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Home My WebLink About2002-03-08 Revised Drainage CalculationsDRAINAGE CALCULATIONS OAK PARK HEIGHTS, MN 36 & OSGOOD AVENUE WALGREEN'S SITE REVISED March 8, 2002 0••- LANDFORM MINNEAPOLIS 'PHOENIX 510 FIRST AVENUE NORTH, SUITE 650, MINNEAPOLIS, MN 55403 (612) 252-9070 FAX/DATA: (612) 252-9077 SD01025 March 8, 2002 Drainage Analysis & Storm Sewer Narrative EXISTING ANALYSIS The existing site consists of a funeral home with bituminous parking. Approximately 60% of the site (with 40% impervious area) drains to the east off the property into a drainage ditch that flows to the south. This storm water runoff continues south through storm sewer culverts under State Highway No. 36. The other 40% of the site (with 82% impervious area) drains to the south into the State Highway No. 36 Right -of Way. Currently, there is no water quantity or quality ponding on the site. There is an existing 18" storm sewer pipe that runs across the middle of the site from west to east and connects to a 30" storm pipe that flows south. The 30" storm pipe system runs south of the site and eventually outlets to a regional storm water treatment pond referred to as Perril Pond. This storm pipe system collects storm water run -off from a portion of the adjacent roadway, Osgood Avenue North (CSAH 24). It appears the 18" storm sewer pipe is not located within a drainage and utility easement. PROPOSED ANALYSIS Oak Park Heights — Walgreen's The proposed site redevelopment includes collection of the on -site impervious and pervious runoff with concrete curb and gutter, catch basins, and storm sewer pipe. The sites overall drainage pattern will be revised to direct the on -site run-off into the existing storm sewer system described above that currently runs across the middle of the site. The 18" storm sewer pipe is currently located underneath the proposed building, therefore this existing pipe will be rerouted to the south of the proposed Walgreen's building. Due to the tight constraints of the site, on -site ponding is not feasible. To provide best management practices, an in -line storm water treatment structure (V2B1) will be provided for storm water treatment at the end of our on -site storm sewer system. Even though the impervious area of the site is only increasing by 0.16 acres, the V2B1 will be treating all of the proposed site's impervious run -off as well as the 0.90 acres of Osgood Avenue run -off. Field investigation and Washington County topography /aerial maps as attached determined the amount of storm water run-off draining into the 1 8" pipe from Osgood Avenue. A "drywell" manhole sized for storing the first %2 " of rainfall of the additional impervious area of the proposed site will be constructed after the V2B 1 system per direction of the watershed. Both of these structures are located prior to connection into the existing 30" storm sewer system described above. The appropriate calculations are attached. Landforrn 510 First Ave. N. Suite 650, Mpls, MN 55403 (612) 252-9070 * Fax (612) 252 --9077 t r . , . .. • - 1 , • _.,•• .161 niVis'd ., ,,---- , 3 :•..-.= - .. . ,_ ,. ■ , : •• speo F.01119 (7,4.95, TV 'XV b3d Sta.15 was .1.11 • boo 6 < 0 . . On o f ( .10 :All - •-• _ „ - • •• • • o „.. 4 o co , . ict;o+-Q4 iM An -- . , ,.' , .•::.:` . 2,' - .1Yii I.. ._.E1::..,-.::.. .„..„...L. ! , ,,. .,...• . ._. :,...- \ I - r 'i .... .,. -....,_ ..____...........,_ _. . ..--,, .,•: .: .. . ,. ..... ,. /1 ri. :.,..., -." ''';', ''' •.-_. , -..;,-;;_ - !:•'_:=•;1 / / '.• ---.,.-. ,, •-,,,,,;-:......:-,, .,.r. ._.., . • = • z • • -, Site Walgreen's Proposed Project # SD01025 Existing Location Oak Park Heights, MN Preparer J. Taveggia Basin Existing Site date 1/3112002 Land Use Description p Acres Per Practice Percentage I siPS b Percentage s has 8 Percentage SI 0 aEqueoJed snas 0 Product Residential: average lot size 5500 s.f., 65% impervious Storm #1 77 85 90 92 0 Residential: average lot size 11000 s.f., 38% impervious 1 61 75 83 87 Residential: average lot size 14500 s.f., 30% impervious Swamp with No Open Water 57 72 81 86 IIIIMMIIIIIIIMENIMMIIIIIMENI C:3 C) C) a o Residential: average lot size 22000 s.f., 25% impervious Runoff Q 54 70 80 85 Residential: average lot size 1 acre, 20% impervious Inches 51 68 79 84 Residential: average lot size 2 acre, 15% impervious 47 65 76 82 Farmsteads 59 74 82 86 Open Water Lakes or Ponds Storm #1 100 100 100 100 0 Swamp with 1/3 Open Water 1 85 85 85 85 0 Swamp with No Open Water 2.3 78 78 78 78 0 Meadow: good condition Pasture or Range Land: poor condition Pasture or Range Land: good condition Cultivated Land: without conservation treatment Cultivated Land: with conservation treatment Wood or Forest Land: thin stand, poor cover, no mulch Wood or Forest Land: good cover Open Space, Lawns, Parks, Golf Courses: good condition Open Space, Lawns, Parks, Golf Courses: fair condition Commercial and Business Areas (85% impervious) Industrial Districts (72% impervious) Paved Parking Lots, Roofs, Driveways Streets and Roads: paved with curb and gutter Streets and Roads: gravel Streets and Roads: dirt Hydrologic Curve Number Computation sheet 0.48 0.21 1.36 0.04 72 62 68 39 30 45 25 39 49 89 81 98 98 76 72 81 71 79 61 58 66 100% 55 61 100% 69 92 88 100% 98 98 100% 85 82 88 78 86 74 71 77 70 74 79 94 91 98 98 89 87 Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 91 81 89 80 78 83 77 80 84 95 l 0 93 0 0 0 0 0 26.4 0 14.49 0 98 98 91 89 133.28 0 3.4 0 i 2.09 Total Acres Product Total Weighted Runoff Curve # 177.57 85 Storm #1 Storm #2 Storm #3 Units Frequency 1 10 100 Year Rainfall 2.3 4.2 5.9 Inches Runoff Q 1.00 2.60 4.20 Inches Meadow: good condition Pasture or Range Land: poor condition Pasture or Range Land: good condition Cultivated Land: without conservation treatment Cultivated Land: with conservation treatment Wood or Forest Land: thin stand, poor cover, no mulch Wood or Forest Land: good cover Open Space, Lawns, Parks, Golf Courses: good condition Open Space, Lawns, Parks, Golf Courses: fair condition Commercial and Business Areas (85% impervious) Industrial Districts (72% impervious) Paved Parking Lots, Roofs, Driveways Streets and Roads: paved with curb and gutter Streets and Roads: gravel Streets and Roads: dirt Hydrologic Curve Number Computation sheet 0.48 0.21 1.36 0.04 72 62 68 39 30 45 25 39 49 89 81 98 98 76 72 81 71 79 61 58 66 100% 55 61 100% 69 92 88 100% 98 98 100% 85 82 88 78 86 74 71 77 70 74 79 94 91 98 98 89 87 Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 91 81 89 80 78 83 77 80 84 95 l 0 93 0 0 0 0 0 26.4 0 14.49 0 98 98 91 89 133.28 0 3.4 0 i 2.09 Total Acres Product Total Weighted Runoff Curve # 177.57 85 o Site Waigreen's ' Proposed Project # SD01025 Existing Location Oak Park Heights, MN Preparer J. Taveggia Basin Existing Site Date 1/31/2002 Drainage Area Runoff Curve Number Time of Concentration Rainfall Distribution Type Pond and Areas Spread Throughout Watershed Frequency Rainfall, P Initial Abstraction, la Compute la /P Unit Peak Discharge, qu Runoff, Q Pond and Swamp Adjustment Factor, Fp Peak Discharge Qp Graphical Peak Discharge m CN To Inch CSM 1 Inch Inch CFS 0.0033 85 0.25 11 0.353 0.15 725 1.00 1.0 2.37 Square Miles Hours Percent of Am 10 4.2 0.353 0.08 775 2.60 1.0 6.58 Landform, 650 Butler North Building, 510 First Avenue North, Minneapois, MN 55403, Phone (612) 252 -9070, Fax (612) 252 -9077 Storm #3 100 5.9 0.353 0.06 800 4.20 1.0 10.97 Site Walgreen's Proposed Project # SD01025 Existing Location Oak Park Heights Preparer J. Taveggia Basin Existing Date 5/7/2001 Sheet Flow 1. Surface Description 2. Mannings Roughness Coeff. , 3. Flow Length, L 4. Two - Year, 24 Hour Rainfall, P 5. Land Slope, s 6. Travel Time Shallow Concentrated Flow 7. Surface Description 8. Flow Length, L 9. Watercourse Slope, s 10. Average Velocity, V 11. Travel Time Channel Flow 12. Cross Sectional Flow Area, a 13. Wetted Perimeter, P 14. Hydraulic Radius 15. Channel Slope, s 16. Manning's Roughness Coeff., n 17. Velocity 18. Flow Length, L 19. Travel Time :A P•4 Time of Concentration or Travel Time Segment ID Feet Inches Ft/Ft Hours Segment ID N/A Feet Ft/Ft Ft/Sec Hours Segment ID SF Feet Feet Ft/Ft Ft/Sec Feet Hours bit. pavement N/A #DIV/0! 0.011 74 2.7 0.014 0.02 0.00 1 1 0.00 0 woodland N/A #DIVIO! 0.4 130 2.7 0.131 0.23 1 0.00 0.00 0.00 0.00 Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 N/A 1 0.00 0.00 1 1 0 #DIV /0! 1 0.00 1 1 0.00 0 0.25 0.00 N/A 20. Watershed or Subarea Time of Concentration 0.25 VISSMIMISISSISSMINUMIEMil v.v...Viv1/4\\XV ( ---__... Z Ng ---: -- Ill UM • - --- ,--, fa I_i RI EFS! rINNw 21 mar Rao io ez--- xi vi amivii EINI5 i \ ii Ai WAWA , NMI, iiiii , .,:gausiNV ISEil .easivinSWEINFLIMEINALIEtwiglarfieigr& ii..\ ic 1 1 . ,_E__ ,,,i 1 131 , :-.,• , 7 \_ 1 i ' I / '''• ----, 1 ' 1 4i A , i i t 1 \ ‘,__. 11%1 1 .L .,,,,,_ riez. b----111.11111°—°--"MINIMINIffilowilliilk --- ...maimmorri. MY P.11.111.111.011./.64131,7' :TM .. W 1.11.1•1.111,.11,110.:1 .0 IIMIlbalgft"...........,.. ..--"... ■ _.-. :.,.<„,, ..-- ....- .,-. „---- ,,,--:,-_-_:-. „„ -,:::,--- - ,. -- 1.------ ----.2.-----,------; '.- - - -----;:---: - -- - 2: , - -- --'',- - ....--- '' ,„, ..._.... ----- --, , „. ,-,-....f.;--------:-..:1------ --...---- , \\\,\\\.\, "— , ' . 7 . ,,,, 7.. ::::,--;_:=...,.....". ...., •--....-::::-...„...---- ''''\ k ,\:.--------,-.,•-- - „.„....---___,. . ,-.1 _, ' \ , ----- .4 — 1 f 1 ''' '::— :: ---. 7 ------F--- - - ) / 1 \ C' , i ) j r • e_g\V Ob' 0 ri 1 Land Use Description p Acres Per Practice Percentage suuoS d ebe11.1e0.1ed sliOS 8 Percentage [;uos 0 ebelua0 .19d S�IOS Q Product Basin Proposed Date Rev. 03108/02 5.9 Cultivated Land: without conservation treatment Cultivated Land: with conservation treatment Runoff Q 1.30 _ 72 62 4.60 81 71 88 78 91 81 0 0 Pasture or Range Land: poor condition Pasture or Range Land: good condition 68 39 79 61 86 74 89 80 0 0 Meadow: good condition 30 58 71 78 0 Wood or Forest Land: thin stand, poor cover, no mulch Wood or Forest Land: good cover 45 25 66 55 77 70 83 77 0 0 Open Space, Lawns, Parks, Golf Courses: good condition Open Space, Lawns, Parks, Golf Courses: fair condition 0.53 39 49 100% 61 69 74 79 80 84 32.33 0 94] 95 0 Commercial and Business Areas (85% impervious) 89 92 Industrial Districts (72% impervious) 81 88 91 93 0 Residential: average lot size 5500 s.f., 65% impervious Residential: average lot size 11000 s.f., 38% impervious Residential: average lot size 14500 s.f., 30% impervious Residential: average lot size 22000 s.f., 25% impervious Residential: average lot size 1 acre, 20% impervious Residential: average lot size 2 acre, 15% impervious Farmsteads 77 61 57 54 51 47 59 85 75 72 70 68 65 74 90 83 81 80 79 76 82 92 87 86 85 84 82 86 Paved Parking Lots, Roofs, Driveways 1.56 98 100% 98 98 98 152.88 Streets and Roads: paved with curb and gutter Streets and Roads: gravel Streets and Roads: dirt 98 76 72 98 85 82 98 89 87 98 91 89 0 0 0 Open Water Lakes or Ponds Swamp with 113 Open Water Swamp with No Open Water 100 85 78 100 85 78 100 85 78 100 85 78 0 0 0 Other 0 0 Site 2.09 Total Acres Product Total 185.21 w Frequency Location Weighted Runoff Curve # 89 \ Site Walgreen's Proposed Project # SD01 025 Existing Frequency Location Oak Park Heights, MN Preparer J. Taveggia Basin Proposed Date Rev. 03108/02 Hydrologic Curve Number Computation Sheet Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 Storm #1 Storm #2 Storm #3 Units Frequency 10 IIIII 100 Year Rainfall EINE. 11111 4.2 111111 5.9 Inches Runoff Q 1.30 _ 3.00 MI 4.60 Inches Hydrologic Curve Number Computation Sheet Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 Site Walgreen's Proposed Project # SD01025 Existing Location Oak Park Heights, MN Preparer J. Taveggia Basin Proposed Date Rev. 03/08/02 Frequency Rainfall, P Runoff, Q Compute I a/P Initial Abstraction, la Unit Peak Discharge, qu Pond and Swamp Adjustment Factor, Fp Peak Discharge Qp Graphical Peak Discharge Drainage Area Runoff Curve Number Time of Concentration Rainfall Distribution Type Pond and Areas Spread Throughout Watershed CN Tc 0.0033 89 0.21 11 Square Miles Hours Percent of Am CSM 1 Inch Inch CFS 2.3 4.2 5.9 Inch 0.247 0.11 775 1.30 1.0 3.29 0.06 825 3.00 1.0 8.08 Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 0.247 0.04 860 4.60 1.0 12.92 Comments Downstream Structure PU 9 I z9: X9'9 1 ov'9 19L'9 z6'5 I ts 1 95'L 99'9 IaBALI' 1 94'Z06 L6'006 92 1.0'668 1.8'868 1.6'L68 99'L68 ttW'L68 99':68 1 . 0 . 1 1 1 89'506 85'L06 905.43 1 905.43 90'506 Es I oo'sos 1 905.00 oE'oos Upstream Structure pr eu 99': 1 6L'9 eu 0 I58'9 � zo tii7'L 1 99'L 1 1.1anu 1 902.48 902.02 L8'006 eu :8'868 1.3'868 897.81 99'L68 17E169 0 l eu 89'06 85'L06 eu 1 905.43 90'506) 1 :9 905.00 1 905.00 a) a 0 L.L. a.. 0 0 19 [9z 1z 1i7 6 (8�z� 1.'9E L W Li. 917 f VL1. 6 6 :9 9 0'91. a)) d I 0 zv 00'1. 09'0 C9 9 :`0 9 :'0 99'0 OL'0 03'9 a) 0 Z 00'1. 1 os'o :5 9E'0 9: - 0 99'0 0E0 o z's 0 a E. o — • 31- � Iz� � 81. 1,3 12 ii: a) co o 0'01• 0'8 :' i 5z 0'01, 0'01. U a u. 61, , z 8'0 z - 0 9'0 eu eu - i 9'9 1-'01• 1111 11 111111 NINE imis 6'a OEM UZI- 6'0 BM 9'14- 6'0 9'9 006 6'0 ciel 0'66 01. isai 9'06 0'L 11 I 4'S SE 6'0 ilimmel 6'0 }2.g' C.3 Q 0) Q Q 1 9C'0 1 9V0 I 8" 1 os'o 9[1- 1 s1-7 [ co 2 d Q SE*o oG'o f7o os'o Ez 91. zt10 J oo'o oo*o J 6 Z 1 1zo1,) 1 eu l 98 I Ez I [ L 1. 11 I Down - Stream Struct. e0 � s ao � z 90 1. 90 � 1,azn: 11 L HW1S 1 HW X3 Up- Stream Struct. 990 j7 9 0 e llsJ4 O :90 390 1. 90 Ir8z11 V1•HWiS - 3 2 a 0 ° cL a o0 s.:-- — (\} o : co 0 0 o N ILO J 121 0) 0) 0 co 03 cal CO (-0 U C0 w (0 -„^, 27 8 t O .L 650 BUTLER NORTH BUILDING 510 FIRST AVENUE NORTH Date: 03/08/02 PHONE: 612.252.9070 FAX: 612.252.9077 wvvw.landform.net MINNEAPOLIS, MN 55403 STORAGE FOR 1/2" OF RAINFALL OVER INCREASED IMPERVIOUS AREA STORMWATER VOLUME (BASED ON RATIONAL FORMULA) DRYWELL DESIGN 6' Dia MH/ 16.2' Build ADDNL IMP. SITE AREA (acres) A= RUNOFF COEFFICIENT C= INFILTRATION RATE (in/hr) I DRYWELL INFILTRATION AREA (sf) IA1= DESIGN RAINFALL EVENT (IN) d= STORAGE VOLUME REQUIRED (CF) d*A= 0.26 0.90 0.5 468.0 0.5 471.91 HEIGHT PERFORATED MH INSIDE MH RADIUS OUTSIDE MH RADIUS HEIGHT STONE BELOW MH OUTSIDE STONE RADIUS STORAGE VOLUME PROVIDED (CF) H1 (feet)= R1 (feet)= R2 (feet)= H2 (feet)= R3 (feet)= P1= WALGREEN'S OAK PARK HEIGHTS, MN SD01025 8.5 3 3.58 5.6 3.141593 1 482.6