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Studies Applicant 8/23/2024
380 Q Street, Ste 200 Springfield, Oregon 97477 (541)302-9790 destinta@ao-engr.com A & O Engineering LLC Drainage Memorandum To: Timberview Construction Y4 ft Wm., PE {} com 0=A a S Cull l; OEn neerng� "Smolt From: Destin Takenaka-Amodo, EITUeRy 5m� Reviewed by: Scott Monis, PE 1' ��`� 3=-0'ar Date: 8/22/2024 DEAR Taxmap & T.L.: 17-02-32-41-00400 EXPIRES 12-3124 Re: Tentative Stormwater Design for Parcel 3 of Cherry Springs Partition (Potential Development) Project Overview The applicant is proposing to partition to create 3 lots. One lot on each side of "B" Street as it extends to 48th Street through the city -approved Cherry Springs Apartments and one lot fronting Main Street for future commercial development. The project site is located at 4800 B Street in Springfield. The applicant submitted a detailed Stormwater Management Plan for the residential portion of the property fronting 48th Street. The lot intended for future commercial development fronting Main Street is a sufficient size to allow an on-site stormwater management system. There is a potential development plan shown for the partitioned parcel along Main Street. The storm management plan and calculations show there is adequate space to provide a storm management facility to meet city requirements. Stonnwater Calculation Parameters To perform the stormwater calculations City of Springfield standards were followed. HydroCAD software was utilized to perform hydraulic and hydrology calculations. Below are the parameters that were used for the stormwater calculations with their respective sources in (parenthesis). All parameters were taken from the City of Springfield Engineering Design Standard & Procedures Manual unless otherwise noted: On -Site Design Storm: 2 -Year Design Storm Water Quality Precipitation: 0.83" in 24 hours Destination Precipitation: 3.30" in 24 hours Storm Distribution Type: IA — 24-hour (NRCS SCS Rainfall Distributions) Manning's n Number: 0.011 Runoff Method: Santa Barbara Urban Hydrograph Method (SBUH) Time of Concentration: Minimum 10 minutes Design Calculations Infiltration rate found through Web Soil Survey, being 0.57 to 1.98 in/hr. The design infiltration rate will be 0.50 in/hr and the depth to the water table is more than 80 inches. An infiltration test will be conducted to determine the infiltration rate for tentative submittal. To establish the runoff volume HydroCAD software was utilized to perform the calculations. The new impervious surface for the driveway and the roof was assumed to be 41,273 square feet with a curve number of 98. The proposed dry detention pond will have a 12" growing medium and 12" rock chamber layer beneath the storage areas. Both impervious surfaces are to be hard piped to the proposed detention pond for stormwater treatment and disposal. The physical characteristics of the proposed detention pond is summarized in the tables below: Table 1: Detention Pond Dimensions & Characteristics Layer Top Elev. (ft) Bottom Elev (ft) Side Slopes (H:V) Top Area (sf) Bottom Area (sf) Open Storage 500.00 498.00 3:1 1,836 606 Growing Medium 498.00 497.00 n/a 1,836 1,836 Rock Chamber 497.00 496.00 n/a 1,836 1,836 Table 2. Outlet Dimensions & Characteristics Overflow Infiltration Perf Pipe WQ Destination Grate EI Rate Rate (in/hr) 2" Orifice FL Primary Primary (ft) (in/hr) 499.64 (ft) Outlet Length (ft) 499.55 8" Pipe 26.5 499.83 0.5 2.5 Summarized above are the physical characteristics of the proposed facilities. In the table below pertinent elevations are listed including the peak HGL water elevation during the design storm event. Table 3. Detention Pond Water Quality Elevations and HGL 9 Page 2 2 -Year 25 -Year WQ Destination Destination HGL Destination HGL HGL [ft] [ft] [ft] 496.03 499.64 499.64 9 Page 2 As shown in Table 3 above, all stormwater is fully treated through infiltration in the water quality storm. All proposed landscaping plants are chosen to withstand fluctuating water levels and require low maintenance. All stormwater runoff is also modeled to be treated, contained, and conveyed either through infiltration or overflow to the public main. Conclusion The stormwater plan and calculations shall only be referenced for the potential development. The stormwater management facility is to be re-examined during the site review process when an actual development is proposed. Field infiltration testing shall be conducted during the site review process to determine actual infiltration rates. The proposed detention pond is sized to completely detain the flood design storm and infiltrate all stormwater runoff for the water quality event from all proposed pavement and roof runoff on the subject property. All stormwater during the water quality storm event will be treated through infiltration. Larger storm events will be treated through the proposed landscaping and infiltration through the soil medium then discharged into the public system from the orifice and perforated pipe. The proposed system meets City of Springfield standards and will operate safely protecting the public and surrounding structures from damage. Appendix • Drainage Basin Map for Cherry Springs a HydroCAD calculations for Parcel 3 of Cherry Springs Partition 0 Page 3 qn— — 0616-ZOE(W):3NONd UK6'8O'0131dONINds o0Z mns as 008E 9NLL'InV0) IUMOIWO ills 8 DNIV33NION311W al'"i �uuaau15ug o 2y d C Q �F+ cL a c U, .� c L inC c C C c`a a 0 U) U00a.co hjunoa auv7 pyagEU?.cds s,6u,uds &4.tayj NMONS N d-ejV a2-eutea(j fib i� aid 4Z -9I-9 '3.Lva I� I I I 3 BLDG 2 i - 4800 SF N I I • m � 11 3 I I1 3 �•. I a �. CD o i I is O i i' m LO I� 3 1: I I. I -R r: it y l l ll� ........ ...._.._.._.._.._.._.._.._.._.._.._.._.._. .._.._.._.._.�.._ _.._....._.._.._.. N 3 i I;I I i i Iil� y U) 0 0 U) v LL LL U) N M aO � r � W � m mm c o c a � a m 00 0 a I� I I I 3 BLDG 2 i - 4800 SF N I I • m � 11 3 I I1 3 �•. I a �. CD o i I is O i i' m LO I� 3 1: I I. I -R r: it y l l ll� ........ ...._.._.._.._.._.._.._.._.._.._.._.._.._. .._.._.._.._.�.._ _.._....._.._.._.. N 3 i I;I I i i Iil� 10S Existing Conditions 12S i 3S ',- Pond Su ace Area Paved Area 6S 10 is Building #2 Detention Pond Building #1 Subcat Reach on Link Routing Diagram for Cherry Springs 8-2-24 ❑ Prepared by A&O Engineering LLC, Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 0 2023 HydroCAD Software Solutions LLC Cherry Springs_8-2-24 Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 © 2023 HydroCAD Software Solutions LLC Page 2 Area Listing (selected nodes) Area CN Description (acres) (subcatchment-numbers) 0.963 69 50-75% Grass cover, Fair, HSG B (10S) 0.269 67 Brush, Poor, HSG B (10S) 0.723 98 Paved parking, HSG B (13S) 0.225 98 Roofs, HSG B (1 S, 6S) 0.042 98 Water Surface, HSG B (12S) 2.222 82 TOTAL AREA Cherry Springs_8-2-24 Prepared by A&O Engineering LLC Printed 8/20/2024 H droCAD®10.20-5b s/n 04993 © 2023 HvdroCAD Software Solutions LLC Pa e 3 Soil Listing (selected nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 2.222 HSG B 1 S, 6S, 10S, 12S, 13S 0.000 HSG C 0.000 HSG D 0.000 Other 2.222 TOTAL AREA Cherry Springs 8-2-24 Prepared by MO_Engineering LLC H droCAD® 10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Printed 8/20/2024 Page 4 Ground Covers (selected nodes) HSG -A HSG -B HSG -C HSG -D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 0.963 0.000 0.000 0.000 0.963 50-75% Grass cover, Fair 10S 0.000 0.269 0.000 0.000 0.000 0.269 Brush, Poor 10S 0.000 0.723 0.000 0.000 0.000 0.723 Paved parking 13S 0.000 0.225 0.000 0.000 0.000 0.225 Roofs 1 S, 6S 0.000 0.042 0.000 0.000 0.000 0.042 Water Surface 12S 0.000 2.222 0.000 0.000 0.000 2.222 TOTAL AREA Cherry Springs_8-2-24 Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 © 2023 HydroCAD Software Solutions LLC Page 5 Pipe Listing (selected nodes) Line# Node In -Invert Out -Invert Length Slope n Width Diam/Height Inside -Fill Node Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) Name 1 10P 488.57 486.45 26.5 0.0800 0.010 0.0 8.0 0.0 Cherry Springs_8-2-24 Type lA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 H droCAD®10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Page 6 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SBUH method, Split Pervious/Imperv. Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment1S: Building#1 Runoff Area=5,000 sf 100.00% Impervious Runoff Depth=0.63" Tc=10.0 min CN=0198 Runoff=0.02 cfs 0.006 of Subcatchment6S: Building #2 Runoff Area=4,800 sf 100.00% Impervious Runoff Depth=0.63" Tc=10.0 min CN=0/98 Runoff ---0.02 cfs 0.006 of Subcatchment10S: Existing Conditions Runoff Area=53,668 sf 0.00% Impervious Runoff Depth=0.00" Flow Length=317' Slope=0.0100 T Tc=13.4 min CN=69/0 Runoff=0.00 cfs 0.000 of Subcatchment92S: Pond Surface Area Runoff Area= 1,836 sf 100.00% Impervious Runoff Depth=0.63" Tc=0.0 min CN=0/98 Runoff=0.01 cfs 0.002 of Subcatchmentl3S: Paved Area Runoff Area=31,473 sf 100.00% Impervious Runoff Depth=0.63" Tc=10.0 min CN=0/98 Runoff=0.11 cfs 0.038 of Pond 10P: Detention Pond Peak Elev=496.03' Storage=21 cf Inflow --O.1 5 cfs 0.052 of Discarded=0.02 cfs 0.009 of Primary=0.11 cfs 0.043 of Outflow=0.13 cfs 0.052 of Total Runoff Area = 2.222 ac Runoff Volume = 0.052 of Average Runoff Depth = 0.28" 55.46% Pervious = 1.232 ac 44.54% Impervious = 0.990 ac Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HvdroCAD®10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Page 7 Subcatchment 1S: Building #1 Hydrograph 0.019 - - - - - - - - - - - - - - " - I I - 1 -I - I - I -, ❑Runoff 0.018 0.017 in �_-•_!_� _ 0.016 0.016 _ _ 1 1 • i i I I I I I I I I I _I _ L _ _ Woo, ]A24Th r- 0.015 _1 1_J_ _L - _L_1 L _I__1__ L_ 1_J__I_-L_L_J__I__L_ 0.014 I I _- - - _L I I I I R/� •�� �I1 �� I1 AILwS J__I _L_1-__�__L_•__I7\Qi-���R\� 0.013 � --1--L�j-1--1-�j��--I-- 1_�---- 0.012 _� _�ynQT0-re O.011 I I I I I I I I 1 I I I -Runoff-Volume=11.006 of 3 0.01 -+-'�--1--F-+-a -F-i-_...F-+--I--1---+---I---+---1--�- 0.009 I I I I I - + - 1 - - - � - + I I I 1 1 I I a y,� ^ M�/�I I + - � - - - - - + Debth4:0a IT„ - LLI I i�luhdff 0.008 +_�__,__�_}- � 1 I 1 I I I I I I I 1 _�_+_+_�I�_a IIH_+ _A +__h_�_ 0.007- o-,1 min - 0.006 0.005 -r-r--r-y--I--r-r-y--r-r- ' 0.004 --- r-r-ti--r-r-r-7--r-r-r- -'- r- 0.003 1 I I - r-r--+--r-r-rt- I I I I I I I --I--r-r y--I--r - 0.002 --r r �--r-r- 0.001 1 I I 0 0 1 2 3 4 5 6 7 8 8 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD® 10.20-5b s/n 04993 © 2023 HydroCAD Software Solutions LLC Page 8 Hydrograph for Subcatchment 1S: Building #1 'Time Precip. Perv.Excess Imp.Excess Runoff hours inches inches inches cfs 0.00 0.00 0.00 0.00 0.00 1.00 0.02 0.00 0.00 0.00 2.00 0.04 0.00 0.00 0.00 3.00 0.07 0.00 0.00 0.00 4.00 0.10 0.00 0.01 0.00 5.00 0.13 0.00 0.03 0.00 6.00 0.17 0.00 0.05 0.00 7.00 0.22 0.00 0.09 0.00 8.00 0.35 0.00 0.19 0.02 9.00 0.43 0.00 0.26 0.01 10.00 0.48 0.00 0.30 0.00 11.00 0.52 0.00 0.33 0.00 12.00 0.55 0.00 0.36 0.00 13.00 0.58 0.00 0.39 0.00 14.00 0.61 0.00 0.42 0.00 15.00 0.64 0.00 0.45 0.00 16.00 0.66 0.00 0.47 0.00 17.00 0.69 0.00 0.49 0.00 18.00 0.71 0.00 0.52 0.00 19.00 0.74 0.00 0.54 0.00 20.00 0.76 0.00 0.56 0.00 21.00 0.78 0.00 0.58 0.00 22.00 0.80 0.00 0.59 0.00 23.00 0.81 0.00 0.61 0.00 24.00 0.83 0.00 0.63 0.00 25.00 0.83 0.00 0.63 0.00 26.00 0.83 0.00 0.63 0.00 27.00 0.83 0.00 0.63 0.00 28.00 0.83 0.00 0.63 0.00 29.00 0.83 0.00 0.63 0.00 30.00 0.83 0.00 0.63 0.00 Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 H droCAD®10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Page 9 Subcatchment 6S: Building #2 Hydrograph 0.01 -r 1 - r-�--I- �- r-�-�--r-r �-�--r-r-r--1--r-r-T--1• -r-r• �--I--r-' ❑Rl1IlOff 0.0187 / 0.02 da. -r-7-7--r-r-7--I--I--r-r--I--I--r-t--I--r- 0.017 ' I , .016 0.016- 0.015- -+ --�-+- -+- - - _ _ ----I---+---I-- -+---I--�- 0.014 -}-J--I--�-+-�- +--a-� -� .,_-;----'--- ---� �'-- 1 0.013 _1_J_-IL_1_J_ -D�.83��_ -L_1_JL_1.1 ._-L_1_J_Rain;fall: 0.01 _1_J__I__L_1_J_ I I I I I I _L_1_ _L_1_ _I__L�_bAJxT�I�r I 1 I i I I I I 0.01, -L_J__+_ 1_J_ 1 I _L _1111 _1II L_M1 I L I I 1 1 0.01 /_�J 111_J__I__■/L�■ RI�J �S/v�l ilm=�lJ� At _ 0.009 I 1 I I ----- I I I I I I I I I I I 1 y,,��y y�I 1 ,'- -------------------Ruih-dff -DeOt`h N. 0.00 --J----L-L-J- Y'.VJ '---'--'--'--`-'--'--1--L-L----I--'----J----I--L--II--I--� - 0.007 , - �- � -� - I -I - -,-, -,-,-----------,��-, �0� .F 0.006 1 1 II 1- 1 - - -' - - _ _ I , I I I I - - - - -I - - - - - -I _ -I - I I I I I I I I I I I I , I I I --------------- C 019$ - 0.005 - I- - I I 1 1 1 I 1 1 1 I -----1--j----,--,--j--,--,--,- j --,--�------,--,-- 0.004 ' I I __'__1- - - - - -- I I I I I I I I ,--,--, -- - I I I I 1 I I I-- 0.003 0.002 I I I I I I 1 I 1 I II I r - -I- -1- - r -- 0.001 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 rime (hours) Cherry Springs 8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&07 Engineering LLC Printed 8/20/2024 H droCAD® 10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Pae 10 Hydrograph for Subcatchment 6S: Building #2 Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches) (inches) (inches) (cfs) 0.00 0.00 0.00 0.00 0.00 1.00 0.02 0.00 0.00 0.00 2.00 0.04 0.00 0.00 0.00 3.00 0.07 0.00 0.00 0.00 4.00 0.10 0.00 0.01 0.00 5.00 0.13 0.00 0.03 0.00 6.00 0.17 0.00 0.05 0.00 7.00 0.22 0.00 0.09 0.00 8.00 0.35 0.00 0.19 0.02 9.00 0.43 0.00 0.26 0.01 10.00 0.48 0.00 0.30 0.00 11.00 0.52 0.00 0.33 0.00 12.00 0.55 0.00 0.36 0.00 13.00 0.58 0.00 0.39 0.00 14.00 0.61 0.00 0.42 0.00 15.00 0.64 0.00 0.45 0.00 16.00 0.66 0.00 0.47 0.00 17.00 0.69 0.00 0.49 0.00 18.00 0.71 0.00 0.52 0.00 19.00 0.74 0.00 0.54 0.00 20.00 0.76 0.00 0.56 0.00 21.00 0.78 0.00 0.58 0.00 22.00 0.80 0.00 0.59 0.00 23.00 0.81 0.00 0.61 0.00 24.00 0.83 0.00 0.63 0.00 25.00 0.83 0.00 0.63 0.00 26.00 0.83 0.00 0.63 0.00 27.00 0.83 0.00 0.63 0.00 28.00 0.83 0.00 0.63 0.00 29.00 0.83 0.00 0.63 0.00 30.00 0.83 0.00 0.63 0.00 Cherry Springs -8-2-24 Type 1A 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 © 2023 HydroCAD Software Solutions LLC Page 11 c C M LExisfm Conditions Subcatchment 10S: Existing Conditions Hydrograph I � I I I I � I I I I I I I i , i I I I ❑ Runoll I 1 I I I 1 I I I I I I I■ jpe 1#4 ,24 -fir I I I , I , WI 1 I I I I I I I I O kall■� nfa�1=0.$3+' I I I I I I I I 1 I I I I I I I I I I I I Runoff, /4rea=5$ X68 9f I , , , I , , I� I , a" � U: nOff Volume=0.006 of ftnoff bepth=0.00'' Flovli Lien91 th=317' I I I 1 �Iope:0,'0100 T I I I I I I 1 I I I I I e 1�."f min I I I I I I , I I I I I I I I I ■ V SII UW6V/0 I I , I I 1 I I I I I■ . I I I I I I I I I I 1 I I I I I I 1 I I I I I I I I I I I I I I I I I I 1 I I 1 I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 @2023 HydroCAD Software Solutions LLC Page 12 Hydrograph for Subcatchment 10S: Existing Conditions Time Precip. Perv.Excess Imp.Excess Runoff hours inches inches inches) (cfs) 0.00 0.00 0.00 0.00 0.00 1.00 0.02 0.00 0.00 0.00 2.00 0.04 0.00 0.00 0.00 3.00 0.07 0.00 0.00 0.00 4.00 0.10 0.00 0.00 0.00 5.00 0.13 0.00 0.00 0.00 6.00 0.17 0.00 0.00 0.00 7.00 0.22 0.00 0.00 0.00 8.00 0.35 0.00 0.00 0.00 9.00 0.43 0.00 0.00 0.00 10.00 0.48 0.00 0.00 0.00 11.00 0.52 0.00 0.00 0.00 12.00 0.55 0.00 0.00 0.00 13.00 0.58 0.00 0.00 0.00 14.00 0.61 0.00 0.00 0.00 15.00 0.64 0.00 0.00 0.00 16.00 0.66 0.00 0.00 0.00 17.00 0.69 0.00 0.00 0.00 18.00 0.71 0.00 0.00 0.00 19.00 0.74 0.00 0.00 0.00 20.00 0.76 0.00 0.00 0.00 21.00 0.78 0.00 0.00 0.00 22.00 0.80 0.00 0.00 0.00 23.00 0.81 0.00 0.00 0.00 24.00 0.83 0.00 0.00 0.00 25.00 0.83 0.00 0.00 0.00 26.00 0.83 0.00 0.00 0.00 27.00 0.83 0.00 0.00 0.00 28.00 0.83 0.00 0.00 0.00 29.00 0.83 0.00 0.00 0.00 30.00 0.83 0.00 0.00 0.00 Cherry Springs_8-2-24 Type lA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 © 2023 H,�droCAD Software Solutions LLC Page 13 Subcatchment 12S: Pond Surface Area Hydrograph 0.007-:I I I 1 J --I- L 1_J__I__L_L_J__I__L_ I I i I I I I I I I I I I I I I I I I I I I I I I I I ❑ Runoll o.01 ds -I--� -�---I--� -� - T --I--j ---I--I -r- II --,--j - -r- i 0.007 1 L _ 1 I w I/. L _ 1 _ J _ _ L _ L _ 1 _ J _ _ I- _ L - 1 _ _I _ - I_ � `W� A�.■ ■ . � -��� - I I I 1 I I I SIU 0.006. I I 1 Ir 17� TI � . i �- r-i--1--i--r-i -i--i -i IA 244 0.006 - _.- 1 Il�p�i L-1_ �_L_1_J____L_1-_I-_I__L_-.L_J 0.005 - - __I__L_L_AJ •I I I 11 I l�},l..�C'T" _ _rr _Ii _r_7__,__1__r-r-� 0.005 I - - _ I � T�n, I I I I 1 I I I I I I//�� //�� 1 _ L _ 1 _ L _ 1 _ J _ _I_ _ IL ll�O_Aliei—L� JX 6:-s f _ I I I I I I I I 1 I 1 I �1 I 0.004 � 0.004 -- - _ I I I I I 1 I I I 1 I I I I r r �--r-r-'r-�--*�/{(L■ try■ x- 1 I I I RralrIOJ- I= ■�=� Ola - _ -'L _ 1 _ J _ _ L _ 1 _ J _ _ I_ _ L _ 1 _ J _ L- I J- 0.003 I r 7 - r -r-I TRiuhdff Debth=0.63"_ 0.003 1 I I I _1 1_ _ �_1_J IT I I 1. i - - .. _ _ - _ J. J1 1 1. 1 --- --,---- r 0.002I I I l..T..•f I 11�_ 1 1 1 11 - --- i -i ---r-Z --I--r -r-•1-•: --- i--1 /1 0.002 I I �/N=-0/IYY _L _ L _ -J -I- L- 0.001 - r - 1 - -1- - r 1 - - - - - - - - - - - - - 0.001 r T • !_____ _ _L_ 0.000 I I 1 I I I I i I 1 I 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 25 27 28 29 30 Time (hours) Cherry Springs_8-2-24 Type lA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 H droCAD®10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Pae 14 Hydrograph for Subcatchment 12S: Pond Surface Area Time Precip. Perv.Excess Imp.Excess Runoff hours inches inches inches cfs 0.00 0.00 0.00 0.00 0.00 1.00 0.02 0.00 0.00 0.00 2.00 0.04 0.00 0.00 0.00 3.00 0.07 0.00 0.00 0.00 4.00 0.10 0.00 0.01 0.00 5.00 0.13 0.00 0.03 0.00 6.00 0.17 0.00 0.05 0.00 7.00 0.22 0.00 0.09 0.00 8.00 0.35 0.00 0.19 0.01 9.00 0.43 0.00 0.26 0.00 10.00 0.48 0.00 0.30 0.00 11.00 0.52 0.00 0.33 0.00 12.00 0.55 0.00 0.36 0.00 13.00 0.58 0.00 0.39 0.00 14.00 0.61 0.00 0.42 0.00 15.00 0.64 0.00 0.45 0.00 16.00 0.66 0.00 0.47 0.00 17.00 0.69 0.00 0.49 0.00 18.00 0.71 0.00 0.52 0.00 19.00 0.74 0.00 0.54 0.00 20.00 0.76 0.00 0.56 0.00 21.00 0.78 0.00 0.58 0.00 22.00 0.80 0.00 0.59 0.00 23.00 0.81 0.00 0.61 0.00 24.00 0.83 0.00 0.63 0.00 25.00 0.83 0.00 0.63 0.00 26.00 0.83 0.00 0.63 0.00 27.00 0.83 0.00 0.63 0.00 28.00 0.83 0.00 0.63 0.00 29.00 0.83 0.00 0.63 0.00 30.00 0.83 0.00 0.63 0.00 Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 © 2023 HydroCAD Software Solutions LLC Page 15 Subcatchment 13S: Paved Area Hydrograph 1 I I I 1 I -r-�---r r-�--r-�-r----I--r-Y-I--r-r--I--I--r-r----r 1 .I _I_ _ L 1 0.12 I I I I -r---r-r-� - 0.115 --J--'--�-� -'C' I I I I I 0.11- .11 I req- - �IY - -- _______1 0.105-'-- D.105 � .1 0.1- 0.095: 0.095 - i ----i--; - 0.09 1 0.085 I I I I I I -r---r-r-7 -1- 0.08 -L--''--'--'--1--'- I I I I I I 0.075y - L 0.07 - -J--;- --- --- 4S0.06 I I I I I I I I I I I I I I I 3 0.0 -; -----r- ;-- �0.055 -�-----�-a- - 0.05 -r----I--r 0.045 -1------L-1--'- I 1 0.04 -r--i--r-�--I- 0.03s -'--'--'--'-- --'- I I I I I I 0.03 -+-I--�-+- 0.025 - --'--'-- T 0.02 0.015 -r----1- 0.01 0.005 Subcatchment 13S: Paved Area Hydrograph 1 I I I 1 I -r-�---r r-�--r-�-r----I--r-Y-I--r-r--I--I--r-r----r I I I I- I I I I ❑Runoff I req- - �IY - -- _______1 - 1 - -.-'r - - I --I- I I I I - - - •.- -I--I - Iii•---©\!!l��� ■-/}-I--F - r - 1 --I- - 1- 1t, � 1 _ -I- r -T - 1 - - I_ - r - -f -1 d �A3 --- = �- I ,I .�-! _ L _ L _ J I_ _ L _ I I_ _ L -*31 -r-+-�RWa IAKee=s;�i .i�� - I_ 11 I I I I I I L I I I I I I _RunWM-61iuirh&:i& W &of_ I I I I I I I I I I I I I I I I I I I I I I t I I I II L FMF I I I I I_ r - • r--1--I--r-T--1----r-T--I--I--r-T--I--r-r-1--I-- I I =-'--'--'--=--'------'--I I I I I I I I I I 1 I ----Cw=BOE,99- - �__I- I I I I I --------- - I I I I I I I ____I______-__I_ I I I I r- l--I--r-r -1 L_1_J I I I I --I--I--}-J---~-+-�--I- I 1 I I T --I- --1-'f r -7--I-- _I__L _1_J_ _ IL_1_1I__ I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 26 26 27 28 29 30 Time (hours) Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 C 2023 H droCAD Software Solutions LLC Page 1 Hydrograph for Subcatchment 13S: Paved Area Time Precip. Perv.Excess Imp.Excess Runoff (hours) (inches} (inches) (inches) cfs) 0.00 0.00 0.00 0.00 0.00 1.00 0.02 0.00 0.00 0.00 2.00 0.04 0.00 0.00 0.00 3.00 0.07 0.00 0.00 0.00 4.00 0.10 0.00 0.01 0.01 5.00 0.13 0.00 0.03 0.01 6.00 0.17 0.00 0.05 0.02 7.00 0.22 0.00 0.09 0.03 8.00 0.35 0.00 0.19 0.11 9.00 0.43 0.00 0.26 0.04 10.00 0.48 0.00 0.30 0.03 11.00 0.52 0.00 0.33 0.02 12.00 0.55 0.00 0.36 0.02 13.00 0.58 0.00 0.39 0.02 14.00 0.61 0.00 0.42 0.02 15.00 0.64 0.00 0.45 0.02 16.00 0.66 0.00 0.47 0.02 17.00 0.69 0.00 0.49 0.02 18.00 0.71 0.00 0.52 0.02 19.00 0.74 0.00 0.54 0.02 20.00 0.76 0.00 0.56 0.01 21.00 0.78 0.00 0.58 0.01 22.00 0.80 0.00 0.59 0.01 23.00 0.81 0.00 0.61 0.01 24.00 0.83 0.00 0.63 0.01 25.00 0.83 0.00 0.63 0.00 26.00 0.83 0.00 0.63 0.00 27.00 0.83 0.00 0.63 0.00 28.00 0.83 0.00 0.63 0.00 29.00 0.83 0.00 0.63 0.00 30.00 0.83 0.00 0.63 0.00 Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 0 2023 HydroCAD Software Solutions LLC Pane 17 Cjr 8" Pipe Pond 10P: Detention Pond Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 25 27 2a 29 30 Time (hours) ■ Inflow Q outflow ■ Discarded 0 Primary Cherry Springs_8-2-24 Type IA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 H droCAD®10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Pae 18 Pond 10P: Detention Pond Stage -Discharge 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 Discharge (cfs) 0 500 1.000 1.500 Pond 10P: Detention Pond Stage -Area -Storage Surface/HorizontaiNVetted Area (sq -ft) 2.000 2.500 3,000 3,500 4,000 4,500 5,000 5,500 p Surface ❑ Storage Q Total ■ Discarded 0 Primary 0 500 1,000 1,500 2,000 2,500 3,000 Storage (cubic -feet) Cherry Springs_8-2-24 Type iA 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 HydroCAD®10.20-5b s/n 04993 02023 HydroCAD Software Solutions LLC Page 19 Hydrograph for Pond 10P: Detention Pond Time Inflow Storage Elevation Outflow Discarded Primary {hours cfs(cubic-feet) (feet; xfs' cfsi {cfs:s 0.00 0.00 0 496.00 0.00 0.00 0.00 1.00 0.00 0 496.00 0.00 0.00 0.00 2.00 0.00 0 496.00 0.00 0.00 0.00 3.00 0.00 0 496.00 0.00 0.00 0.00 4.00 0.01 0 496.00 0.01 0.00 0.01 5.00 0.02 0 496.00 0.02 0.00 0.01 6.00 0.03 0 496.00 0.03 0.00 0.02 7.00 0.04 0 496.00 0.04 0.01 0.03 8.00 0.15 15 496.02 0.13 0.02 0.11 9.00 0.06 0 496.00 0.07 0.01 0.06 10.00 0.04 0 496.00 0.05 0.01 0.05 11.00 0.03 0 496.00 0.05 0.01 0.04 12.00 0.03 0 496.00 0.04 0.01 0.04 13.00 0.03 0 496.00 0.04 0.01 0.04 14.00 0.03 0 496.00 0.04 0.01 0.03 15.00 0.03 0 496.00 0.04 0.01 0.03 16.00 0.02 0 496.00 0.04 0.01 0.03 17.00 0.02 0 496.00 0.04 0.01 0.03 18.00 0.02 0 496.00 0.04 0.01 0.03 19.00 0.02 0 496.00 0.04 0.01 0.03 20.00 0.02 0 496.00 0.03 0.01 0.03 21.00 0.02 0 496.00 0.03 0.01 0.03 22.00 0.02 0 496.00 0.03 0.01 0.03 23.00 0.02 0 496.00 0.03 0.01 0.03 24.00 0.02 0 496.00 0.03 0.00 0.02 25.00 0.00 0 496.00 0.00 0.00 0.00 26.00 0.00 0 496.00 0.00 0.00 0.00 27.00 0.00 0 496.00 0.00 0.00 0.00 28.00 0.00 0 496.00 0.00 0.00 0.00 29.00 0.00 0 496.00 0.00 0.00 0.00 30.00 0.00 0 496.00 0.00 0.00 0.00 Cherry Springs_8-2-24 Type 1A 24 -hr WQ RainfaU=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 H droCAD®10.20-5b s/n 04993 @2023 H droCAD Software Solutions LLC Pa a 20 Stage -Discharge for Pond 10P: Detention Pond Elevation Discharge Discarded Primary (feet) (cfs) (cfs) (cfs) 496.00 0.00 0.00 0.00 496.05 0.13 0.02 0.11 496.10 0.13 0.02 0.11 496.15 0.13 0.02 0.11 496.20 0.13 0.02 0.11 496.25 0.13 0.02 0.11 496.30 0.13 0.02 0.11 496.35 0.13 0.02 0.11 496.40 0.13 0.02 0.11 496.45 0.13 0.02 0.11 496.50 0.13 0.02 0.11 496.55 0.13 0.02 0.11 496.60 0.13 0.02 0.11 496.65 0.13 0.02 0.11 496.70 0.13 0.02 0.11 496.75 0.13 0.02 0.11 496.80 0.13 0.02 0.11 496.85 0.13 0.02 0.11 496.90 0.13 0.02 0.11 496.95 0.13 0.02 0.11 497.00 0.13 0.02 0.11 497.05 0.13 0.02 0.11 497.10 0.13 0.02 0.11 497.15 0.13 0.02 0.11 497.20 0.13 0.02 0.11 497.25 0.13 0.02 0.11 497.30 0.13 0.02 0.11 497.35 0.13 0.02 0.11 497.40 0.13 0.02 0.11 497.45 0.13 0.02 0.11 497.50 0.13 0.02 0.11 497.55 0.13 0.02 0.11 497.60 0.13 0.02 0.11 497.65 0.13 0.02 0.11 497.70 0.13 0.02 0.11 497.75 0.13 0.02 0.11 497.80 0.13 0.02 0.11 497.85 0.13 0.02 0.11 497.90 0.13 0.02 0.11 497.95 0.13 0.02 0.11 498.00 0.13 0.02 0.11 498.05 0.13 0.02 0.11 498.10 0.13 0.02 0.11 498.15 0.13 0.02 0.11 498.20 0.13 0.02 0.11 498.25 0.13 0.02 0.11 498.30 0.13 0,02 0.11 498.35 0.13 0.02 0.11 498.40 0.13 0.02 0.11 498.45 0.13 0.02 0.11 498.50 0.13 0.02 0.11 498.55 0.13 0.02 0,11 Elevation Discharge Discarded Primary (feet) (cfs) (cfs) (cfs) 498.60 0.13 0.02 0.11 498.65 0.13 0.02 0.11 498.70 0.13 0.02 0.11 498.75 0.13 0.02 0.11 498.80 0.13 0.02 0.11 498.85 0.13 0.02 0.11 498.90 0.13 0.02 0.11 498.95 0.13 0.02 0.11 499.00 0.13 0.02 0.11 499.05 0.13 0.02 0.11 499.10 0.13 0.02 0.11 499.15 0.13 0.02 0.11 499.20 0.13 0.02 0.11 499.25 0.13 0.02 0.11 499.30 0.13 0.02 0.11 499.35 0.13 0.02 0.11 499.40 0.13 0.02 0.11 499.45 0.13 0.02 0.11 499.50 0.13 0.02 0.11 499.55 0.13 0.02 0.11 499.60 0.13 0.02 0.11 499.65 0.14 0.02 0.12 499.70 0.15 0.02 0.13 499.75 0.16 0.02 0.14 499.80 0.17 0.02 0.15 499.85 0.41 0.02 0.39 499.90 0.63 0.02 0.61 499.95 0.77 0.02 0.75 500.00 0.88 0.02 0.86 Cherry Springs_8-2-24 Type 1A 24 -hr WQ Rainfall=0.83" Prepared by A&O Engineering LLC Printed 8/20/2024 H droCAD®10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC Page 21 Stage -Area -Storage for Pond 10P: Detention Pond Elevation Surface Storage i feet) (S2 -ft) � cubio-feet) 496.00 1,836 0 496.05 1,836 32 496.10 1,836 64 496.15 1,836 96 496.20 1,836 129 496.25 1,836 161 496.30 1,836 193 496.35 1,836 225 496.40 1,836 257 496.45 1,836 289 496.50 1,836 321 496.55 1,836 353 496.60 1,836 386 496.65 1,836 418 496.70 1,836 450 496.75 1,836 482 496.80 1,836 514 496.85 1,836 546 496.90 1,836 578 496.95 1,836 610 497.00 3,672 643 497.05 3,672 652 497.10 3,672 661 497.15 3,672 670 497.20 3,672 679 497.25 3,672 688 497.30 3,672 698 497.35 3,672 707 497.40 3,672 716 497.45 3,672 725 497.50 3,672 734 497.55 3,672 744 497.60 3,672 753 497.65 3,672 762 497.70 3,672 771 497.75 3,672 780 497.80 3,672 789 497.85 3,672 799 497.90 3,672 808 497.95 3,672 817 498.00 4,278 826 498.05 4,307 857 498.10 4,336 890 498.15 4,365 924 498.20 4,394 959 498.25 4,423 996 498.30 4,452 1,034 498.35 4,481 1,074 498.40 4,510 1,115 498.45 4,539 1,158 498.50 4,568 1,202 498.55 4,596 1,247 Elevation Surface Storage (feet) rsc-fta cubic -feet) 498.60 4,625 1,294 498.65 4,654 1,342 498.70 4,683 1,392 498.75 4,712 1,444 498.80 4,741 1,496 498.85 4,770 1,550 498.90 4,799 1,606 498.95 4,828 1,663 499.00 4,857 1,722 499.05 4,890 1,782 499.10 4,922 1,843 499.15 4,955 1,907 499.20 4,987 1,972 499.25 5,020 2,038 499.30 5,052 2,106 499.35 5,085 2,176 499.40 5,117 2,248 499.45 5,150 2,321 499.50 5,183 2,396 499.55 5,215 2,472 499.60 5,248 2,550 499.65 5,280 2,629 499.70 5,313 2,711 499.75 5,345 2,794 499.80 5,378 2,878 499.85 5,410 2,964 499.90 5,443 3,052 499.95 5,475 3,141 500.00 5,508 3,232 Cherry Springs_8-2-24 Table of Contents Prepared by A&O Engineering LLC Printed 8/20/2024 H droCADO 10.20-5b s/n 04993 © 2023 H droCAD Software Solutions LLC TABLE OF CONTENTS Proiect Reports 1 Routing Diagram 2 Area Listing (selected nodes) 3 Soil Listing (selected nodes) 4 Ground Covers (selected nodes) 5 Pipe Listing (selected nodes) Current Event 6 Node Listing 7 Subcat 1S: Building #1 9 Subcat 6S: Building #2 11 Subcat 10S: Existing Conditions 13 Subcat 12S: Pond Surface Area 15 Subcat 13S: Paved Area 17 Pond 10P: Detention Pond