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HomeMy WebLinkAboutre: storm water runoff DEC-05-2003 FRI 02;34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P, 02 — �- -._., . . �G, �/�o��..v�8�a3 10:-�S, � �L .�� � � �,f�,�`'€� �'�N� r+� ��� 1�'3 5��, �� O1����'+�l�"' ' � 1�►Q(v�~'�'l TFf� "w�"�" !S �U,,..�,�.�x �s����w� ' n ��� MEMORA� ND UM bATE: December 5,2443 TO: File FROM: Dan Bowar,M�'1�, S�JBJECT: Site Drainage The siagle-family home site far Ac.thony Thomas Homes at 380 I.�af Street in Orano Minnesota.has been investigated for storm watcr ru��off. Using a topograplucal map provided by the city, site plan from Lot Survey Company,Inc.,c.ut�d No�vember 3,2003 and the Hennepin County soil map th� follov��ing has been concluded. 10- 100- Existin rur��ft 10.64 cfs 4.64 cfs 41.62 cfs. Pro osed .90 cfs 15.60 afs 18.61 cfs Peak eleva:ion of Wetland 76.31' 77.08' 977.75' This shows that in tho three propo�ed cases the rate of runoff has beea reduced. The proposcd outlet is a 2�E"CMP with an inlet of 975!}0' and outlet of 973.90'. The driveway will act as an emergency overflow at 978.00'. The propose•:1 fini.shed floor elevation of the home is 979.00'. DEC-05-2003 FRI 02:34 PM TONY EIDEN COMPANY FAX N0. 763 559 6423 P. 03 . , . . Z�� TMpMpg.r� Type ll 24-hr Rainfa -2.75" Prepared by MFRA H�rdroCAD�8.00 s/n 000887 �1966-2011 .4EIAIIBd MICfOCOf11QUter SySt@fT1S 12I�I200Ci Si.ibcatchtnent 1S: Fxi�ting Runoff � 10.64 cfs� 12.08 lyrs, Volume� 0.638 af Runoff by SCS TR 20 method, UH=SC,:;�Tlme Span=5.00-20.00 hrs�dt=0.05 hrs Type Il 24�hr Rainfslt=2.75' Area(sfl CN Descriation 450 100 Water � 172 100 Water 4��321 100 Wate� 367.421 74 >759� Orass :o►�er, Good. HSG C 411�364 77 We(ghted Av��rage Tc Length Slops Velocihr �:apadty Descrip�on (min) (feet) (ftfft� (ft/sec) � (cfs) 14.6 300 0.0900 0.3 3heet Flovv�Q�rass Grass: Short n=0.150 P2=2.50" DEC-05-2003 FRI 02,34 PM TONY EIDEN COMPANY FAX N0. 763 559 6423 P. 04 . . � �� THOMA�'w1 Type 1124hr Rainfal�2.7b" Prepared by MFRA . Page 1 HydroCAD�8.00 s/n 000887 �1986-2��)1 Applied Microcomauter Svstems 12/5J2003 S�i br.�tchmerlt 2.�: Proposed Ru�ff = 11.36 cfs (� 12.08 h�rs� Volume= ' � 0.677 af Runoff by SCS TR 20 metE�od, UH=SC 3,Time Span=5.00-20.00 hrs��=0.05 hrs Type II 24-hr Rainfall=2.75" Area(sf� CN Description � , 450 100 Water 172 100 Water 43,321 100 Water 351�963 74 >75 ib C3rass:�✓er,Good, HSG C 4�205 98 Paved parklr;�i�roofs _ 11.253 98 Paved uarkir;��roofs 411,364 78 Weighted Av�:rige Tc Ler�th Slope Velocity �:apadty Desc�ptian (min) (feet) (ft/ft) (ft/sec) (cfisl 14.6 300 0.0900 0.3 � Sheet Flow,Propoaed • Gcass: Short n=0.150 P2=2.50" DEC-05-2003 FRI 02�34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P. 05 ► �r �Q��..'� Type ll 24-hi Ralnfall=275° Prepared by MFRA �� HvdroCAD�6.00 sJn 000887 O 1886-204�1 A alied Microcomputer Svstems 1� Pond 1 P: Wetiand 1s pr��P in�ow = ��.ss c�s� �Z.os �•r�, va�me= o.sn a� putflow = 7.90 cFs� 12.19 'r rs� Vdume= 0.672 af, Atten=30q6, L�=6.6 min Prirrtary = 7.90 cfs� 12.19 h�s� Vdume= 0.872 af Second�y= 0.00 cfs� 5.Q0 I�rs. Volume= 0.000 af Roudng by Stor-Ind method,Time Spa^=5.00-20.00 hrs,dt=0.05 hrs Peak Elev=976.31' Storage=3,610 cF Plug-Flow detention timme=7.9 min calc ul�ted for 0.670 af(99°�6 of inflow) Storage and wetted areas determined �y Prismatic sections Elevation Surf.Anea In�:.Store Cum.Store lfeet) (sq-ft) (cut io-feet) cubio-feet) 975.00 400 0 0 976.00 1�700 1�050 1.Q50 977.00 15�000 8,350 9�400 978.00 26,285 ;?0,643 30,043 � Primary OutFlow (Fr��Disd�arge) � 'L1=Culvert Secartd�ry OutFlow (Free Discharge;� L2=Broad-Crested Rectangular Weir # Routi�ny Invert Outlet De�„rices 1 Primary 975.00' 24.0" x 4!i.0'long Culvert CMP�end-section ccnforming�fill. Ke=0.500 Outlet Irn i�rl=973.90' S=0.0244'P n=0.024 C�0.900 2 Secondary 878.00' 12.0' lon� x 72.0'breadth Broad-Crested Rectan�ular Weir Head (fef;�:) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (Er�=�li3h) 2.57 2.62 2.70 2.67 2.66 2.67 2.66 2.64 DEC-05-2003 FRI 02�34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P, 06 . . t� � THOMA�-1 Type 1124fir Reinfa .2b" Prepared by MFRA P HyqrvCADt�6.00 sfi 000887 �1986-201�1 Apolied Micrxanoute�S�rstems 12/5/2003 S Gibcatchmerrt 1 S: Existing Runoff = 24.64 cfs � 12A7 ^rs, Volume= 1,447 af Runoff by SCS TR-20 rnethod� UH=SC;�.Time Span�5.00-20.00 hrs,dt=0.05 hrs Type il 24hr Rair�fall=4.25" Area(s� CN Description � 450 100 Water 172 100 Water 4�3,321 100 Water 367,421 74 >75qo Grass �over, Good, HSG C 411,384 77 Weighted Av��rage Tc �ength Slope Velodty ���apacity Descriptinn (min) (feet) (ft/ft� (ft/sec) _ cfs) 14.6 300 0.0900 0.3 Sheet Flaw,Grass Grass: Short n=0.150 P2=2.50" DEC-05-2003 FRI 02;34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P, 07 �U�� THOMA.r�1 Type ll 24-hr Ralnfelh�-4.25" Prepared by MFRA Pa�e 1 Hv�droCAD�6.00 s/n 000887 �198&2Cii1 Applied Microcorr�puter Svstems 1� Su!�c:atchment 2S: Propo�ed Runoff = 25.64 cfs(� 1207 h�rs., Volume= 1.507 af Runaff by SCS TR-20 me�hod. UH=SC!3,Tirne Span=5.00-20.00 hrs,dt=0.05 hrs Type Il 24-hr Raintall=4.25" A�a(sf� CN Descrfptlon p 450 100 Water 172 100 Water 43.321 100 Water 351�963 74 >759� Grass c�a�er,Good, HSG C 4,205 98 Paved parkir.�� �roofs 11,253 98 Paved aarkirc� �roofs 411.364 78 Weighted Av�::rage Tc Length Slope Velopty �;apacity Description (min) �feet) (ft/ft) (ff/sec) „ (efis) 14.6 300 0.0900 0.3 Sheet Flow� Propo�ed Grass: Short n=0.150 P2=2.50" DEC-05-2003 FRI 02�34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P. 08 � ��{� THOMASr-1 Type ll 24-hr Rsinfa11�.2'5" Prepared by MFRA Page 1 HvdroCAD�6.00 sM 000887 �1986-20�1 Aaplied Microcompute�Svstems 12/5/�003 Pond 1 P: Wetiand Inflow - 25.64 cfs (� 12.07 irs, Volume= 1.507 af Outflow � 15.60 cfis� 12.20 7rs, Volume= .1.500 af� Atten=3996. Lag=8.0 min Primary = 15.60 cFs� 12.20 irs. Volutne= 1.500 af Sscondary= 0.00 cfs� 5.00 �rs� Volume= 0.000 af Routing by Stor-Ind method�Ttme Spari= 5.00-20.00 hrs,dt=0.05 hrs Peak Eler�977.08' Storagee� 11,124 ;.f Plug-Flaw deten�on time=8.5 min calc�dated for 1.5U0 af(100°Yo of inflow) Storage and wetted areas determined I:�y I'rismatic sec�ons Eleva�on Surf.Area In�.Store Cum.Store (teet) (sv-ft) (cubi�:-1'eet) (cubio-feet) 975_00 400 0 0 976.00 1,700 1,050 1,050 877.00 15�000 8,350 9�400 978.00 26,285 �'.fl,643 30,043 irimary�utFlow (Fres Dfsdiarge) 1�Culv�ert S�econdary OutFlow (Free Discharge j 2=Broad-Crestsd Rectangular Weir # Routin� Invert Outlet Deuioas 1 Primary 975.00' 24.0" x 4:�.0'long Culvert CMP, end-section confcnning to fill. Ke=0.500 Outlet Invk:rt=973.80' S=0.0244'P n=0.024 Cc=0.900 2 Secondary 978.00' 12.0'lon�� x 1�.0'breadth Broad-Crested Rectangular Weir Nead (fee�l) 0.20 0.40 0.60 Q.SO 1.00 1.20 1.40 1.60 Ccef. (En�;l(�;h) 2.57 2.62 2.70 2.87 2.66 2.67 2.66 2.64 DEC-05-2003 FRI 02�34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P. 08 ��d��- THOMA�i�1 Type ll 24 hr Rainfall=�.90" Prepared by MFRA Page 1 HvdroCAD�6.00 Nn 000887 �1986-2C��1 Applied Microcomputer Systems 1 y5/2p(L3 S�ibcatchment 1S: Existing Runoff = 41.62 cfs � 12.07 r�s, Volume= 2.466 af Rut�off by SCS TR 20 method� UH=SC�i�Time Span=5.00-20.00 hrs�dr O.OS hrs Typa II 24hr Rairrfia11�.90" Area (sfl CN Descrip�on 450 100 Water 172 100 Water 43,321 100 Watsr _ 36J�421 74 >759� Grass caverLC3ood, HSG C 411�364 Tl Weighted Av,�rage Tc Length Slope Vsloaty ���a�adty Desuipqon _ (min) (feet) (ftKt) (ft/sec� (cfis� 14.6 300 0.0900 0.3 Sheet F1ow,�3rass Grass: Short n=0.150 P2=2.50' DEC-05-2003 FRI 02�34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P, 10 . - ��o ,�- 4-hr Rainfall=5 �" TMon�� ry�n 2 s Prepared by MFRA P�9e� NvdroCAD�6.00 s/n 000687 O 1986-2C�;�1 Aaalied Microcomauter SYste 12/5/2003 Sul�atchment 2S: Proposed Runoff = 42.78 cfs(� 12.06 h rs� Volume= 2.541 af Runoff by SCS TR-20 method. UH=SC,3�Time Span=5.00-20.00 hrs.d�0.05 hrs Type 1124-h�Rainfai1=5.90" Ar�a(sfl CN Description � 450 100 Water 172 100 Water 43�321 100 Wafr.r 3b1�963 74 >759�6 Grass r,�ier,C3ood, HSG C 4,205 98 Paved parkin�;� &roofs 11,253 98 Paved parkir.�� t��roofs 411,364 78 Weighted AvL�r�ge Tc Length Slope Velocity �:apaciiy Description (min) (feet) (ft/ft) (ft/sec) (cfs) . _ , 14.6 300 0.0900 0.3 Shest Flo7nrr,Proposed Grass: Shart n=0.150 P2=2.gp" DEC-05-2003 FRI 02;34 PM TONY EIDEN COMPANY FAX N0, 763 559 6423 P, 11 �l0 o y�,., THOMA$�1 TYPe I124-hr Ralnfelh�5.90" Prepared by MFRA Page 1 HyQnoCAtX�6.00 s/n 000887 �►198C�2a1�1 A�pAed Microcomauter Svstems 12/512003 Pond 1 P:Wetland (85j Waming: Oscilla�ons rtray require E�iner Routing>1 Inflow - 42.78 cfs � 12.06 �'rs, Vdume= 2541 af Outflow = 18.61 cfs(�D 12.41 ��s. Volume= 2.533 af, Atten=5696� L.a�21.0 min Primary = 18.61 cfs � 12.41 I'rs� Volume= 2.533 af Seconda�►= 0.00 c�s� 5.00 r rs, Volum� 0.000 af Routlng by Stor-Ind method�Time Spa�^=5.00-20.00 hrs,dt=0.05 hrs Peak Elev=977.75' Storage=24.788 e�f Plug-Flow detention tirr�e= 11.5 min ca rulated for 2.533 af(100% of iriflaw) Storage and wetted areas detertnined �y Prismatic sections Eleva�on Su�f.Area In�::.:►"to�e Cum.Store (feet) (sQ f�) (cuk lo-feet) (cubi�feet) 975.00 400 � 0 0 976.00 1,700 1,050 1�050 - 977.00 15,000 8,350 9,400 978.00 26,285 ;?0,643 30�043 �n�ry dutFlow (Free Discharge) � � 1=Culvert � �ndary OutFlow (Free Disc�argE;;� 2-Bro�d-Crested Rectangular Wei� # Routinp Invert Outlet De�,hces 1 Primary 975.00' 24.0" x 4;i.b'long Cutvert CMP�end�sectlon conforming to flll, Ke=0.500 Ou�et In�•�3�I=973.90' S=0.0244'P n=0.024 C�0.900 2 Secondary 978.00' 12.0'lon�� Y 120'bread�Broad-Crested Rectangula�Welr Head (feE:•:) 0.20 0.40 0.60 0.80 1.� 1.20 1.40 1.60 Coef. (Er;�lish) 2.57 2.62 2.70 2.67 2.66 2.67 2.86 2.64