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Home My WebLink About2002-02-01 Revised Drainage CalculationsDRAINAGE CALCULATIONS OAK PARK HEIGHTS, MN 36 & OSGOOD AVENUE WALGREEN'S SITE REVISED February 1, 2002, sP r ° 7 -- 194 - 111 LANDFORM MINNEAPOLIS PHOENIX 510 FIRST AVENUE NORTH, SUITE 650, MINNEAPOLIS, MN 55403 (612) 252-9070 FAX/DATA: (612) 252-9077 PILE COPY flIECIEFSE rs FEB U I SD01025 February 1, 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 storrn 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" storrn 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" storrn sewer pipe is not located within a drainage and utility easement. PROPOSED ANALYSIS Landforn7 510 First Ave. N. Suite 650, Mpls, MN 55403 (612) 252 -9070 * Fax (612) 252 -9077 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 (V2B 1) 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 increasing by 0.26 acres, the V2B I will be treating all of the proposed site's impervious run -off as well as the 0.35 acres of Osgood Avenue run -off. Also, a "drywell" manhole sized for storing the first 1/2" of rainfall of the additional impervious area of the proposed site will be constructed after the V2B 1 system. Both of these structures are located prior to connection into the existing 30" storm sewer system described above. The appropriate calculations are attached. - 7 ' • J••••-•-•• •••.■ , , .„. • - ••• [.■ ,<• '' Cliateie - J60 ft/ / • - VIATer. MON,. .■ • z „-/ e / .. [ --------- / i ---- ----- 1 IRAN Ar111.6 A r \\, 101 5.0 19.2. z 2 W 0 0 \ --- e / / ///1 7 7 -------- ---- - tn , 5i: \ r ,.47)6.177 1 1 1 X z 0 a_ 0. z z Ln r • 11 Site Walgreen's Proposed J. Taveggia Project # SD01025 Existing Location Oak Park Heights, MN Preparer Basin Existing Site Date 1/31/2002 Meadow: good condition LAIDFO Land Use Description Cultivated Land: without conservation treatment Cultivated Land: with conservation treatment Pasture or Range Land: poor condition Pasture or Range Land: good condition 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) 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 Paved Parking Lots, Roofs, Driveways Streets and Roads: paved with curb and gutter Streets and Roads: gravel Streets and Roads: dirt Open Water Lakes or Ponds Swamp with 1/3 Open Water Swamp with No Open Water Other Hydrologic Curve Number Computation Sheet Acres Per Practice 68 39 0.48 0.21 1.36 0.04 m 0) cu U a_ 0 0 CO 72 62 30 45 25 39 49 89 81 77 61 57 54 51 47 59 98 98 76 72 100 85 78 0 0) 0 0 0 81 71 79 61 58 61 100% 69 92 88 85 75 72 70 68 65 74 100% 98 98 100% 85 82 100 85 78 0 88 78 86 74 71 66 77 100% 55 70 74 79 94 91 90 83 81 80 79 76 82 N 0) 0 C 0 0 98 98 98 89 87 100 85 78 Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 0 CO D 91 81 89 80 78 83 77 80 84 95 93 92 87 86 85 84 82 86 98 91 89 100 85 78 Product 0 0 0 0 0 0 26.4 0 14.49 0 0 0 0 0 0 0 0 0 133.28 0 3.4 0 0 0 0 0 2.09 Total Acres Product Total Weighted Runoff Curve # 177.57 85 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 LAIDFO Land Use Description Cultivated Land: without conservation treatment Cultivated Land: with conservation treatment Pasture or Range Land: poor condition Pasture or Range Land: good condition 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) 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 Paved Parking Lots, Roofs, Driveways Streets and Roads: paved with curb and gutter Streets and Roads: gravel Streets and Roads: dirt Open Water Lakes or Ponds Swamp with 1/3 Open Water Swamp with No Open Water Other Hydrologic Curve Number Computation Sheet Acres Per Practice 68 39 0.48 0.21 1.36 0.04 m 0) cu U a_ 0 0 CO 72 62 30 45 25 39 49 89 81 77 61 57 54 51 47 59 98 98 76 72 100 85 78 0 0) 0 0 0 81 71 79 61 58 61 100% 69 92 88 85 75 72 70 68 65 74 100% 98 98 100% 85 82 100 85 78 0 88 78 86 74 71 66 77 100% 55 70 74 79 94 91 90 83 81 80 79 76 82 N 0) 0 C 0 0 98 98 98 89 87 100 85 78 Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 0 CO D 91 81 89 80 78 83 77 80 84 95 93 92 87 86 85 84 82 86 98 91 89 100 85 78 Product 0 0 0 0 0 0 26.4 0 14.49 0 0 0 0 0 0 0 0 0 133.28 0 3.4 0 0 0 0 0 2.09 Total Acres Product Total Weighted Runoff Curve # 177.57 85 85 Site Walgreen's Proposed Project # 3001025 Existing Location Oak Park Heights, MN Preparer J. Taveggia Basin Existing Site Date 1/31/2002 L Drainage Area Runoff Curve Number Time of Concentration Rainfall Distribution Type DFORM Pond and Areas Spread Throughout Watershed Graphical Peak Discharge Am CN Tc 0.0033 85 0.25 I l Square Miles Hours Percent of Am Landform, 650 Butler North Building, 510 First Avenue North, Minneapoks, MN 55403, Phone (612) 252 -9070, Fax (612) 252 -9077 Storm #1 Storm #2 Storm #3 Frequency Year 10 100 Rainfall, P Inch 2.3 4.2 5.9 Initial Abstraction, la Inch 0.353 0.353 0.353 1 1 1 E 1 1 , Compute l a/P 0.15 0.08 0.06 e k E 1 e 1 Unit Peak Discharge, qu GSM 1 Inch 725 775 800 1 1 1 E E E 1 1 1 Runoff, Q 1 Inch 1.00 2.60 4.20 { 1 1 1 1 1 Pond and Swamp Adjustment Factor, Fp 1.0 1.0 1.0 E 1 1 1 1 E Peak Discharge Qp CFS 2.37 6.58 10.97 L Drainage Area Runoff Curve Number Time of Concentration Rainfall Distribution Type DFORM Pond and Areas Spread Throughout Watershed Graphical Peak Discharge Am CN Tc 0.0033 85 0.25 I l Square Miles Hours Percent of Am Landform, 650 Butler North Building, 510 First Avenue North, Minneapoks, MN 55403, Phone (612) 252 -9070, Fax (612) 252 -9077 Site Walgreen's Proposed N/A Project # SD01025 Existing woodland Location Oak Park Heights Preparer J. Taveggia Basin Existing Date 5/7/2001 Segment ID 1 2 N/A 1. Surface Description 12. Cross Sectional Flow Area, a bit. pavement woodland D 2. Mannings Roughness Coeff. , n 0 0.011 0.4 3. Flow Length, L Feet 74 130 Feet 4. Two - Year, 24 Hour Rainfall, P2 Inches 2.7 2.7 15. Channel Slope, s 5. Land Slope, s Ft/Ft 0.014 0.131 1 6. Travel Time Hours 0.02 0.23 0.00 Segment ID N/A N/A N/A 12. Cross Sectional Flow Area, a SF D 0 0 13. Wetted Perimeter, P Feet 1 1 1 14. Hydraulic Radius Feet 0.00 0.00 0.00 15. Channel Slope, s Ft/Ft 1 1 1 16. Manning's Roughness Coeff., n 1 1 1 17. Velocity Ft/Sec 0.00 0.00 0.00 18. Flow Length, L Feet 0 0 0 19. Travel Time Hours #DIV /0! #DIV /O! #DIV /0! Sheet Flow LANDFORM M f.£. N £3 3: 3 0.E f Shallow Concentrated Flow 7. Surface Description 8. Flow Length, L 9. Watercourse Slope, s 10. Average Velocity, V 11. Travel Time Channel Flow 20. Watershed or Subarea Time of Concentration Time of Concentration or Travel Time Segment ID N/A Feet Ft/Ft Ft/Sec Hours 0.00 N/A 0.00 Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 N/A 0.00 1 0.25 0.00 N/A 0.25 111113111 ‘i21, II Wiltwing • ___,,.....•••• _ - - ' ,..,.., '.,,, .,,,,, _._.._.. .. ---4 _:•:;„:--__ '- : :::1: , _ i !: .. 1: I .1 : .•• ...... ..„,q , 7/--- \,\;,, 1 \ \ \` --- • --, ' ---___.; _..,..... .. 1 . - - • . . -- < V g 0 : ... ,, .,. l.S ,,,,,, - / , - ,. .......w. - ,,,,,, ,,,,,,..... ,,, .,/ ., ... i - ----'----. ['''.( -; 1 \ \ / i \ ------------- ....,...--. - • •-, \ , i' 'S'\, N X z LU (f) 0 uJ z 1 Land Use Description p Acres Per Practice Percentage sIioS V Percentage slioS 9 Percentage SI!OS 0 ebe ueoied silos 0 Product J. Taveggia Basin Proposed Date Rev. 0 1/31102 Cultivated Land: without conservation treatment Cultivated Land: with conservation treatment 5.9 72 62 Runoff Q 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 I- 30 58 71 78 0 Meadow: good condition 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 0.47 39 49 100% 61 69 74 79 80 84 28.67 0 Commercial and Business Areas (85% impervious) 89 [ 92 94 95 0 Industrial Districts (72% impervious) 81 J 88 91 93 0 Residential: average lot size 5500 s.f., 65% impervious Residential: average lot size 11 000 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 CD CD o Paved Parking Lots, Roofs, Driveways 1.62 98 100% 98 98 98 158.76 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 1/3 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 Walgreen's Proposed Storm #2 Project # S D0 1025 Existing Frequency Location Oak Park Heights, MN Preparer J. Taveggia Basin Proposed Date Rev. 0 1/31102 DFORM 3r# 3 . 3., rc - Fy83 *x.Nt Hydrologic Curve Number Computation Sheet 2.09 Total Acres Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 Product Total Weighted Runoff Curve # 187.43 90 90 Storm #1 Storm #2 Storm #3 l Units Frequency 1 10 100 Year Rainfall 2.3 4.2 5.9 Inches Runoff Q 1.35 3.10 4.70 Inches DFORM 3r# 3 . 3., rc - Fy83 *x.Nt Hydrologic Curve Number Computation Sheet 2.09 Total Acres Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 Product Total Weighted Runoff Curve # 187.43 90 90 LAN DFO 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 /F Unit Peak Discharge, qu Runoff, Q Peak Discharge Qp Pond and Swamp Adjustment Factor, Fp Graphical Peak Discharge =I= Site Project # Location Basin Walgreen's SD01 025 Oak Park Heights, MN Preparer Proposed Date Rev. 01/31/02 Am CN Tc Inch Inch CSM /Inch Inch CFS 0.0033 90 0.21 I I 0 Storm #1 0 2.3 0.222 0.10 780 1.35 1.0 3,44 Proposed Existing Square Miles Hours Percent of Am Storm #2 10 4.2 0.222 0.05 850 3.10 1.0 8.60 J. Taveggia Landform, 510 First Avenue North, Suite 650, Minneapolis, MN 55403, Phone 612.252.9070, Fax 612.252.9077 Storm #3 100 5.9 0.222 0.04 860 4.70 1.0 13.20 0 D N 2 c w < 0 �o� - � N ct a- 0 0o o 73 0 a 0, . 0 Ci 0 0 E :§." Q) al 0 H co c co 0 U U CU To 0 0 II U i n (o IL (ll E = E o u) 0 (0 < z 2 (1) _07 'D (Q = ( N LO (a J CN Q 0 (3 c >C N—. 2 6 Q ,SG Q °oo E L d L Q) 0 0 5 m N a 0 >— ( , : i 2 co L D v . m co c U F- Cv c i co 0- ca u_ 0L 0 0 CU 11 ca.. 13 ii a Cu (l0 0- 0 U 0_ 0 m � � : U 1 - 0 a) Q : L U U) Q Q (a a) 0 N U ....<< a .J (Y3 LO 10 N 0) 00 (o 10 0 a) T co LC) a7 6 o a3 co to co 0 as ., 0 N 6 a) CY) `' 10 0 a) 0 10 co 0 ai co Co 16 Q rn 10 co 0d CO (o 0 Lri 0 a) N a) 10 T- O) CO co Co cri 0 a) (o co Cfl 1- CO 0 Q Ei 0 a) ca in oo 0 Q Q a) 10 0 (0 to co cri op 0 c3 0 0 a) (a c Nt Q a) c 0 0 (3 0 00 V op (o ui 0) r ti L 0 Q a) oo to Co 0 aa) co a c 0 co (o co co cci a) 03 co 0 aa) to co co r N a) co CD 0 1' 0) N 0 co T 00 W co oo ( 0 a) d~ co to a) 00 o 0 tri a) 0 (o co a 03 0 0 a) N cv Q N co to co Q 0 0 N .-. (7 V to (I) 10 Nt 00 a) 0 rn Q CN co N 10 co 0 co 0 co 6 CN nk- r- 0 co ((3 10 00 to co 03 0 co 0 (v 0 to CO 0 co 0 co Q CO co 00 CO co Q LO 13 Q co N- 6 6 Q N Co C'7 Q N co Q r co 0 Q 0 CO 00 CN Lri 00 as a? 0 . Q r Q r N 1111 1111 ELME 1 0 Q in Q r- Q r✓ c 0 Q T Q 0 0 0 to 0 0 co 10 a, Q 0 03 Q co a a7 0 (0 a (, 0 Lo co Q co Q to Q Q 0 oo Q 0 Q Lo (o Q Lo co 0 CO 0 X co Q r to Q 0 TV cv 0 (o r (o o 0 Q U' Q 0 co 0 r 0 co a CO T✓ co co cv T 10 op 0 0 f co 0 to co 0 co co 0 CO 0 ((3 co 0 0 co 0 N CIO 0 (o co 0 cc U N co 0 m CN r m 0 T^ 1 2 N- CO CN 1 2 W itt C = C H u) 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) 1R= DRYWELL INFILTRATION AREA (sf) IA1= DESIGN RAINFALL EVENT (1N) d= STORAGE VOLUME REQUIRED (CF) d*A= 0.26 0.90 0.5 468.0 0.5 i 471.91 HEIGHT PERFORATED MH INSIDE MH RADIUS OUTSIDE MH RADIUS HEIGHT STONE BELOW MH OUTSIDE STONE RADIUS STORAGE VOLUME PROVIDED (CF) H 1 (feet)= R1 (feet)= R2 (feet)= H2 (feet)= R3 (feet)= PI= WALL REEN'S OAK PARK HEIGHTS, MN SDO1025 8.5 3 3.58 2 5.6 3.141593 1 482.6