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HomeMy WebLinkAbout1995-05-23 Wetland Drainge Calculations 1 Ift 20,QA Norah Andover Middle School Wetland Drainage Calculations i Prepared For: DiNisco Design. Partnership Limited MAY, 1.995 Prepared By: MONTGOMERY WATSON HAVENS AND EMERSON Dlvlelon OF JAgWAE R. SAHSANTI CIVILNo.38401 ¢�9 ae 'AF, ASS/ANAL Nortli`A dover Middle School Wetiand Drainage Calculations Report TABLE OF CONTENTS 0 Section Desion Page 1 Introduction 2 1.1 Purpose 2 1.2 Methodology 2 1.3 Site Description 2 2 Drainage to Wetlands 3 2.1 Existing Conditions 3 2.1.1 Site Visit 3 2.2 Proposed Conditions 4 2.2.1 Proposed Conditions - Flow and Volume Equal to Existing Conditions 4 2.2.2 Option A 4 2.3 Summary of Peak Flowrates and Volumes 5 3 Water Quality 7 3.1 Existing Conditions 7 3.2 Proposed Conditions Flow and Volume Equal to Existing Conditions 7 3.3 Option A 7 4 Conclusions and Recommendations 8 4.1 Conclusions 8 4.2 Recommendations 8 5 Appendices 9 5.1 Curve Numbers, Time of Concentration and Hydrograph Output CorlCOM DaC Page 1 May 2, 1995 Noah Andover Middle School Wetland Drainage Calculations Report u iJ 1 INTRODUCTION 1.1 Purpose The following report was prepared in accordance with the North Andover Conservation Commission's site plan information requirements relating to existing and proposed drainage to the wetland area depicted on the site plan. The report and calculations herein were prepared to present the predevelopment and postdevelopment peak flowrates and volumes for the 1, 10 and 100 year storm event contributing to the wetland in the northerly portion of the site. 1.2 Methodology Hydrologic calculations of existing and proposed site runoff were performed using the methods outlined in the United States Department of Agriculture, Soil Conservation Service, Technical Release 55 (TR-55), Urban Hydrology for Small Watersheds. This method presents procedures to calculate storm runoff volume, peak rate of discharge, hydrographs, and storage volumes. It is used widely for applications similar to those proposed for this site. The Haestad Methods Quick TR-55 computer program was used to perform the calculations of the existing and proposed runoff hydrographs for the 1, 10 and 100 year storms, 1.3 Site Description The site consists of a parcel of land situated along the Main Street and Chickering Road intersection. The site topography slopes generally from south to north with a high point along Chickering Road at elevation 190, to a low point along Main Street of 149. The school is set well above Main Street, at an average ground elevation of 164, and consists of the school building and grounds, bituminous concrete parking areas, driveways and walkways. An athletic field is located at the westerly portion of the site, above the school grounds, at elevation 176. The northerly section of the parcel is undeveloped and consists of wooded vegetation and a wetland area. This wetland is approximately 0.50 acres, and abuts the properties of the Lafond's and the Ventura's. CONCONCDOC Page 2 May 2, 1995 i II North Andover Middle School Wetland Drainage Calculations Report J 2.0 Drainage to Wetlands 2.1 Existing Conditions The portion of the site that contributes runoff to the wetlands includes a grass area above the upper parking lot, approximately half of the upper paved parking lot and a portion of the site driveway, and the upper wooded area above the wetlands. The tributary area to this wetland is 4 acres, and the boundary of the contributing drainage area is depicted on the Existing Conditions Drainage Plan submitted with the Notice of Intent Site Plans. The Soil Conservation Service was contacted to supply a soil map of the area. Review of this map indicated that the site is classified as Udorthants. According to SCS, the properties of this unit are variable due to the excavation and deposition of the original soils. Most areas of this type are used for schools and atheletic fields. SCS does not assign a classification (Soil Type A, B, C, D ) to this soil type. Review of the surrounding soils bordering the site indicated a Soil Type C Classification and it was assumed for the purposes of these calculations that the Site was classified Soil Type C. This soil type consists of sandy clay loam with a low infiltration rate. This assumption provides a conservative basis for calculation of the runoff hydrographs. 2.1.1 Site Visit The site was visited after two small rainfall events (4/28/95) and (5/1/95), and soils in the wetlands were observed to be wet and muddy. Standing water at a depth of one foot was observed at a low point in the vicinity of wetland flag 41, near the Lafond's property line. During the public hearing of 4/19/95, the downstream abutter's clearly stated that there was an existing drainage problem associated with this wetland, with frequent standing water, and actual flows observed along the Ventura's and Lafond's common property line during certain rainfall events. A shallow trench ( approximately 6" deep and 1 foot wide) exists along this property line which conveys flow to a catch basin inlet on Tavern Road. In the area of the upper parking lot and the access drive, sediment washouts were observed in the vicinity of wetlands flags 9 and 13. This provides evidence that the portion of the upper parking area and the access drive as delineated on the existing conditions drainage area plan contribute runoff to the wetland. A shallow channel (3" deep , 6" wide) was observed starting near wetland flag 9 and meandering approximately 30 feet into the wetland area, and dissipating in the vicinity of wetland flag 10. This channel was likely created by flows discharging at wetland flag 9 and eroding a channel out of the existing ground over a course of several years. CONCONI.DOC Page 3 May 2, 1995 0 ?forth Andover Middle School Wetland Drainage Calculations Report 2.2 Proposed Conditions The proposed site conditions consist of expansion of the school building footprint, reconfiguration of the site driveways and parking areas around the building, and expansion of the upper parking lot. Additional site improvements will include construction of bituminous concrete curbing around paved areas to collect and direct runoff to catch basin inlets. The calculation of SCS Curve Number (CN) for the existing and proposed conditions, and their Time of Concentration, Tc, are presented on the TR-55 Worksheets in the Hydrograph output Appendix. 2.2.1 Proposed Conditions - Flow and Volume Equal to Existing Conditions The Conservation Commission performance standards require the peak flowrate and volume to the wetlands be equal to existing conditions. In order to accomplish this , a portion of the new school addition roof and access drive have been proposed to contribute flow to a wetlands replication area that is proposed to be connected to the existing wetlands. The proposed conditions drainage area boundary is depicted on the "Drainage Calculations" site plan submitted as part of the Notice of Intent, and is 3.6 acres in size. The contributing area includes the upper woods and grass, and these aforementioned impervious surfaces. Drainage from the roof will be directly piped to a catch basin along the curb of the access road as shown on the site plan. The catch basin inlet will collect surface water in this area, and flow will be discharged via an 8" pipe to the replication area. The pipe will discharge to a stone trench constructed along the bank of the replication area, designed to allow flow to seep out from the trench into the replication area. A detail of the catch basin location and trench are depicted as part of the site plan documents. The stone trench will serve to buffer the flow as well as provide filtration of the runoff. 2.2.2 Option A As part of this analysis, calculations, termed Option A, were performed to quantify the flow contributing to the wetlands from the upper woods and grass area. This area is 2.9 acres in size, and its boundary is depicted on the site plan. These calculations were performed to determine if this area provides enough direct runoff to augment the direct precipitation water contribution to the wetland, in other words, to maintain wet conditions in the wetland area. Since the area has an existing, historical reputation for standing and flowing water, it is appropriate in the context of this project to determine if measures can be made to reduce the problem, and still meet the intent of the Commission's performance standards. CQNCOM.DQC Page 4 May 2, 1995 u if u North Andover Middle School Wetland Drainage Calculations Report o 2.3 Summary of Peak Flowrates and Volumes Detailed information regarding the runoff hydrographs for the existing , proposed and Option A conditions for the 1, 10 and 100 year storms are located in the Appendix. A summary of existing and proposed peak flow rates are shown in Table 2.1. Table 2.1 Summary of Peak li lowrates (cfs)to Wetlands Storm (yr) Existing Proposed Option A 1 1 1 1 10 5 5 3 100 9 8 6 Table 2.2 Summary of Volume (gallons) to Wetlands Storm (yr) Existing Proposed Option A 1 80,371 77,221 48,032 10 248,715 232,641 161,421 100 435,524 401,746 291,345 The results presented in Tables 2.1 and 2.2 indicate that the proposed conditions will return flow and volume sufficient to meet a strict interpretation of the Commission's performance standards. However, in regard to historical flooding of this wetland, Option A is more desirable because it returns flows at approximately the same rate of runoff, but reduces the volume by approximately 40%. CONCOADOC Page 5 May 2, 1995 u North Andover Middle School Wetland Drainage Calculations Report V To gain a better understanding of these results in terms of maintaining wet soil conditions in the wetland, the following depths were calculated by assuming the entire volume as presented in Table 2.2 is equally distributed over the area of the wetlands (0.47 acres): Table 2.3 Depth (inches) Equally Distributed over Wetland Area(0.47 acres) Storm (yr) Existing Proposed Option A 1 6 6 4 10 20 18 13 100 34 32 23 The information presented in Table 2.3 indicates that the proposed conditions will meet the strict interpretation of the Commission's performance standards. However, the Option A calculations indicate that sufficient water will be available to maintain wet soil conditions, notwithstanding the contribution of direct precipitation to this area. CONCOM.DOC Page 6 May 2, 1995 Nonh Andover Middle school wetland Drainage Calculations Report 3.0 Water Quality 3.1 Existing Conditions The major water quality impact related to the existing conditions of the site include direct contribution of sediment to the wetlands from the paved surfaces. Oil and greases are likely being contributed from the parking area and access drives, and to a lesser extent, heavy metals from exhaust fumes may also be impacting this wetland. These impacts are directly related to the paved surfaces and lack of curbing and catch basin inlets in these areas. 3.2 Proposed Conditions - Flow and Volume Equal to Existing Conditions The proposed conditions of the site will significantly mitigate the existing water quality impacts associated with this wetland. Curbing will be provided along the entire paved perimeter of the site to collect and direct runoff to the catch basin inlets. catch basins are equipped with sumps to store sediment for future removal. Numerous catch basin inlets have been proposed and are depicted on the site plans. As discussed in Section 2, the catch basin and pipe designed to contribute runoff to the ,ketlands will be equipped with a sump and an oil and grease trap. Discharge will be via a seepage trench, which will provide additional filtration of the runoff. 3.3 Option A Option A provides the optimum water quality benefit to the wetlands. The proposed impervious surface contributions are eliminated, thereby eliminating sediment, oil and grease and heavy metal contribution from these areas. CONCOADOC Page 7 May 2, 1995 a North Andover Middle School Wetland Drainage Calculations Report j 4.0 Conclusions and Recommendations 4.1 Conclusions Calculations for the 1, 10 and 100 year storm have been performed per the Conservation Commission requirements and performance standards, with existing conditions and two proposed conditions scenarios summarized in Section 2. 4.2 Recommendations From the results of this analysis, it is our opinion that Option A meets the intent of the Commission's performance standards and is the recommended plan for the following reasons: • Historical flooding exists in this wetland which impacts the quality of life of the downstream abutters. Option A provides a 40% reduction in volume to this wetland, while maintaining approximately the same peak flowrates for the storms analyzed; • Calculations summarized in Table 2.3 indicate that Option A provides water to maintain wet soil conditions within the wetland area; • Option A minimizes water quality impacts due to the development by eliminating direct impervious surface contributions to the wetland. CONCOM.DOC Page 8 May 2, 1995 tl u North Andover Middle School Wetland Drainage Calculations Report 0 0 9 5.0 Appendix 5.1 Curve Number, Time of Concentration, and Hydrograph Output CONCOM.I3oC Page 9 May z. 1995 Worksheet 2: Runoff carve number and runoff :Project Aloa-r" X00VEa A1001-E 49"LF! By Date Location rA To W E7'i-r4,v,0S Checked Date Circle one: Present Developed 1. Runoff curve number (CN) Soil name Cover description 1/ Area Product and CN -- of hydrologic (cover type, treatment, and C14 CN x area group hydrologic condition; c:, `i vi `acres percent impervious; `� `�' ❑mil unconnected/connected impervious ❑`/. (appendix A) area ratio) C jMPE2vfa�s 9[f 0, 6 y 67, C GA ss 74 �ran� s Q �r -rL q'V'O S 77 0, 43 43 3 1/ Use only one CN source per line. Totals = A C) 3N (weighted} �, total product =3D7.Z = 76r$ Use CN total area �— ; Z. Runoff Storm lit Storm #2 Storm #3 Frequency . . . . .. . . .. . . . . . . .. .. . . . . .. . . .. yr rainfall, P (24-hour) .. . .. . . . . . . . . . . .. . in 2 ,5 4-, runoff, Q in �� r� 2 . 2 1 ,01 (Use P and CN with table 2-1, fig. 2-1, or eqs. 2-3 and 2-4.) (210-VI-TR-55, Second Ed., June 1986) i I Worksheet 2: Runoff curve number and runoff Project o�zT�{ T1NObV x A1O471-E SCf,( By Jg" Date. Location Ttzi6v r Ali i d rCAKO Checked Date Circle one: Present Developed 1. Runoff curve number (CN) Soil name Cover description 1/ Area Product and C:1 — of hydrologic (cover type, treatment, and ry CN x area group hydrologic condition; N i' viMOO acres percent impervious; 0 ' cvmi2 unconnected/connected impervious �a ❑% (appendix A) area ratio) .14 C 6a4 s .s C 70 77 . 4 7 37, ! 1/ Use only one CN source per line. Totals = �� Z CN (weighted) total product 7 7,� Use CN a 7 0 total area �.� 2. Runoff Storm #1 Storm #2 Storm #3 Frequency . .. . .. . . ... . . .. . . ... . . . . .. . ... yr D A)Q Rainfall, P (24--hour) ..... . . . .. . . .. . .. . in �r � 4� (.:p 6 ' �O Runoff, Q • . . . . .. in (Use P and CN with table 2-1, fig. 2--1, or eqs. 2--3 and 2--4.) (210-VI-TR-55, Second Ed., June 1986) Worksheet 2: Runoff curve number and runoff ?ro ject �� &100fiQ2 A140,01E S. 4( By Date ..ocation �U(3,ggEA ClJy al°T aw,4 Checked Date :ircle one: Present Developed 1. Runoff curve number (CN) Soil name Cover description 1/ Area Product and CN — of hydrologic (cover type, treatment, and CN x area group hydrologic condition; N rl I acres percent impervious; ❑mi2 unconnected/connected impervious ❑`/. (appendix A) area ratio) ro .11 - o ao 70 J.S1 lr•7 C G CZA S 5 ?4 . S�Z 60,6 0, b �j L 7e,A ILra q 047 37, 13 Use only one CN source per line. Totals = Zr l product 2)3.3 I N (weighted) total--p _ _ Use CN total area Runoff storm #1 Storm #2 Storm #3 l0 requency . . . . . . .. .. . . . . . . . . . . . .. . .. .. .. yr /0 0/� I ainfall, P (24--hour) .. ... . . . . . . . . . . .. . in �• `, • 14 (004 unoff, Q . . .. .. in O - GI 2 . 05 3. !0 (Use P and CN with table 2-1, fig. 2-1, or eqs. 2-3 and 2-4,) (210-VI-TR•55, Second Ed., June 1986) u 9 Worksheet 3: Time of concentration (Tc) or travel time (TO Project 9�Q7H �� /Dp1,6Say sy �! � Date Location 1 a1Q /o Checked Date Circle one: FT Developed Circle one: t through subarea NOTES: Space for as many as two segments per flow type can be used for each worksheet. Include a map, schematic, or description of flow segments. Sheet flow (Applicable to Tc only) Segment ID r 1. Surface description (table 3-1) ............ �+ 2. Manning's roughness coeff., n (table 3-1) .. o, 24- 3. - Flow length, L (total L C 300 ft) .. ft Z 4 o 4. Two-yr 24-hr rainfall, P2 in 3,Z 0` b S. Land slope, s .............................. ft/ft 0.8 , S + d• S 6. Tt ,. 0.0o75(nL0)4 Compute Tt ... ... hr O P2 s Shallow concentrated flow Segment ID 7. Surface description (paved or unpaved) ..... (lN PA V 8. Flow length, L .................... ......... ft �d 9. Watercourse Slope, S ........................ ft/ft 0, 07, 10. Average velocity, V (figure 3-1) ........... ft/s 2 11. T L Compute Tt ...... hr 0. 1 t 3600 V Channel flow Segment ID 12. Cross sectional flow area, a ft2 13. Wetted perimeter, pw ft 14. Hydraulic radius, r Pg Compute r ....... ft w 15. Channel slope, s ........................... ft/ft 16. Manning's roughness coeff., n .............. 2/3 1/2 17. V 1 .49 r s Compute V ....... ft/s n 18. Flow length, L ............................. ft 19. Tt 3600 V- L Compute Tt ...... hr + - O 20. Watershed or subarea Tc or Tt (add Tt in steps 6, 11, and 19) ....... hr PES16n' 4-0 j,4 ,1.vv-r6s (210-VI-TR-55, Second Ed., June 1986) D-3 Worksheet 3: Time of concentration (Tc) or travel time (Tt) Project r VOit rK '!' e0tlj�2 / '110,04,C FCAK By Date Location L(2IQ • D' Checked Date Circle one: Present Developed Circle one: fc Tt through subarea NOTES: Space for as many as two segments per flow type can be used for each worksheet. Include a map, schematic, or description of flow segments. Sheet flow (Applicable to Tc only) Segment ID 1. Surface description (table 3-1) 2. Manning's roughness coeff., n (table 3-1) D. Z 3. - Flow length, L (total L C 300 ft) .......... ft ?4 4. Two-yr 24-hr rainfall, P2 .................. in -3 1 5. Land slope, s ............ ....... ........ ... ft/ft 0.$ 6. T .. 0.007 (nL) Compute Tt ...... hr �� � + a a� t P 0.5 s0.4 2 Shallow concentrated flow Segment ID 7. Surface description (paved or unpaved) ..... 8. Flow length, L ................ ............. ft. 9. Watercourse slope, s .................... ... ft/ft 0' 10. Average velocity, V (figure 3-1) ........... ft/s 11. Tt 3600 V Compute Tt ...... hr 0 + Q, i Channel flow Segment ID 12. Cross sectional flow area, a ............... ft2 13. Wetted perimeter, pw ft 14. Hydraulic radius, r Pa Compute r ....... ft w 15. Channel slope, s ft/ft 16. Manning's roughness coeff., n .............. 2/3 1/2 17. V 1 .49 r s Compute V ....... ft/s n 18. Flow length, L ft Compute Tt ...... hr 19. Tt 3600 V 0 20. Watershed or subarea Tc or Tt (add Tt in steps 6, 11 , and 19) hr �r (210-VI-TR-55, Second Ed., June 1986) D-3 nick TR-55 Version: 5 . 42 SIN: 1240540150 Page 1 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :41 :49 Watershed file : A2E1 .WSD Hydrograph file : A2E1 .HYD »» Input Parameters Used to Compute Hydrograph « Subarea -- AREA CN Tc * Tt Precip. Runoff Ia/p ascription (acres) (hrs) (hrs) (in) (in) input/used ------ ---- -- ------------------------------- ------------------ ------------ --- {isting wet 4 . 00 77 . 0 0 . 75 0 . 00 2 . 50 0 . 74 . 24 . 30 Travel time from subarea outfall to composite watershed outfall point . Total area = 4 . 00 acres or 0 . 00625 sq.mi Peak discharge = 1 cfs »» Computer Modifications of Input Parameters <«« ------------- -------------------------------------------------------- -------- Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Ia/p ascription (hr) (hr) (hr) (hr) (Yes/No) Messages --------- --- ----------------------------------------------------------------- fisting wet 0 . 67 0 . 00 0 . 75 0 . 00 No ------- ---------------------------------------------------------------- ------ Travel time from subarea outfall to composite watershed outfall point . tick TR-55 Version: 5 .42 SIN: 1240540150 Page 2 TR--55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :41 :49 Watershed file : A2EI .WSD Hydrograph file : A2E1 .HYD »» Summary of Subarea Times to Peak <<<< Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea NO) (hrs) existing wet 1 12 . 5 Composite Watershed 1 12 . 5 tick TR-55 Version: 5 . 42 SIN: 1240540150 Page 4 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :41 :49 Watershed file : --> A2E1 .WSD Hydrograph file : --> A2E1 .HYD Time Flow Time Flow (hrs) (cf s) (hrs) (cf s) ---------- ------- ----- ----- ------- 11 . 0 0 14 . 8 0 11 . 1 0 14 . 9 0 11 . 2 0 15 . 0 0 11 . 3 0 15 . 1 0 11 . 4 0 15 . 2 0 11 . 5 0 15 . 3 0 11 . 6 0 15 .4 0 11 . 7 0 15 . 5 0 11 . 8 0 15 . 6 0 11 . 9 0 15 . 7 0 12 . 0 0 15 . 8 0 12 . 1 0 15 . 9 0 12 . 2 0 16 . 0 0 12 . 3 0 16 . 1 0 12 .4 0 16 . 2 0 12 . 5 1 16 . 3 0 12 . 6 1 16 .4 0 12 . 7 1 16 . 5 0 12 . 8 1 16 . 6 0 12 . 9 1 16 . 7 0 13 . 0 1 16 . 8 0 1.3 . 1 1 16 . 9 0 13 . 2 1 17 . 0 0 13 . 3 1 17 . 1 0 13 .4 1 17 . 2 0 13 . 5 1 17 . 3 0 13 . 6 1 17 .4 0 13 . 7 1 17 . 5 0 13 . 8 1 17 . 6 0 13 . 9 0 17 . 7 0 14 . 0 0 17 . 8 0 14 . 1 0 17 . 9 0 14 . 2 0 18 . 0 0 14 . 3 0 18 . 1 0 14 .4 0 18 . 2 0 14 . 5 0 18 . 3 0 14 . 6 0 18 .4 0 14 . 7 0 18 . 5 0 E i ck TR-55 Version: 5 .42 SIN: 1240540150 )tied: 05-01-1995 14 : 51 :33 Flow (cfs) 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 f 7 I * i * i * i * I * f * . 3 i * * . 5 - I * f * . 7 - i * * . 9 - I * f i * * f * . 7 - � . 9 i TIME (hrs) * File : A2E1 HYD Qmax = 1 . 0 cfs tick TR-55 Version: 5 . 42 SIN: 1240540150 Page 1 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :42 : 13 Watershed file : --> A2E10 .WSD Hydrograph file : --> A2E10 .HYD >>>> Input Parameters Used to Compute Hydrograph «« -Subarea AREA CN Tc * Tt Precip. Runoff Ia/p scription (acres) (hrs) (hrs) (in) (in) input/used --- - -- - ------------------------------------------------- --- ---- --- -- - -- -- -- - isting wet 4 . 00 77 . 0 0 . 75 0 . 00 4 . 60 1 2 . 29 . 13 . 10 --- -- ---------------------------------------------------------- ------- -- -- -- Travel time from subarea outfall to composite watershed outfall point . Total area = 4 . 00 acres or 0 . 00625 sq.mi Peak discharge = 5 cfs >>>> Computer Modifications of Input Parameters <<<<< --- - -- --------- ----------------------------------------- -------- ---- -- ------ Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Xa/p scription (hr) (hr) (hr) (hr) (Yes/No) Messages ----- ------------------------------------------------------------ ----- --- --- sting wet 0 . 67 0 . 00 0 . 75 0 . 00 No -- ---- -- --------------------------------------------------------------- -- ---- - Travel time from subarea outfall to composite watershed outfall point . uick TR-55 Version: 5 . 42 SIN: 1.240540150 Page 2 TR-55 TABULAR HYDROGRAPH METHOD Type z11 Distribution (24 hr. Duration Storm) Executed: 05-01--1995 14 :42 : 13 Watershed file : A2E10 .WSD Hydrograph file : A2E10 .HYD »» Summary of Subarea Times to Peak «<< Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) (hrs) existing wet 5 12 . 7 Composite Watershed 5 12 . 7 uick TR--55 Version: 5 .42 SIN: 1240540150 Page 4 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :42 :13 Watershed file : A2E10 .WSD Hydrograph file : --> A2E10 HYD Time Flow Time Flow (hrs) (cf s) (hrs) (cf s) 11 . 0 0 14 . 8 1 11 . 1 0 14 . 9 1 11 . 2 0 15 . 0 1 11 . 3 0 15 . 1 1 11 . 4 0 15 . 2 1 11 . 5 0 15 . 3 1 11 . 6 0 15 . 4 1 11 . 7 0 15 . 5 1 11 . 8 1 15 . 6 1 11 . 9 1 15 . 7 1 12 . 0 1 15 . 8 0 12 . 1 1 15 . 9 0 12 . 2 1 16 . 0 0 12 . 3 1 16 . 1 0 12 .4 2 16 . 2 0 12 . 5 3 16 . 3 0 12 . 6 4 16 . 4 0 12 . 7 5 16 . 5 0 12 . 8 5 16 . 6 0 12 . 9 4 16 . 7 0 13 . 0 4 16 . 8 0 13 . 1 3 16 . 9 0 13 . 2 3 17 . 0 0 13 . 3 2 17 . 1 0 13 . 4 2 17 . 2 0 13 . 5 2 17 . 3 0 13 . 6 2 17 .4 0 13 . 7 1 17 . 5 0 13 . 8 1 17 . 6 0 13 . 9 1 17 . 7 0 14 . 0 1 17 . 8 0 14 . 1 1 17 . 9 0 14 . 2 1 18 . 0 0 14 . 3 1 18 . 1 0 14 .4 1 18 . 2 0 14 . 5 1 18 . 3 0 14 . 6 1 18 . 4 0 14 . 7 1 18 . 5 0 Lck TR--55 Version: 5 .42 SIN: 1240540150 >tted: 05-01-1995 15 : 09 : 53 Flow (cfs) 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 . ----- I ----- I ----- I ----- I ----- I -_..�_ I �..--- I --_-- I ----- I _�__ I --___ I _ I .2 - I * I * . 5 - I * I * . 8 - I * .4 - I I * . 7 I . 0 - I I * . 3 - . 6 - * . 9 - * . 2 - * . 5 - * . 1 - I .4 - I I .7 - I I * . 0 - I * I * . 3 - I * I * . 6 - * I * . 9 - * I * TIME (hrs) File : A2E10 HYD Qmax = 5 . 0 cfs >>>> Input Parameters Used to Compute Hydrograph <<<< -------------------- ---------------------------------------------- -------- - - Subarea AREA CN Tc * Tt Precip . Runoff Ia/p !scription (acres) (hrs) (hrs) (in) (in) input/used ;isting wet 4 . 00 77 . 0 0 . 75 0 . 00 6 . 60 4 . 01 . 09 . 10 ----------------------------------------------------------------------------- Travel time from subarea outfall to composite watershed outfall point . Total area = 4 . 00 acres or 0 . 00625 sq.mi Peak discharge = 9 cfs >>>> Computer Modifications of Input Parameters C<CCC Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Ia/p ascription (hr) (hr) (hr) (hr) (Yes/No) Messages isting wet 0 . 67 0 . 00 0 . 75 0 . 00 No Computed Ia/p < 1 ------------------------ ---- --- - - - ----------- - -- - ----------- ------- ----- ---- Travel time from subarea outfall to composite watershed outfall point . 2uick TR-55 Version: 5 .42 SIN: 1240540150 Page 2 TR--55 TABULAR HYDROGRAPH METHOD Type ITT Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :42 : 38 Watershed file : A2E100 .WSD Hydrograph file : - A2E100 .HYD »» Summary of Subarea Times to Peak «< Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) (hrs) existing wet 9 12 . 8 Composite Watershed 9 12 . 8 wick TR--55 Version: 5 .42 SIN: 1240540150 Page 4 TR--55 TABULAR HYDROGRAPH METHOD Type T11 Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :42 : 38 Watershed file : - > A2E100 .WSD Hydrograph file : --> A2E100 .HYD Time Flow Time Flow (hrs) (cf s) (hrs) (cf s) ----------------- ----------------- 11 . 0 0 14 . 8 1 11 . 1 0 14 . 9 1 11 . 2 1 15 . 0 1 11 . 3 1 15 . 1 1 11 .4 1 15 . 2 1 11 . 5 1 15 . 3 1 11 . 6 1 15 .4 1 11 . 7 1 15 . 5 1 11 . 8 1 15 . 6 1 11 . 9 1 15 .7 1 12 . 0 1 15 . 8 1 12 . 1 1 15 . 9 1 12 . 2 2 16 . 0 1 12 . 3 3 16 . 1 1 12 . 4 4 16 . 2 1 12 . 5 5 16 . 3 1 12 . 6 7 16 . 4 1 12 . 7 8 16 . 5 1 12 . 8 9 16 . 6 1 12 . 9 8 16 . 7 1 13 . 0 8 16 . 8 1 13 . 1 7 16 . 9 1 13 . 2 6 17 . 0 1 13 . 3 5 17 . 1 1 13 . 4 4 17 . 2 1 13 . 5 4 17 . 3 1 13 . 6 3 17 .4 1 13 . 7 2 17 . 5 1 13 . 8 2 17 . 6 1 13 . 9 2 17 . 7 1 14 . 0 2 17 . 8 1 14 . 1 2 17 . 9 1 14 . 2 2 18 . 0 1 14 . 3 2 18 . 1 1 14 . 4 2 18 . 2 1 14 . 5 1 18 .3 1 14 . 6 1 18 .4 1 14 . 7 1 18 . 5 1 Eck TR-55 Version: 5 .42 SIN: 1240540150 )tted: 05-01-1995 15 :07 : 11 Flow (cfs) 0 . 0 1 . 0 2 . 0 3 . 0 4 . 0 5 . 0 6 . 0 7 . 0 8 . 0 9 . 0 10 . 0 11 . 0 . ------ I ----- I ----- I ----- I ----- I ----- I ----- I -- --- I ------ I -____ I __..__ I - . 0 I . 6 - I * . 2 - I I * * . 8 - I I * I . 4 - I * * . 0 - � * * . 6 - I I * * . 2 - � * * . 8 - I I * I * . 4 - I * I * . 0 - I I . 6 - I I * * . 2 - I I * I * 4 0 TIME (hrs) File : A2E100 HYD Qmax w 9 . 0 cfs d I jQuick TR-55 Version: 5 .42 SIN: 1240540150 Page 1 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :40 :35 Watershed file : A2P1 .WSD Hydrograph file: --> A2P1 .HYD »>> Input Parameters Used to Compute Hydrograph <<<< ------------- ------ ------------------------------------------------- ---------- Subarea AREA CN Tc * Tt Precip. Runoff Ia/p )ascription (acres) (hrs) (hrs) (in) (in) input/used -------------------------------- ------------------------------------ --- ---- -- - >roposed wet 3 . 60 78 . 0 0 . 75 0 . 00 2 . 50 0 . 79 . 23 . 30 Travel time from subarea outfall to composite watershed outfall point . Total area = 3 . 60 acres or 0 . 00562 sq.mi Peak discharge = 1 cfs >>>> Computer Modifications of Input Parameters <<<<< ----- - ---------- ---------- - ------ - ----------------------- ------ --------- -- ---- Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Ia/p )escription (hr) (hr) (hr) (hr) (Yes/No) Messages -------------------------------------------------------------- ------ --- --- - -- - -oposed wet 0 . 67 0 . 00 0 . 75 0 . 00 No - - ------------------- ------------------------------------------------•------- ------- --- Travel time from subarea outfall to composite watershed outfall point . Quick TR-55 Version: 5 . 42 SIN: 1240540150 Page 2 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :40 :35 Watershed file : --> A2P1 .WSD Hydrograph file : A2P1 .HYD »» Summary of Subarea Times to Peak <<<< Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) (hrs) proposed wet 1 12 . 5 Composite Watershed 1 12 . 5 Quick TR-55 Version: 5 . 42 SIN: 1240540150 Page 4 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01--1995 14 :40 : 35 Watershed file : --> A2P1 WSD Hydrograph file : A2P1 HYD Time Flow Time Flow (hrs) (cfs) (hrs) (cf s) 11 . 0 0 14 . 8 0 11 . 1 0 14 . 9 0 11 . 2 0 15 . 0 0 11 . 3 0 15 . 1 0 11 . 4 0 15 . 2 0 11 . 5 0 15 .3 0 11 . 6 0 15 .4 0 11 . 7 0 15 . 5 0 11 . 8 0 15 . 6 0 11 . 9 0 15 . 7 0 12 . 0 0 15 . 8 0 12 . 1 0 15 . 9 0 12 . 2 0 16 . 0 0 12 . 3 0 16 . 1 0 12 . 4 0 16 .2 0 12 . 5 1 16 . 3 0 12 . 6 1 16 .4 0 12 . 7 1 16 . 5 0 12 . 8 1 16 . 6 0 12 . 9 1 16 . 7 0 13 . 0 1 16 . 8 0 13 . 1 1 16 . 9 0 13 . 2 1 17 . 0 0 13 . 3 1 17 . 1 0 13 .4 1 17 . 2 0 13 . 5 1 17 . 3 0 13 . 6 1 17 .4 0 13 . 7 1 17 . 5 0 13 . 8 1 17 . 6 a 13 . 9 0 17 . 7 0 14 . 0 0 17 . 8 0 14 . 1 0 17 . 9 0 14 . 2 0 18 . 0 0 14 .3 0 18 . 1 0 14 .4 0 18 . 2 0 14 . 5 0 18 . 3 0 14 . 6 0 18 . 4 0 14 . 7 0 18 . 5 0 u lick TR-55 Version: 5 .42 SIN: 1240540150 .otted: 05-01-1995 15 : 17 :29 Flow (cfs) 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 _ . 0 _ . 3 l . 6 L . 9 2 . 2 r 1 * 9 I * 3 . 1 - ( * 3 .4 - * s3 . 7 - * 4 . 0 - * 4 . 3 - * 11 . 6 - 1 * I * n� . 9 - I * r I * 5 . 2 - [ * 5 . 5 . 8 - ( * I * 6 . 4 - * ,.6 . 7 - °7 . 0 - * 7 .3 - 7 . 6 - 7 . 9 * TIME (hrs) ' * File : A2PI .HYD Qmax = 1 . 0 cfs o s u I d quick TR-55 Version: 5 .42 SIN: 1240540150 Page 1 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :40 : 02 Watershed file : A2P10 .WSD Hydrograph file : A2P10 .HYD Input Parameters Used to Compute Hydrograph <<<< `-Subarea AREA CN Tc * Tt Precip. Runoff Ia/p lescription (acres) (hrs) (hrs) (in) (in) input/used --------------------------- proposed wet 3 . 60 78 . 0 0 . 75 0 . 00 4 . 60 2 . 38 . 12 . 10 ------ --------------------------------------------------------- -------------- Travel time from subarea outfall to composite watershed outfall point . Total area = 3 . 60 acres or 0 . 00562 sq.mi Peak discharge = 5 cfs »» Computer Modifications of Input Parameters <<<<< -- ----------------- -- --------------------------------------------------------- Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Ia/p )escription (hr) (hr) (hr) (hr) (Yes/No) Messages ------------ ----------------------------------------------------------- ------- roposed wet 0 . 67 0 . 00 0 . 75 0 . 00 No -- ---------------- -- ------------------- ---------------------------------------- k Travel time from subarea outfall to composite watershed outfall point . ;quick TR-55 Version: 5 .42 SIN: 1240540150 Page 2 TR-55 TABULAR HYDROGRAPH METHOD Type TIT Distribution (24 hr. Duration Storm) Executed: 05-01-1995 14 :40 : 02 Watershed file : A2P10 .WSD Hydrograph file : A2P10 .HYD »> Summary of Subarea Times to Peak CCCC Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) (hrs) proposed wet 5 12 . 8 Composite Watershed 5 12 . 8 Quick TR--55 Version: 5 .42 SIN: 1240540150 Page 4 TR--55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05--01-1995 14 :40 : 02 Watershed file : A2P10 .WSD Hydrograph file: W> A2P10 .HYD Time Flow Time Flow (hrs) (cf s) (hrs) (cf s) 11 . 0 0 14 . 8 1 11 . 1 0 14 . 9 1 11 . 2 0 15 . 0 1 11 . 3 0 15 . 1 1 11 . 4 0 15 . 2 1 11 . 5 0 15 . 3 1 11 . 6 0 15 .4 1 11 . 7 0 15 . 5 1 11 . 8 1 15 . 6 1 11 . 9 1 15 . 7 1 12 . 0 1 15 . 8 0 12 . 1 1 15 . 9 0 12 . 2 1 16 . 0 0 12 . 3 1 16 . 1 0 12 . 4 2 16 . 2 0 12 . 5 3 16 .3 0 12 . 6 4 16 .4 0 12 . 7 4 16 . 5 0 12 . 8 5 16 . 6 0 12 . 9 4 16 . 7 0 13 . 0 4 16 . 8 0 13 . 1 3 16 . 9 0 13 . 2 3 17 . 0 0 13 . 3 2 17 . 1 0 13 . 4 2 17 . 2 0 f 3 13 . 5 2 17 .3 0 13 . 6 2 17 .4 a 13 . 7 1 17 . 5 0 13 . 8 1 17 . 6 0 13 . 9 1 17 . 7 a 14 . 0 1 17 . 8 a 14 . 1 1 17 . 9 0 14 . 2 1 18 . 0 0 14 . 3 1 18 . 1 a 14 . 4 1 18 . 2 d 14 . 5 1 18 . 3 a 14 . 6 1 18 .4 d 14 . 7 1 18 . 5 0 ck TR-55 Version: 5 .42 SIN: 1240540150 tied: 05-01-1995 15 : 18 : 14 Flow (cfs) 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 . --___ i ----- i ----- i ----- i ----- i - --- I ----- I ----- i ----- i -_--- I ----- i - i 3 - I * i * 6 i * 9 i * 2 - I I * 5 i i 8 - 1 - ( I * 4 - i I * 7 i i 0 - i * 3 - � * 6 . 9 - I I * , 2 - i i * . 5 - � I * I * i * .4 i * i * . 7 I * . 0 - I * I * .3 - i * . 6 9 � * . 2 TIME (hrs) k File : A2P10 HYD Qmax = 5 . 0 c£s 4 nick TR-55 Version: 5 .42 SIN: 1240540150 Page 1 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 11 : 02 : 20 Watershed file : A2P100 .WSD Hydrograph file : A2P100 .HYD >>>> Input Parameters Used to Compute Hydrograph <<<< ---- ---- `---- Subarea AREA CN Tc * Tt Precip. j Runoff Ia/p :scription (acres) (hrs) (hrs) (in) (in) input/used --- -oposed wet 3 . 60 78 . 0 0 . 75 0 . 00 6 . 60 1 4 . 11 . 09 . 10 ------- ------------------------------------------------------------------- -- - Travel time from subarea outfall to composite watershed outfall point . Total area = 3 . 60 acres or 0 . 00562 sq.mi Peak discharge = 8 cfs »» Computer Modifications of Input Parameters �«« --- ------ -------- Input Values Rounded Values Ia/p dSubarea Tc * Tt Tc * Tt Interpolated Ia/p '.scription (hr) (hr) (hr) (hr) (Yes/No) Messages ----------------- --_---------------------------------------- ------- ------ ------- --- Pposed wet 0 . 67 0 . 00 0 . 75 0. 00 No Computed Ia/p < 1 ---- -------------------------------------_------------------------------ -- --- ---- � Travel time from subarea outfall to composite watershed outfall point . 4 nick TR-55 Version: 5 . 42 SIN: 1240540150 Page 2 TR-55 TABULAR HYDROGRAPH METHOD Type ITT Distribution (24 hr. Duration Storm) Executed: 05-01-1995 11 : 02 :20 Watershed file : A2P100 .WSD Hydrograph file : A2P100 .HYD »» Summary of Subarea Times to Peak <<<< Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) (hrs) proposed wet 8 12 . 7 Composite Watershed 8 12 . 7 s d nick TR-55 Version: 5 .42 SIN: 1240540150 Page 4 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05--01-1995 11. : 02 : 20 Watershed file : --> A2P100 .WSD Hydrograph file : A2P100 HYD Time Flow Time Flow (hrs) (cf s) (hrs) (cf s) 11 . 0 0 14 . 8 1 11 . 1 0 14 . 9 1 11 . 2 1 15 . 0 1 11 . 3 1 15 . 1 1 11 . 4 1 15 . 2 1 11 . 5 1 15 . 3 1 11 . 6 1 15 .4 1 11 . 7 1 15 . 5 1 11 . 8 1 15 . 6 1 11 . 9 1 15 . 7 1 12 . 0 1 15 . 8 1 12 . 1. 1 15 . 9 1 12 . 2 2 16 . 0 1 12 . 3 2 16 . 1 1 12 . 4 3 16 .2 1 12 . 5 5 16 . 3 1 12 . 6 6 16 .4 1 12 . 7 8 16 . 5 1 12 . 8 8 16 . 6 1 12 . 9 7 16 . 7 1 13 . 0 7 16 . 8 1 13 . 1 6 16 . 9 1 13 . 2 5 17 . 0 1 13 . 3 4 17 . 1 1 13 . 4 4 17 . 2 1 13 . 5 4 17 . 3 1 13 . 6 3 17 .4 1 13 .7 2 17 . 5 1 13 . 8 2 17 . 6 1 13 . 9 2 17 . 7 1 14 . 0 2 17 . 8 0 14 . 1 2 17 . 9 0 14 . 2 1 18 . 0 a 14 . 3 1 18 . 1 a 14 .4 1 18 . 2 0 14 . 5 1 18 .3 0 14 . 6 1 18 .4 a 14 . 7 1 18 . 5 0 I i ii Pk TR-55 Version: 5 .42 SIN: 1240540150 fitted: 05-01--1995 15 :34 : 09 Y Flow (cfs) 0 . 0 1 . 0 2 . 0 3 . 0 4 . 0 5 . 0 5 . 0 7 . 0 8 . 0 9 . 0 10 . 0 11 . 0 1 - � * 5 - 9 - 3 - � * ,7 - * . 1 - * . 5 - * . 9 - I I * . 3 - I * .7 - I .1 - I I * i. 5 - . 9 - � i I * 1. 3 - R. 7 - I * . 1 - I 1 � * I * 9 - I * I f * i TIME (hrs) '* File : A2P100 .HYD Qmax = 8 . 0 cfs 9 wick TR-55 Version: 5 .42 SIN: 12405401.50 Page 1 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01--1.995 15 :41. :44 Watershed file : OPA1 .WSD Hydrograph file : - OPA1 .HYD »>> Input Parameters Used to Compute Hydrograph <<<< - M- - Subarea AREA CN Tc * Tt Precip . Runoff Ia/p escription (acres) (hrs) (hrs) (in) (in) input/used ----------------- ption A 2 . 90 74 . 0 0 . 75 0 . 00 2 . 50 0 . 61 . 28 . 30 - ---------- ------ ---- ---- - ------ --- --------------------------------------- --- Travel time from subarea outfall to composite watershed outfall point . Total area = 2 . 90 acres or 0 . 00453 sq.mi Peak discharge = 1 cfs >>>> Computer Modifications of Input Parameters ««< ------- ----------- ----- --------- --------------------------------------------- Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Ia/p ;escription (hr) (hr) (hr) (hr) (yes/No) Messages ------------------------------------------- - ----- --------------------------- Ition A 0 . 67 0 . 00 0 . 75 0 . 00 No -- u I - ...___��----"''"__- --"_ ... ------------ ____----"__'"----...____ Travel time from subarea outfall to composite watershed outfall point . a tick TR--55 Version: 5 .42 SIN: 1240540150 Page 2 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 15 :41 :44 Watershed file: --> OPA1 .WSD Hydrograph file : OPA1 .HYD »» Summary of Subarea Times to Peak <«< Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) (hrs) option A 1 12 . 6 j 12 . 6 Composite Watershed 1 3 3 d wick TR-55 Version: 5 .42 SIN: 1240540150 page 4 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 15 :41 :44 Watershed file : OPA1 .WSD Hydrograph file : --> OPA1 .HYD Time Flow Time Flow (hrs) (cf s) (hrs) (cf s) ------ ----------- ----------------- 11 . 0 0 14 . 8 0 11 . 1 0 14 . 9 0 11 . 2 0 15 . 0 0 11 . 3 0 15 . 1 0 11 .4 0 15 . 2 0 11 . 5 0 15 . 3 0 11 . 6 0 15 . 4 0 11 . 7 0 15 . 5 0 11 . 8 0 15 . 6 0 11 . 9 0 15 . 7 0 12 . 0 0 15 . 8 0 12 . 1 0 15 . 9 0 12 . 2 0 16 . 0 0 12 .3 0 16 . 1 0 12 .4 0 16 . 2 0 12 . 5 0 16 . 3 0 12 . 6 1 16 . 4 0 12 . 7 1 16 . 5 0 12 . 8 1 16 . 6 0 12 . 9 1 16 . 7 0 13 . 0 1 16 . 8 0 13 . 1 1 16 . 9 0 13 . 2 1 17 . 0 0 13 . 3 0 17 . 1 0 13 . 4 0 17 . 2 0 13 . 5 0 17 . 3 0 13 . 6 0 17 .4 0 13 . 7 0 17 . 5 0 13 . 8 0 17 . 6 0 13 . 9 0 17 . 7 0 14 . 0 0 17 . 8 0 14 . 1 0 17 . 9 0 14 . 2 0 18 . 0 0 14 .3 0 18 . 1 0 14 .4 0 18 . 2 0 14 . 5 0 18 . 3 0 14 . 6 0 18 .4 0 14 . 7 0 18 . 5 0 3 1 g .ck TR-55 Version: 5 .42 SIN: 1240540150 )tted: 05-01-1995 1.5 :49 : 39 Flow (cfs) 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 I I * , 2 _ I * I * ; 4 _ I * I * I * 8 - I * V SO * �. 2 8 I * u.4 I I * 6 - I Q. 6 * I * 0 - I I * ". 2 - I 1 * 4 I * I * .'. 6 - I * 8 - I * I * 0 " I * TIME (hrs) '* File : OPA1 HYD Qmax = 1 . 0 cfs 3uick TR--55 Version: 5 .42 SIN: 1240540150 Page 1 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05--01-1995 15 :47 :25 Watershed file : --> OPA10 .WSD Hydrograph file: OPA10 .HYD o o g »» Input Parameters Used to Compute Hydrograph <<<< ° ------------------------�--_T_---------------------�------------W--- --- -------- - - -- „ Subarea AREA CN Tc * Tt Precip. Runoff Ia/p ;ascription (acres) (hrs) (hrs) (in) (in) input/used ---------------- - --- ------ a ------------------------------------------ ---�---_ -- sotion a 2 . 90 74 . 0 0 . 75 0 . 00 4 . 60 j 2 . 05 . 15 . 10 {:Travel-time-from subarea outfall to composite watershed outfall point . Total area = 2 . 90 acres or 0 . 00453 sq.mi Peak discharge = 3 cfs »» Computer Modifications of Input Parameters <<<<< -------------------- ---- - -- ------ -- --- ---- Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Ia/p :ascription (hr) (hr) (hr) (hr) (Yes/No) Messages ----------------- - 'pion a 0 . 67 0 . 00 0 . 75 0 . 00 No -- : Travel time from subarea outfall to composite watershed outfall point . quick TR--55 Version: 5 .42 SIN: 1240540150 Page 2 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 15 :47 : 25 Watershed file : --> OPA10 WSD Hydrograph file : -> OPA1.0 .HYD u 0 l u o »» Summary of Subarea Times to Peak «« n Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) {hrs} option a 3 12 . 6 12 . 6 Composite Watershed 3 fuick TR-55 Version: 5 .42 SIN: 1240540150 Page 4 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 15 :47 : 25 Watershed file: --> OPA10 .WSD Hydrograph file : --> OPA10 .HYD Time Flow Time Flow (hrs) (cf s) (hrs) (cf s) ----------------- ----------_--_---- 11 . 0 0 14 . 8 0 s 11 . 1 0 14 . 9 0 11 . 2 0 15 . 0 0 v. 11 . 3 0 15 . 1 0 11 . 4 0 15 . 2 0 11 . 5 0 15 . 3 0 11 . 6 0 15 .4 0 11 . 7 0 15 . 5 0 11 . 8 0 15 . 6 0 11 . 9 0 15 . 7 0 12 . 0 0 15 . 8 0 12 . 1 1 15 . 9 0 12 . 2 1 16 . 0 0 12 . 3 1 16 . 1 0 12 .4 1 16 . 2 0 12 . 5 2 16 . 3 0 12 . 6 3 16 .4 0 12 . 7 3 16 . 5 0 12 . 8 3 16 . 6 0 12 . 9 3 16 . 7 0 13 . 0 3 16 . 8 0 13 . 1 2 16 . 9 0 13 . 2 2 17 . 0 0 13 . 3 2 17 . 1 0 13 . 4 2 17 . 2 0 13 . 5 2 17 .3 0 13 . 6 1 17 .4 0 13 . 7 1 17 . 5 0 13 . 8 1 17 . 6 0 13 . 9 1 17 .7 0 14 . 0 1 17 . 8 0 14 . 1 1 17 . 9 0 14 . 2 1 18 . 0 0 14 . 3 1 16 . 1 0 14 . 4 1 18 .2 0 14 . 5 0 18 . 3 a 14 . 6 0 18 .4 0 14 . 7 0 18 . 5 0 9 B 9 rt 0 ii' ick TR-55 Version: 5 .42 SIN: 1240540150 atted: 05-01-1995 15 : 50 :13 Flow (cfs) 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 3 . 0 3 . 5 4 . 0 4 . 5 5 . 0 5 . 5 . ------ l ----- I ----- I ----WI ---- I ----- l ----- l ----- I --�-- I --_-- ! _---- I - I * .4 - I * ! * - ! * ! * • 0 1 * l 3 - I 6 - � * . 9 - ! ! * 2 ! a' 5 y I * . 8 - i I Jr ! * ! * 4 - ! 1 * - I * 0 ( * I * :.3 _ I 6 - I * I * I * '. 2 - I * ! * l * .8 - ! * I * V * 4 1 . 7 I � TIME (hrs) File : OPA10 .HYD Qmax = 3 . 0 cfs I Quick TR-55 Version: 5 .42 SIN: 1240540150 Page 1 TR--55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01--1995 1.5 :48 : 51 Watershed file : -> OPA1.00 .WSD Hydrograph file : 0PA100 .HYD >>>> Input Parameters Used to Compute Hydrograph <«< --- ----------- ---- -------------------------------------------- --------------- Subarea AREA CN Tc * Tt Precip. I Runoff Ia/p vscription (acres) (hrs) (hrs) (in) (in) input/used ----- -- ------ ----------------------------------------------------- - --- - -- ---- Dtion a 2 . 90 74 . 0 0 . 75 0 . 00 6 . 60 3 . 70 . 11 . 10 - -- -- - -- ------ -- ----------------------------------------------------- ---- --- - Travel time from subarea outfall to composite watershed outfall point . Total area = 2 . 90 acres or 0 . 00453 sq.mi Peak discharge = 6 cfs >>>> Computer Modifications of Input Parameters ««< ---- -------------- --------------------------------------------------- --- ---- - Input Values Rounded Values Ia/p Subarea Tc * Tt Tc * Tt Interpolated Ia/p ascription (hr) (hr) (hr) (hr) (Yes/No) Messages --------------- -------------------------------------------------------------- --ion a 0 . 67 0 . 00 0 . 75 0 . 00 No -- --------------- - ---------- --------------------------------------------------- Travel time from subarea outfall to composite watershed outfall point . wick TR--55 Version: 5 .42 SIN: 1240540150 Page 2 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01-1995 15 :48 : 51 Watershed file : OPA100 .WSD Hydrograph file : --> OPA100 .HYD »» Summary of Subarea Times to Peak «« Peak Discharge at Time to Peak at Composite Outfall Composite Outfall Subarea (cfs) (hrs) option a 6 12 . 8 Composite Watershed 6 12 . 8 wick TR-55 Version: 5 . 42 SIN: 1240540150 Page 4 TR-55 TABULAR HYDROGRAPH METHOD Type III Distribution (24 hr. Duration Storm) Executed: 05-01--1.995 1.5 :48 : 51 Watershed file : OPA100 .WSD Hydrograph file: OPA100 .HYD Time Flow Time Flow (hrs) (cfs) (hrs) (cf s) 11 . 0 0 14 . 8 1 11 . 1 0 1.4 . 9 1 11 . 2 0 15 . 0 1 11 . 3 0 15 . 1 1 11 . 4 0 15 . 2 1 11. . 5 0 15 . 3 1 11 . 6 0 15 .4 1 11 . 7 0 15 . 5 1 11 . 8 1 15 . 6 1 11 . 9 1 15 . 7 1 12 . 0 1 15 . 8 1 12 . 1 1 15 . 9 1 12 . 2 1 16 . 0 1 12 .3 2 16 . 1 1 12 .4 3 16 .2 1 12 . 5 4 16 . 3 0 12 . 6 5 16 .4 0 12 . 7 5 16 . 5 0 12 . 8 6 16 . 6 0 12 . 9 5 16 . 7 0 13 . 0 5 16 . 8 0 13 . 1 4 16 . 9 0 13 . 2 4 17 . 0 0 13 . 3 3 17 . 1 0 13 . 4 3 17 . 2 0 ij i1 6 ry� k 9 13 . 5 3 17 . 3 0 13 . 6 2 17 .4 0 13 . 7 2 17 . 5 0 13 . 8 2 17 . 6 0 13 . 9 1 17 . 7 0 14 . 0 1 17 . 8 0 14 . 1 1 17 . 9 0 14 . 2 1 18 . 0 0 14 . 3 1 18 . 1 0 14 .4 1 18 . 2 0 14 . 5 1 18 . 3 0 14 . 6 1 18 .4 0 14 . 7 1 18 . 5 0 ick TR-55 Version: 5 . 42 SIN; 124054015p atted: 05-01-1995 15 :50 :56 0 . 0 1 . 0 2 . 0 3 . 0 4 . 0 Flow (cfs) 5 . 0 6 . 0 7. a 8 . 0 9 . 0 , 2 6 - f * f * o - f I * 4 _ f I B f f 1 * - f 1 * - f f F 1 � 1 * f ! * _ f * f * - f * f * _ f * f * f * I * f * f * I * I * u f * � . 6 9 f * f * TIME (hrs) * File : OPA100 .HYD Qrrtax = 6 . 0 cts