The URL can be used to link to this page

Home My WebLink AboutSW4230101_Stormwater Narrative_20230510 NARRATIVE / CALCULATIONS / MAPS/ SUPPORTING INFORMATION FOR STORMWATER, EROSION AND SEDIMENT CONTROL REVIEW for project EM HOLT ELEMENTARY SCHOOL QUEUING IMPROVEMENTS TG#52013 Stormwater Permit No. SW4230101 * * * * * 7k * RLIKGTON SC h ** Juiy 3, 1996SF��*** 144 ahlti+�` 5,� NG SUCCE$ * * Site Address: 4751 NC-62, Burlington, NC 27215 Issued: May 03, 2023 TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. 5410 Trini ty Road, Sui to 102 Raleigh, North Carolina 27607 Phone: 919.866.4951 Fax: 919.859.5663 TABLE OF CONTENTS Project Narrative USGS, Soils, & FIRM Maps Deed Supporting Calculations: Rip Rap Outlet Protection Design Sediment Basin Design Channel Design Pre/Post Impervious Map. (Refer to Full size plan set for additional information) PROJECT NARRATIVE Proiect Narrative 1. General Information a. Project: EM Holt Elementary School On-Site Queuing Improvements b. Address: 4751 NC-62, Burlington,NC 27215 c. Site Area: 30.2 Acres d. Disturbed Area: 4.64 Acres e. Wetlands and Jurisdictional Streams: None located within project area. f. Ownership: Alamance-Burlington School System g. Proposed Development: This project will be to provide an approximate 1,300 LF two-lane on-site queuing drive at EM Holt Elementary School in Burlington,North Carolina. The site work will include asphalt paving of the new queuing drive, concrete sidewalks,and installation of drainage culverts to accommodate the site improvements. The project will also repave an existing staff and visitor parking lot in front of the school. The total disturbed area is approximately 4.64 acres. The disturbed area will flow to a temporary diversion ditch to a temporary sediment basin to treat most of the disturbed area. The remaining disturbed area will be protected by silt fence, silt fence stone outlets, inlet protection, and rock pipe inlet protection. This project meets all low-density stormwater requirements. The proposed development will have a built upon area(BUA)below 24%and has maximized the usage of vegetated swales and culverts only for driveway crossings. The amount of impervious area flowing to the existing unmodified storm network has been reduced with new impervious flowing through the proposed swales. h. Phasing: This project will be completed in a single phase. i. Water& Sewer Service: None j. Historic Sites &Public Funding: This project is being funded with public monies. This site is not an historic site. k. NCDEQ Compliance Issues: None. 1. FEMA FIRM 4 3710885200K, dated November 17, 2017 indicates there are no 100-year or 500-year flood plains that exist on the project site. in. Soils on the site consist of predominately Cullen clay loam (CnB2), Cullen clay loam (CnD2) and Udorthents loamy(Ud). Cn132 and CnD2 has an HSG Classifications of B. n. River Basin: Cape Fear o. Receiving Stream: Big Alamance Creek, Class WS-V;NSW 2. Permanent Ditch Calculations Length Bottom Right Left Flow Slope g Slope Depth Permanent Velocity Erosive Ditch Width Slope pe p (o�O) (FT) (FT)) (H:V) H:V (FT) Liner (FPS) (Y/N) PDD1 3.2 138 0 4:1 5:1 0.35 Curled Mat 2.73 N PDD2 1.9 155 2 20:1 11:1 0.40 Curled Mat 3.37 N PDD3 1.6 122 2 12:1 14:1 0.15 Curled Mat 1.90 N PDD4 3.7 195 0 9:1 13:1 0.35 Curled Mat 2.98 N PDD5 3.1 159 0 11:1 7:1 0.35 Curled Mat 2.74 N PDD6 1.0 357 0 4:1 6:1 1.10 Curled Mat 3.19 N PDD7 4.7 147 1 0 3:1 7:1 0.30 Curled Mat 2.93 N *PDD8 2.9 70 1 2 20:1 1 18:1 0.35 Curled Mat 3.36 N * The maximum achievable length of PDD8 is 70-ft compared to the required 100-ft. The location of this curb outlet swale is to improve existing drainage issues by directing flow to the existing drop inlet `AF and preventing sheet flow across the proposed queue lanes to PDD2. PLANNED EROSION AND SEDIMENT CONTROL PRACTICES: 1. Silt Fence: Silt fence will be utilized to filter sediment laden runoff in locations where the drainage area is less than 1/4 acre per 100-ft of fence. 2. Tree Protection Fencing: Tree protection fencing will be installed to protect existing trees that are intended to remain. In some locations, silt fence will serve as tree protection fence 3. Construction Entrance: Temporary gravel construction entrances will be utilized to minimize soil being tracked off the site by construction traffic. 4. Outlet Protection: Riprap outlet protection aprons will be installed at outlets as they are constructed to slow storm-water velocities and dissipate energy to protect downstream channels from erosion. 5. Sediment Skimmer Basin: Sediment skimmer basin will be installed to filter concentrated sediment laden runoff prior to discharge from the site. 6. Channel Matting: Straw or excelsior matting will be installed in permanent channels and swales to stabilize the seedbed and promote vegetative growth. 7. Check Dams: Rock check dams will be installed in permanent channels to reduce flow velocities and erosion in the channel. 8. Temporary Wattles: Temporary Wattles will be installed around installed curb inlet to prevent sediment from entering storm drainage systems. 9. Temporary Inlet Protection: Gravel block inlet protection will be installed around existing drop inlets to prevent sediment from entering storm drainage systems. 10. Rock Pipe Inlet Protection: Rock pipe inlet protection will trap sediment at the approach to the storm drainage systems. Refer to drawings C-4.0-4.1 for Erosion Control Construction Sequences and Maintenance Plan. U SGS, SOILS, Et FIRM MAPS 14 NN I : - fi n � m .k 1Cl lip i >l I .. 1 I � , Eon ® can ru-niviru,t L- €�u i,4 i i, v4un in IVq (Sheet # ) 0 SITE _ m ....rr.. v. �.. m.......__.... SITE ALAMANCE COUNTY: NORTH CAROLNA 21 a&i!a DOb F t a : x ; _ l Lb8 x MxC3. . ��,q c t ; litC2- x �y. la8t x • Ia8 ObC �Y Bz po� 0 1We soU,_•�; (Sheet 2511 79030'21.7V W 3601'59.WN UE:LAGE OFALAa�`:(• ��.. � � �;i(.. 303» SITE EFWA a t = y � ff fit•. ` .'�E� may-,. _ r .may � ! :,. � y:•:•-�. "� �f S' � � 9 �aE�Mi�iMA�FL000 Ar uu.t `� ••~�,.•r- 1 � \'ILL•A4EOE�iE�\'CE•ETI J,0a l r ALAMANGE•!]NTY J10001 .) r FLOOD HAZARD INFORMATI ON NOTES TO USERS SCALE sEE FIs FOR ORAFrrlRm vnxEL urour Ex mAp um Lseo C FLOOD L FLOOD INSURANCE RATE MAP PROGRAM l>7 FLOOD INSURANCE RATE MAP Wilmn a Bew E .(BFE) a ,eieilwwrsierce,m .xa dwee uneren eemeememmWrwemem xvm laeweem. ooa '� w¢n aFE.oePm zone aeAR,aH.uE aR warervw aY 1vFlsl R:aen ,wa,wm��1alHnnnpe://me�(:`m::wr ervFly p pAxEE 8852 of 9920 v. .m Clem onedwmmFlH tlmis m+ oaf uwsrendw�axn e�In rera n � xAZARO AR ......... 1:8,000 ,.00C W d o W a Nn.e�allw�m�fw�wwnn a� �: Fkw nwrerc p remel,mnauaua. ""'""Y`"'I.nwv,lrcwm®.s=m v,wilne rvoevml t C Me— �= C 0 60 100 200 300 600 1� ( \e\\�a 7 Penei Con[alns: Creas ess awaoa max awmtewe m.m.m.vawwvow uses rvmo,.i d.n.omoi ,.w,�.il�xmmx�owzo.Y�v°`rv�1Y°rlusosl. � CUMMUNITY NUMBER PANEL OROo0 xAURo Area w,sn Flood Rlsk euemtewe zoaeo x'nwes uvmmw,vmv v.nsn.xdmry..,rrm.rema.soniremem,arv�a++ulaooim.ma„ea,e O azoasz aess ke.e.w.e.. O AtwaxcE couxx a�000. eesa NO SCREEN A,ee of minimal FNaa xa rere..wo.em.«M..imxle.mm.rs.Flkx re.I..ma.,em Flw.n.wwew. zones L.L O ExMrve LUMRs � OTHER AR Area d UnEetr,m-Fleotl HmNzeaeo STREEM. aee ke o,Flwawen we, W Z Crow s aww noel Manee O 1]3� ion ew oo Ion Une(pHEI F—R. —�axeeimiaamwaan MAP NUMBER 37108852OOK EFFECTIVE DATE November 17,2017 IC— DEED - - - - - — -�-RECORD OF DEED 64 11 204 STATE OF NORTH CAROLINA---Alamance County S �•4 C. - . G T�� t; .-.-er e�A.r J /•Grp, ('7 T,iLti9 IlEl:Il.M1[ado tb[er"u-.�`!1.....dW et...........................................fl. 191.V.^r br«.1�;...F....'7�4'C�Fackus.ewF.!�.....[..«........:fit.�!;�fr.Y..Es.-.....1..!7..•� , (iGn•l.c' } •t C .v.�L•v .........'.••�f �J � 1�.... .. _4-i;t..•f�. 4r...n ...+�... -... �-.-,�:.ti...�. .....i....�.�`:7.J... l='^it�.....�.,,:t„�-;•.... .-V-.... �'l:,i+...l! _ l/' -•Z....�� .,.«.Z�l�•� `.r1 1......(f�•�s}� C...a,.•.�[r.ia- �,�.•..�,.-r.e..�c� r`a X ...... ��, Yl:=��1.•�},�7 y.-.C'•��^^/i.�-`, ' ' Q,rYr1.,.1�.� a...�..,c,,. tc�!_........ .f.."..�.�ouetY,,athd 8tal° ot................�Y..i.a*.FT:�4.•...t.:..c�.+...a-�.w'�...,.�...�� ..,.°,.........of rho!lest rt.to ol...._ (� ( f�.�/� ,,/ «/ y.� yp ^ �+�/-fir• +�! q -y /gyp r �-. �.•..... �.............ff.. � S/}/� /� .«....... WITN1:39IiT}I.TPhat en1A.. .:..c�t�'a5-+�......t';....�'.�*-�....�-zr.Y..� .G�r�..._�........._............................... ._..........._.........__......._._........................ L..........._...............--........................................................................Dollars, to co !?::,:x-....Hard by....................... 4w: .... �< t�ram....z.... �i d... r �^ [he rocofpt of which is he acko w edged,ho.f`�.._bargained _ � rr �II �J �^1 I and Bold.and by these presents doZ fir,......LarlTnln,sell,and convey to saki .Gk.��t4r ....lh �tL� 1J`�'C�'u:•rr•..ry.r�f�S. `Lt�t1.1:.....�f..-4.:!� C:!;+�:x'.Y.i- d 1 ... 4 . ... �.�..... .. 'f .................... ...batre�wd assIgns,a certain tract or parcel of land 1nc..s..:!.. .Q:..V.:.. ........y.........}.•... ..............Tow4ahln............. :!~ +yr..R...�a....r..a2i�»...». �•,,, ■ �i County.State of North Carolina,adletning the land■oG.•r.�...P,C..-..�.}, lJ,Jr..... --'..l..C.L.......a?�,:�a�,. ........../..�i,C1..fr..r^ «.......»..« Count . ....... ........................................-........._. ........................................-......»....1........ ........».................. ..... ............................ .-.ad others,and banded a follows,vla.l r� .._. .11.c?, .. ^, 'ar.-,.,,.•..r�.�... ..«.'tit.......c�iac.+ ... ...r..:.'..-rt..Y...br.......t ...`..l-v' ..... . . S.rl„... ,.r , i � .........q6. C:x.-.s.....:v?.-.-l1Vt....... r'ITV'.f i,r�.✓-+.r.+.•.... �.�'x1c ^.:..«.. .. . .,1.�% ,(..._[�?.cr :.. .. ......... •' ....a. i f.f ......... .......ki,�-J •��x.. �.ti_-Gr ...........'l..t_.... L _ _ _ __ _ _ _ _..............._ «..«.».»»«.«»...«.«.....».......»............«.»».. «....«,..._�...»....»»«................•.......«...«.......................-........._............ »................ «�.._....�..�- - ---�•....•....-..............�«...... �. 1 t _..«. ...........».......»_..»....«..«. ..-.-.._........«......................_.............--....--...._.......--..................-...........--_....................................._....«—...._._...._.._..._.__.....__•___.-...._...+.._..........»......... .�F ............«.«....»...»...............»...... .... ...... ..«.... «».«............ .»..«..«....t........ .....................»n«.......««........._.....�.... .«».««.......» «...w._' _.ram...— y-.................. .....'-»....................... «-»........«:=. , ' .«..«..«.................»..«»........»...«.....«.......»......»«............-».....«.»......__1...-..-......«.•.------............._.....__._.......-.... --_---------- _---- __._.-------...._ ...r.y r ...».».._.....»».»_..........................«......»...«.........................................»..«.».........................«.....----....._..........».._._..._._ ....... .. _. TO Tlst^VF4.ANI)TO 110 D the ntorenald tract or parcel of land,and all prlvtleaes and appurtenances therotQby(iSaging.to the sold.,°. (�//o Gt tp 1-... .. la/li)T....�/ - L..hefre'rt hd wo►dne.to............. .........only ue and baboof forever. p' And the sals>~ . ..C4/l 6RlSL..... ..... ..t�!l�_ .................. «......._ l • 11 Cat:................... ... /r »...................................I............_...._..... 1 covanant{-te"d th the said....f l.Cf -^Q....<�U......47...! :.....---..1. .:C; lei!t..c .--.-.. .rr..t c .. I,: ....;«.:........... 5VJ g .try�?:,c ?ir.....Q 2r.. ... -Ke11... I Doran I ..............................hats.•.ad-a..itm■........._.............................................that.... .....r..i.�.S.1..................._,.....seized of said premises In lea,and ha+•f.. i6ht to convey ....:... f the same 1n fee simple; that the acme are tree and clear from all lacumbranco4*nd that........! will warrant and defend the said Me to the eamo ho q against iha-Cialme of all persona wbomsoavrt.J�...................................... ................................... ... 1. INivi4N+3Pi9 �i'1[F.T1E0>•.TAe,f.a.id.t(lG,rr.<:.•---.N" r.. .....:,.:� ...rx...: . .. ....`.7....V.�. . ..-ice .F<.!_..y.,......,,`- W.,, .�:.«:.i:-5 ............./.1. Via.? ce wU.,r `% h >rr J d I t--�-+.*... ..f8ea1? : - ..... LT rk c nn fir...... . ... . �i ttaet ............J..,'1�...� j, �!l-t.... "..t .9.J..... ..........................._~�....'-:4_t�P'L. .....i.:..7......-.• 1 U_...... d... . .h�....�..*.`i.._ ....(9anq Attest; /1 NgE�7It C.1l101.l fA, ..-.. ..:.._ c 4,C C- Cannty - 1t _ NOAT TY µ �- �q .. ... .cam yy C .U GI7�T'i. .� ./90u�� '�ln..•.4 li�rau-,:.��_r ... , ••n said q. --- �' dG-,P r nd........._ B.-L. .............. . ........._.._. • - 1 t E Y\O 'fF! f 5T'>71.1\.t-Llmm�ynre�I'nn ty. � 4 J� �•<,:� /r am �,L,�.: .�Q �j�77 BTAT r ma�.yy"--��w�.� � �Y•�-�� `� ��;��1�. � �.�i. 7..��ZZgyri� A�...�.¢,�io/�•.C�s�..r+l ' (.�G �r...•gr-„y_ r ....,.�..�,. T,g .h-w. •�cf-ef-.�� ate.-b4 c-�.. due✓t... for Let the t Witness my hand,thlet"lw.d�,.'-....«day of.... ... vrw.a..G'�rt..x f_....................7D1�.... � 1 NORTII CAIIOLINA-Alamance C KUTIJ The foregoing cartldcnte�ot.C ^'�•v�Ta'vw/; , cs+y.!t.'.(.��.� r.-Fa,,, ,c_rt+•.-L�,,..�!'�. o�-�'-t� •s Q . ..VZ— �nl � ......_»..>�.....�:._ ��.`,:.`.��...`^"`�-�• Olerlc Superior Court. od for tration at IF poeda olr Alamance■Connq,to taook to_(.�,ia d_- ,1. ,th1a.....LW Ir_..._day af.....r ^7 ;; 1�7 1�..and ragletn'ra 1�1 ottlae at the Register ofDeeda t � .- _...---......_._..__...._.......». .�.. » �� r.4 ,7. ........,Register of Deeds. _ I , SUPPORTING CALCULATIONS RIP RAP OUTLET DESIGN • " • lei 01 05/01/2023 a i EM Holt ElementarySchool Queuin Improvements 52013 TIMMQNS GROUP YOUR VISION 0.CHIFVEC THROUGH OURS. LOCATION Burlington, NC JLMB RR EW-1 Pipe Diameter: 18.00 in Upper Invert: 640.06 Lower Invert: 639.91 Pipe Length: 43.30 ft *Discharge from Storm Sewers Pipe Slope: 0.003 Discharge: 6.20 cfs Pipe Material: RCP Qto= 6.20 cfs Qto/QfuII = 1.00 QfuII = 6.19 cfs V/VfuII = 1.14 VfuII = 3.50 fps V= 3.99 fps Dissipator Dimensions* Zone= 1 Stone Filling Class= A Entry Width(3 X Do)= 4.5 ft Length(4 X Do)= 6.0 ft Width(La+Do)= 7.5 ft Min.Thickness= 12 inches Stone Diameter(D50)= 3 inches 6.0 I 4.5 7.5 IF All units are in feet "Dissipator pad designed for full flow of pipe Rip Rap Calcs 5/3/2023 Page 1 of 6 • " • lei 01 05/01/2023 a i EM Holt ElementarySchool Queuin Improvements 52013 TIMMQNS GROUP YOUR VISION 0.CHIFVEC THROUGH OURS. LOCATION Burlington, NC JLMB RR FES 1131 Pipe Diameter: 12.00 in Upper Invert: 635.95 Lower Invert: 635.25 Pipe Length: 46.05 ft *Discharge from Storm Sewers Pipe Slope: 0.015 Discharge: 0.85 cfs Pipe Material: DIP Qto= 0.85 cfs Qto/Qfull = 0.19 Qfull = 4.40 cfs V/Vfull = 0.75 Vfull = 5.60 fps V= 4.21 fps Dissipator Dimensions* Zone= 1 Stone Filling Class= A Entry Width(3 X Do)= 3.0 ft Length(4 X Do)= 4.0 ft Width(La+Do)= 5.0 ft Min.Thickness= 12 inches Stone Diameter(D50)= 3 inches 4.0 I 3.0 5.0 IF All units are in feet "Dissipator pad designed for full flow of pipe Rip Rap Calcs 5/3/2023 Page 2 of 6 • " • lei 01 05/01/2023 a i EM Holt ElementarySchool Queuin Improvements 52013 TIMMQNS GROUP YOUR VISION 0.CHIFVEC THROUGH OURS. LOCATION Burlington, NC JLMB RR FES C1 Pipe Diameter: 18.00 in Upper Invert: 637.00 Lower Invert: 635.00 Pipe Length: 38.69 ft *Discharge from Storm Sewers Pipe Slope: 0.052 Discharge: 8.96 cfs Pipe Material: RCP Qto= 8.96 cfs Qto/QfuII = 0.37 QfuII = 23.92 cfs V/VfuII = 0.91 VfuII = 13.54 fps V= 12.34 fps Dissipator Dimensions* Zone= 2 Stone Filling Class= B Entry Width(3 X Do)= 4.5 ft Length(4 X Do)= 6.0 ft Width(La+Do)= 7.5 ft Min.Thickness= 22 inches Stone Diameter(D50)= 6 inches 6.0 I 4.5 7.5 IF All units are in feet "Dissipator pad designed for full flow of pipe Rip Rap Calcs 5/3/2023 Page 3 of 6 • " • lei 01 05/01/2023 a i EM Holt ElementarySchool Queuin Improvements 52013 TIMMQNS GROUP YOUR VISION 0.CHIFVEC THROUGH OURS. LOCATION Burlington, NC JLMB RR FES D1 Pipe Diameter: 15.00 in Upper Invert: 636.00 Lower Invert: 635.00 Pipe Length: 36.78 ft *Discharge from Storm Sewers Pipe Slope: 0.027 Discharge: 2.75 cfs Pipe Material: RCP Qto= 2.75 cfs Qto/QfuII = 0.26 QfuII = 10.67 cfs V/VfuII = 0.83 VfuII = 8.69 fps V= 7.22 fps Dissipator Dimensions* Zone= 2 Stone Filling Class= B Entry Width(3 X Do)= 3.8 ft Length(4 X Do)= 5.0 ft Width(La+Do)= 6.3 ft Min.Thickness= 22 inches Stone Diameter(D50)= 6 inches 5.0 I 3.8 6.3 IF All units are in feet "Dissipator pad designed for full flow of pipe Rip Rap Calcs 5/3/2023 Page 4 of 6 • " • lei 01 05/01/2023 a i EM Holt ElementarySchool Queuin Improvements 52013 TIMMQNS GROUP YOUR VISION 0.CHIFVEC THROUGH OURS. LOCATION Burlington, NC JLMB RR FES E1 Pipe Diameter: 15.00 in Upper Invert: 636.50 Lower Invert: 634.50 Pipe Length: 45.72 ft *Discharge from Storm Sewers Pipe Slope: 0.044 Discharge: 2.07 cfs Pipe Material: RCP Qto= 2.07 cfs Qto/QfuII = 0.15 QfuII = 13.53 cfs V/VfuII = 0.72 VfuII = 11.03 fps V= 7.93 fps Dissipator Dimensions* Zone= 2 Stone Filling Class= B Entry Width(3 X Do)= 3.8 ft Length(4 X Do)= 5.0 ft Width(La+Do)= 6.3 ft Min.Thickness= 22 inches Stone Diameter(D50)= 6 inches 5.0 I 3.8 6.3 IF All units are in feet "Dissipator pad designed for full flow of pipe Rip Rap Calcs 5/3/2023 Page 5 of 6 • " • lei 01 05/01/2023 a i EM Holt ElementarySchool Queuin Improvements 52013 TIMMQNS GROUP YOUR VISION 0.CHIFVEC THROUGH OURS. LOCATION Burlington, NC JLMB RR FES F1 Pipe Diameter: 15.00 in Upper Invert: 640.50 Lower Invert: 638.50 Pipe Length: 61.50 ft *Discharge from Storm Sewers Pipe Slope: 0.033 Discharge: 2.50 cfs Pipe Material: RCP Qto= 2.50 cfs Qto/QfuII = 0.21 QfuII = 11.67 cfs V/VfuII = 0.78 VfuII = 9.51 fps V= 7.42 fps Dissipator Dimensions* Zone= 2 Stone Filling Class= B Entry Width(3 X Do)= 3.8 ft Length(4 X Do)= 5.0 ft Width(La+Do)= 6.3 ft Min.Thickness= 22 inches Stone Diameter(D50)= 6 inches 5.0 I 3.8 6.3 IF All units are in feet "Dissipator pad designed for full flow of pipe Rip Rap Calcs 5/3/2023 Page 6 of 6 SEDIMENT BASIN DESIGN : I C4�0.#,. - Skimmer Basin A it 4F EM Holt Elementary School " TIMMONS GROUP " " • Angad Singh ENGINEERING I DESIGN I TECHNaLOC' 52013 Time of Concentration Calculation BASIN NAME: Skimmer Basin A Modified Rational Highest Elevation = 650 feet Inlet Elevation = 634 feet Difference = 16 feet Travel Length = 556 feet Equation 2.3 Kirpich Equation Tc = L[ 3 f H)u.385 128 VVhere Tc =Time of Concentration (min) H =Height of the most remote point on the watershed above the outlet (ft) L =Length of fla v from the most remote point on the watershed to the outlet (ft) (Civil Engineering, Vol. 10, No. 6.June 1940,p.362.) A graph of the Kirpich Equation also appears in Figure 2.4. Tc= 3.98 min Tc= 5 min Intensity 10 year= 7.08 in/hr C = 0.60 Disturbed Area = 4.31 acres Additional Drainage Area = 0.00 acres Total Drainage Area = 4.31 acres Equation 2.1 Rational Equation Q = C I A Where: Q = Peak flow from the drainage area (cfs) C = Coefficient of runoff (dimensionless) I = Rainfall intensity for a given time to peak (in/hr) A = Drainage area (acres) Q10 = 18.31 cfs *RED IS USER INPUT LATEST REVISION: 1/2/2023 11:41 AM Skimmer Basin A 4& a EM Holt Elementary School TIMMONS GROUP IIIIINUETW94THMMEME Angad Singh ENGINEERING I DESIGN I TECHNOLOGY 52013 Skimmer Basin A Skimmer Basin A Type of Basin: SKIMMER Disturbed Area: 4.31 ac Additional Drainage Area: 0.00 ac Total Drainage Area: 4.31 ac Runoff Coeff[Cc]: 0.60 10-yr Rainfall Intensity[1]: 7.08 in/hr 10-yr Discharge[Q10]: 18.31 cfs Sizing of Basin 7758 Required Volume ft3 (Disturbed Area x 1800 cf/ac) 5950 Required Surface Area ft2 (Q10 x 325) 54.5 Suggested Width ft 109.1 Suggested Length ft 112 Width at Surface Area(ft) 125 Length at Surface Area(ft) 3 Side Slope Ratio Z:1 2 Depth(ft) 24 Bottom Width(ft) 79 Bottom Length(ft) 4177 Bottom Area(ft2) 14854 Actual Volume(ft3) Okay 6500 Actual Surface Area(ft2) Okay Skimmer Size 7 Emergency Spillway Width(ft) (Inches) 1 Depth of Flow(ft) 1.5 21.0 Spillway Capacity(cfs) Okay 2 2.5 4 Skimmer Size(in) 3 0.333 Head on Skimmer(ft) 4 1.25 Orifice Size(1/4 inch increments) 5 3.72 Dewatering Time(days) 6 Suggest about 3 days 8 Elevation Area(sf) Depth(ft) Incr.Vol. (cf) Cumulative Volume (cf) 631.50 4177 0.00 0 0 632.50 5310 1.00 4744 4744 633.50 6500 2.00 5905 10649 634.50 7746 3.00 7123 17772 635.50 9049 4.00 8398 26169 Emergency Spillway Elevation: 634.00 ft Top of Embankment Elevation: 635.00 ft Bottom Elevation: 631.50 ft Embankment Width: 5 ft "RED IS USER INPUT LATEST REVISION: 1/2/2023 11:41 AM CHANNEL DESIGN TDD Al 0 s E M HOLT TIMMONS GROUP ' Angad Singh ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) TEMPORARY • DD Al This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope, &channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired). (Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 2.70 (Acres) Coef.(C)= 0.75 (Dimensionless) Inte. (1)= 7.08 (in/hr) Flow(Qlo)= 14.3 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 183 LF Slope= 0.005 (ft/ft) Highest Elevation= 635.5 Z Required= 3.90 Ratio Lowest Elevation= 634.5 Side Slope(M)= 3 :1 QuantitiesVariable Flow Depth(Y)= 1.35 ft 16.2 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.46 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) General Lining LBISF North American Jute Net 0.45 Green Lining LBISF Curled Mat 1.55 675 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I (12"@22"THK) 5.00 C125 2.25 Class II (18"@30"THK) 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 5.47 SF New P= 8.54 Wetted perimeter New R= 0.64 Hydraulic radius Z Actual= 4.06 Must be greater than z required=> 3.90 Okay New V= 2.73 fps Liner: Curled Mat 1.55 LB/SF>0.47 LB/SF Okay ............ ..................: Top Width=8.1 ft Min. Ditch Depth 1.35 ft ........................... 3 Flow Depth(Y)=1.35 ft ;1 Bottom Width(B)=0 ft Ditch Geometry Min. Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) Side Slope 1.35 1 0.00 1.35 8.1 3:Ditch Liner Curled Mat *RED IS USER INPUT LATEST REVISION: 12/8/2022 4:12 PM TDD Al E M HOLT ' TIMMONS GROUP • Angad Singh ENGINEERING I DESIGN I TECHNOLOGY 52013 Ditch Outlet Protection (NYDOT Method) ' Ditch Name: DD Al Velocity= 2.73 fps From Fig. 8.06.c: ZONE= 1 Top Width = 8.1 ft Ditch Area= 5.4675 sf Rip Rap Class= A Equivalent Pipe Diameter= 31.66 in Apron Thickness= 12 in Equivalent Pipe Diameter= 36 in Apron Length = 12.0 ft Apron Width =Top Width.= 8.1 ft From Fig. 8.06.e: s Length LATEST REVISION:12/8/2022 4:12 PM TDD A2 0 s E M HOLT TIMMONS GROUP ' Angad Singh ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) TEMPORARY • DD This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope, &channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired). (Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.47 (Acres) Coef.(C)= 0.75 (Dimensionless) Inte. (1)= 7.08 (in/hr) Flow(Qlo)= 2.5 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 79.1 LF Slope= 0.040 (ft/ft) Highest Elevation= 643.6 Z Required= 0.25 Ratio Lowest Elevation= 640.4 Side Slope(M)= 3 :1 QuantitiesVariable Flow Depth(Y)= 0.50 ft 6.0 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 1.26 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) General Lining LBISF North American Jute Net 0.45 Green Lining LBISF Curled Mat 1.55 675 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I (12"@22"THK) 5.00 C125 2.25 Class II (18"@30"THK) 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 0.75 SF New P= 3.16 Wetted perimeter New R= 0.24 Hydraulic radius Z Actual= 0.29 Must be greater than z required=> 0.25 Okay New V= 3.83 fps Liner: Curled Mat 1.55 LB/SF>1.27 LB/SF Okay ............ ..................: Top Width=3 ft Min. Ditch Depth 0.5 ft ........................... 3 Flow Depth(Y)=0.5 ft ;1 Bottom Width(B)=0 ft Ditch Geometry Min. Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) Side Slope 0.50 1 0.00 0.50 3 3:Ditch Liner Curled Mat *RED IS USER INPUT LATEST REVISION: 12/8/2022 4:13 PM TDD A2 E M HOLT ' TIMMONS GROUP • Angad Singh ENGINEERING I DESIGN I TECHNOLOGY 52013 Ditch Outlet Protection (NYDOT Method) ' Ditch Name: DD Velocity= 3.83 fps From Fig. 8.06.c: ZONE= 1 Top Width = 3 ft Ditch Area= 0.75 sf Rip Rap Class= A Equivalent Pipe Diameter= 11.73 in Apron Thickness= 12 in Equivalent Pipe Diameter= 18 in Apron Length = 6.0 ft Apron Width =Top Width.= 3.0 ft From Fig. 8.06.e: s Length LATEST REVISION:12/8/2022 4:13 PM TDD A3 0 s E M HOLT TIMMONS GROUP ' Angad Singh ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) TEMPORARY • DD This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope, &channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired). (Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.78 (Acres) Coef.(C)= 0.60 (Dimensionless) Inte. (1)= 7.08 (in/hr) Flow(Qlo)= 3.3 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 293.5 LF Slope= 0.032 (ft/ft) Highest Elevation= 640 Z Required= 0.37 Ratio Lowest Elevation= 630.5 Side Slope(M)= 3 :1 QuantitiesVariable Flow Depth(Y)= 0.60 ft 7.2 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 1.21 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) General Lining LBISF North American Jute Net 0.45 Green Lining LBISF Curled Mat 1.55 675 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I (12"@22"THK) 5.00 C125 2.25 Class II (18"@30"THK) 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 1.08 SF New P= 3.79 Wetted perimeter New R= 0.28 Hydraulic radius Z Actual= 0.47 Must be greater than z required=> 0.37 Okay New V= 3.87 fps Liner: Curled Mat 1.55 LB/SF>1.22 LB/SF Okay ............ ..................: Top Width=3.6 ft Min. Ditch Depth 0.6 ft ........................... 3 Flow Depth(Y)=0.6 ft ;1 Bottom Width(B)=0 ft Ditch Geometry Min. Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) Side Slope 0.60 1 0.00 0.60 3.6 3:Ditch Liner Curled Mat *RED IS USER INPUT LATEST REVISION: 12/8/2022 4:13 PM TDD A3 E M HOLT ' TIMMONS GROUP • Angad Singh ENGINEERING I DESIGN I TECHNOLOGY 52013 Ditch Outlet Protection (NYDOT Method) ' Ditch Name: DD Velocity= 3.87 fps From Fig. 8.06.c: ZONE= 1 Top Width = 3.6 ft Ditch Area= 1.08 sf Rip Rap Class= A Equivalent Pipe Diameter= 14.07 in Apron Thickness= 12 in Equivalent Pipe Diameter= 18 in Apron Length = 6.0 ft Apron Width =Top Width.= 3.6 ft From Fig. 8.06.e: s Length LATEST REVISION:12/8/2022 4:13 PM ",SOif '• PD61 ' EM Holt ES ' - TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.31 (Acres) Coef.(C)= 0.54 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 1.2 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 138 LF Slope= 0.032 (ft/ft) Highest Elevation= 644.7 Z Required= 0.13 Ratio Lowest Elevation= 640.25 Side Slope(M)= 4 :1 Variable RWidth -. Flow Depth(Y)= 0.35 ft 4.2 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.70 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 0.49 SF New P= 2.89 Wetted perimeter New R= 0.17 Hydraulic radius Z Actual= 0.15 Must be greater than z required=> 0.13 Okay New V= 2.73 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.71 LB/SF Okay ---------- - 2----ft------------ Top Width Min. Ditch Depth 0.35 ft --------------------. 4 Flow Depth(Y)=0.35 ft ----------------------- Bottom Width(B)=0 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 0.35 1 0.00 1 0.35 2.8 1 41 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/1/2023 2:49 PM ",SOif '• PD62 ' EM Holt ES ' - TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 1.64 (Acres) Coef.(C)= 0.58 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 6.7 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 155 LF Slope= 0.032 (ft/ft) Highest Elevation= 639.9 Z Required= 0.76 Ratio Lowest Elevation= 635 Side Slope(M)= 11 :1 Variable RWidth -. Flow Depth(Y)= 0.40 ft 4.8 in Bottom Width(B)= 2.00 ft 24.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.79 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 2.56 SF New P= 10.84 Wetted perimeter New R= 0.24 Hydraulic radius Z Actual= 0.98 Must be greater than z required=> 0.76 Okay New V= 3.37 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.79 LB/SF Okay ---------------------------------------------------- Top Width=10.8 ft Min. Ditch Depth 0.4 ft --------------------. 11 Flow Depth(Y)=0.4 ft 1 Bottom Width(B)=2 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 0.40 1 2.00 1 0.40 10.8 1 111 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/3/2023 7:32 AM ",SOif '• PD63 ' EM Holt ES ' - TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.18 (Acres) Coef.(C)= 0.76 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 1.0 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 122 LF Slope= 0.031 (ft/ft) Highest Elevation= 638.75 Z Required= 0.11 Ratio Lowest Elevation= 635 Side Slope(M)= 12 :1 Variable RWidth -. Flow Depth(Y)= 0.15 ft 1.8 in Bottom Width(B)= 2.00 ft 24.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.29 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 0.57 SF New P= 5.61 Wetted perimeter New R= 0.10 Hydraulic radius Z Actual= 0.12 Must be greater than z required=> 0.11 Okay New V= 1.90 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.29 LB/SF Okay ---------------------------------------------------- Top Width=5.6 ft Min. Ditch Depth 0.15 ft --------------------. 12 Flow Depth(Y)=0.15 ft ----------------------- Bottom Width(B)=2 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 0.15 1 2.00 1 0.15 5.6 1 121 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/3/2023 7:34 AM PDD4 & 0 EM Holt ES - 11 TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD- This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.65 (Acres) Coef.(C)= 0.63 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 2.9 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 195 LF Slope= 0.037 (ft/ft) Highest Elevation= 644.25 Z Required= 0.30 Ratio Lowest Elevation= 637 Side Slope(M)= 9 :1 Variable RWidth -. Flow Depth(Y)= 0.35 ft 4.2 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.81 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 1.10 SF New P= 6.34 Wetted perimeter New R= 0.17 Hydraulic radius Z Actual= 0.34 Must be greater than z required=> 0.30 Okay New V= 2.98 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.82 LB/SF Okay ----------Top Width- ---3-ft------------ Min. Ditch Depth 0.35 ft --------------------. 9 Flow Depth(Y)=0.35 ft ----------------------- Bottom Width(B)=0 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 0.35 1 0.00 1 0.35 6.3 1 91 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/1/2023 2:58 PM ",SOif '• PD65 ' EM Holt ES ' - TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.49 (Acres) Coef.(C)= 0.46 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 1.6 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 159 LF Slope= 0.031 (ft/ft) Highest Elevation= 641.5 Z Required= 0.18 Ratio Lowest Elevation= 636.5 Side Slope(M)= 7 :1 Variable RWidth -. Flow Depth(Y)= 0.35 ft 4.2 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.69 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 0.86 SF New P= 4.95 Wetted perimeter New R= 0.17 Hydraulic radius Z Actual= 0.27 Must be greater than z required=> 0.18 Okay New V= 2.74 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.69 LB/SF Okay ---------- - 4-9-ft------------ Top Width Min. Ditch Depth 0.35 ft --------------------. 1 Flow Depth(Y)=0.35 ft ----------------------- Bottom Width(B)=0 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 0.35 1 0.00 1 0.35 4.9 1 71 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/1/2023 3:03 PM PD66 % EM Holt ES ' - �TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD. This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 3.71 (Acres) Coef.(C)= 0.55 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 14.4 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 357 LF Slope= 0.010 (ft/ft) Highest Elevation= 635 Z Required= 2.98 Ratio Lowest Elevation= 631.6 Side Slope(M)= 4 :1 Variable RWidth -. Flow Depth(Y)= 1.10 ft 13.2 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.65 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 4.84 SF New P= 9.07 Wetted perimeter New R= 0.53 Hydraulic radius Z Actual= 3.18 Must be greater than z required=> 2.98 Okay New V= 3.19 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.66 LB/SF Okay ----------Top Width- -------------------- Min. Ditch Depth 1.1 ft ----- --------- ---------------- . 4 Flow Depth(Y)=1.1 ft ----------------------- Bottom Width(B)=0 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 1.10 1 0.00 1.10 8.8 1 41 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/1/2023 3:03 PM ",SOif '• PD67 ' EM Holt ES ' - TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.23 (Acres) Coef.(C)= 0.45 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 0.7 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 147 LF Slope= 0.047 (ft/ft) Highest Elevation= 642.9 Z Required= 0.07 Ratio Lowest Elevation= 636 Side Slope(M)= 3 :1 Variable RWidth -. Flow Depth(Y)= 0.30 ft 3.6 in Bottom Width(B)= 0.00 ft 0.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.88 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 0.27 SF New P= 1.90 Wetted perimeter New R= 0.14 Hydraulic radius Z Actual= 0.07 Must be greater than z required=> 0.07 Okay New V= 2.93 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.88 LB/SF Okay ----------Top Width- 1----ft------------ Min. Ditch Depth 0.3 ft --------------------. 3 Flow Depth(Y)=0.3 ft 1 Bottom Width(B)=0 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 0.30 1 0.00 1 0.30 1.8 1 31 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/1/2023 3:05 PM ",SOif '• PD68 ' EM Holt ES ' - TIMMONS GROUP - Lynsie Barnes ENGINEERING I DESIGN I TECHNOLOGY 52013 Drainage Ditch Design (Velocity Constraint) DIVERSIONPERMANENT •DD: This worksheet is designed to determine channel lining based on flow and ditch geometry(base width,side slope,&channel slope).This program determines depth of flow,velocity and tractive force assuming n=0.03 for grass or rip rap(n can be varied if desired).(Vary depth until z actual equals z required;v&t will be correct;select appropriate lining based on tractive force) Watershed Data Area(A)= 0.64 (Acres) Coef.(C)= 0.61 (Dimensionless) Inte.(1)= 7.08 (in/hr) Flow(Q10)= 2.8 (cfs) QuantitiesKnown Line channel with: 6 "rip-rap (Assume 6"even if using grass) Manning n= 0.030 (Dimensionless) Ditch Length= 70 LF Slope= 0.029 (ft/ft) Highest Elevation= 645 Z Required= 0.33 Ratio Lowest Elevation= 643 Side Slope(M)= 3 :1 Variable RWidth -. Flow Depth(Y)= 0.35 ft 4.2 in Bottom Width(B)= 2.00 ft 24.0 in Freeboard= 0.00 ft 0.0 in Compute . T=YxDxS Y=Weight of water(62.4 LB/CUFT) T= 0.62 LB/SF D=Depth of flow in channel(ft) S=Slope of channel(ft/ft) LeTg-jgn North American Jute Net 0.45 Green Lining LB/SF Curled Mat 1.55 S75 1.55 Class A(4"@9"THK) 2.00 S150 1.75 Class B(8"@18"THK) 3.50 SC150 2.10 Class I(12"@22"THK) 5.007 C125 2.25 Class 11 18" 30"THK 7.50 P300 8.00 Determine If Z Actual Is Greater Than Z Required New A= 1.07 SF New P= 4.21 Wetted perimeter New R= 0.25 Hydraulic radius Z Actual= 0.43 Must be greater than z required=> 0.33 Okay New V= 3.36 fps Minimum Design Geometry Liner: Curled Mat 1.55 LB/SF>0.63 LB/SF Okay ---------------------------------------------------- Top Width=4.1 ft Min. Ditch Depth 0.35 ft --------------------. 3 Flow Depth(Y)=0.35 ft ---------------------------- ----------------------- Bottom Width(B)=2 ft Ditch Ditch Depth(ft) Bottom Width(ft) Flow Depth(ft) Top Width(ft) ISide Slope 0.35 1 2.00 1 0.35 4.1 1 31 Curled Mat I *RED IS USER INPUT LATEST REVISION:5/3/2023 10:27 AM PRE/POST IMPERVIOUS MAP FOR REVIEW ONLY c e • L y — s 570 �a �SS7Z ac , INQ- • TT W DO NOT USE FOR CONSTRUCTION E I I g o c o N E W u E Z 0 1u is a � — ? z Lu 0 o -m O 1 , 1 a- it i it i o _ �' 1 / ' 1Lu 1 1f pi tf N i --- '' '--- a x cn a ,Q w � 0 0 U-) L O ----------- l \+ I ----------- I \+ I ~ CD W Li Li Ln W ui x x p I F_ I I w W U 0 o o Lr) DATE \ 1 \ 1 0510512023 1 1 0 DRAWN BY LMB X _ ® X_ ��1 1 / X _ ® XJ DESIGNED BY GWF —XJ ` �1 \ L —XJ • CHECKED BY ` 1 ` / \ • GWF Al � \ _ Al \ SCALE AS SHOWN 3 / 3 OAP 011( • IL cu / O = z X__�7 019 / X� off` CL cn Q Q N LJJ c 0A ,0-j0F z 01 j0F z w a z z SCALE 1"=100' SCALE 1"=100' LJJ (0 a z a 0 100' 200' 0 160, 200' J w c LJJ c EXISTING CONDITIONS POST CONDITIONS z W U a J U � 0 c 0 W a O J z �� Q � � � 0 M U � 0 � _ c~n co M ID N E M HOLT RENOVATION AND ADDITION BUA: E M HOLT RENOVATION AND ADDITION BUA: a o M0 U In O O A: TOTAL PARCEL SIZE: 30.2 AC EXISTING IMPERVIOUS z = z N o O a�'i a B: 2007 GRANDFATHERED BUA: 5.46 AC (PRE-ORDINANCE) 3 PROPOSED IMPERVIOUS r a C (A-B): NEW"PARCEL" SIZE SUBJECT TO 24% BUA: 24.74 AC d L D (C X 24%): ALLOWABLE IMPERVIOUS: 5.94 AC — — PROPERTY BOUNDARY ui a U > c Y m E (B + D): TOTAL ALLOWABLE IMPERVIOUS: 11.40 AC cn M X c 0 .0 o F: TOTAL ONSITE IMPERVIOUS 2023: 5.77 AC b THIS DRAWING IS FOR AGENCY REVIEW ONLY- NOT FOR CONSTRUCTION G (F- B): 2023 ADDITIONAL IMPERVIOUS: 0.31 AC ° ° aa) o H (G/C x 100): % BUA 2023: 1.25% (UNDER 24%) = DRAINAGE TO EXISTING PIPE NETWORK-POINT OF ANALYSIS 1 $ m o IMPERVIOUS AREA UNDER ALLOWABLE (D-G): 5.63 ±ACRES PRE-DEVELOPMENT POST-DEVELOPMENT DIFFERENCE ' w JOB NO. o _� % BUA UNDER ALLOWABLE (24% - H): 22.75% BUA IMPERVOUS AREA 0.457 ACRES 0.439 ACRES 0.018 ACRES ° w (19,923 SQFT) (19,119 SQFT) (804 SQFT) 52013 N N c 0 oN SHEET NO. m co n co coC3. 1 M f— L