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HomeMy WebLinkAboutStormwater Report - 700 CHICKERING ROAD 12/23/1993 PRELIMINARY DRAINAGE CALCULATIONS O HERI TA . T NORTH NORTH ANDOVER, MASSACHUSETTS December 23, 1993 Owner: A•D•S ANDOVER & A•D•S SENIOR HOUSING 159 Main Street Cambridge, Massachusetts Architect: CBT ARCHITECTS, INC. 60 Dartmouth Street Boston, Massachusetts 02116 Landscape Architect: GELLER ASSOCIATES, INC. 77 North Washington Street Boston, Massachusetts 02114 Civil Engineer: SITE ENGINEERING CONSULTANTS, INC. 137 Hammond Street Waltham, Massachusetts 02154 - TR-.S�, _r__uR11E_1�duM8ER COMPUTAT_ION____ ------------- JOB I\� /-1ryi�c r/�� S�hll02 f��tJ✓SINS �r'�t>OV -nr �Oc�78 Site Engineering Consultants, Inc. SHEET NO. / OF 137 Hammond Street DATE /z�! L 3 Waltham, Massachusetts 02154 CALCULATED BY 4 (617) 891-8739 CHECKED BY DATE CONSULTING CIVIL ENGINEERS SCALE S f �K M W F7 Eft M p Ct L M G I-I T '-QE.SIGhI CrGITEIcIaa - �"1 ETl-roC>��OG.Y � SCS r'Jopl F1E f'a �bIL C.ovEl� �-c, f.,I 1 ��.: -� t 1 d: -T r r D 1�) PE S IGrI F=r?-F- CY - !00 YERRZ - Z4 I� u2 ST�IZM 1Z RTE • Co• O �2EGIP1 -r F?T Ip�r �u IN I1M u r� TI ME OF Cory c-F-t-4 -T F?-P-1 10*-1 � HSG Soi � C L_ RSS �r� ICr -r : orcS t) sC��BS ll�oor-, 3Iz-InC-E CUJr(� � C. Z� C, r E� t-otr CCma� - rInIC Sr-rra�Y Lo��1-, 3.o r� t ,o _ s�opES - I3 IZ ri c, I=�= C�.�2v r-% 13 e= r<S (C N CN LIzND VS E SOIL l rr�c W o C -7 O Ln wl-1 (C.00D / b Lp,wr-' (G OvD Co1JD•) PgvEP'tEN`r�TzovFs 98 Wn- TG: Su2FRCE S b-J E 5 T F L 0 l,U C G,I-1 G Z Y c is rc Z� tlovr� Slorcrl QF>, c 3. I In, i°rI -- 4 h{S NirtrlrllliGs 2ovGril�fESS CoCt=F �c� I6rIT (Jrl} L Fr tit c:> USE rl WOODS Cam. `}-� Lr_)�,ur.IS %G ZFSS6 S O' + AV ---- 1. 11 TR-55 To and Tt THRU SUBAREA COMPUTATION VERSION A- S- Dates 12-19-93 User : Date: 1ject N. s N Andover Senior Housing MA Checked: — i inty - Essex Runoff - Watershed ------------------ ,titles Predevelopment -----_____ - Wat-1 - Wp Velocity Time Subarea #i n Area (hr) ------------- Slope Surface (sq/ft) (ft) (ft/sec) - ow Type rain 2 year Length (ft/ft) code -------------------------------0. 361 rain - --------------- 0, 046 ----------------- ,0452 f --------- ---- 248 0.041 eet , 0253 P = 0, 45* ,allow Concent'd 503 .0447 u Time of Concentration - �a1low Concent d Codes Shallow Concentrated Sheet Flow Surface F Grass, Dense Surface Codes A Smooth Surface G Grass, Burmuda p paved B Fallow (No Res. ) H Woods, Light U Unpaved C Cultivated < 20 76 Res- 1 Woods, Dense D Cultivated > 20 % Res. E Grass:-Range, Short Generated for use by TABULAR method VERSION 1 - ii TR-55 TABULAR DISCHARGE METHOD Date: 12-19-93 User : A. S. Date: aject N. State: MA Andover Senior Housing Checked: unty Essex - Watershed i ears Predevelopmen type:Runoff Frequency: --- Y btitle: II ______________ 0.007 sq mi Rainfall tYPeS---------__ tal watershed_area: __________________ Subareas Wat-1 -ea(sq mi) 0.01* Linfal l (in) 6.5 irve number 79* inoff (in) 0.45* (hrs) 0.40 (Used) imeToOutlet 0.00 3./P 0.08 __--------- (Used) 0. 10_ (cfs) - ___---- Subarea Contribution to Total Flow ime Total -____ hr) Flow Wat-i 1 1 1 .0 1 1 1.3 1 1 1.6 2 2 1.9 4 2.0 4 8 2. 1 8 14 2. 2 2.3 i8P 18P 2.4 18 18 2. 5 13 13 9 2.6 9 7 7 2.7 5 5 2.8 3 3.0 3 2 2 3.2 2 2 3.4 3.6 2 2 1 3.8 1 1 1 4.0 1 4.3 1 1 1 4.6 1 5.0 1 1 1 5. 5 1 6.0 1 1 1 6. 5 1 7. 0 1 1 1 7.5 1 8. 0 1 9. 0 O 0 0 0. 0 0 0 2.0 0 0 6. 0 0 routines - Peak Flow # - value(s) provided from TR-55 system VERSION 1. 11 TR-55 CURVE NUMBER COMPUTATION Date: 12-19-93 User : A. S. Date: --- Senior Housing Checked: oject N. Andover State: MA _--- Essex meet Runoff - Watershed 2 -------------- --__ untY evelop ---'��- ibtitle: Pred2 --------------------------'Hydrologic Soil Group D ibarea . Wa _--------- g C ------------- A Acres (CN) COVER DESCRIPTION-------------------------------------------- _ __ ----AREAS (Veg Estab• ) - URBAN .073(61) .468(74) ULLY DEVELOPED arks etc. ) - pen space (LawnspP > 75%cover _ Good condition; grass _ _ .533(98) mpervious Areas roofs, driveways _ - parking lots, _ •027(98) Paved p 100% urban (F9 to define) p96 Jser defined % impervious 98 % unconnected impervious pervious curve number . 133(70) OTHER AGRICULTURAL LANDS good Woods .606 .6_2_8_ Area (by Hydrologic Soil Group) Total CURVE NUMBER:84 ___------ WEIGHTED __------. ------- --- --AREA: 1.234 Acres SUBAREA: Wat _____---------- __---- TOTAL DRAINAGE __----------'- -- -2-------------------------- TR-55 To and Tt THRU SUBAREA COMPUTATION VERSION i - ii User : A. S. Date: 12-19-93 ,oject : N. Andover Senior Housing Checked: Date: �— State: MA )unty Essex - Watershed 2 ibtitle: Predevelopment Runoff -------------------- _________ _---- Subarea #i - Wat-2 Velocity Time ----------------------- --- Slope Surface n Area ft (hr) year Length (sq/ft) (f t) (ft/sec) -- low Type 2 Y (ft) (ft/ft) code ------------------------- rain -------------------- 0. 444 ------------------------------.0394 f heet .0172 P 0. 022 3. 1 300 215 0. 015 hallow Concent' d 150 .0313 u = 0. 48* hallow Concent' d Time of Concentration __--- Sheet Flow Surface Codes --- --- Shallow Concentrated Dense F Grass, - Surface Codes A Smooth Surface G Grass, Burmuda p paved B Fallow (No Res. ) H Woods, Light U Unpaved C Cultivated < 20 % Res. I Woods, Dense D Cultivated > Res. E Grass-Rang e, Short Generated for use by TABULAR method TR-55 TABULAR DISCHARGE METHOD VERSION i. ii User : A. S. Date: 12-19-93 � oject N. Andover Senior HouStates MA Checked: Date: ____—---- ,)unty : Essex - Watershed 2 .ibtitle: Predevelopment Runoff 100 years 0.002 sq mi Rainfall type: II -__-Frequency__--_---- ptal watershed are a: Subareas -- Wat-2 rea(sq mi) 0.00* ainfall (in) 6.5 urve number 67* unoff (in) 4.0. 7 'c (hrs) (Used) 0. 50 'imeToOutlet 0. 06 a/P (Used) 0. 10 ---------- _ 'ime Total _____________ Subarea Contribution to Total Flow (cfs) - hr) Flow . Wat-2 1.0 0 0 .1.3 0 0 .1.6 0 O .1.9 1 1 .2.0 1 1 .2. 1 2 2 2.2 3 3 2.3 4 4 2.4 5P 5P 2. 5 5 5 2.6 4 4 2.7 3 3 2.8 2 2 3.0 1 1 3.2 1 1 3.4 1 1 3.6 1 1 3.8 O O 4.0 O 0 4.3 0 O 4.6 0 0 5.0 0 0 .5.5 0 0 .6. 0 0 0 L6. 5 0 0 17.0 0 0 L7.5 0 0 l8.O 0 0 .9.0 0 0 ?O.0 0 0 ?2.0 0 0 ?6.0 O O - Peak Flow * - value(s) provided from TR-55 system routines TR-55 CURVE NUMBER COMPUTATION VERSION 1. 11 User : A. S. Date: 12-19-93 oject : N. Andover Senior Housing Checked: Date- �-- State: MA ' unty : Essex - Watershed 3 btitle: Predevelopment Runoff bares . Wat-3 ---------------------------------- Group --------------------------------------------------------- ----- Hydrologic Soil P D ------------------ -- A B C COVER DESCRIPTION Acres (CN) ILLY DEVELOPED URBAN AREAS (Veg Estab. ) - >en space (Lawns, parks etc. ) _ - . 505(74) Good condition; grass cover > 75% - 1.06(98) - Zpervious Areas roofs, driveways - Paved parking lots, 'HER AGRICULTURAL LANDS _ -good . 143(70) ods 1.70 )tal Area (by Hydrologic Soil Group) --------------------------------- ------------------------WEIGHTED CURVE NUMBER:89 --------------- O8 Acres ------------------ ------------ JBAREA: Wat-3 TOTAL DRAINAGE AREA: _______________ TR-55 Tc and Tt THRU SUBAREA COMPUTATION VERSION 1 . 11 User: A.S. Date: 12-19-93 oject : N. Andover Senior Housing Checked: Date: State: MA unty : Essex _ Watershed 3 btitle: Predevelopment Runoff -------- Subarea #1 - Wat- Area P Velocity Time ----------�-year Length Slope Surface n (ft) (ft/ft) code (sq/ft) (ft) (ft/sec) (hr) ow Type ----- rain -------°--- ------------ _ -------- 0.016 1 3 ----------- . 105 .0429 a 0.488 eet `'. 1 188 .0122 f 0.03,E eet 243 .0099 P 0.008 allow Concent 'd .0877 u = 0.55# 146 callow Concent 'd Time of Concentration _---- Sheet Flow Surface Codes --- --- Shallow Concentrated --- F Grass, Dense Surface Codes --- A Smooth Surface G Grass, Burmuda B Fallow (No Res. ) P Paved C Cultivated < 20 % Res. H Woods, Light U Unpaved D Cultivated ? 20 % Res. I Woods, Dense E Grass-Range, Short - Generated for use by TABULAR method TR-55 TABULAR DISCHARGE METHOD VERSION 1. 11 User : A. S. Date: 12-19-93 roject N. Andover Senior Housing Checked : — Date: Essex State: MA ounty - Watershed 3 ubtitle: Predevelopment Runoff Frequency: 100 years otal watershed area: 0.003 sq miRainfall type: -II ---------------------- Subareas - Wat-3 rea(sq mi ) 0.00* ainfall (in) 6.5 urve number 89* unoff ( in) 5. 22 'c (hrs) 0. 55* (Used) 0.50 'imeToOutlet 0. 00 a/P 0. 04 (Used) 0. 10 ubarea Contribution to Total Flow (cfs) ------------ ime Total ------------- S hr) Flow . Wat-3 1.0 0 0 1. 3 0 0 1.6 0 0 1.9 1 1 2.0 1 1 2. 1 2 2 2.2 4 4 2.3 7P 7P .2.4 7 7 .2. 5 7 7 .2.6 6 6 .2.7 4 4 .2.8 3 3 .3. 0 2 2 .3.2 1 1 .3. 4 1 1 .3.6 1 1 .3. 8 1 1 .4.0 1 1 .4. 3 1 1 .4.6 1 1 .5. 0 0 0 5.5 0 0 6.0 0 0 6.5 0 0 7.0 O 0 7.5 0 0 B. 0 O 0 9.0 0 O 3. 0 0 O 2.0 0 0 5.0 O O * - value(s) provided from TR-55 system routines — Peak Flow TR-55 CURVE NUMBER COMPUTATION VERSION 1. 11 User : A. S. Date: 12-19-93 N. Andover Senior Housing Checked: Date: roject State: MA aunty Essex ubtitle: Predevelopment Runoff - Watershed - ubarea -------------------------- Group ---------------- Hydrologic Soil A B C COVER DESCRIPTION Acres (CN) ULLY DEVELOPED URBAN AREAS (Veg Estab. ) - pen space (Lawns, parks etc. ) _ - .291 (74)Good condition; g rass cover > 75% THER AGRICULTURAL LANDS _good - . 114(70) nods . 405 :)tal Area *(by Hydrologic Soil Group) - INAGE AREA: .405 Acres -WEIGHTED-CURVE-NUMBER_73 UBAREA: Wat-4 -- TOTAL DRAINAGE ---------- ----- ----- TR-55 Tc and Tt THRU SUBAREA COMPUTATION VERSION i. il User : A. S. Date: 12-19-93 roject : N. Andover Senior Housing Checked: — Date: -_--_--- aunty Essex State: MA ubtitle: Predevelopment Runoff - Watershed 4 ----------------- ----------------------------- Subarea #1 - -----W-a-t-n-4----Area W P Velocity Time low Type 2 Y ear Length Slope Surface (sq/f t) (ft) (ft/sec) (hr) rain (ft) (ft/ft) code ------------------ ------- 0.234 -------------- ------------------- , 0624 f 0. 122 58 beet 3. 1 0 . 1034 h 0. 36* heet Time of Concentration = ----- --- Sheet Flow Surface Codes - Dense --- Shallow Concentrated A Smooth Surface Dense --- Surface Codes G Grass, P Paved B Fallow (No Res. ) C Cultivated < 20 % Res. H Light Woods, U Unpaved D Cultivated > 20 % Res. I Woods, Dense E Grass-Range, Short - Generated for use by TABULAR method TR-55 TABULAR DISCHARGE METHOD VERSION 1 . 11 User : A. S. Date: 12-19-93 oject : N. Andover Senior Housing Checked : Date' Essex State: MA ' unty went Runoff - Watershed 4 ibtitle: Predevelop Frequency:.001 sq m 100 years ital watershed area: 0i Rainfall type: II --- -------------- ----- Subareas -- - - Wat-4 �ea(sq mi ) 0.00* Linfal 1 (in) 6. 5 irve number 73* inoff ( in) 3. 51 (hrs) 0. 36* (Used) 0. 40 imeToOutlet 0.00 i/P 0. 1i __ Lme Total ------------ Subarea Contribution to Total Flow (cfs) --------- hr) Flow Wat-4 1.0 0 0 1.3 0 0 1.6 0 0 1.9 0 0 2.0 0 0 2. 1 iP iP 2.2 1 1 2. 3 1 1 2.4 1 1 2. 5 1 1 .2.6 1 1 .2.7 0 0 .2.8 0 0 .3. 0 0 0 .3.2 0 O .3. 4 O 0 .3.6 0 0 .3. 8 0 0 .4.0 0 0 L4. 3 0 0 .4.6 0 0 L5.0 0 0 .5.5 0 0 .6.0 0 0 6.5 0 0 7.0 O 0 7.5 0 0 8.0 0 0 9.0 0 0 0.0 O 0 2.0 O 0 3.0 0 0 - Peak Flow * - value(s) provided from TR-55 system routines TR-55 CURVE NUMBER COMPUTATION VERSION 1. 11 User : A. S. Date: 12-22-93 oject N. Andover Senior Hous�nage• MA Checked: __ Date: .�---- unty Essex - 'Watershed 1 _____----_- Postdevelopment Runoff ------__ ibtitle: t_1 ----------------- Group ibarea . Wa -------------------------- Hydrologic Soil D ---------- B C ----- A COVER DESCRIPTION Acres------------------------------------(CN)----------------- JI,LY DEVELOPED URBAN AREAS (Veg Estab. ) _ arks etc. ) _ 1 . 45(61) 1.96(74) pen space (Lawns. Prass cover > 75� Good condition, g 1.35(98) mpervious Areas lots, roofs, driveways _ Paved parking _ . 059(98) (F9 to define) 100% ser defined %rimpervious 0% % unconnected impervious 98 pervious curve number _ - .055(70) - ITHER AGRICULTURAL LANDS good loads 1. 50 3.36 ratal Area (by Hydrologic Soil Group) --------------------------------Acres WEIGHTED-CURVE-NUMBER_77_- ----------- TOTAL DRAINAGE AREA: ---------------- SUBAREA_-Wat_1------------------------------ TR-55 Tc and Tt THRU SUBAREA COMPUTATION VERSION 1. 11 User : A. S. Date: 12-22-93 ,oject N. Andover Senior HouSta Date: ____ te: MA Checked: ---- runty Essex - 'Watershed 1 ibtitle: Postdevelopment Runoff _______________________ ___-- Subarea #1 - Wat-1 ----------------------------- Time ------------------------th Slope Surface n Area ft) (f t) (ft/sec) (hr) low Type 2 year L(ft) (ft/ft) code (5 -------------------------- rain ------------------ 0. 104 ---_ ------------ ---- f 0. 008 beet---_---_3' 1 --------------------------- .044 a 0. 040 45.0 = 0. 15* beet . 0439 u Time of Concentration -_ hallow Concent' d 490.0 Sheet Flow Surface Codes - Dense --- Shallow Concentrated F Grass, -- Surface Codes A Smooth Surface G Grass, Burmuda - p Paved B Fallow (No Res. ) H Woods, Light U Unpaved C Cultivated < 20 % Res. 1 Woods, Dense D Cul ti.vated > 20 % Res. E Grass-Rang e, * - Generated for use by TABULAR method TR-55 TABULAR DISCHARGE METHOD VERSION 1. 11 User : A. S. Date: 12-22-93 -oject : N. Andover Senior Housing Checked: _ Date: Essex State: MA ° ,)unty - 'Watershed 1 jbtitle: Postdevelopment Runoff Frequency: 100 years 0.008 sq mi Rainfall type_ watershed area: -Il ---------------------- otal -------------------------- Subareas Wat-1 rea(sq mi ) 0. 01* ainfall (in) 6.5 urve number 3.92* unoff ( in) 'c (hrs) 0. 15* (Used) 0. 20 imeToOutlet 00. 09 a/P (Used) 0. 10 ----------- ---------"--- Subarea Contribution to Total Flow (cfs) - 'ime T otal :hr) Flow Wat-1 1.0 1 1 ,1.3 1 1 L1.6 1 1 11.9 6 6 L2.0 12 12 12. 1 22 22 12.2 24P 24P 12.3 14 14 12.4 7 7 12.5 5 5 12.6 4 4 12. 7 3 3 12.8 3 3 13.0 2 2 13.2 2 2 13. 4 2 2 13.6 1 1 13. 8 1 1 14.0 1 1 14. 3 1 1 14.6 1 1 15. 0 1 1 15. 5 1 1 16. 0 1 1 16. 5 1 1 17. 0 1 1 17.5 1 1 L8.0 i 1 19.0 0 0 >0.0 0 0 22.0 0 0 >.6.0 0 O - Peak Flow * - value(s) provided from TR-55 system routines VERSION 1. 11 CURVE NUMBER COMPUTATION TR_gg Date: 12-22-93 User: A. S. Date: Andover Senior HOUstag MA Checked: _-- or te: 'ontYt . Essex do elopment Runoff - Watershed 2_ c Sol,_Group btitle: pOStdev ______ ___ HYdrologi C D ubarea Wat_?___----- A pores COVER DESCRIPTION AREAS (Veg Estab• ) _ . 070(61) .703(74) Y DEVELOPED URBAN AREAS ?ULL (Lawns parks space cover > 75% �pGoodpconditiOn' grass s Areas roofs, driveways ,023(98) Impervious - 100% Paved parking (F9 to 98 define) 0% ed urba User definn % impervious impervious % unconnected number pervious curve . 100(70) OTHER AGRICULTURAL LANDS good Woods . 603 . 306 -_ H drologic Soil Group) --___-_-- Total Area (by Y :78 ____----- WEIGHTED CURVE NUMBER_____ --- 1 109 Acres RpINAGE AREA: ----------------- UBAREA' Wat-2 TOTAL S ______-- TR-55 To and Tt THRU SUBAREA COMPUTATION VERSION 1. 11 User : A.S. Date: 12-22-93 N Andover Senior Housing Checked: Date: roject . State: MA ounty : Essex _ 'Watershed 2 ubtitle: Postdevelopment Runoff --P------------------ __________ __-_-- Subarea #1 - Wat-2 - W Velocity Time Length Slope Surface n Area (sq/f t) (ft) (ft/sec) (hr) glow Type (ft) (ft/ft) code ----------- 0. 500 •----------------°----300.0 .0293 f 0. 027 iheet 270. 0 .0293 u 0. 008 ;hallow Concent' d 90.0 . 0422 u = 0. 53* ;hallow Concent' d Time of Concentration --_-- Sheet Flow Surface Codes - --- Shallow Concentrated Dense F Grass' Surface Codes A Smooth Surface G Grass, Burmuda --- p paved B Fallow (No Res. ) H Woods, Light U Unpaved C Cultivated < 20 % Res. Dense D Cultivated > Sho%tRes. 1 Woods, E Grass-Rang e, * - Generated for use by TABULAR method TR-55 TABULAR DISCHARGE METHOD VERSION 1- ii User: A. S. Date: 12-22-93 Project : N. Andover Senior Housing Checked: Date: -- State: MA County : Essex Subtitle: Postdevelopment Runoff - 'Watershed 100 years Total watershed area: 0.002 sq mi Rainfall type: -Il -__-Frequency----------------- Subareas - Wat-2 Area(sq mi ) 0. 00* Rainfall ( in) 6.5 Curve number 78* Runoff ( in) 4.02 To (hrs) 0. 53* (Used) 0.50 TimeToOutlet 0.00 Ia/P 0. 09 (Used) 0. 10 ----------- Subarea Contribution to Total Flow (cfs) - Time Total ------------- (hr) Flow . Wat-2 11.0 O 0 11.3 O 0 11.6 0 0 11.9 0 0 12.0 1 1 12. 1 1 1 12.2 2 2 12.3 3 3 12.4 4P 4P 12.5 4 4 12. 6 3 3 12. 7 2 2 12.8 2 2 13. 0 1 J. 13. 2 1 1 13.4 1 1 13.6 0 0 13. 8 0 O 14.0 0 0 14. 31 0 0 14.6 0 O 15. 0 0 O 15. 5 0 0 16. 0 0 0 t6. 5 0 0 17. 0 0 O t7.5 0 0 18. 0 0 0 t9.0 O 0 20. 0 O 0 ?2.0 0 0 26. 0 O 0 * - value(s) provided from TR-55 system routines Peak Flow TR-55 CURVE NUMBER COMPUTATION VERSION I. User : A. S. Date: 12-22- Project : N. Andover Senior Housing Checked: Date: County Essex State: MA Subtitle: Postdevelopment Runoff - Watershed Subarea : Wat-3 _ -------------------------------------- ----------- ---------------- -- -------------"'-- Hydrologic Soil Group ----------------------- ----- A B C I COVER DESCRIPTION Acres (CN) FULLY DEVELOPED URBAN AREAS (Veg Estab. ) Open space (Lawns, parks etc. ) _ _ , 372(74) Good condition; grass cover > 75% Impervious Areas _ - .380(98) Paved parking lots, roofs, driveways OTHER AGRICULTURAL LANDS good _ - .072(70) Woods . 624 Total Area (by Hydrologic Soil Group) WEIGHTED CURVE NUMBER-- TOTAL DRAINAGE AREA: . 824 Acres------ - - ------- Wat 3 ----- TR-55 Tc and Tt THRU SUBAREA COMPUTATION VERSION 1. 11 User : A. S. Date: 12-22-93 Andover er Senior Housing Checked: — Date: --- Project State: MA . County : Essex 'Watershed 3 Subtitle: Postdevelopment Runoff - ---------------------- ________ ----- Subarea #1 - Wat-3 ----'-- Velocity Time _ W (hr) ---- a Surface n Area p Flow Type 2 year Length Slop (sq/ft) --(ft) --(ft-sec) ------ (ft) (ft/f t) code -- rain ------------------ 0.049 ------------------- -270. 0 ---0163 a 0.064 Sheet 3. 1 . 050 f = 0. 11* 30.0 Time of Concentration ----- Sheet ---- Sheet Flow Surface Codes -- --- Shallow Concentrated Dense F Grass, Surface Codes A Smooth Surface G Grass, Burmuda --- p paved B Fallow (No Res. ) H Woods, Light U Unpaved C Cultivated < 20 % Res. I Woods, Dense D Cultivated > Sho�tRes. E Grass.-Rang e, * - Generated for use by TABULAR method TR-55 TABULAR DISCHARGE METHOD VERSION 1 . 11 User : A. S. Date: 12-22-93 Project : N. Andover Senior Houstage: MA Checked : Date: _-______-- County Essex Subtitle: Postdevelopment Runoff - 'Watershed 3 Total watershed area: 0. 001 sq mi Rainfall type: -II ----Frequency:-10--years Subareas - Wat-3 Area(sq mi ) 0. 00# Rainfall ( in) 6.5 Curve number 85x Runoff ( in) 4.78 Tc (hrs) 0. 11# (Used) 0. 10 TimeToOutlet 0.00 Ia/P 0.05 (Used) 0. 10 Subarea Contribution to Total Flow (cfs) ------------ Time Total ------------- (hr) Flow . Wat-3 11.0 0 0 11.3 0 0 11 .6 0 0 11.9 2 2 12.0 4 4 12. 1 6P 6P 12.2 4 4 12.3 1 1 12.4 1 1 .t2. 5 1 1 12.6 1 1 12.7 1 1 12.8 0 0 13.0 0 0 13.2 0 0 13. 4 0 0 13.6 0 0 13. 8 0 0 14.0 0 0 14. 3 0 0 14.6 0 0 15. 0 0 0 15. 5 0 0 16. 0 0 0 16. 5 0 0 17. 0 0 0 17.5 0 0 18. 0 0 0 19. 0 0 O 20. 0 O 0 22. 0 0 0 26. 0 O 0 * - value(s) provided from TR-55 system routines P Peak Flow TR-55 CURVE NUMBER COMPUTATION VERSION i. ii User : A. S. Date: 12-22-93 Project N. Andover Senior Housing MA Checked : Date: County Essex : • Subtitle: Postdevelopment Runoff - 'Watershed 4 Subarea : Wat-4 ---------------- --------------- ----------------------- -------------- Hydrologic Soil Group C D COVER DESCRIPTION A B Acres (CN) FULLY DEVELOPED URBAN AREAS (Veg Estab. ) Open space (Lawns, parks etc. ) _ - , 521(74) - Good condition; grass cover > 75% Impervious Areas _ - . 170(98) - Paved parking lots, roofs, driveways OTHER AGRICULTURAL LANDS good - - . 180(70) - Woods Total Area (by Hydrologic Soil Group) . 871 ------------------------ ------------------------------- WEIGHTED CURVE NUMBER: SUBAREA: Wat-4 TOTAL DRAINAGE AREA: . 871 Acres ------------------------- TR-55 Tc and Tt THRU SUBAREA COMPUTATION VERSION 1. 11 User : A. S. Date: 12-22-93 Project N. Andover Senior Housing Checked: Date- ________ County : Essex State: MA Subtitle: Postdevelopment Runoff —Watershed 4 -------------- ------------------------------ Subarea #1 - Wat- --Wp----- Velocity Time Flow Type 2 year Length Slope Surface n Area (ft) (ft/sec) (hr) rain (ft) (f t/f t) code ( q --------------------- 0.239 Sheet 3. 1 165.0 . 0558 f 0. 145 Sheet 55.0 . 0600 h Time of Concentration = 0. 38# --- Sheet Flow Surface Codes --- - Shallow Concentrated --- A Smooth Surface F Grass, Dense -- --- G Grass B Fallow (No Res. ) ' Burmuda --- Surface Codes p Paved C Cultivated < 20 % Res. H Woods, Light U Unpaved D Cultivated > 20 % Res. I Woods, Dense E Grass-Range, Short �t - Generated for use by TABULAR method TR-55 TABULAR DISCHARGE METHOD VERSION 1. 11 Project : N. Andover Senior Housing User: A. S. Date: 12-22-93 County : Essex State: MA Checked: Date: Subtitle: Postdevelopment Runoff - 'Watershed 4 Total watershed area: 0.001 sq mi Rainfall type: II Frequency: 100-years Subareas ---------------------- Wat-4 Area(sq mi ) 0.00* Rainfall ( in) 6.5 Curve number 78* Runoff ( in) 4.02 Tc (hrs) 0.38* (Used) 0.40 TimeToOutlet 0.00 la/P 0.09 (Used) 0. 10 Time Total ------- ------ Subarea Contribution to Total Flow (cfs) ------------ (hr) Flow . Wat-4 11. 0 0 0 11. 3 0 0 11.6 0 0 11. 9 0 0 12.0 1 1 12. 1 1 1 12. 2 3P 3P 12.3 3 3 12. 4 3 3 12. 5 2 2 12.6 2 2 12. 7 1 1 12.8 1 1 13. 0 1 1 13.2 0 0 13. 4 0 0 13.6 0 0 13. 8 0 0 14. 0 0 0 14. 3 0 0 14.6 0 0 15. 0 0 0 15. 5 0 0 16. 0 0 0 16. 5 0 0 17. 0 0 0 17. 5 0 0 18. 0 0 0 19. 0 0 0 20. 0 0 0 22. 0 0 0 26. 0 0 0 P - Peak Flow * - value(s) provided from TR-55 system routines TR-55 STORAGE VOLUME FOR DETENTION BASINS VERSION 1. 11 Project : N. Andover Senior Housing User: A. S. Date: 12-22-93 County : Essex State: MA Checked: Date: Subtitle: Approximate volume of required detention basin Drainage Area: 5.75 Acres Rainfall Frequency: 100 years Rainfall-Type: 11 24-Hour Rainfall : 6. 5 inches Runoff Curve Number: 78 Peak Inflow: 27 cf s Peak Outflow: 15 cfs Runoff Volume: 4. 0 inches Detention Basin Storage Volume: 1.03 inches or 0.5 acre feet