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HomeMy WebLinkAboutDrainage Reports - 04/12/2007City of Ft. Collins ApproveUlans Approved By MOPMTT OF »a COUMS UTUXrM DRAINAGE AND EROSION CONTROL REPORT HOLSINGER DRYWALL (Prospect Industrial Park, Lot 19, Replat) Prepared for: Holsinger Drywall 1312 Blue Spruce Drive #6 Fort Collins, CO 80524 Prepared by: Interwest Consulting Group .1218 West Ash, Suite C Windsor, Colorado 80550 (970)674-3300 April 2, 2007 February 14, 2007 December 19, 2006 Job N6mber 1053-038-00 i INTERWEST W CONSULTING G R O U P April 2, 2007 Basil Hamdan City of Fort Collins Stormwater 700 Wood Street Fort Collins, CO 80522-0580 RE: Drainage and Erosion Control Report for Holsinger Drywall Dear Basil, I am pleased to submit for your review and approval, this Drainage and Erosion Control Report for Holsinger Drywall. I certify that this report for the drainage design was prepared in accordance with the criteria in the City of Fort Collins Storm Drainage Manual. No changes have been made to the report since the February 14 submittal. I appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Sincerely,' Michael Oberlander, P.E., L.S.I. ii 1218 W. ASH, STE. C • WINDSOR, COLORADO 80550 TEL. 970.674.3300 •. pAx.970. 67d.3303 11 TABLE OF CONTENTS ' TABLE OF CONTENTS............................................................................................................... iii 1. GENERAL LOCATION AND DESCRIPTION 1.1 Location ........................................................................................................1 1.2 Description of Property ............................................................................................1 2. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description..........................................................................................1 ' 2.2 Sub -Basin Description.............................................................................................1 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations..............................................................................................................2 3.2 Development Criteria Reference and Constraints.....................................................2 3.3 Hydrologic Criteria..................................................................................................2 ' 3.4 Hydraulic Criteria....................................................................................................3 4. DRAINAGE FACILITY DESIGN 4.1 General Concept.......................................................................................................3 ' 4.2 Specific Flow Routing.............................................................................................4 4.3 Drainage Summary ...................................................................................................4 ' 5. EROSION CONTROL 5.1 General Concept......................................................................................................5 ' 5.2 Specific Details........................................................................................................5 6. CONCLUSIONS 6.1 Compliance with Standards....................................................................................5 6.2 Drainage Concept.....................................................................................................6 7. REFERENCES....................................................................................................................6 ' APPENDICES A Vicinity Map ' B Hydrologic Computations C Hydraulic Calculations D Detention and Water Quality Pond Sizing E Erosion Control Calculations F Figures and Tables �I iii 1 GENERAL LOCATION AND DESCRIPTION ' 1.1 Location Holsinger Drywall is located in southeast Fort Collins. The project is located on Lot 19, Prospect Industrial Park Subdivision and will be replatted to dedicate right of way and ' site specific easements. It is located Section 20, Township 7 North, Range 68 West of the Sixth Principal Meridian, in the City. of Fort Collins, Larimer County, Colorado. See the location map in Appendix A. ' The project is located on the north side of Midpoint Drive approximately % mile east of ' Timberline Road and 1100 feet northwest of Midpoint Drive's intersection with Sharp Point Drive. The Liberty Common School Track and Field Facility is behind the property, the City of Fort Collins' indoor shooting range is adjacent to the northwest (Lot ' 20) and Lot 18 on the southwest side is vacant. ' 1.2 Description of Property The entire project consists of approximately 0.85 acres of land, all of which will undergo grading and other construction activity. The project will consist of an office -warehouse building, associated parking and drives, and area for future pavement expansion. The land currently slopes to the southeast (to Lot 18 and Midpoint Drive) at approximately 1%. The land is vacant with dryland vegetation over approximately 70% of the site. There is off site flow from the west (Lot 20) that. presently drains through the property. There are no mapped floodplains on the property. ' 2. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description ' The proposed development lies within the Poudre River Master Drainage Basin. ' 2.2 Sub -basin Description This site drains south to Midpoint Drive. Midpoint drains south to the intersection with ' Sharp Point Drive. At the intersection, there is a small storm sewer system which drains to the ponds adjacent to the river; any flows above the storm sewer's capacity top over the C' ' road to the ponds. The existing drainage paths will be maintained with the development ' of this site. 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage ' Design Criteria Manual' specifications. Where applicable, the criteria established in the "Urban Storm Drainage Criteria Manual" (UDFCD), developed by the Denver Regional ' Council of Governments, has been used. 3.2 Development Criteria Reference and Constraints The runoff from this site has been routed to conform to the requirements of the City Stormwater Department. Water quality facilities are required for the new construction proposed on the site. The Poudre River Basin requires that new development detain the 100-year event to the 2-year historic rate. ' 3.3 Hydrologic Criteria ' Runoff computations were prepared for the 2-year and 10-year minor and 100-year major storm frequency utilizing the rational method. ' All hydrologic calculations associated with the basins are included in Appendix B of this report. Standard Form 8 (SF-8) provides time of concentration calculations for all sub - basins. Standard Form 9 (SF-9) provides a summary of the design flows for all Sub - basins and Design Points associated with this site. Water quality volume was calculated using the method recommended in the "Urban Storm Drainage Criteria Manual'. Detention volume was determined using the "Rational" or "FAA" method. All pond calculations are in Appendix D of this report. 1 2 III I ' 3.4 Hydraulic Criteria All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are included in Appendix C of this report. 4. DRAINAGE FACILITY DESIGN ' 4.1 General Concept ' The majority of the proposed development will be routed via sheet and gutter flow to the proposed detention and water quality pond around the perimeter of the site. The pond ' releases to a sidewalk culvert and into Midpoint Drive. The pond has 0.8' of depth for water quality and an additional 1.0' of depth for detention. The pond has a pan at 0.4% at the bottom and will back up into the parking and yard areas (all of which are going to be tconcrete). The pond will accept the flows from Lot 20 (0.32 acres) and will free release the basin adjacent to Midpoint Drive (Basin 3). The pond was calculated using all of Lot 19 (including Basin 3). This was done in order to determine the ideal pond size for the lot (if all of the lot could drain to a pond): Since the off site area draining into the pond is larger than what is lost, the pond meets and exceeds the City's requirement. For any given storm, downstream facilities will be less impacted with the proposed development and detention pond than with existing conditions. If Lot 20 redeveloped, it would be required to have detention and would no longer drain ' through this site. In that case, the pond is oversized and with detention on both lots, downstream conditions would be further improved. None of the sites in this area will be 1 able to detail for the adjacent street. Because there is no storm sewer in the street, all ponds must release to the curb and gutter. With this situation, it is impossible to both ' take water off of the street and into a detention pond, and then release back to the street. The only variance needed on this project is related to freeboard. The pond spillway ' elevation is 1.0' lower than the finished floor of the building and the spillway is only 0.4' deep. When the spillway is flowing, there will not be 12" of elevation between the water .and the building. This is mostly due to the very flat nature of this site. The building is protected adequately from large storms as proposed. L�J 3 I 1 1 1 1 F J I] IF 1 4.2 Specific Flow Routing A summary of the drainage patterns within each basin is provided in the following paragraphs. Basin OS includes the portion of Lot 20 that drains into the site from the northwest. From a field visit and aerial photography, it appears that the southeast half of the building roof drains into the site as well as a portion of the land to the north of the building. Because of existing trees on Lot 20, it does not appear that it is possible to route this lot to Midpoint Drive rather than into Lot 19. The proposed culvert pipe, as well as the spillway from the pond have been designed to convey the 100-year flows from this off site area. Basin 1 includes the majority of the roof which will drain to the swale on the west side of the Lot. The roof will sheet flow to the west and then the channel carries runoff to the south. Basin 1 and Basin OS both flow to the proposed 12" culvert pipe and into the detention and water quality pond. Basin 2 includes the majority of the site including all of the parking, the proposed detention pond, a portion of the building and the small area to the north that could be used for future expansion of the concrete pavement. The basin sheet flows to the north and east to a perimeter trickle pan. The pan is in the bottom of a large but shallow water quality and detention pond. The area inundated by the pond includes most of the site. Basin 3 includes the front face of the detention pond and the portion of the driveway that drains directly to Midpoint Drive. This area does not reach the detention pond. The off site area that drains to the pond offsets this, deficiency. If the off site area is ever rerouted, the pond effectively is oversized. In this case, downstream facilities will see an even larger runoff reduction from the combination of the two sites. 4.3 Drainage Summary Drainage facilities located outside of the right of way (including the detention and water quality pond, proposed storm drain system and the pond outlet) will be maintained by the owners of the property. 4 ' S. 1 1 1 1 1 EROSION CONTROL 5.1 General Concept This site lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort Collins Zone Maps. The potential exists for silt movement from the site and into the existing drainage areas on the west and north sides of the site. Potential also exists for tracking of mud onto existing streets which could then wash into existing storm systems. The required performance standard for the site is 77%. During construction and after final paving and building construction, this figure has been exceeded with the use of silt fence and by using the detention and water quality pond and a sediment trap during construction. The erosion control escrow amount is $2,625. 5.2 Specific Details To limit the amount of silt leaving the site several erosion control measures shall be implemented during construction. Wattles will be used where appropriate, and the boundaries of the property shall have silt fence installed. A vehicle tracking pads shall be installed at the proposed drive connection to Midpoint Drive to control the mud being tracked onto the existing pavement. During overlot grading, disturbed areas are to be kept in a roughened condition and watered to reduce wind erosion. The detention and water quality pond will be used as a sediment trap during construction. All disturbed areas not immediately built upon shall be seeded and mulched. This site is less than one acre and does not require a State of Colorado Stormwater Discharge Permit Associated with Construction Activities. CONCLUSIONS 6.1 Compliance with Standards All computations that have been completed within this report are in compliance with the City of Fort Collins Erosion Control Reference Manual for Construction Sites and the Storm Drainage Design Criteria Manual. E 6.2 Drainage Concept The proposed drainage concepts presented in this report and on the construction plans adequately_ provide for stormwater quantity and quality treatment of proposed impervious areas. Conveyance elements have been designed to pass required flows and to minimize future maintenance. If, at the time of construction, groundwater is encountered, a Colorado Department of Health Construction Dewatering Permit will be required. 7. REFERENCES 1. City of Fort Collins, "Storm Drainage Criteria Manual", (SDCM), dated March, 1986. 2. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria Manual", Volumes 1 and 2, dated June 2001, and Volume 3 dated September 1999. 6 APPENDIX A ate)WIN =Mi U- A D E. ROSPEC RD. SITE o%T� o w m a E. DRAKE RD. VICINITY MAP SCALE: 1 " = 1000` I APPENDIX B HYDROLOGIC COMPUTATIONS 1 1 1 1 1 t 1 I I I I I I I I S - } � \ kk O �f q LL L « \{ § § ) §k ƒ. /\ §± ` kE 2§ (� o a= 0 2f \({& §§ 358j O r{ §ma0e I %U =§omm CD. q§ / )$ _ e%! } / \ \ � °\) uj k 0, �: E OC a. w#»;& syw §$7 § )\\ °4LQ \(\ ).kk 0 0 \\( „ — 2f[/4 § § \\w} } , })k §§|2q f§3 \\ : ,mG + \ ( g � .LD �£§f |a°o 2 f0 ® k§d/ \ \%)a ; u § 0 a .0§kIk ,f. ®�o� < < )� u �.� / L) 9 ) I W } O nl � nZ 20 C Z O W �U N Z O U LL O cW G_ } Y 0 a z Z W y O a a WIx J Q LL a 03 O J U) K o � �WW Wpm O a U O o emo n n may J Q e N N M O) N � •- m 0 p z.. 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GD N CO N N N N N N N N N N m V 0 :..% r w tr0 w U o 0 0 0 0 0 0 0 In f N I Q � 000"M O N � w aD � LL LL O - y M w Jm w N (h O O+ Q �+ U rn w C O c H O o a z 7 U IL 0 O 3 E w O w C w � r mN U _ N C C (mo v O N y fU U N N (0 p U N U N Q N U r C p N O _ l0 IT w C a 41 C n 2 a) C N It II II m Q m L U o U H I I 0 a D c d W O z 0 LL LL O z Y a a W } 0 w J a z O Q II U E m0 y i OU o F O_FF F w a 0K O O J n U z w O W z n a J a U � W 4 0 Q LL O J N J coR W Z yY Q 1=- tan Q r W j n O W ~ a D O a:W W U a 'o y th O O N N N t0 Q < d O f O H U Q � W O U N <D Q 3.`c ormrtn c�mm _ o w r m o r r v � N 4 (h V f+0 fh fh C7 c .� on rmc� L6 mirim ui �oio o m m m r m r m U o 0 0 0 0 0 0 0 U N Nf UI O N It) Q m N O O O UN In CC! OO OO 0 OO OO 0 0 � LL LL O Z y w N t7O nc�U O+O as ) + H F � W K c N � m a O m Z 7 U IL 0 o— E w O` w c� y Of tp N a U N (0 N a) m U N U CC) Q O D U C O c Y 0 CU — N Q C N C C 11 II II It II m C1 U U 11 Q A m Q 0 IL U o U N II CY V � n _T N c d c lu F O z O_ d I� Y N C II U Ei O z z 0 o O O d O 04 aaUL1 z z W z a ¢ a J W ItLU U 0 LL Q 0 >i J Ix W J U Ix F- z O Q a H N j jtn0 ¢ ~ X a D O W tL U d 6 O N m N a0 M O N O N ¢ TJ O N f7 O �' M f0 n O O F O m C O w O � > E c K O O <wja N M It N O N N O N O N 00 � N m c� v ai co of n n� ai U �nmmmco N O) a0 O t0 vvw n 0p n U 66 O CI 6 o 66 LL] f7 N N �O ¢ O 00 N N q fh UO N O LL O o Q'� w � N t70 O+O H O U LU C o a° O_ d I 11 LEI FJ I 1 rl L J 1 APPENDIX C HYDRAULIC CALCULATIONS Culvert Calculator Report ' Worksheet-1 Solve For. Headwater Elevation Culvert Summary lad e1r1] �� 1 Allowable HW Elevation 97.00 ft Headwater Depth/Height 1.78 Computed Headwater Elev: 97.06 ft Discharge 3.20 cf ' Inlet Control HW Elev. 96.63 ft Tailwater Elevation 95.70 Outlet Control HW Elev. 97.06 ft Control Type Outlet Control ' Grades Upstream Invert 95.30 ft Downstream Invert 94.95 ft ' Length 105.00 ft Constructed Slope 0.003333 ft/ft ' Hydraulic Profile Profile CompositeM2PressureProfile Depth, Downstream 0.77 ft Slope Type Mild Normal Depth N/A ft Flow Regime Subcritical Critical Depth 0.77 ft ' Velocity Downstream 4.95 ft/s Critical Slope 0.009240 ft/ft ' Section Section Shape Circular Mannings Coefficient 0.013 Section Material Concrete Span 1.00 ft ' Section Size 12 inch Rise 1.00 ft Number Sections 1 ' Outlet Control Properties Outlet Control HW Elev. 97.06 ft Upstream Velocity Head 0.26 ft Ke 0.50 Entrance Loss 0.13 ft Inlet Control Properties Inlet Control HW Elev. 96.63 ft Flow Control Submerged Inlet Type Square edge w/headwall Area Full 0.8 ft' K 0.00980 HDS 5 Chart 1 M 2.00000 HDS 5 Scale 1 C 0.03980 Equation Form 1 Y 0.67000 1 1 Project Engineer: Interwest Consulting Group untitled.cvm Intenwest Consulting Group CulvertMaster v3.0 [3.0003] ' 12/07/06 12:08:21 PM ®Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA +1-203-755-1666 Page 1 of 1 APPENDIX D DETENTION AND WATER QUALITY POND SIZING r7 II'' `Desia Procedure. Form: Extended Detention Basin (EDB),=- Sedimentation Facility II Sheet 1 of 3 Designer: Lot 19 - Prospect Industrial Park Company: Date: December 13, 2006 Project: Location: 1. Basin Storage Volume A) Tributary Area's Imperviousness Ratio (i = I, / 100 ) B) Contributing Watershed Area (Area) C) Water Quality Capture Volume (WQCV) (WQCV =1.0 - (0.91 ' P - 1.19h + 0.78 ' 1)) D) Design Volume: Vol = (WQCV / 12)' Area' 1.2 2. Outlet Works A) Outlet Type (Check One) B) Depth at Outlet Above Lowest Perforation (H) C) Recommended Maximum Outlet Area per Row, (N) D) Perforation Dimensions: i) Circular Perforation Diameter or ii) Width of 2" High Rectangular Perforations E) Number of Columns (nc, See Table 6a-1 For Maximum) F) Actual Design Outlet Area per Row (A.) G) Number of Rows (nr) H) Total Outlet Area (Aar) 3. Trash Rack A) Needed Open Area: A. = 0.5' (Figure 7 Value)' Aar B) Type of Outlet Opening (Check One) C) For 2", or Smaller, Round Opening (Ref.: Figure 6a): i) Width of Trash Rack and Concrete Opening (W..) from Table 6a-1 ii) Height of Trash Rack Screen (H�) I, = 59.00 % Area = 0.850 acres WQCV 'e0'r23 watershed inches Volacre-feet„_"_"' .tyZ Orifice Plate Perforated Riser Pipe Other. H = 0.90 feet A. P;:;02 '"1square inches D = i = = inches ---� W =t 7:1 inches �. nc =�.......... `t._'_.��number Ao =; 0 2 `� ,( square inches nr F. }....0.3. '. number Aae = ).... :�0"5 '�: square inches Ae square inches 2" Diameter Round - ;-12" High Rectangular Other. Wmw'" :.=,;^;y �"'-` inches 3 HTR .. _--�-41,.,_=.';inches UD-BMP v2.06.xis, EDB 12/13/2006, 3:07 PM DETENTION VOLUME CALCULATIONS .Rational Volumetric (FAA) Method 100-Year Event LOCATION: Lot 19, Prospect Industrial Park PROJECT NO: 1053-038-00 COMPUTATIONS BY: MPO DATE: 12/13/200.6 Equations: Area trib. to pond = 0.85 acre Developed flow = Qo = CIA C (100) = 0.84 Vol. In = Vi = T C I A = T Qo Developed C A = 0.7 acre Vol. Out = Vo =K QPo T Release rate, QPo = 0.2 cfs -fig=- storage = S = Vi - Vo K = 1.0 (from fig 2.1) Rainfall intensity from City of Fort Collins IDF Curve with (3.67') rainfall Storm Duration, T (min) Rainfall Intensity, I (in/hr) Qo (cfs) Vol. in Vi (ft) Vol. Out Vo (ft) Storage S (ft) Storage S (ac-ft) 5 9.95 7.1 2131 60 2071 0.05 10 7.72 5.5 3307 120 3187 0.07 20 5.60 4.0 4798 240 4558 0.10 30 4.52 3.2 5809 360 5449 0.13 40 3.74 2.7 6409 480 5929 0.14 50 3.23 2.3 6919 600 6319 0.15 60 2.86 2.0 7351 720 6631 0.15 70 2.60 1.9 7797 840 6957 0.16 80 2.34 1.7 8020 960 7060 0.16 90 2.17 1.5 8367 1080 7287 0.17 100 1.99 1.4 8525 1200 7325 0.17 110 1.87 1.3 8812 1320 7492 0.17 120 1.75 1.2 8996 1440 7556 0.17 130 1.66 1.2 9245 1560 7685 0.18, 140 1.57 1:1 9416 1680 7736 0.18 150 1.48 1.1 9510 1800 7710 0.18 160 1.42 1.0 9733 1920 7813 0.18 170 1.36 1.0 9905 2040 7865 0.18 180 1.29 0.9 9947 2160 7787 0.18 Required Storage Volume: 7865 ft' 0.18 acre-ft detention.xls,FAA-100yr Proposed Detention Pond - Stage/Storage LOCATION: Lot 19, Prospect Industrial Park PROJECT NO: 1053-038-00 COMPUTATIONS BY: MPO DATE: 2/8/2007 WQ WSEL- 100-yr WSEL- SPILLWAY - TOP OF BERM - detention.xls V = 1 /3 d (A + B + s9rt(A'B)) where V = volume between contours, ft3 d = depth between contours, ft A = surface area of contour WATER QUALITY REQD: 862 (ft) DETENTION REGD: 7865 (ft) TOTAL REQD: 8727 (ft3). Stage (ft) Surface Area W) Incremental Storage (ft) Detention Storage (ft) Total Storage 4894.75 0 4895.00 250 21 21 4895.50 2410 573 594 4895.60 3272 283 0 877 4896.00 6720 1957 1957 2834 4896.50 13720 5007 6964 7841 4896.56 14656 851 7816 8692 4896.60 15280 599 8414 9291 4897.00 J Worksheet for Rectangular Weir - 1L-- protect Flow Element: Rectangular Weir Friction Method: Manning Formula Solve Far. Crest Length Input,Data 6, Discharge: 0.20 Headwater Elevation: 96.60 95.70a""-� CrestElevation: Tailwater Elevation: 95.70 ft Weir Coefficient: 0.65 us Number of Contractions: 0 Results s A, Crest Length: 4.32 +�_- .�/ �+ r� �j �{. in Headwater Height Above Crest: 0.90 ft Tailwater Height Above Crest: 0.00 ft Flow Area: 0.32 ft' Velocity: 0.62 ft/s Wetted Perimeter. 2.16 ft Top Width: " 0.36 ft ' Detention Pond ' Emergency Overflow Spillway Sizing LOCATION: Lot 19, Prospect Industrial Park PROJECT NO: 1053-038-00 COMPUTATIONS BY: MPO DATE: 12/13/2006 by of berm Equation for flow over a broad crested weir . _ ' Q = cLH312 i spill elevation where C = weir coefficient = 2.6 ♦_ L H = overflow height L = length of the weir The pond has a spill elevation equal to the maximum water surface elevation in the pond ' Design spillway with 0.5 ft flow depth, thus H = 0.4 ft Size the spillway assuming that the pond outlet is completely clogged. Pond Q (100) = 8 cfs (peak flow into pond) Spill elev = 4896.60 ft = 100-year WSEL Min top of berm elev.= 4897.00 Weir length required: L= 12 ft Use L = 12 ft v = 1.17 ft/s I I I ' spillway, detentionAs [1 11 s s S Y L � d o C / � m I �a � W � � I 7 I s � CIO GGS `CI CBI okgg= .. — I g•' U r �= Z �- W sQ is j G " I lHUM eu N s m H J I � � I g 3 ova= ga Z N O H L m w� io lam N<2 q�l q�l 2 1 1 1 1 1 1 1 1 1 1 1 1 1 i 1 1 1 1 APPENDIX E EROSION CONTROL CALCULATIONS E I I I I i i 1 J 0 as o Q 0 q y ci o z Q F Q vi G J � 0 o v � o0 e d o e c * o � c 0 d a m o s F o L h 7 9 e Y d ¢ V c 0 m 0 QI 1�1 O r F F, O � � W A W � a N ? H W D !r7 a m N + o F c � a U C � > al y�al m y L y O U N y L tO Y d y O T O m _ Y � C O C O ? V d Iti •y o 0 as x 2 d ro 3 0 m o la o m 3 E= o > C C O O r E C E -C td ° p on on w U °c cn Cn C/n > > O O li a II it li W 3 d.4cnnacnn 0. Y 0 w Interwest Consulting Group 1218 West Ash, Suite C Windsor. Colorado EFFECTIVENESS CALCULATIONS - DURING CONSTRUCTION PROJECT: Replat of Lot 19 Prospect Industrial STANDARD FORM B COMPLETED BY: MPO DATE: 8-Feb-07 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 SMOOTH CONDITION ROADS/WALKS 0.01 STRAW MULCH 0.06 ESTABLISHED GRASS 0.08 ROUGHENED GROUND 0.90 SEDIMENT BASIN/ WQ POND 0.50 INLET PROTECTION 0.80 SILT FENCE 0.50 WATTLE BARRIERS 0.80 EFF=(I-C*P)•100 MAJOR SUB BASIN AREA EROSION CONTROL METHODS BASIN BASIN (Ac) Eror= 0 zE:�)-7 TOTAL AREA = TOTAL EFF = REQUIRED PS = o. 85 77.0% Erosion Holsinger.xls 1 of 1 Interwest Consulting Group 1218 West Ash, Suite C Windsor, Colorado EFFECTIVENESS CALCULATIONS - POST CONSTRUCTION PROJECT: Replat of Lot 19 Prospect Industrial STANDARD FORM B COMPLETED BY: MPO DATE: 8-Feb-07 EROSION CONTROL C-FACTOR P-FACTOR METHOD VALUE VALUE COMMENT BARE SOIL 1.00 SMOOTH CONDITION ROADS/WALKS 0.01 STRAW MULCH 0.06 ESTABLISHED GRASS 0.08 ROUGHENED GROUND 0.90 SEDIMENT BASIN/ WQ POND 0.50 INLET PROTECTION 0.80 SILT FENCE 0.50 WATTLE BARRIERS 0.80 EFF = (1-C-P)• 100 MAJOR SUB BASIN AREA EROSION CONTROL METHODS BASIN BASIN (Ac) 55 Ac Rvrtl » r C ,SSA . o t • 3..: ° _ �. p3 0. w PC. Lwo . ffi 5 TOTAL AREA = TOTAL EFF = REQUIRED PS = D,S5,AC• `jut ©� 77.0% Erosion Holsinger.xls 1 of 1 Cost Est EROSION CONTROL COST ESTIMATE Project: Replat of Lot 19 Prospect Industrial Prepared by: MPO ITEM IQUANTITY JUNIT COST/UNIT JTO=ST Silt Fence 400 LF $3 $1,200 Straw Bale Barrier 0 EA $150 $0 Inlet Protection 0 EA $150 $0 Construction Entrance 1 EA $550 $550 Subtotal Contingency (50%) Total $1,750 $875 $2,625 CITY RESEEDING COST " Reseed/Mulch 0.85 ACRE $775 $659 Subtotal Contingency (50%) Total $659 $329 $988 EROSION CONTROL ESCROW AMOUNT $2,625 Page 1 ' APPENDIX F FIGURES AND TABLES 1 1 1 F No Text 1 1 1 1 1 1 1 1 1 1 1 City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (5 minutes - 30 minutes) Figure 3-1a Duration (minutes) 2-year Intensity in/hr 10-year Intensity in/hr 100-year Intensity in/hr 5.00 2.85 4.87 9.95 6.00 2.67 4.56 9.31 7.00 2.52 4.31 8.80 8.00 2.40 4.10 8.38 9.00 2.30 3.93 .8.03 10.00 2.21 3.78 7.72 11.00 2.13 3.63 7.42 12.00 2.05 3.50 7.16 13.00 1.98 3.39 6.92 14.00 1.92 3.29 6.71 15.00 1.87 3.19 6.52 16.00 1.81 3.08 6.30 17.00 1.75 2.99 6.10 18.00 1.70 2.90 5.92 19.00 1.65 2.82 5.75 20.00 1.61 2.74 5.60 21.00 1.56 2.67 5.46 22.00 1.53 2.61 5.32 23.00 1.49 2.55 5.20 24:00 1.46 2.49 5.09 25.00 1.43 2.44 4.98 26.00 1.40 2.39 4.87 27.00 1.37 2.34 4.78 28.00 1.34 2.29 4.69 29.00 1.32 2.25 4.60 30.00 1.30 2.21 4.52 City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (31 minutes - 60 minutes) Figure 3-1 b Duration (minutes) 2-year Intensity in/hr 10-.year Intensity in/hr 100-year Intensity in/hr 31.00 1.27 2.16 4.42 32.00 1.24 2.12 4.33 33.00 1.22 2.08 4.24 34.00 1.19 2.04 4.16 35.00 1.17 2.00 4.08 36.00 1.15 1.96 4.01 37.00 1.13 1.93 3.93 38.00 1.11 1.89 3.87 39.00 1.09 1.86 3.80 40.00. 1.07 1.83 3.74 41.00 1.05 1.80 3.68 42.00 1.04 1.77 3.62 43.00 1.02 1.74 3.56 44.00 1.01 1.72 3.51 45.00 0.99 1.69 3.46 46.00 0.98 1.67 3.41 47.00 0.96 1.64 3.36 48.00 0.95 1.62 3.31 49.00 0.94 1.60 3.27 50.00 0.92 1.58 3.23 51.00 .0.91 1.56 3.18 52.00 0.90. 1.54 3.14 53.00 0.89 1.52 3.10 54.00 0.88 .1.50 3.07 55.00 0.87 1.48 3.03 56.00 0.86 1.47 2.99 57.00 0.85 1.45 2.96 58.00 0.84 1.43 2.92 59.00 0.83 1.42 2.89 60.00 0.82 1.40 2.86 1 LOT 2 I WPO/NT I L--- 1 I I�� 3 47 I LOT20 -_j PAN AT / I I 1 I I i 1 07." � AIS CONSTRUCTION SHALL BE THE FIRST STEP DURING ADE PRIOR TO SITE CERTIFICATION AND LANDSCAPING. )VERALL CONSTRUCTION IN AN AREA IS FINISHED. IT WILL R).4FAIAN ----------_ -Er mote a¢esatr. M ,v6u..Pi EX. 1.5' 06 —-------- yomg .Ic)_ Mall,. r.yM .vb, cmN mm.w Ma W __ _ _ pma and .wlm anbd rwp dN e..Nm m. Pq, y w1k y .at.tl w w t. mk1„k..Y,d town IPlatim Mm e. RnR.d to tn...d•) r.RUY.d b Y,.n.mat. wn.eRct)P, Iupt Ina .w,,,.,.e maB., by by I m . 4Mk9 -mP la,a cvntays kqA In .ar Ma rm,mn .ma..y 0 lmd dMMr, "Ir .dm atM.k. m o by Ie. Ctr/mmtx f/ h e LOT f9 11H1 jubtu HOLSINGER DRYWALL OF -SINGE REHOUSE /MINIMUM OPENING AN 79 1 / I / I 1 I -----A—AdVm W" # g 60' ROM i .-- — — — --- ---- _ ___ __ _ Er, tam£ wr — Ili L OT27 I nalnxt.d w a.aw.y k . w mv. M,. mmR R.krm.,w of a a ..dk,mt -,d d.bk M1an a d,.M.E. kkwbuce.. and an. Nlq . a w PAIk MOW 0 W. U..t. and .M M. s. and kc.11m w w „oe t. Nrr aM ti0 kb my .ae.. a IM tmlt.d by ..bc. rcuOmb,% ..t.Y,G and p. Mr at find C My d clWm 0 M,. I.a).ct and W. Wming U,. moMm. a,. t. 1M . dbd q a my pa tmt . cmtm,M.t.d ata mnMaclo, Mw. Mct% IKt., and . It.y .wt. 1,. dm.lc M.R a< a Nnw t NU, my and a upPllmM. k.d..tal., and l.d.,f ryWatbna m m,eak .amwt m.t.p and I w od a kwt mty (W) b and P" I, m.Pw.d a P.I. W m. ERA eM1 ral..i Btm. Ma I. k.tdka and makta w wR IM kt. m. tute mtly '!I V. Ma lmpl-„mt Matra. mw..w m. at.mk.d w.mvy, w 3E.SUMMARY TABLE C 100 Tc 10 YIN Tc 100 YIN) 0 10 (CFS) O 100 (CPS 0.96 SA SO 0.9 2.2 0.83 9.9 7.9 1.4 3.8 0.4E 5.0 1 SO 0.1 0.3 0.58 11.7 11.7 0.3 1-4 CALL UMUTT NOTIFICATION DOTER OF COLORADO 1.800-922-1987 m�=nRE)a -� MADE M E]UAVATE FOR 1tE MA1axc OF UNDERTAaR4 MEMBER URrtEa CITY OF FORT COLONS, COLORADO UTILITY PLAN APPROVAL APPROVED: Ott ENOEDI CHECKED BY: WATER R MASIDYATER U111fIT CHECKED BY: s)lMe1RATER UWW CHECKED BY: Pu s REGREAIOM CHECKED BY: ERtaREvl CHECKED BY: 11 ID J woo 4 - 00 q O c 79v ¢ C aV0 w 19 W (A a) D: Z Z)? W a m�z 00 0 Num D. 0 LL PR"M. 1o6iO3B001 70F9