 02.00 Storm Sewer Inventory Report Page 1 Line Alignment Flow Data Physical Data Line ID No. Dnstr Line DO Junc Known Drng Runoff Inlet Invert Line Invert Line Line N J-Loss Inlet/ Line Length angle Type 0 Area Coeff Time El Dn Slope El Up Size Shape Value Coeff Rim El No. (ft) (deg) (cfs) (ac) (C) (min) (ft) M (ft) (in) (n) (K) (ft) 1 End 70 -90 Grate 0,00 0,00 0,00 0,0 260.25 0,20 260.39 36 Cir 0,013 1,50 267.85 Pipe A-2 2 1 156 -90 Grate 0,00 0,91 0,70 5,0 261.48 0,30 261.95 18 Cir 0,013 1,00 266.45 Pipe A-8 3 1 103 0 Grate 0,00 0,52 0,95 5,0 260.39 0,20 260.60 36 Cir 0,013 1,50 267.00 Pipe A-4 4 3 95 -90 Grate 0,00 0,53 0,95 5,0 261.08 0,20 261.27 30 Cir 0,013 1,50 267.00 Pipe A-5 5 4 193 90 Grate 0,00 0,77 0,95 5,0 261.79 0,30 262.37 24 Cir 0,013 1,30 267.40 Pipe A-6 6 5 155 57 Grate 0,00 0,38 0,95 5,0 262.87 0,30 263.34 18 Cir 0,013 1,00 267.40 Pipe A-7 Project File: A-Network.stm Number of lines: 6 Date: 9/5/2019 Storm Sewers 02.00 Storm Sewer Summary Report Page 1 Line Line ID Flow Line Line Line Invert Invert Line HGL HGL Minor HGL Dns Junction No. rate Size shape length EL Dn EL Up Slope Down Up loss Junct Line Type (cfs) (in) (ft) (ft) (ft) N (ft) (ft) (ft) (ft) No. 1 Pipe A-2 18.24 36 Cir 70 260.25 260.39 0,200 261.79 262.02 0,51 262.52 End Grate 2 Pipe A-8 5,07 18 Cir 156 261.48 261.95 0,301 262.57 263.04 0,21 263.25 1 Grate 3 Pipe A-4 14.41 36 Cir 103 260.39 260.60 0,204 262.52 262.58 0,20 262.78 1 Grate 4 Pipe A-5 11.29 30 Cir 95 261.08 261.27 0,200 262.78 262.88 0,27 263.14 3 Grate 5 Pipe A-6 8,11 24 Cir 193 261.79 262.37 0,301 263.14 263.55 0,36 263.91 4 Grate 6 Pipe A-7 2.87 18 Cir 155 262.87 263.34 0,303 263.91 264.12 0,15 264.27 5 Grate Project File: A-Network.stm Number of lines: 6 ---- FRun Date: 9/5/2019 NOTES: Return period = 10 Yrs. Storm Sewers 02.00 Hydraulic Grade Line Computations Page 1 Line Size Q Downstream Len Upstream Check JL Minor coeff loss Invert HGL Depth Area Vel Val EGL Sf Invert HGL Depth Area Vel Val EGL Sf Ave Enrgy elev elev head elev elev elev head elev Sf loss (in) (cfs) (ft) (ft) (ft) (sqft) (ft1s) (ft) (ft) M (ft) (ft) (ft) (ft) (sqft) (ft1s) (ft) (ft) N N (ft) (K) (ft) 1 36 18.24 260.25 261.79 1,54 3,65 4,99 0,39 262.18 0,274 70 260.39 262.02 1,63 3,92 4,65 0,34 262.36 0,228 0,251 0,176 1,50 0,51 2 18 5,07 261.48 262.57 1,09* 1,38 3,68 0,21 262.78 0,301 156 261.95 263.04 1,09 1,37 3,69 0,21 263.25 0,302 0,302 0,471 1,00 0,21 3 36 14.41 260.39 262.52 2.13 5,38 2.68 0,11 262.64 0,064 103 260.60 262.58 1,98 4,94 2.91 0,13 262.71 0,078 0,071 0,073 1,50 0,20 4 30 11.29 261.08 262.78 1,70 3,55 3,18 0,16 262.93 0,117 95 261.27 262.88 1,61 3,33 3,39 0,18 263.05 0,137 0,127 0,121 1,50 0,27 5 24 8,11 261.79 263.14 1,35 2.26 3,58 0,20 263.34 0,201 193 262.37 263.55 1,18 1,93 4,20 0,27 263.83 0,298 0,250 0,482 1,30 0,36 6 18 2.87 262.87 263.91 1,04 1,30 2.20 0,08 263.98 0,110 155 263.34 264.12 0,78 0,93 3,08 0,15 264.27 0,260 0,185 0,287 1,00 0,15 Project File: A-Network.stm _FNumb'erof lines: 6 -- Run Date: 9/5/2019 Notes: * Normal depth assumed ; c = cir e = ellip b = box Storm Sewers 02.00 Storm Sewer Profile Proj. file: A-Network.stm Elev. (ft) 273.00 M o= _. o= oS �o o 50 100 HGL 017*1 es 257.00 150 200 250 300 350 400 450 500 550 600 650 Reach (ft) Storm Sewers Storm Sewer Profile Proj. file: A-Network.stm Elev. (ft) 0 CLO q LO O cq Q (0 0 � C'4 W + 0 -6 W rn CD C O.S L' CD CO CI cq C) "t C) co co c; CN N rl- . + 1 F WW U) re r- 5 cq 0 LO 10 C> "4:0) C) 0 r OCO (6 cm cq N . + 1 0 W U) re, 5 277.00 — 273.00 277.00 273.00 — 269.00 269.00 — 265.00 — 261.00 265.00 261.00 --Tsun---w 0.300 — 257.00 257.00 ya 0 25 50 75 100 125 150 175 200 225 250 — HGL Reach(ft) Storm Sewers Hydraflow Storm Sewers Extension for Autodesk® AutoCAD® Civil 3D® Plan B-8 m Q a B-7 B-5 . 0 a D tP m CA B-4 B-6 -a m m cp � 00 w B-3 Q d 3 Outfall Pipe B-2 B-2 Project File: B-Network.stm Number of lines: 7 Date: 9/5/2019 Storm Sewers 02.00 Storm Sewer Inventory Report Page 1 Line Alignment Flow Data Physical Data Line ID No. Dnstr Line DO Junc Known Drng Runoff Inlet Invert Line Invert Line Line N J-Loss Inlet/ Line Length angle Type 0 Area Coeff Time El Dn Slope El Up Size Shape Value Coeff Rim El No. (ft) (deg) (cfs) (ac) (C) (min) (ft) M (ft) (in) (n) (K) (ft) 1 End 197 0 MH 0,00 0,00 0,00 0,0 255.00 0,50 255.99 42 Cir 0,013 1,00 269.95 Pipe B-2 2 1 202 -20 Grate 0,00 1.14 0,60 5,0 256.99 0,50 258.00 30 Cir 0,013 1,43 267.00 Pipe B-3 3 2 85 -70 Grate 0,00 0,88 0,69 5,0 258.60 0,51 259.03 24 Cir 0,013 0,50 267.00 Pipe B-4 4 3 85 0 Grate 0,00 1,55 0,65 5,0 259.53 0,51 259.96 18 Cir 0,013 1,00 268.00 Pipe B-5 5 1 146 -90 Grate 0,00 0,07 0,52 5,0 257.49 0,50 258.22 24 Cir 0,013 1,01 268.30 Pipe B-6 6 5 137 -39 Grate 0,00 0,85 0,95 5,0 258.22 0,50 258.91 24 Cir 0,013 1,01 267.00 Pipe B-7 7 6 218 39 Grate 0,00 1,05 0,66 5,0 259.41 0,50 260.50 18 Cir 0,013 1,00 267.00 Pipe B-8 Project File: B-Network.stm Number of lines: 7 Date: 9/5/2019 Storm Sewers 02.00 Storm Sewer Summary Report Page 1 Line Line ID Flow Line Line Line Invert Invert Line HGL HGL Minor HGL Dns Junction No. rate Size shape length EL Dn EL Up Slope Down Up loss Junct Line Type (cfs) (in) (ft) (ft) (ft) N (ft) (ft) (ft) (ft) No. 1 Pipe B-2 30.50 42 Cir 197 255.00 255.99 0,503 259.23 259.40 0,16 259.56 End Manhole 2 Pipe B-3 18.28 30 Cir 202 256.99 258.00 0,499 259.56 259.88 0,47 260.35 1 Grate 3 Pipe B-4 12.84 24 Cir 85 258.60 259.03 0,506 260.35 260.55 0,20 260.74 2 Grate 4 Pipe B-5 8,01 18 Cir 85 259.53 259.96 0,506 260.91 261.34 0,35 261.68 3 Grate 5 Pipe B-6 12.22 24 Cir 146 257.49 258.22 0,500 259.56 259.92 0,29 260.21 1 Grate 6 Pipe B-7 11.93 24 Cir 137 258.22 258.91 0,505 260.21 260.50 0,31 260.81 5 Grate 7 Pipe B-8 5,51 18 Cir 218 259.41 260.50 0,500 260.81 261.46 0,33 261.79 6 Grate Project File: B-Network.stm Number of lines: 7 Run Date: 9/5/2019 NOTES: Return period = 10 Yrs. Storm Sewers 02.00 Hydraulic Grade Line Computations Page 1 Line Size Q Downstream Len Upstream Check JL Minor coeff loss Invert HGL Depth Area Vel Val EGL Sf Invert HGL Depth Area Vel Val EGL Sf Ave Enrgy elev elev head elev elev elev head elev Sf loss (in) (cfS) (ft) (ft) (ft) (sqft) (ft1s) (ft) (ft) M (ft) (ft) (ft) (ft) (sqft) (ft1s) (ft) (ft) N N (ft) (K) (ft) 1 42 30.50 255.00 259.23 3,50 9,62 3,17 0,16 259.39 0,092 197 255.99 259.40 3,41 9,55 3,19 0,16 259.56 0,081 0,087 0,171 1,00 0,16 2 30 18.28 256.99 259.56 2.50 4,91 3,72 0,22 259.77 0,199 202 258.00 259.88 1,88 3,96 4,62 0,33 260.21 0,237 0,218 0,441 1,43 0,47 3 24 12.84 258.60 260.35 1,75 2.92 4,40 0,30 260.65 0,291 85 259.03 260.55 1,52 2.55 5,03 0,39 260.94 0,378 0,335 0,285 0,50 0,20 4 18 8,01 259.53 260.91 1,38* 1,70 4.72 0,35 261.25 0,506 85 259.96 261.34 1,38 1,70 4.72 0,35 261.68 0,506 0,506 0,430 1,00 0,35 5 24 12.22 257.49 259.56 2.00 3,14 3,89 0,24 259.79 0,292 146 258.22 259.92 1,70 2.84 4,30 0,29 260.21 0,275 0,284 0,414 1,01 0,29 6 24 11.93 258.22 260.21 1,99 3,14 3,80 0,22 260.43 0,261 137 258.91 260.50 1,59 2.69 4.44 0,31 260.81 0,293 0,277 0,379 1,01 0,31 7 18 5,51 259.41 260.81 1,40 1.72 3,20 0,16 260.97 0,238 218 260.50 261.46 0,96 1,19 4,64 0,33 261.79 0,511 0,374 0,815 1,00 0,33 Project File: B-Network.stm Number of lines: 7 Run Date: 9/5/2019 Notes: * Normal depth assumed ; c = cir e = ellip b = box Storm Sewers 02.00 Storm Sewer Profile Proj. file: B-Network.stm Elev. (ft) 280.00 274.00 ~5 oS oS (o os r` o M MEN MEME MEME MERM I -�111110M EMINIMEME MEME IMEINMEME MEME MEME MEMEI ■MEN MEME MEMEM� I MEME MEM1111111111i�!MR11MEN MEME IMEMEMEME MEME MEME MEMEI ■ MEN I�MEME EMIN I MEME MEME EMIN I IMEME MEMEME I INM11111111111MM �M MEME MEME EMINIMEME MEME M111111111111MMIl� 1M MEME z + +` MEMEMEME -------------- -------------- -------------- -------------- + 50 — HGL w 280.00 274.00 250.00 100 150 200 250 300 350 400 450 500 550 600 650 700 Reach (ft) Storm Sewers Storm Sewer Profile Proj. file: B-Network.stm Elev. (ft) 280.00 274.00 — -5 E C).s " -5 CO 7 15 E C).s E O.E C C) ------------ ------------ 50 HGL 274.00 268.00 -a' 250.00 100 150 200 250 300 350 400 450 500 550 600 Reach (ft) Storm Sewers Hydraflow Storm Sewers Extension for Autodesk® AutoCAD® Civil 3D® Plan Exhibit 3-4 C-3 C-4 ipl C--4 c*� U a) a a k-7 4C- c+a C1 a) Q C-1 C-5 % Pipe C-5 Outfall Ptpe C Project File: C-Network.stm Number of lines: 7 Date: 9/5/2019 Storm Sewers 02.00 Storm Sewer Inventory Report Page 1 Line Alignment Flow Data Physical Data Line ID No. Dnstr Line DO Junc Known Drng Runoff Inlet Invert Line Invert Line Line N J-Loss Inlet/ Line Length angle Type 0 Area Coeff Time El Dn Slope El Up Size Shape Value Coeff Rim El No. (ft) (deg) (cfs) (ac) (C) (min) (ft) M (ft) (in) (n) (K) (ft) 1 End 211 -8 Grate 0,00 0,15 0,95 10.0 259.00 0,21 259.45 18 Cir 0,013 1,49 262.53 Pipe C-1 2 1 37 8 Grate 0,00 0,13 0,95 10.0 259.95 0,51 260.14 12 Cir 0,013 1,00 262.76 Pipe C-5 3 1 179 -83 Grate 0,00 0,12 0,95 10.0 259.45 0,30 259.99 18 Cir 0,013 1,50 263.50 Pipe C-2 4 3 336 0 Grate 0,00 0,08 0,95 10.0 259.99 0,50 261.67 18 Cir 0,013 1,50 266.79 Pipe C-3 5 4 37 90 Grate 0,00 0,33 0,53 10.0 261.92 0,51 262.11 15 Cir 0,013 1,00 267.10 Pipe C-4 6 3 37 90 Grate 0,00 0,79 0,31 10.0 260.24 0,51 260.43 15 Cir 0,013 1,20 263.54 Pipe C-6 7 6 35 -50 Hdwl 0,00 0,37 0,20 10.0 260.43 0,51 260.61 15 Cir 0,013 1,00 262.03 Pipe C-7 Project File: C-Network.stm Number of lines: 7 Date: 9/5/2019 Storm Sewers 02.00 Storm Sewer Summary Report Page 1 Line Line ID Flow Line Line Line Invert Invert Line HGL HGL Minor HGL Dns Junction No. rate Size shape length EL Dn EL Up Slope Down Up loss Junct Line Type (cfs) (in) (ft) (ft) (ft) N (ft) (ft) (ft) (ft) No. 1 Pipe C-1 4,86 18 Cir 211 259.00 259.45 0,213 260.06 260.66 0,24 260.89 End Grate 2 Pipe C-5 0,81 12 Cir 37 259.95 260.14 0,514 260.89 260.90 0,02 260.93 1 Grate 3 Pipe C-2 3,62 18 Cir 179 259.45 259.99 0,302 260.89 261.08 0,16 261.24 1 Grate 4 Pipe C-3 1,60 18 Cir 336 259.99 261.67 0,500 261.24 262.15 0,26 262.15 3 Grate 5 Pipe C-4 1.14 15 Cir 37 261.92 262.11 0,513 262.34 262.53 0,15 262.69 4 Grate 6 Pipe C-6 1,98 15 Cir 37 260.24 260.43 0,514 261.24 261.26 0,10 261.36 3 Grate 7 Pipe C-7 0,48 15 Cir 35 260.43 260.61 0,514 261.36 261.36 0,01 261.37 6 OpenHeadwall Project File: C-Network.stm Number of lines: 7 Run Date: 9/5/2019 NOTES: Return period = 10 Yrs. Storm Sewers 02.00 Hydraulic Grade Line Computations Page 1 Line Size Q Downstream Len Upstream Check JL Minor coeff loss Invert HGL Depth Area Vel Val EGL Sf Invert HGL Depth Area Vel Val EGL Sf Ave Enrgy elev elev head elev elev elev head elev Sf loss (in) (cfS) (ft) (ft) (ft) (sqft) (ft1s) (ft) (ft) M (ft) (ft) (ft) (ft) (sqft) (ft1s) (ft) (ft) N N (ft) (K) (ft) 1 18 4,86 259.00 260.06 1,06 1,33 3,64 0,21 260.27 0,298 211 259.45 260.66 1.21 1,52 3,19 0,16 260.82 0,222 0,260 0,549 1,49 0,24 2 12 0,81 259.95 260.89 0,94 0,77 1,05 0,02 260.91 0,044 37 260.14 260.90 0,76 0,64 1,25 0,02 260.93 0,059 0,052 0,019 1,00 0,02 3 18 3,62 259.45 260.89 1.44 1.74 2.08 0,07 260.96 0,104 179 259.99 261.08 1,09 1,38 2.63 0,11 261.19 0,154 0,129 0,230 1,50 0,16 4 18 1,60 259.99 261.24 1,25 0,48 1,02 0,17 261.42 0,000 336 261.67 262.15 0,48** 0,48 3,33 0,17 262.32 0,000 0,000 n/a 1,50 0,26 5 15 1.14 261.92 262.34 0,42* 0,36 3,12 0,15 262.50 0,513 37 262.11 262.53 0,42** 0,37 3,12 0,15 262.69 0,512 0,512 0,190 1,00 0,15 6 15 1,98 260.24 261.24 1,00 1,06 1,88 0,05 261.30 0,098 37 260.43 261.26 0,83 0,87 2.28 0,08 261.34 0,153 0,125 0,046 1,20 0,10 7 15 0,48 260.43 261.36 0,93 0,98 0,49 0,00 261.36 0,007 35 260.61 261.36 0,75 0,77 0,63 0,01 261.37 0,012 0,010 0,003 1,00 0,01 Project File: C-Network.stm Number of lines: 7 Run Date: 9/5/2019 Notes: * Normal depth assumed; ** Critical depth. ; c = cir e = ellip b = box Storm Sewers 02.00 Storm Sewer Profile Proj. file: C-Network.stm Storm Sewers Storm Sewer Profile Proj. file: C-Network.stm Elev. (ft) 272.00 as. Me 42 n co C c pS c QS c ")0 s IN MEN IN MEN MEN MEN MEN MEN MEN■MEN IN_MEN MEN� 1■ MEN I �■MEN IN p� MEN ��■1MEN N MEN MEN MEN MEN MEN IN1■ MEN 1■\\� �iiirl�ll ������■�■� ��������■�1!■1�1 !!1MEN 260.00 0 257.00 50 100 150 200 250 300 350 400 450 500 HGL Reach (ft) Storm Sewers Storm Sewer Profile Proj. file: C-Network.stm Elev. (ft) 42 0co LO T OS {1� O co O W Storm Sewers REVISED NETWORK C XPSTORM SUMMARY ' oink 130 LInkl31 HodoZ55 Ilod•4 132 Link 133 Hode 25,onk 134 11oda _; s c Army LID Planning and Cost Tool Report PROJECT INFO Date 8/30/2022 Army Command IMCOM Army Installation Fort Bragg Project name Ft. Bragg SOF Annex Project description Surface runoff from the project site drains to four bio-retention facilities via inlets. All User Name BRO Master Planner SITE INFO AND EISA VOLUME REQUIREMENT Project limit of disturbance (ac) 13.98 95% rainfall depth (in) 1.8 Soil type Sandy -Loam Hydrologic Soil Group (HSG) B Pre -project curve number (CN) 70 Post -project curve number (CN) 83 Pre -project runoff volume (cf) 8628 Post -project runoff volume (cf) 28329 EISA Section 438 retention volume 19901 requirement (cf) LID PLANNING SUMMARY Structural BMP Surface area Runoff volume Non-structural BMP Surface (s� retained (co area (ac) Bioretention: 22260 18073 Veg. Filter Strip (Slope >2%, Short Grass): 0.00 Swale: 2 0 Veg. Filter Strip (Slope >2%, Tall Grass): 0.00 Permeable Pavement: 0 0 Veg. Filter Strip (Slope <2%, Short Grass): 0.00 Rainwater Harvesting: 0 Veg. Filter Strip (Slope <2%, Tall Grass): 0.00 Green Roof: 0 0 Reforestation (Trees - Short Grass): 0.00 Infiltration Practice: 6265 1880 Reforestation (Trees - Shrubs and Tall Grass): 0.00 Total retention volume provided by BMPs (co: 19953 Project complies with EISA Section 438. LID COST SUMMARY