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Home My WebLink AboutDrainage Report 10-31-19 402 E 13th Street, Ste 101 • Jasper, IN 47546 • P: 812-634-5015 • F: 812-634-5017 Jasper • Evansville www.cashwaggner.com October 31, 2019 City of Carmel Department of Engineering City Hall, One Civic Square Carmel, IN 46032 Attention: Mr. Jeremy Kashman, PE City Engineer RE: Storm Water Drainage Report Willow Haven Senior Homes – Memory Care Homes 13145 West Road Our Project #: 19-3957 Dear Mr. Kashman, In accordance with the requirements of The City of Carmel Stormwater Technical Standards Manual, this drainage report is being submitted for your review and consideration for approval of the subject development site. Below is a description of the proposed development for the subject site and a summary of the drainage calculations for the above-referenced project. Copies of the calculations are also included. Project Description The project involves the construction of a new residential group home consisting of an office, twelve (12) bedrooms for single occupancy, a kitchen and dining room, laundry room, and other necessary rooms. Development of the site will also include construction of infrastructure required to support the proposed facility. The new/improved infrastructure may include, but is not limited to, the following: a paved entrance drive from West Road; parking spaces and sidewalks, including handicap parking and ramps; sanitary sewer; potable water service; electrical service; a storm water management system consisting of vegetated ditches/swales, storm sewer pipe, area drain inlets, positive grading of all areas, and a dry detention basin; and other utilities as needed. The new construction will require demolition and removal of the existing single story residential structure and crushed stone driveway, as well as minor regrading of portions of the site. The layout of the proposed detention basin, vegetated ditches/swales, and other components of the onsite storm water management system are depicted on the Grading & Drainage Plan drawing (sheet C- 102). Site Location The project site comprises approximately 1.28 acres located on the east side of West Road, approximately 500 feet north of West 131st Street, on the far west side of the City of Carmel. The site is bounded by residential parcels and subdivisions on all sides. The property legal description is as follows: part of the Northwest Quarter of Section 30, Township 18 North, Range 3 East, in Clay Township, Hamilton County, Indiana. General Site Conditions The proposed construction site presently contains a single story, brick residential structure with an attached garage. There is also a small utility shed and a crushed stone driveway entering the property from West Road to the west. The remainder of the site is covered with residential lawn grasses and other ground Willow Haven Senior Homes 2 Memory Care Homes CWA Project No. 19-3957 402 E 13th Street, Ste 101 Jasper, IN 47546 • Ph: 812-634-5015 Fax: 812-634-5017 Jasper Evansville | www.cashwaggner.com cover vegetation, as well as various trees and shrubberies. There are no natural lakes, ponds, or major water courses located on the project site. The surface of the site gently slopes from the southeast to the northwest, toward West Road. Soil Properties The Soil Survey for Hamilton County, IN, as published by the United States Department of Agriculture (USDA), Natural Resource Conservation Service (NRCS), and found online at http://websoilsurvey.nrcs.usda.gov/app/, indicates that the following soils are present on the proposed site: Brookston silty clay loam (Br), 0 to 2 percent slopes; Crosby silt loam, fine-loamy subsoil (CrA), 0 to 2 percent slopes; and Miami silt loam (MmB2), 2 to 6 percent slopes, eroded. According to the soil survey, the Miami silt loam unit comprises just over 60 percent of the surface area. The hydrologic soil group classification for each type is as follows: Brookston silty clay loam – B/D; Crosby silt loam – C/D; and Miami silt loam – C. A soils map of the site is included in the Custom Soil Survey prepared from the USDA Soil Survey for Dubois County. Floodplain Data The project site is located on Map Number 18057C0205G of the National Flood Insurance Program’s Flood Insurance Rate Maps (FIRM) for Hamilton County, Indiana and Incorporated Areas, dated November 19, 2014. According to the information on the FIRM panel, no portion of the site lies within the limits of the 1% chance annual flood zone, also known as the 100-year flood zone. There appear to be no defined floodplains, flood fringes, or regulatory floodways located on any of the other immediately adjacent properties. Storm Water System Design Design of the storm water system components was performed in accordance with the design standards and criteria presented in The City of Carmel Stormwater Technical Standards Manual. All hydrologic and hydraulic calculations were performed utilizing generally accepted methods in accordance with the acceptable standards outlined in the HERPICC Storm Water Drainage Manual published by the Purdue Research Foundation, West Lafayette, Indiana. Pre-Developed Drainage Conditions The 1.28 acre project site is bounded on the west side by West Road and a residential subdivision, an individual residential parcel and a residential subdivision to the north, and by individual residential parcels to the east and south. Presently, the surface area of the project site consists of single story, brick residential structure with an attached garage. A crushed stone driveway enters the property from West Road and a small utility shed is located near the northeast corner of the property. The remainder of the site is covered with residential lawn grasses and other ground cover vegetation, as well as various trees and shrubberies. Available topographic mapping indicates that the site generally slopes in a northwesterly direction toward West Road. The majority of storm water runoff from the existing project site appears to exit the site along the north property line as sheet flow or shallow concentrated flow. A small portion of runoff appears to exit along the west property line, entering a shallow drainage ditch along the east side of West Road. After exiting the site, storm water runoff will continue draining north-northwest until it enters a culvert beneath West Road, which conveys the storm water to the west side of the road. The runoff continues flowing northwest in an unnamed tributary (UNT) to Little Eagle Creek, which conveys it into Boone County to enter the Little Eagle Creek channel. For the purposes of the hydrologic and hydraulic (H&H) analyses, the total drainage area of approximately 1.282 acres of the pre-developed area was analyzed as two sub-basins. Sub-basin U-1 represents approximately fifty-three percent (53%) of the site, containing approximately 0.681 acres. U-1 is comprised mostly of the west portion of the parcel, including the West Road right-of-way. The sub-basin contains Willow Haven Senior Homes 3 Memory Care Homes CWA Project No. 19-3957 402 E 13th Street, Ste 101 Jasper, IN 47546 • Ph: 812-634-5015 Fax: 812-634-5017 Jasper Evansville | www.cashwaggner.com approximately two-thirds of the residential structure roof and the entire gravel driveway. Storm water runoff from U-1 drains in a west-northwest direction toward the roadway, where it is collected in a shallow roadside ditch and flows north along the road before it enters an east-west storm culvert beneath the road, approximately 230 feet north of the north property line of the parcel. The culvert discharges into a small, unnamed tributary (UNT) to Little Eagle Creek, which conveys the storm water west into Boone County and enters the main channel for Little Eagle Creek. The water is conveyed in a southerly direction to discharge into the Eagle Creek channel, which continues south into Marion County. Sub-basin U-2 contains approximately 0.601 acres and comprises the east portion of the parcel. U-2 includes approximately one-third of the residential structure and the utility shed. Storm water runoff from U-2 drains generally in a north-northwesterly direction toward residential property to the north. All of the runoff drains across the north property line of the site and onto the north parcel. The majority of the runoff appears to exit the site as sheet flow, although a portion of it exits as shallow concentrated flow in a small natural swale/ditch which flows to the northwest toward West Road. The storm water enters the north- south ditch along the east side of West Road to merge with the runoff from U-1 and continues north to the storm culvert approximately 230 feet north of the site. The runoff is conveyed beneath West Road and discharges into the UNT Little Eagle Creek and eventually into Eagle Creek. Storm water runoff from off-site areas enters the site along the south and east property lines. The off-site drainage areas which produce runoff which enters the project site have been delineated as three sub-basins designated as OS-1, OS-2 and OS-3. OS-1 is a drainage area immediately south of the site and consists of approximately 0.290 acres. Runoff from OS-1 enters the site as sheet flow and flows in a northwesterly direction to enter the West Road ditch. OS-2 consists of approximately 1.274 acres and is situated south and east of the project site. Most of the storm water runoff from OS-2 enters the site as sheet flow and crosses the parcel to exit over the north property line. The runoff enters the shallow valley and flows in a northwesterly direction to also enter the West Road ditch. The layout of the pre-developed sub-basins is depicted on the attached exhibit drawing Ex-1. The off-site sub-basins are delineated on aerial photographs with elevation contours from the Hamilton County GIS website. They are included in the report. Post-Developed Drainage Conditions The proposed improvements to the project site will include the construction of the following new/improved infrastructure: a paved entrance drive from West Road; parking spaces and sidewalks, including handicap parking and ramps; sanitary sewer; potable water service; electrical service; a storm water management system consisting of vegetated ditches/swales, storm sewer pipe, area drain inlets, positive grading of all areas, and a dry detention basin; appropriate erosion and sediment control measures; and other utilities as needed. The dry detention basin will be constructed on the west end of the project site to provide temporary storm water storage for runoff from areas east of the basin. Appropriate temporary storm water detention for the project site will be provided by the dry detention basin, which will be constructed as shown on the Grading & Drainage Plan drawing. The general topography of the site will not be noticeably altered to accommodate the proposed improvements. The general drainage patterns of the site will remain essentially the same, with all of the storm water runoff flowing over the site in a west and/or northwesterly direction. For the purposes of the hydrologic and hydraulic (H&H) analyses, the developed site was divided into seven (7) delineated sub- basins. The 7 sub-basins comprise the entirety of the 1.282 acre drainage area which comprises the project site, including the West Road ROW. Sub-basins D-3 and D-6 comprise the majority of the project site, containing 0.293 and 0.459 acres, respectively, for a total of 0.752 acres. Storm water runoff from D-3 and D-6 will be directed into the dry detention basin via positive grading of the site, an onsite storm sewer pipe, and a vegetated swale. Sub- basin D-3 represents much of the north half of the site, comprised of a portion of the proposed building, Willow Haven Senior Homes 4 Memory Care Homes CWA Project No. 19-3957 402 E 13th Street, Ste 101 Jasper, IN 47546 • Ph: 812-634-5015 Fax: 812-634-5017 Jasper Evansville | www.cashwaggner.com paved drive and parking, and the grassed patio area east of the building. Runoff from D-3 will be directed to a storm inlet along the north side of the driveway and conveyed to the detention basin via a 12-inch HDPE storm sewer. Sub-basin D-6 represents much of the south portion of the site, consisting of a portion of the building, paved drive and parking, and side yard. Much of the runoff from D-6 will enter the detention basin via a vegetated swale located along the south side of the site. The remaining runoff will enter the basin as sheet flow. The five remaining developed sub-basins will not be directed to the detention basin and will drain from the project site undetained. Two of the five sub-basins (D-1 and D-2, totaling 0.155 acres) make up the majority of the West Road ROW and will continue to drain north in the roadside ditch. Sub-basin 1A, totaling 0.030 acres, consists of a portion of the proposed paved driveway and will drain north into the West Road ROW and into the ditch. Sub-basin D-4 represents a narrow strip of vegetated ground totaling approximately 0.058 acres which will border the north side of the paved driveway. Runoff from D-4 will exit the site as sheet flow across the north property line. Sub-basin D-5 consists of approximately 0.286 acres of the eastern portion of the project site. Runoff from D-5 will flow in a north-northwesterly direction to exit the site across the north property line. All storm water runoff from the undetained 0.530 acres of the site will enter the West Road ditch and enter the UNT to Little Eagle Creek. The proposed storm water management system (detention basin, storm sewer, driveway culvert, swale) has been designed to effectively handle the peak runoff from a minimum 10-year storm event. The detention basin has also been designed to handle runoff from a 100-year storm event. Although runoff from developed sub-basins D-1, D-1A, D-2, D-4 and D-5 will not enter the detention basin, the design of the proposed storm water management system was designed to account for the peak discharge rates from the undetained sub-basins and maintain the peak flow rates downstream for the 10-year and 100-year events at or below the pre-developed rates. Runoff from sub-basin D-3 will drain to a single curb inlet (CI 200) located along the north edge of the driveway. A 12-inch storm pipe has been designed to convey the storm water to the detention basin. The pipe was sized to carry the peak discharge rate for a 10-year storm event. Hydraulic grade line calculations were performed for the storm pipe for the 100-year event. The culvert beneath the driveway entrance will be an 18-inch RCP and will convey the peak discharge from a 100-year storm event. The drainage area for the driveway culvert consists of sub-basins D-2 and OS-3. It also includes the spillway outlet discharge from the detention basin. The layout of the post-developed sub-basins is shown on the attached exhibit drawing Ex-2. Storm Water Detention The proposed storm water management system has been designed to provide temporary storage for the 10-year and 100-year frequency storm events under post-developed conditions. The dry detention basin will provide the sufficient onsite storage and will be located on the site as depicted on the Grading & Drainage Plan drawing (sheet C-102). The detention basin will capture runoff from approximately 0.752 acres of project site (Sub-basins D-3 and D-6) and 0.290 acres of off-site drainage (OS-1). Runoff from the 1.042 acres will be conveyed to the detention basin via direct sheet flow, the storm sewer beneath the paved driveway, and the vegetated swale along the south side of the parcel. The basin has been designed to provide temporary storage for the 100-year storm frequency event under post-developed conditions, as well as the 10-year storm event. Runoff from the remaining onsite 0.530 acres will exit the site undetained along the north and west property lines. In accordance with the design criteria contained in The City of Carmel Stormwater Technical Standards Manual (Manual), calculations were performed to determine the allowable release rate from the proposed project site and the adjacent off-site drainage areas. The design standards for the release rate state that the post-developed rate for a site of this nature shall be equal to or less than 0.1 cubic feet per second (cfs) Willow Haven Senior Homes 5 Memory Care Homes CWA Project No. 19-3957 402 E 13th Street, Ste 101 Jasper, IN 47546 • Ph: 812-634-5015 Fax: 812-634-5017 Jasper Evansville | www.cashwaggner.com per acre of the development site for the 10-year storm event and equal to or less than 0.3 cfs/acre for the 100-year storm event. Also, the calculated allowable release rates would have to be adjusted to account for the peak discharge rates from any undetained areas of the project site. Due to the topography of the site and the necessary layout of the proposed improvements to the site, it was determined that it would be impossible to meet these design standards. After consultation with personnel from the City of Carmel Engineering Department, it was agreed that the allowable release rates for the project site would be determined as follows: the maximum release rate for the pos-developed 10-year event would be equal to or less than the peak rate for the pre-developed 2-year event; and the maximum release rate for the post- developed 100-year event would be equal to or less than the peak rate for the pre-developed 10-year event. The final design release rates would then be determined by reducing the maximum allowable rates by subtracting the peak discharge rates from the undetained, onsite sub-basins. The peak runoff rates were calculated for each of the two pre-developed sub-basins (U-1 and U-2) for the 2-year and 10-year storm events. The combined peak runoff rate for the 1.282 acre site for the 2-year and 10-year storm events under pre-developed conditions were determined to be 1.57 cfs and 2.07 cfs, respectively. These discharge rates were determined to occur at the primary points of exit from the project site. These rates are the maximum allowable release rates from the site for the 10-year and 100-year storm events under post-developed conditions. The design release rates for the detention basin for the 10-year and 100-year post-developed events were then determined by adjusting the maximum allowable rates to account for the release rates from the undetained sub-basins. The peak discharge rates for the five undetained developed sub-basins were calculated for the 10-year and 100-year storm events. The rates from all five sub-basins were combined for each storm event to determine how much each allowable release rate would be reduced to produce the design release rates. The resulting maximum design discharge rates were determined to be 0.46 cfs for the 10-year post-developed storm and 0.42 cfs for the 100-year post-developed storm. The maximum design discharge rates were utilized in calculations to determine the required storage volumes for the 10-year and 100-year storm events. Iterative calculations were performed to determine the necessary size of the spillway outlet to restrict the release rates to the maximum design discharge rates and to achieve the storage volumes required for each design storm. Following the design procedure for determining the basin storage volume outlined in the Manual, the calculations were performed for the 100- year storm event. After a series of iterative calculations, the design release rate was reduced to 0.41 cfs for the 100-year event. Using the design release rate of 0.41 cfs, the calculations resulted in a minimum required storage volume of 4,472 cubic feet. The minimum storage volume was increased by ten percent (10%) to 4,919 cubic feet in accordance with the Manual. It was determined that a 2.9 inch diameter orifice with the invert elevation (IE) at 894.30 feet would produce a release rate of 0.41 cfs with a peak water surface elevation of 897.90 feet and a storage volume of 5,096 cubic feet. The basin storage design procedure was then applied to the 10-year storm event through a series of iterative calculations. The design release rate for the 10-year event was reduced from 0.46 cfs to 0.35 cfs, which produced a minimum required storage volume of 2,686 cubic feet. For the release rate of 0.35 cfs, the peak water surface elevation of 897.00 feet produced a storage volume of 2,835 cubic feet. The final design release rates from the detention basin were designed to ensure that the peak runoff rates from the entire site under post- developed conditions would not exceed the peak rates for undeveloped conditions. The principal spillway outlet will consist of a 12-inch diameter reinforced concrete pipe (RCP) with a flared end section (FES). An orifice plate will be installed at the entrance to the first section of RCP pipe with a 6-inch diameter orifice opening through the plate with the IE at 894.30 feet. The following table summarizes the discharge rates and storage volumes for each storm event for the detention basin. Willow Haven Senior Homes 6 Memory Care Homes CWA Project No. 19-3957 402 E 13th Street, Ste 101 Jasper, IN 47546 • Ph: 812-634-5015 Fax: 812-634-5017 Jasper Evansville | www.cashwaggner.com Design Summary Table Description Notes Release Rates Pre-Developed 2-Year Peak Q 1.57 cfs Sub-basins U-1 and U-2 Combined Post-Developed 10-Year Peak Q 1.11 cfs Undetained Sub-basins D-1, D-1A, D-2, D-4 & D-5 10-Year Post-Developed Maximum Allowable Release Rate 0.46 cfs Pre-Developed 10-Year Peak Q 2.07 cfs Sub-basins U-1 and U-2 Combined Post-Developed 100-Year Peak Q 1.65 cfs Undetained Sub-basins D-1, D-1A, D-2, D-4 & D-5 10-Year Post-Developed Maximum Allowable Release Rate 0.42 cfs Detention Basin Primary Spillway I.E. 894.30 ft. 2.9-inch Opening Emergency Overflow Spillway I.E. 898.00 ft. Open-channel: 10-foot bottom, 3:1 ss Minimum Top of Bank Elevation 898.50 ft. 100-Year Storm Event Post-Developed Peak Inflow 3.64 cfs Sub-basins D-3 & D-6 Minimum Req’d Storage Volume 4,472 cu. ft. Min. Storage Volume + 10% 4,919 cu. ft. Peak Discharge 0.41 cfs 2.9-inch Orifice Peak Storage Elevation 897.90 ft. Storage Volume Provided 5,096 cu. Ft. 10-Year Storm Event Post-Developed Peak Inflow 2.44 cfs Sub-basins D-3 & D-6 Minimum Req’d Storage Volume 2,686 cu. ft. Peak Discharge 0.35 cfs 2.9-inch Orifice Peak Storage Elevation 897.00 ft. Storage Volume Provided 2,835 cu. Ft. Final Design Primary Spillway I.E. 894.30 ft. 6-inch Dia. Orifice Opening A trapezoidal-shaped emergency overflow spillway (EOS) will be provided over the embankment berm for the basin. In the event that the primary spillway pipe would become inoperable, the emergency overflow spillway will be capable of discharging the maximum 100-year inflow without exceeding the capacity of the EOS. The EOS will have a 10-foot bottom width with 3H to 1V side slopes, minimum. The crest elevation of the EOS for the basin is listed in the summary table above and depicted on the Grading & Drainage Plan. The elevation-discharge relationship for the open channel emergency spillways was determined using standard equations for channel flow and weir flow. The emergency spillway will only become engaged for storm events in excess of the 100-year storm or if the principal spillway outlet becomes inoperative. Printouts of the calculations for all the spillway system components are included with this report. Willow Haven Senior Homes 7 Memory Care Homes CWA Project No. 19-3957 402 E 13th Street, Ste 101 Jasper, IN 47546 • Ph: 812-634-5015 Fax: 812-634-5017 Jasper Evansville | www.cashwaggner.com The minimum top of bank elevation for the detention basin is also listed in the summary table above, which will provide a minimum of one-half foot of freeboard above the 100-year storm storage elevation. Storm Water Quality Control Measures The dry detention basin will provide an effective measure of treatment to the storm water runoff from the site by the filtering effect of the grass cover of the surface of the basin removing total suspended solids (TSS) and other typical pollutants. A mixture of plant species will be used to vegetate the bottom and side slopes of the basin that have been proven to be effective at filtering out silt, sediment and other pollutants. During active construction, a rock check dam will be constructed to encircle the entrance to the FES of the spillway pipe to allow sediment to settle out and not exit the basin during rainfall events. After completion of construction and stabilization of the site, the check dam will be removed and excess sediment will be excavated to return the basin to the final design configuration. Calculations to determine the required Water Quality Volume (WQV) indicate that the minimum volume is 1,615 cubic feet. The peak volume available in the basin is 5,096 cubic feet at elevation 897.90 feet. Please review this report and the attached calculations at your earliest convenience. If you have any questions or comments, please contact Nathan Waggner at 812.634.5051 or me at 812.401-5561. Thank you. Sincerely, Daryl J. Helfert, PE, CFM Senior Water Resources Engineer Cash Waggner & Associates , PC cc: File Encls. Drainage calculations Grading & Drainage Plan, sheet C-102 Sub-Basin Exhibits Ex-1 and Ex-2 DETENTION FACILITY DESIGN VOLUME CALCULATIONS PROJECT:19-3957 DETENTION FACILITY DESIGN RETURN PERIOD:100 YRS Willow Haven Senior Homes - Carmel - Onsite & Offsite Restricted DESIGNER:Cash Waggner & Associates, pc RELEASE RATE RETURN PERIOD:10 YRS WATERSHED AREA:1.042 ACRES TIME OF CONCENTRATION (UNDEVELOPED WATERSHED):11.40 MINUTES RAINFALL INTENSITY (Iu): 5.032 INCHES/HR (100 Yr) UNDEVELOPED RUNOFF COEFFICIENT (Cu):0.315 (Weighted) UNDEVELOPED RUNOFF RATE (O = Cu*Iu*A):0.41 CFS (0.3cfs/ac) DEVELOPED RUNOFF COEFFICIENT (Cd):0.509 (Weighted) STORM RAINFALL INFLOW OUTFLOW STORAGE REQUIRED DURATION INTENSITY RATE RATE RATE STORAGE Td Id I(Td)O (Cd*Id*A)(Cu*Iu*A)I(Td)-O (I(Td)-O)*Td/12 (HRS)(INCH/HR)(CFS)(CFS)(CFS) (ACRE-FT) 0.08 9.120 4.84 0.41 4.43 0.031 0.17 7.780 4.13 0.41 3.71 0.052 0.25 6.770 3.59 0.41 3.18 0.066 0.33 5.990 3.18 0.41 2.76 0.077 0.42 5.415 2.87 0.41 2.46 0.085 0.50 4.840 2.57 0.41 2.16 0.090 0.58 4.445 2.36 0.41 1.95 0.095 0.67 4.050 2.15 0.41 1.74 0.096 0.75 3.760 1.99 0.41 1.58 0.099 0.83 3.470 1.84 0.41 1.43 0.099 0.92 3.250 1.72 0.41 1.31 0.100 1.00 3.030 1.61 0.41 1.20 0.100 1.25 2.635 1.40 0.41 0.99 0.103 1.50 2.240 1.19 0.41 0.78 0.097 1.75 2.055 1.09 0.41 0.68 0.099 2.00 1.870 0.99 0.41 0.58 0.097 2.50 1.645 0.87 0.41 0.46 0.096 3.00 1.420 0.75 0.41 0.34 0.085 4.00 1.150 0.61 0.41 0.20 0.066 PEAK STORAGE (ACRE/FT):0.10 PEAK STORAGE (CUBIC FT):4,472 DETENTION FACILITY DESIGN VOLUME CALCULATIONS PROJECT:19-3957 DETENTION FACILITY DESIGN RETURN PERIOD:10 YRS Willow Haven Senior Homes - Carmel - Onsite & Offsite Restricted DESIGNER:Cash Waggner & Associates, pc RELEASE RATE RETURN PERIOD:2 YRS WATERSHED AREA:1.042 ACRES TIME OF CONCENTRATION (UNDEVELOPED WATERSHED):11.40 MINUTES RAINFALL INTENSITY (Iu): 3.807 INCHES/HR (2 Yr) UNDEVELOPED RUNOFF COEFFICIENT (Cu):0.315 (Weighted) UNDEVELOPED RUNOFF RATE (O = Cu*Iu*A):0.35 CFS Restricted DEVELOPED RUNOFF COEFFICIENT (Cd):0.509 (Weighted) STORM RAINFALL INFLOW OUTFLOW STORAGE REQUIRED DURATION INTENSITY RATE RATE RATE STORAGE Td Id I(Td)O (Cd*Id*A)(Cu*Iu*A)I(Td)-O (I(Td)-O)*Td/12 (HRS)(INCH/HR)(CFS)(CFS)(CFS) (ACRE-FT) 0.08 6.120 3.25 0.35 2.90 0.020 0.17 5.220 2.77 0.35 2.42 0.034 0.25 4.550 2.41 0.35 2.06 0.043 0.33 4.020 2.13 0.35 1.78 0.050 0.42 3.635 1.93 0.35 1.58 0.055 0.50 3.250 1.72 0.35 1.37 0.057 0.58 2.980 1.58 0.35 1.23 0.060 0.67 2.710 1.44 0.35 1.09 0.060 0.75 2.520 1.34 0.35 0.99 0.062 0.83 2.330 1.24 0.35 0.89 0.062 0.92 2.180 1.16 0.35 0.81 0.062 1.00 2.030 1.08 0.35 0.73 0.061 1.25 1.725 0.91 0.35 0.56 0.059 1.50 1.420 0.75 0.35 0.40 0.050 1.75 1.265 0.67 0.35 0.32 0.047 2.00 1.110 0.59 0.35 0.24 0.040 2.50 0.975 0.52 0.35 0.17 0.035 3.00 0.840 0.45 0.35 0.10 0.024 4.00 0.680 0.36 0.35 0.01 0.004 PEAK STORAGE (ACRE/FT):0.06 PEAK STORAGE (CUBIC FT):2,686 Average Incremental Cumulative Detention Elevation HW Area Area Volume Volume Volume (ft.)(ft.)(s.f.)(s.f.)(c.f.)(c.f.)(c.f.) I.E.894.30 0.00 0.0 0.0 0.0 0.0 0.0 894.40 0.10 50.6 25.3 2.5 2.5 2.5 894.50 0.20 101.2 75.9 7.6 10.1 10.1 894.60 0.30 151.7 126.5 12.6 22.8 22.8 894.70 0.40 202.3 177.0 17.7 40.5 40.5 894.80 0.50 252.9 227.6 22.8 63.2 63.2 894.90 0.60 303.5 278.2 27.8 91.0 91.0 895.00 0.70 354.1 328.8 32.9 123.9 123.9 895.10 0.80 463.8 408.9 40.9 164.8 164.8 895.20 0.90 573.6 518.7 51.9 216.7 216.7 895.30 1.00 683.4 628.5 62.8 279.5 279.5 895.40 1.10 793.1 738.2 73.8 353.4 353.4 895.50 1.20 902.9 848.0 84.8 438.2 438.2 895.60 1.30 1,012.6 957.8 95.8 533.9 533.9 895.70 1.40 1,122.4 1,067.5 106.8 640.7 640.7 895.80 1.50 1,232.2 1,177.3 117.7 758.4 758.4 895.90 1.60 1,341.9 1,287.1 128.7 887.1 887.1 896.00 1.70 1,451.7 1,396.8 139.7 1,026.8 1,026.8 896.10 1.80 1,523.1 1,487.4 148.7 1,175.5 1,175.5 896.20 1.90 1,594.4 1,558.8 155.9 1,331.4 1,331.4 896.30 2.00 1,665.8 1,630.1 163.0 1,494.4 1,494.4 896.40 2.10 1,737.2 1,701.5 170.1 1,664.6 1,664.6 896.50 2.20 1,808.6 1,772.9 177.3 1,841.9 1,841.9 896.60 2.30 1,879.9 1,844.2 184.4 2,026.3 2,026.3 896.70 2.40 1,951.3 1,915.6 191.6 2,217.9 2,217.9 896.80 2.50 2,022.7 1,987.0 198.7 2,416.5 2,416.5 896.90 2.60 2,094.0 2,058.3 205.8 2,622.4 2,622.4 897.00 2.70 2,165.4 2,129.7 213.0 2,835.4 2,835.4 897.10 2.80 2,242.4 2,203.9 220.4 3,055.7 3,055.7 897.20 2.90 2,319.3 2,280.8 228.1 3,283.8 3,283.8 897.30 3.00 2,396.3 2,357.8 235.8 3,519.6 3,519.6 897.40 3.10 2,473.2 2,434.8 243.5 3,763.1 3,763.1 897.50 3.20 2,550.2 2,511.7 251.2 4,014.3 4,014.3 897.60 3.30 2,627.2 2,588.7 258.9 4,273.1 4,273.1 897.70 3.40 2,704.1 2,665.6 266.6 4,539.7 4,539.7 897.80 3.50 2,781.1 2,742.6 274.3 4,813.9 4,813.9 897.90 3.60 2,858.0 2,819.6 282.0 5,095.9 5,095.9 EOS 898.00 3.70 2,935.0 2,896.5 289.7 5,385.6 5,385.6 898.10 3.80 3,016.4 2,975.7 297.6 5,683.1 5,683.1 898.20 3.90 3,097.8 3,057.1 305.7 5,988.8 5,988.8 898.30 4.00 3,179.2 3,138.5 313.9 6,302.7 6,302.7 898.40 4.10 3,260.6 3,219.9 322.0 6,624.7 6,624.7 TOB 898.50 4.20 3,342.0 3,301.3 330.1 6,954.8 6,954.8 (per ACAD) Willow Haven Senior Homes West Road Carmel, IN Main Detention Basin Provided Detention Volumes Q = C A (2g(h-d/2))1/2 C - orifice coefficient h - height of water above invert of orifice opening A - area of orifice opening g - 32.2 ft/sec2 d - diameter of orifice opening 100-Yr Maximum Release Rate - 0.42 cfs Pipe/orifice I.E. = 894.30 feet Water Elev. = 897.90 feet Allowable Q = 0.42 cfs Cd =0.60 g = 32.20 ft/sec2 h =3.600 ft d =2.900 in A = 0.046 sq.ft. Design Q =0.41 cfs Use 2.90" Circular Orifice Opening at 894.30 10-Yr Maximum Release Rate - 0.46 cfs Target Release Rate = 0.25-0.35 cfs Pipe/orifice I.E. = 894.30 feet Water Elev. = 897.00 feet Target Q = 0.46 cfs Cd =0.60 g = 32.20 ft/sec2 h =2.700 ft d =2.900 in A = 0.046 sq.ft. Design Q =0.35 cfs Use 2.90" Circular Orifice Opening at 894.30 Vertical Orifice Calculations Willow Haven Senior Home 13145 West Road Carmel, Hamilton County, IN Dry Detention Basin Primary Spillway Orifice Outlet Max Q100 =4.31 cfs Qreqd =5.39 cfs Trapezoidal Weir SOLVE FOR Q = CW x W avg x D1.5 BW =10 ft. SS =3 D =0.5 ft. TW =13 ft. Wavg = 11.5 CW = 3.3 Q=13.42 CFS CALCULATIONS FOR WEIR FLOW Willow Haven Senior Homes 13145 West Road Carmel, Hamilton County, IN Detention Basin Emergency Spillway Peak Developed Discharge Rv =0.05 + 0.009(I) I =41.8607 % impervious P =1 inch Rv =0.427 A =1.042 acres WQv =0.037 acre-feet =1,615 cubic-feet WQV-Avail =0.117 acre-feet =5,096 cubic-feet Water Quality Volume Willow Haven Senior Home Carmel, Hamilton County, IN Volume Provided in Basin to Elevation 897.90 Ft. 13145 West Road Total Detained Onsite + Offsite - 1.042 Ac. (0.436 ac. Impervious) STORM SEWER CALCULATIONS Project:Willow Haven Senior Homes Design Return Period:10 Years Project #:19-3957 Mannings 'n':0.013 Date:Oct. 2019 SUM PIPE PIPE PIPE TRAVEL LINE SUB-BASIN PIPE LENGTH Cj Aj CjAj CjAj Tj Tcum I5 Q DIA.SLOPE CAP.VELOCITY TIME NO.NO.STR. NO.INV. ELEV.STR. NO.STR. NO.INV. ELEV.(ft)(ac.)(min)(min)(in/hr)(cfs)(in)(ft/ft)(cfs)(ft/sec)(min) 1 D-3 200 895.50 201 202 895.25 48 0.664 0.293 0.195 0.195 10.42 10.42 5.164 1.01 12 0.0052 2.57 3.27 0.24 Design Return Period:100 Years 2 D-2 0.506 0.115 0.058 0.058 5.71 5.71 8.930 0.52 2 OS-3 0.350 2.868 1.004 1.062 19.19 19.19 6.231 6.62 2 Basin Outlet 207 893.70 208 209 893.50 40 Peak Discharge = 0.41 cfs 7.03 18 0.0050 7.43 4.20 0.16 UPSTREAM DOWNSTREAM (Entrance Culvert) STORM SEWER CALCULATIONS Project:Willow Haven Senior Homes Design Return Period:100 Years Project #:19-3957 Mannings 'n':0.013 Date:Oct. 2019 SUM PIPE PIPE PIPE TRAVEL HGL HGL U/S GROUND LINE SUB-BASIN PIPE LENGTH Cj Aj CjAj CjAj Tj Tcum I5 Q DIA.SLOPE CAP.VELOCITY TIME IN OUT ELEVATION NO.NO.STR. NO.INV. ELEV.STR. NO.STR. NO.INV. ELEV.(ft)(ac.)(min)(min)(in/hr)(cfs)(in)(ft/ft)(cfs)(ft/sec)(min)(ft)(ft)(FT.) 1 D-3 200 895.50 201 202 895.25 48 0.664 0.293 0.195 0.195 10.42 10.42 7.695 1.50 12 0.0052 2.57 3.27 0.24 898.14 897.90 898.33 UPSTREAM DOWNSTREAM UNDEVELOPED DRAINAGE BASIN CALCULATIONS Undeveloped Basin No.:U-1 Total Area =29,659.0 S.F. Willow Haven Senior Homes 0.681 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =1,316.0 S.F. =0.03 Ac.0.85 0.020 Roofs =1,277.0 S.F. =0.03 Ac.0.90 0.020 Gravel =2,734.0 S.F. =0.06 Ac.0.85 0.100 Lawns (Slightly pervious)=24,332.0 S.F. =0.56 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.360 Weighted N = 0.216 L =19 Ft. H =0.25 Ft. S =0.0134 Ft./Ft. t1 =1.43 Minutes L =120 Ft. H =4.00 Ft. S =0.0333 Ft./Ft. t1 =8.96 Minutes L =0 Ft. H =0.00 Ft. S =#DIV/0!Ft./Ft. v =#DIV/0!Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.00 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =Ft.2 Pw =Ft. r =#DIV/0!Ft. n = V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =10.38 Minutes (Min. 5 minutes) I(2) =3.911 In./Hr. I(5) =4.584 In./Hr. I(10) =5.169 In./Hr. I(25) =6.060 In./Hr. I(100) =7.703 In./Hr. Q(2) =0.96 CFS Q(5) =1.12 CFS Q(10) =1.27 CFS Q(25) =1.49 CFS Q(100) =1.89 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass UNDEVELOPED DRAINAGE BASIN CALCULATIONS Undeveloped Basin No.:U-2 Total Area =26,195.0 S.F. Willow Haven Senior Homes 0.601 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =S.F. =0.00 Ac.0.85 0.020 Roofs =599.0 S.F. =0.01 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=25,596.0 S.F. =0.59 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.265 Weighted N = 0.245 L =0 Ft. H =0.00 Ft. S =#DIV/0!Ft./Ft. t1 =0.00 Minutes L =165 Ft. H =3.70 Ft. S =0.0224 Ft./Ft. t1 =11.40 Minutes L =0 Ft. H =0.00 Ft. S =#DIV/0!Ft./Ft. v =#DIV/0!Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.00 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =Ft.2 Pw =Ft. r =#DIV/0!Ft. n = V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =11.40 Minutes (Min. 5 minutes) I(2) =3.807 In./Hr. I(5) =4.462 In./Hr. I(10) =5.032 In./Hr. I(25) =5.899 In./Hr. I(100) =7.497 In./Hr. Q(2) =0.61 CFS Q(5) =0.71 CFS Q(10) =0.80 CFS Q(25) =0.94 CFS Q(100) =1.19 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass DEVELOPED DRAINAGE BASIN CALCULATIONS Developed Basin No.:D-1 Total Area =1,770.0 S.F. Willow Haven Senior Homes 0.041 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =1,281.0 S.F. =0.03 Ac.0.85 0.020 Roofs =S.F. =0.00 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=489.0 S.F. =0.01 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.684 Weighted N = 0.084 L =20 Ft. H =0.40 Ft. S =0.0200 Ft./Ft. t1 =1.34 Minutes L =37 Ft. H =3.20 Ft. S =0.0865 Ft./Ft. t1 =4.14 Minutes L =Ft. H =Ft. S =#DIV/0!Ft./Ft. v =#DIV/0!Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.00 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =5.00 Ft.2 Pw =8.33 Ft. r =0.60 Ft. n =0.03 V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =5.48 Minutes (Min. 5 minutes) I(2) =4.565 In./Hr. I(5) =5.353 In./Hr. I(10) =6.034 In./Hr. I(25) =7.069 In./Hr. I(100) =8.991 In./Hr. Q(2) =0.13 CFS Q(5) =0.15 CFS Q(10) =0.17 CFS Q(25) =0.20 CFS Q(100) =0.25 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass DEVELOPED DRAINAGE BASIN CALCULATIONS Developed Basin No.:D-1A Total Area =1,328.0 S.F. Willow Haven Senior Homes 0.030 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =1,328.0 S.F. =0.03 Ac.0.85 0.020 Roofs =S.F. =0.00 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=S.F. =0.00 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.850 Weighted N = 0.020 L =52 Ft. H =1.62 Ft. S =0.0312 Ft./Ft. t1 =1.89 Minutes L =Ft. H =Ft. S =#DIV/0!Ft./Ft. t1 =0.00 Minutes L =Ft. H =Ft. S =#DIV/0!Ft./Ft. v =#DIV/0!Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.00 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =5.00 Ft.2 Pw =8.33 Ft. r =0.60 Ft. n =0.03 V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =5.00 Minutes (Min. 5 minutes) I(2) =4.630 In./Hr. I(5) =5.430 In./Hr. I(10) =6.120 In./Hr. I(25) =7.170 In./Hr. I(100) =9.120 In./Hr. Q(2) =0.12 CFS Q(5) =0.14 CFS Q(10) =0.16 CFS Q(25) =0.19 CFS Q(100) =0.24 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass DEVELOPED DRAINAGE BASIN CALCULATIONS Developed Basin No.:D-2 Total Area =5,004.0 S.F. Willow Haven Senior Homes 0.115 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =2,136.0 S.F. =0.05 Ac.0.85 0.020 Roofs =S.F. =0.00 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=2,868.0 S.F. =0.07 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.506 Weighted N = 0.152 L =Ft. H =Ft. S =#DIV/0!Ft./Ft. t1 =0.00 Minutes L =35 Ft. H =1.00 Ft. S =0.0286 Ft./Ft. t1 =5.22 Minutes L =80 Ft. H =2.30 Ft. S =0.0288 Ft./Ft. v =2.74 Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.49 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =5.00 Ft.2 Pw =8.33 Ft. r =0.60 Ft. n =0.03 V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =5.71 Minutes (Min. 5 minutes) I(2) =4.533 In./Hr. I(5) =5.316 In./Hr. I(10) =5.992 In./Hr. I(25) =7.021 In./Hr. I(100) =8.930 In./Hr. Q(2) =0.26 CFS Q(5) =0.31 CFS Q(10) =0.35 CFS Q(25) =0.41 CFS Q(100) =0.52 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Unpaved Open Channel Flow - Grass DEVELOPED DRAINAGE BASIN CALCULATIONS Developed Basin No.:D-3 Total Area =12,780.0 S.F. Willow Haven Senior Homes 0.293 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =8,812.0 S.F. =0.20 Ac.0.85 0.020 Roofs =S.F. =0.00 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=3,968.0 S.F. =0.09 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.664 Weighted N = 0.091 L =55 Ft. H =0.55 Ft. S =0.0100 Ft./Ft. t1 =2.53 Minutes L =50 Ft. H =1.00 Ft. S =0.0200 Ft./Ft. t1 =6.71 Minutes L =155 Ft. H =1.80 Ft. S =0.0116 Ft./Ft. v =2.19 Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=1.18 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =5.00 Ft.2 Pw =8.33 Ft. r =0.60 Ft. n =0.03 V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =10.42 Minutes (Min. 5 minutes) I(2) =3.907 In./Hr. I(5) =4.580 In./Hr. I(10) =5.164 In./Hr. I(25) =6.054 In./Hr. I(100) =7.695 In./Hr. Q(2) =0.76 CFS Q(5) =0.89 CFS Q(10) =1.01 CFS Q(25) =1.18 CFS Q(100) =1.50 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass DEVELOPED DRAINAGE BASIN CALCULATIONS Developed Basin No.:D-4 Total Area =2,516.0 S.F. Willow Haven Senior Homes 0.058 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =S.F. =0.00 Ac.0.85 0.020 Roofs =S.F. =0.00 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=2,516.0 S.F. =0.06 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.250 Weighted N = 0.250 L =Ft. H =Ft. S =#DIV/0!Ft./Ft. t1 =0.00 Minutes L =25 Ft. H =1.50 Ft. S =0.0600 Ft./Ft. t1 =3.75 Minutes L =Ft. H =Ft. S =#DIV/0!Ft./Ft. v =#DIV/0!Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.00 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =Ft.2 Pw =Ft. r =#DIV/0!Ft. n = V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =5.00 Minutes (Min. 5 minutes) I(2) =4.630 In./Hr. I(5) =5.430 In./Hr. I(10) =6.120 In./Hr. I(25) =7.170 In./Hr. I(100) =9.120 In./Hr. Q(2) =0.07 CFS Q(5) =0.08 CFS Q(10) =0.09 CFS Q(25) =0.10 CFS Q(100) =0.13 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass DEVELOPED DRAINAGE BASIN CALCULATIONS Developed Basin No.:D-5 Total Area =12,453.0 S.F. Willow Haven Senior Homes 0.286 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =S.F. =0.00 Ac.0.85 0.020 Roofs =S.F. =0.00 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=12,453.0 S.F. =0.29 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.250 Weighted N = 0.250 L =Ft. H =Ft. S =#DIV/0!Ft./Ft. t1 =0.00 Minutes L =200 Ft. H =3.50 Ft. S =0.0175 Ft./Ft. t1 =13.22 Minutes L =Ft. H =Ft. S =#DIV/0!Ft./Ft. v =#DIV/0!Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.00 Minutes L = Ft. H = Ft. s =#DIV/0!Ft./Ft. A =Ft.2 Pw =Ft. r =#DIV/0!Ft. n = V =#DIV/0!Ft./Sec. Tt =0.00 Minutes tc =13.22 Minutes (Min. 5 minutes) I(2) =3.622 In./Hr. I(5) =4.244 In./Hr. I(10) =4.789 In./Hr. I(25) =5.611 In./Hr. I(100) =7.130 In./Hr. Q(2) =0.26 CFS Q(5) =0.30 CFS Q(10) =0.34 CFS Q(25) =0.40 CFS Q(100) =0.51 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass DEVELOPED DRAINAGE BASIN CALCULATIONS Developed Basin No.:D-6 Total Area =20,004.0 S.F. Willow Haven Senior Homes 0.459 Acres Surface C N Paved Streets, Lots, Drives and Sidewalks =2,963.0 S.F. =0.07 Ac.0.85 0.020 Roofs =6,173.0 S.F. =0.14 Ac.0.90 0.020 Gravel =S.F. =0.00 Ac.0.85 0.100 Lawns (Slightly pervious)=10,868.0 S.F. =0.25 Ac.0.25 0.250 Unimproved - Woods, Meadow, etc.=S.F. =0.00 Ac.0.25 0.600 Water =S.F. =0.00 Ac.1.00 0.000 Weighted c = 0.539 Weighted N = 0.145 L =Ft. H =Ft. S =#DIV/0!Ft./Ft. t1 =0.00 Minutes L =40 Ft. H =1.20 Ft. S =0.0300 Ft./Ft. t1 =5.50 Minutes L =100 Ft. H =1.00 Ft. S =0.0100 Ft./Ft. v =2.03 Ft./sec.Paved - 20.3283; Unpaved - 16.1345 t2=0.82 Minutes L = 90 Ft. H = 0.90 Ft. s =0.0100 Ft./Ft. A =5.16 Ft.2 Pw =8.32 Ft. r =0.62 Ft. n =0.04 V =2.71 Ft./Sec. Tt =0.55 Minutes tc =6.87 Minutes (Min. 5 minutes) I(2) =4.376 In./Hr. I(5) =5.131 In./Hr. I(10) =5.783 In./Hr. I(25) =6.777 In./Hr. I(100) =8.619 In./Hr. Q(2) =1.08 CFS Q(5) =1.27 CFS Q(10) =1.43 CFS Q(25) =1.68 CFS Q(100) =2.14 CFS Sheet Flow - Impervious Sheet Flow - Lawn Shallow Concentrated Flow - Paved Open Channel Flow - Grass Onsite Sub-basin Area (SF)C Area x C Sub-basin Area (SF)C Area x C Sub-basin Area (SF)C Area x C U-1 29,659.0 0.360 10,674.80 D-1 1,770.0 0.684 1,211.10 D-3 12,780.0 0.664 8,482.20 U-2 26,195.0 0.265 6,938.10 D-1A 1,328.0 0.850 1,128.80 D-6 20,003.0 0.539 10,790.71 D-2 5,004.0 0.506 2,532.60 D-4 2,516.0 0.250 629.00 55,854.00 17,612.90 D-5 12,453.0 0.250 3,113.25 32,783.0 19,272.91 23,071.00 8,614.75 Predeveloped Onsite Area = 1.282 ac.Onsite Undetained Area = 0.530 ac.Onsite Detained Area = 0.753 ac. Existing Wt'd 'c' = 0.315 Developed Wt'd 'c' = 0.373 Developed Wt'd 'c' = 0.588 Offsite Offsite Offsite Sub-basin Area (SF)C Area x C Sub-basin Sub-basin OS-1 12,620.0 0.304 3,842.70 OS-2 55,517.0 0.363 20,133.00 OS-1 12,620.0 0.304 3,842.70 OS-2 55,517.0 0.363 20,133.00 OS-3 137,547.0 0.350 48,141.45 OS-3 137,547.0 0.350 48,141.45 205,684.00 72,117.15 193,064.00 68,274.45 12,620.00 3,842.70 Offsite Area = 4.722 ac.Offsite Undetained Area = 4.432 ac.Offsite Detained Area = 0.290 ac. Wt'd 'c' = 0.351 Developed Wt'd 'c' = 0.354 Developed Wt'd 'c' = 0.304 Total Drainage Area = 261,538.0 sq. ft.Total Undetained Area = 205,517.0 sq. ft.Total Detained Area = 45,403.0 sq. ft. Total Drainage Area = 6.004 ac.Total Undetained Area = 4.718 ac.Total Detained Area = 1.042 ac. Wt'd 'c' = 0.343 Wt'd 'c' = 0.347 Wt'd 'c' = 0.509 Willow Haven Senior Homes 13145 West Road Carmel, IN Sub-Basin Summary Undetained Sub-Basins Detained Sub-Basins Weighted 'C' Predeveloped Sub-Basins Developed Sub-Basins Willow Haven Senior Homes - Carmel Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), (c) OpenStreetMap contributors, and the GIS User Community Parcels Streets Other Carmel Private INDOT Other Municipality County Clay Terrace Duke Federal IPL Other City Boundary 10' Contours Index Intermediate 5' Contours <all other values> Free Representation Index Intermediate 2' Contours <all other values> Free Representation Index Intermediate 1' Contours <all other values> Free Representation Index Intermediate 2019 Photography Red: Red Green: Green Blue: Blue October 31, 2019 0 0.01 0.030.01 mi 0 0.03 0.050.01 km 1:737 ArcGIS WebApp Builder OS-1 Willow Haven Senior Homes - Carmel Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), (c) OpenStreetMap contributors, and the GIS User Community Parcels Streets Other Carmel Private INDOT Other Municipality County Clay Terrace Duke Federal IPL Other City Boundary 10' Contours Index Intermediate 5' Contours <all other values> Free Representation Index Intermediate 2' Contours <all other values> Free Representation Index Intermediate 1' Contours <all other values> Free Representation Index Intermediate 2019 Photography Red: Red Green: Green Blue: Blue October 31, 2019 0 0.01 0.030.01 mi 0 0.03 0.050.01 km 1:737 ArcGIS WebApp Builder OS-2 Willow Haven Senior Homes - Carmel Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), (c) OpenStreetMap contributors, and the GIS User Community Parcels Streets Other Carmel Private INDOT Other Municipality County Clay Terrace Duke Federal IPL Other City Boundary 10' Contours Index Intermediate 5' Contours <all other values> Free Representation Index Intermediate 2' Contours <all other values> Free Representation Index Intermediate 1' Contours <all other values> Free Representation Index Intermediate 2019 Photography Red: Red Green: Green Blue: Blue October 31, 2019 0 0.01 0.030.01 mi 0 0.03 0.050.01 km 1:737 ArcGIS WebApp Builder OS-3