Loading...
HomeMy WebLinkAboutDrainage report Avery Street Christian R (2) DRAINAGE REPORT FOR SCANNED ADDITIONAL PARKING FOR THE COMMUNITY CHRISTIAN REFORMED CHURCH SOUTH WINDSOR.) CONNECTICUT ' DECEMBER 28,2007 ' PREPARED FOR: COMMUNITY CHRISTIAN REFORMED CHURCH 399 BEELZEBUB ROAD SOUTH WINDSOR, CONNECTICUT �r PREPARED BY- JAN 312008 FEb 017008 SOUTHSOUTH WINDSOi�PANNING DEP1 ENG/NSE,WNG pEP. CIVIL S, LLC ROC B._ P.E. ' 67 Mountain Spring Road,Burlington,CT Ph/Fax:(860)673-7146 Email:rroberts<<i'ciN-iistrate ies coin r rCommunity Christian Reformed Church r 399 Beelzebub Road, South Windsor, CT 06074 rTABLE OF CONTENTS rDESCRIPTION I Executive Summary U.S.G.S. Quad Map II Existing Hydrologic Conditions III Proposed Hydrologic Conditions IV Backup Data State of Connecticut Drainage Criteria 1 1 1 1 r i 1 ' Community Christian Reformed Church December 28,2007 South Windsor,Connecticut 1.0 EXECUTIVE SUNWARY ' General The Community Christian Reformed Church on the corner of Beelzebub Road ' and Avery Street is planning on constructing additional parking in the near future. The additional parking will be required as new programs come online and when the basement is finished adding more usable building area. In addition, the Town ' is planning on realigning Beelzebub Road which will result in the taking of a small portion of the Church's land. The reduced site area caused by the taking would limit the amount of parking the church could apply for since it will exceed the ' pervious area requirements of the town zoning regulations. Therefore, the church is applying now to avoid the need for a variance in the future. ' The site work for this project consists of the construction of new parking areas, access drives, and sidewalks. Additional site lighting will be required to maintain ' safe lighting levels in the parking areas and landscaping will be provided to meet town requirements. As part of the proposed parking areas, supplemental drainage will be provided and connected to existing drainage systems. Due to a small increase in runoff caused by the additional impervious area, minor detention will be required to maintain a zero increase in discharge as required by the town. The proposed detention will include infiltration trenches and drywells. ' The following calculations provide a summary of both pre and post development conditions. Backup data is provided where appropriate ' Design Theory ' The analysis point was selected at the edge of each construction area at the point where the flow would leave the area. The Rational Method was used due to the small areas and short time of concentrations. Rainfall intensities for Hartford ' Connecticut were used. The 24-hr rainfall is as follows: 2-yr 3.2" 10-yr 4.7" 25-yr 5.5" 100-yr 6.9" ' Rational Method Theory - CTDOT Drainage Manual For 2-yr and 10-yr storm => Q=CAi ' For 25-yr storm => Q=1.1 CAi ?y For 100-yr storm => Q=1.25CAi Tc => Use TR-55 Method Runoff Coefficient Values => Pvmt/ roofs, C=0.90 ' Community Christian Reformed Church December 28,2007 South Windsor,Connecticut ' Lawn Areas C=0.30 ' Woods, =0.20 Gravel, C=0.40 Existing Conditions ' In the existing conditions, the estimated flow to each sub-area is as follows: Refer to calcs for watershed map. STORM P.O.S. 1 P.O.S. 2 P.O.S. 3 2-yr 0.37 cfs 0.39 cfs 0.75 cfs ' 10-yr 0.49 cfs 0.51 cfs 0.98 cfs 25-yr 0.59 cfs 0.63 cfs 1.21 cfs 100-yr 0.79 cfs 0.83 cfs 1.60 cfs Proposed Conditions In the proposed conditions, the drainage areas are the same. One theory would be to look at the site overall but the increase in flow would have been negligible. Looking at the construction area only will provide inflated storage numbers but is a more realistic assessment of the increase in flow due to the additional impervious areas. Refer to calcs for watershed map. ' The following is a summary of the post flows at each Point of Stud prior to the p Study affects of any proposed mitigation: STORM P.O.S. 1 P.O.S. 2 P.O.S. 3 ' 2-yr 0.54 cfs 1.31 cfs 0.22 cfs 10-yr 0.71 cfs 1.71 cfs 0.28 cfs 25-yr 0.87 cfs 2.10 cfs 0.35 cfs 100-yr 1.15 cfs 2.78 cfs 0.46 cfs ' Using the 25 yr storm as the design storm, the increase in flow to P.O.S. 1 and 2 is 0.36 cfs and 1.95 cfs, respectively. The flow to P.O.S. 3 is reduced in the post ' construction conditions due to a majority of the area being piped to P.O.S. 2. Both P.O.S. 1 and 2 have minor increases in flow and will require some detention to mitigate the increase. ' Community Christian Reformed Church December 28,2007 South Windsor,Connecticut Proposed Mitigation Design ' Due to limited available site area, underground detention will be used to mitigate the minor increase in discharge. ' Using the modified hydrograph method, the required detention storage volume for P.O.S. 1 is 75 CF. To mitigate this increase, an infiltration trench will be provided. The trench will be 80' long and 2'x2' square with a 4" underdrain ' placed at the bottom. Using a 35% void ration, the storage provided is 112 CF. The required detention storage volume for P.O.S. 2 is 392 cf. Two drywells are ' proposed to mitigate the increase in flow. The drywells are 6' diameter and 5' deep with 18" of 3/" stone around the drywell. The stone is also placed on the bottom of the structure. Each drywell has a volume of 170 CF and the stone adds an additional 33 CF of storage for a total of 203 CF of storage per drywell. Overall, the post construction flow will be less than the pre construction flow. 3 4 L Y IS y Ar E st is --sY ; . t � ffi ' • •eee .e e e — ' Community Christian Reformed Church December 28,2007 South Windsor,Connecticut II. EXISTING CONDITIONS t 07- lozj Ai -tl, ' • �/os'c ��iarfa/ /����oc! Q = C�G 4/`i�rC C=4,9 �u� ' C=©.• 6,v C!:!0,3 morass ss =0, 1 �Xl f�fI14 CrU/?G�'t'7f7 0�'!S � ' - si�c c��a i�,r- -� ��ic �'�✓ c�`�Liy aver /��c.� o r' . t _ �cw e-O,'?X740C-Ao13 1-f Li i cf An 2 are as S-e,— SX 7—,4 Orf 7 4/7 e SD 0 7/-A Y'�o A20117-1 k e sic 76 AA 1 4-eV 746 Iff 0-5, 0,207 CAVO o o 3 z 7613 -SF = 0,/7,S 4c"-.es or CA Cave 111he => OL 0-3-7 CAS Z/.O (olox Osz/ O- q9 cienr Zzs eo,,7 "IlAe 4o, 7.v Celxllz. o.Sq oc 7 k "04- 7 eP 0,-?/,<f 2-5 0,79 cads -P1Z3Averye e- 12/0- z Z. Z 75s F 6, o v.•� T n X ,OBS = ®, 9 ens `n/he '=� Qta a G.O x .OS = ' t 1h o �zs ^ G,7 /ham71 > � G•? x .v�5xl,1=0 �3c.,�s c ,4r�a 7-/0 To 3. s F 4 3 F = O, ©7W eTG/�cs La�,•n �/�. � /37�.5-32y3-f7�7 =875,SsF^ p,Zol�G: E , • Gas � Ce7 `"�hi -=� �i �s" •�6y� �, 7x/.l- 1-Z lc� ]'jCBJFI244A0 urb ' ���� i:B4,TF252.93 w &-xI Bit —w Driv -mHJ F,244,8 SIP- ------ -------- -ISO o�f"Waa w Edge of P Loc;a uct 1yPAppr w MH_TF,258-911 eO M4-TF251,95 w ny Bit, Cu qB,TF,243,' '14 st t sl 3'TF,244� 7 LP E op P , — 0 'f &A 24- Olt' Deed) Ae 50-M-W C!3uu S" S67" *211271 16, AND 9brA w 9 -54-UU- iAl .SNIT N\ J I J c& z 0;& so : I 1, 1 1 1 I l-41,7' /a, xe III� (Out AAA 06ve-1 -'l it',]aNe d % P A. E 4P .0e I DRT All YARD LR� 000 El fig 5 If Bill P V, SOO", 7?5S F 13 L:J ZQ Ci M 4r-lf nv 10� it It, it 01.1"Z10. Pad Sid( — !Occ m tneter IM H,T Sevat; 0 ' " Fire M.- -B,T 11 65 Claragl Nn I Gu -y Wire 35 MIT, Ew,nNG PARKING 21`19,9" AA tit i I Hydrant, SPACES % 'riven Nkp7'� 3 e" Iron pipel"atIr --1P-42T r9 Uj�jht Pole W1 el Mcn Hole m -ment I 'urb orm not found Rebaining W011 ' m steps 'op of Frarne w AL DESIGN Utility Pole 27439' ORIGIN _v It z"19 TAM RX&IMMUM& PROPOSED PARKING ADDITIONS =m wr sm &0 MM I CommunityChristian Reformed Church December 28,2007 South Windsor, Connecticut . PROPOSED HYDROLIGIC CONDITIONS r S S t -.._--- --- --- 07-oz,3 Avey_Chvrcl C>1v;l JV.-4-74,,71; 1, GL c -�+tf� Rx.. /Zl07 P0.5. / o,z o7 4clirs �v 4rea 4i0� 472 / 0,7/ �s �ZSZ (o/ ` ���r +s� s 6,e 7x rG�oD= �,� ��/� > �b�= 7•�x .`s�x1,2s=�,l.sc�s Vie T earl v lar < r he ®�f 97 cfs s Vr - STo/'c-,7e (e�, f�0 Qp Vs Cars o `o® ZOts Leo 4�Gd �a 6oes 700 800 L t 1 �� i 1 f al s�r�b /t 0'O '® ' �✓ xg,?Z' x ` 1 ui�� �o �nlyt�rvsry a„P� � �L 22Z'Q S17 4) 9,6 =IL�5701- 9102 02 1 go7e,r 'Q = -.ys'S9Z 'OZ boo b � Z -s- • o�. o f. ba,� 1 jr I ' efl-o -,ee e0hc:4 14007s -- ' yo/,,o7" f ,4 G- �ivcl ' Q, (03 c.4s -� ' - 5 33 .EC G •• L cr Vv f� �= = 13, 75)g- zoo Hyd,000 a z sa.Edge Of P i F __\W 'UB DA D -, I,E x@. Avv ! ."✓ 7 u "'.• x, [F x� r j 1 t o;8e'} 3 TYPE'(3 TCN eASIN y, �. �u lIItv. ,?{ .]G? 2- `�. Sew • � 2 8 �x y a i� v��� � -`�.�� , x29�m .e;� ��•�` � -PB't, 3 OP '1 - 17 � yyk55 Ed ls� Iep L. X L3 'sr t T 1 P i 88'-12"NOPE ` a"x® �Location G .60` { `'Deed) 3°93'30'-Sz:rtey g?tE: s£aee aen 9fi` � 1— % .._.a�.y �73.Ic' �,.,,. } �, ,� x£` ��' x "5 'OL�' Be t �"" ' 33,:,u 2� °serf 2a& a a,Q Cr vt. 0 O tV `i INV.7 240.20'-(�15 HOPE) � i �bs ax xi s ;oi- i t 1 M..�-!A as E 1NV 240.20'(OVERFL011) � \ 3 ! t j ;i . 5 5"s �� i::'1,�3✓4(ou hg fit ' C , 4. TYPE'C CATCH i s t x�g4'al j kny I —�Fi t } Fa x� Y E T.F.- 218.20 INV.=241.50 (8' s ac 9A \ G CIO IN V.= 241.70 12 $g \ \' s c ,..i 8'H0PE OVERFL PLACE LEYIEL AT y '� xz a' 4 csi ! ' ELEV.-241.50 $mow a° tl 8 5' �` f �. _ *ILI $i z3 <s+ 1 l , MATCH INV. OF EXIST j t ` YARD DRAIN OUTLETPP [yj i s ,1 Wo ORYMELL f11 I AOJUSF FRAME AND } �?� (y 4 59 -1..7"" S �a L� 3 j 1 T.F.=244.75' } ATE TD GRADE(TYP) INV.—241.SO'(OVERFL ' - t- T j € L-Lj ........... 42, JCane.= Concre.e ` Y �CI', — Caner,&a P.d ��" (i^:v bc ' ' E. _ Sew PA€ter EL E4svv'bort ��., "� i„lane"1 rr. Fire pi ace i ° 3s t w ' Garage Floor )y II GVi. = Guy re j .:..,& .-'"�. y$ ���a r .• ' ; 4 - t �R� z DISCH �uTLET J t / §e 3 1#yr. ark(}. �V a a3 to t _ "�..� ON FACE OF RIPRAP �a 'a n tn.+ttxst _7a3b`115' ,�: ej 35 .sg� a t7; 2. lr. tr�f P!{3e 13r �r EXISTING �3 v 11 1 P — Light P-Ala s2u-'t. 4.�5' s' _ _\ 'o PARKING �' � �.� ,;.. (•Y.-.- tA.i . I 's nag ' latars i'ol3 -a s SPACES �\ 1 �� _ {p i� } n l{ _ not 7 CURTAIN DRAIN OU ► ;^ 23:� i + s� I- a! t R�Yd. _ €2e+ai;l:stq AT FACE OF wf. _ 5tC-�e C°3 t� \ at•� a�`1"` jd 1( T.F. :asp of Frame i % ¢ � � � <r c� �tiri� � xsQs� 1 j' �&�'�' b.�`�14 rK�lf. ";� ---'."—` � `��•�"'zl.,K\.i �3i }� yi {} a` it g� x4.1 110 �t 88'-12"HDPE TYPE'C CATCH 9 A LEAK—OFF a age' S-1.OX T.F.- 231.8' (TYP}OF 3) INV.-228.3' ' �ni�Qni ninT�c -�`� '"� P• O• S, ! y� Cl Community Christian Reformed Church December 28,2007 South Windsor,Connecticut t ' IV. BACKUP DATA 1 RAINFALL INTENSITY in/hr DURATION DURATION 2 Yr 5 Yr 10 Yr 2S Yr 50 Yr 100 Yr mm r 5 0.08 4.6 5.5 6.0 6.7 7.3 7.8 6 I 0.10 I 4.4 I 5.2 I 5.8 + 6.5 7.0 I 7.5 7 I 0.12 4.2 I 5.0 5.5 I 6.2 6.8 7.2 8 1 0.13 4.0 I 4.8 I 5.3 6.0 6.5 7.0 ' 9 I 0.15 3.8 , 4.6 5.1 5.7 6.2 I 6.7 10 ( 0.17 I 3.6 I 4.3 4.8 I 5.5 6.0 6.5 ' 11 I 0.18 3.4 4.2 4.7 5.3 I 5.8 6.3 12 0.20 3,3 4.0 4.5 5.1 5.6 6.1 13 0.22 ! 3.1 3.8 4.3 5.0 5.4 I 5.9 14 0.23 3.0 3.7 4.2 4.8 5.3 ( 5.7 15 I 0.25 2.8 3.5 4.0 I 4.6 , 5.1 5.5 16 0.27 I 2.$ I 3.5 I 3.9 I 4.5 5.0 5.4 -v > 17 0.28 2.7 3.4 3.8 4.4 4.9 5.4 0.30 , 2.7 3.3 I 3.8 , 4.4 I 4.8 I 5.3 19 I 0.32 ( 2.6 3.2 3.7 4.3 I 4.7 I 5.2 20 0.33 I 2.5 I 3.2 3.6 4.2 I 4.6 51 t21 0.35 I 2.5 I 3.1 I 3.5 { 4.1 ( 4.5 5.0 22 I 037 2.4 I 3.0 3.4 4.0 4.4 I 4.9 23 038 23 I 2.9 3.4 I 3.9 4.3 I 4.8 24 0.40 2.3 2.9 I 3.3 I 3.8 I 4.2 I 4.7 0.42 21 2.8 3.1 3.7 I 4.2 I 4.6 ' 260.43 I 2.2 I 2.7 I 3.1 3.7 I 4.1 I 4.5 0.45 2.1 2.7 ( _ 3.0 I 3.6 I 4.0 I 4.4 0.47 2.0 I 2.6 I 3.0 3.5 I 3.9 I 43 0.48 I 2.0 ( 2.5 2.9 3.4 , 3.$ 4.2 0.50 1.9 2.4 2.8 3.3 3.7 4.1 1 Intensity/Duration/Frequency Relationship for Connecticut{English Units) ' Table B-2.1 ' = DFainage Manual October 2000 + �.wwr ww.r�w�w���w�wwa�����.��w��ww w���r•�.r�r.,r� rrwi.��w��w�■�■��e�.wwsrrr.�w��w■ww..rr.�i�r�.w�t rrwr�www�w w��wn�.wwr rraa�ww.�w■■■w r■�wrs.ra■■w w.wrwwwww�wlwl■w■wwrrrrr�wwr.�r■wwwrrrAMWA �■MM a� rriwww_.www�w��w■■■.wrrrr.�w■irr�wn.wwwrrrm��■� wws�w•wwm..■i■wl.usage ww..■■7.rr�ran��w �rasannwwwa■ ma1■■:11wwMwimo1ns85►= ,xin w ��ww�/�■mum / �mmm i mmmmmmmom Osman NIMBI=il mass■■r,/�j�mm : �Ir1MMMMMMMM■iN/■11111=r■■0869t■WA�MM i mmmmOMME■Sunni Heil MM MEMO arlonWAMMM f1•f�■�■1�r�11�f1Nonni 1111f■o!■imrdurmmmm f Nonni iii11111111101•t■i►A/!L!ININ ==ME!■ONNI11111 F.111M MMMME mommom■i■lllllllllllnmo■/lif,il���■/ ��i�r�� 111111111111��1�i11►111����� ■■..���,111111111111�i►iill!i111���� ��111!1l11111111�/11 ,1111i����� ■�.�1111111111111111 r/1�i111l1���� ■..■ww.�w■ ■i�w.■■■■...rr.��wr..■■w..r��w�iw■w■w ww.www mmmwm.■■■wwrseem,w�■��iw■■wrwr�w■rwwl�� �immm wwwH Nasal■f1►(ww Am■!■■■■��=Mm wwwmo■■■■■■Nort1wl.MM■■■■■1�ww mw. �Mi MMMESS!ii■1 Will UFA ONES■■■1�MMMM �MMMMMlENi Soong If o11wImriiioml�rrmi . MMM®!■omomnoHl►dill r/m■■■a11ilit �1•f , . ====MEMNONNO■■/t1111'//ENEi1111�MMM� ==mom■■NNi�i1/'t1111:111•11tfi11l/i���®■ 0=ME■■ONNiii11A1111i1 mono Noll 11®mmm■ =0100 101,==a WC Mono sr�,r�r�r��rr rr�rr�r�e�w�w�r.�woiw ew■■••rsww.�.w■■■■rr�wr>,rww�� ��rwArwrrrrlww/.•w 00Wwwwrr ./rtwwCC"n"nw■■■i===2 wwrwr■rw�w w��.■■►.war s.�rr�Cc CC■■ww w■ww.w���w , � rwrrwiwr�r�r�rrwerr��s�awr�.rrr���.�wF■.wwar�w�.w�w-� wwwlrrwrwrwer■wrrrr.■r Mwwf/rrr�■Iw..■■ww wr wr�wwr�rr■wwlwrl r����Lwow■►1■■w,.11lvewwom■■.mm1� �w rMmz=wwMMW ANE/t11111MMME NONE ■1����w �MMMMOMEMPI,!•ii'e1i1/11 Win noon Noon 1 mmmm ��mmm mim■t■f/1■■1111 mm■■MEMO■1�mmmm ��������r�■■i'ti111111 um■■Mono!/�MMMM ���1•■■�r�fi■//11111111 OMEN Evil 11===ME ������/Iii'Iii/11t111���■ii/!11���i•■ ���■ ■ri1111F milli 11111 mono ii1111—���■ ��■ //milli lllliolnsll1111����� IV■ J111111111110111111111MENN■ ■■ • , . /111111111111111111111101MME■ ■■ / JIIIIlItII1111,111111111��r�� ■�®I1r111llllllllflillllllllllr.��1 ��/,fir l���11111111111�/�■ll it ll����■ �i/���/■i��11f11111111����111111��l�■ �fi/i■��l11111111111��I111111�■fir■ „ /�//�11111111111111111111111111■■��I moll ■■11 ■■■■■ ■■il _ 02 , OEM , mono ' " ■■■�� !iri/ I1%�'�r'�/I%/mil%!���'� - �■ grow ■■■m� %M i/Ui/ /��//I� ''ram' ■����■■ �n / /L•�y� •/ y���� %�' �±i Dili _ -- �■■■�►.������ F4 • • / r�- + ann,� f!-- �I