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HomeMy WebLinkAboutDrainage Reports - 08/02/2009I 1 1 1 1 H 1 1 1 FINAL DRAINAGE INVESTIGATION SEDIMENT EROSION CONTROL REPORT for WHITMAN STORAGE FACILITY Located in the Southwest Quarter of Section 12, Township 6 North, Range 69 West of the 6' P.M. (209 East Skyway Drive) CITY OF FORT COLLINS, LARIMER COUNTY , COLORADO 1 150 East Prepared for: Sierra Builders, Ltd, LLC 1104 North Monroe Avenue Loveland, Colorado 80537 City of Ft. Collins Amro Plans Approved a May 2009 Date �. D Project No. GRD - 587 - 08 Prepared by: Loveland, (970)663-2221 ' Engineering, Inc. May 26, 2009 Project No. GRD - 297 - 98 ' Wes LeMarque, P.E. Stormwater Utility ' Service Center 700 Wood Street Fort Collins, Colorado 80522-0580 ' Re: Final Drainage Investigation and Erosion Control Report for Whitman Storage Facility - P. D. P., Fort Collins, Colorado ' Dear Mr. LeMarque: ' We are pleased to resubmit to you, for your review and comment, this "Final Drainage Investigation and Erosion Control Report for Whitman Storage Facility - P. D. P., Fort Collins, Colorado." This final report and the associated exhibits and plans have been revised to address the staff review comments for the ' "Preliminary Drainage Investigation and Erosion Control Report" dated September 12, 2008. This investigation was based upon the proposed site development plan; on -site observation; and available ' topographic information. The investigation and design within this report have been performed according to the criteria established in the City of Fort Collins' Storm Drainage Criteria. We sincerely appreciate your time and consideration in the review of this project. Ifyou should have any questions, please feel free to contact this office. ' Resp Submitted, ' ME E/► `�, Inc. [1 1 H R. Messner, President cc: Sierra Builders & Randy Whitman I hereby state that the attached "Final Drainage Investigation and Erosion Control Report for Whitman Storage Facility - P. D. P., Fort Collins, Colorado" was prepared by me or under my direct supervision in accordance with the provisions of the City of Fort D e Criteria for the owners thereof. Collins'�o R�R Dennis R. Registered State of Cok i Civil Engineering Consultants 150 E. 29th Street, Suite 270 Loveland, Colorado 80538 (970) 663-2221 TABLE OF CONTENTS Description Pace LETTER OF TRANSMITTAL i TABLE OF CONTENTS ii & iii I GENERAL LOCATION AND DESCRIPTION A. Location I B. Description of Property 1 II • DRAINAGE BASINS A. Major Basin Description 2 B. Sub -basin Description 2 III DRAINAGE DESIGN CRITERIA A. Development Regulations 2 B. Development Criteria Reference and Constraints 2 C. Hydrologic Criteria 3 D. Hydraulic Criteria 3 IV DRAINAGE FACILITY DESIGN A. General Concept 4 B. Specific Details - Detention Facility 4 V EROSION CONTROL A. General Concept 5 VI CONCLUSIONS A. Compliance with Standards 6 B.. Drainage Concept 6 VII REFERENCES 7 H TABLE OF CONTENTS (CONTINUED): ' EXHIBITS Vicinity Map ' Existing Conditions Exhibit Proposed Conditions Exhibit ' Offsite Conditions Exhibit ' Grading, Drainage, & Erosion Control Plan ' Stormwater Detention Plan Storm Drain Profile Sheet & Details ' APPENDIX I ' Drainage Calculations APPENDIX II tCharts, Graphs, Figures and Details iu General Location and Description: A. Location 1. The proposed Whitman Storage Facility - P. D. P. is located in the Southwest ' Quarter of Section 12, Township 6 Nortb, Range 69 West of the 611 P.M. in the City of Fort Collins, Larimer County, Colorado. ' 2. The site is specifically located immediately south of Skyway Drive and Boyne Court (Refer to the included Vicinity Map.) ' 3. Skyway Drive borders the site along its north boundary. The area to the north of Skyway Drive contains the single-family residential development known as Huntington Hills. To the west of the site lies commercial properties and US ' Highway 287. The Discovery Montessori School is located directly to the east. Immediately south of the site is undeveloped land extending southward to ' Cherelyn Street. B. Description of property ' 1. The Whitman Storage Facility - P. D. P. site consists of approximately 3.61 acres and currently has a ranch style house and storage building.. 2. The existing ground cover consists mainly of well established non -irrigated grasses and native vegetation with a lawn area surrounding the existing house. ' 3. The "Soil Survey of Larimer County Area, Colorado" prepared by the U.S. Department of Agriculture, Soil Conservation Service, indicates that the surface ' soils consist of "Midway clay loam" The soil typical of this series is described as a shallow, well -drained soil that formed in material from clay shale. The "Soil Survey" identifies the runoff potential as rapid, and the hazard of erosion as severe. ' The soil type is classified in the `D' hydrologic group. 4. The site is generally considered moderate, with slopes between 3% and 6%. ' 5. The Whitman Storage Facility - P. D. P. will involve the construction of one ' enclosed RV storage building and an outdoor storage area. The total building footprint for the structure is proposed to be approximately 7,200 square feet. The proposed walks, drives and other hard surfaced areas are proposed to be ' approximately 14,930 square feet. I ' II. Drainage Basins and Sub -basins: ' A. Major Basin Description 1. The subject area is located on Lot 1, Block 1 of the Lynn Acres Subdivision. ' 2. The site is located within the Stone Creek sub -basin of the Fossil Creek Drainage Basin as identified by the City of Fort Collins' Master Drainage Plan. The ' site is not located within a designated flood way or flood plain. B. Sub -basin Description ' 1. The historic drainage pattern of the property flows from northwest to southeast. Runoff is directed to Stone Creek at the southeast corner of the site. ' 2. A portion of the northern half of the site drains north onto Skyway Drive. ' III. Drainage Design Criteria: ' A. Development Regulations ' 1. Design criteria from the Current City of Fort Collins Storm Drainage Criteria and Construction Standards(Addendum to the Urban Storm Drainage Manuals Volumes I, II, and III) and the Larimer County Urban Area Street Standards were utilized. B. Development Criteria Reference and Constraints 1. The historic drainage pattern will be affected by the development of the site in that flow will be concentrated and channelized. The development of this site will produce more runoff than the historic amount, however, the historical runoff from the property will be maintained through the use of detention facilities and flow control devices. ' a. Stormwater will be released according to the 2-year historic peak flow ' rate as established in the City of Fort Collins Storm Drainage Design Criteria. b. The storm water is to be released at controlled rates onto the adjacent ' property in the historic drainage way. 1 2. The drainage impact of this site will not adversely affect streets or utilities. ' C. Hydrological Criteria ' 1. The Rainfall -Intensity -Duration curve for the City of Fort Collins (Larimer County Area II) was used in conjunction with the Rational Method for determining peak flows at various concentration points. a. Spreadsheets from the Urban Storm Drainage Criteria Manual were used to first determine the weighed imperviousness for a contributing sub - basin, and then to calculate the peak runoff rates. (See the Drainage Calculation Section of this report.) b. Table RO-3 from the Urban Storm Drainage Criteria Manual was used for recommended imperviousness values for various land cover. [l [1 U c. The hydrological group `D' was used in the Urban Storm Drainage, Criteria Spreadsheets for the on -site soils. 2. The 10-year and 100-year storms were analyzed in the design of the storm water management infrastructure in accordance with the City of Fort Collins Storm Drainage Criteria and Construction Standards. 3. The proposed detention facility was sized for the 100-year storm event. The maximum release rates are based on the Fort Collins Storm Drainage Criteria and Construction Standards, which prescribes a unit release rate equal to the historic 2- year release rate for the 100-year storm The release rates were used with the Rational Formula based FAA Method to determine the on -site storage volumes for the proposed detention facilities. D. Hydraulic Criteria 1. A stormwater quality structure was designed for the project based upon the requirements found in Volume III of the Urban Storm Drainage Criteria Manual. a. Sizing of structures are based on the design figures and spreadsheets provided in Volume III of the Urban Storm Drainage Criteria Manual. 2. Proposed storm drain pipes onsite are designed using smooth interior wall High Density Polyethylene (HDPE) pipe. a. A Mannings `n' value of 0.013 is to be used for all storm pipe according to Sec.4.4.2 of the City of Fort Collins Storm Drainage Design Criteria. 3. Recommended Channel Design Roughness Coefficients are per Table MD-1 of ' the Urban Storm Drainage Criteria Manual Volume I. ' IV. Drainage Facility Design: A. General Concept 1. During a large rainfall event, storm water will be conveyed to a central ' detention facility for the site. The western, southern and eastern edges of the site will be conveyed in drainage swales around the perimeter of the site and into the Detention Facility. The open area in the southeast comer of the property will be t utilized as a stormwater quality/detention, facility to capture and temporarily store stormwater from the remainder of the site that otherwise would be routed directly offsite. ' B. Specific Details - Detention Facility ' 1. Sub -Basin `A', as identified on the Proposed Drainage Exhibit, comprises the northern portion of the site with 0.99 acres. The peak runoff rate during the 2- year storm is 0.79 c.fs. and the 100-year peak runoff rate is 4.68 c.fs. . a. This Basin drains to East Skyway Drive and no new improvements are ' proposed for this Basin. This area of the site will not adversely impact existing offsite storm drainage systems, streets or utilities. ' 2. Sub -Basin `B', as identified on the Proposed Drainage Exhibit, comprises the bulk of the site with 3.01 acres. The peak runoff rate during the 2-year storm is 1.39 c.fs. and the 100-year peak runoff rate is 10.68 c.f.s. a. Rainfall will be conveyed as sheetflow across the asphalt and gravel drives of this area and be directed to the Detention Facility located in the southeast comer of the site. The open area will be utilized as a stormwater quality/detention facility to capture and temporarily store stormwater that otherwise would be routed directly offsite. b. A proposed drainage swale along the east edge of the site will prevent runoff from passing offsite and will direct flow from the northeast portion of the site to the Detention Facility. c. A gravel swale in the middle of the site will prevent runoff from passing offsite and will direct flow from the southwest portion of the site to the Detention Facility. 4 I ' d. The open area of Tract `A' will serve as the Detention Facility. A proposed 8-inch diameter HDPE storm drain will extend east from the inlet and discharge into the existing drainage course. e. A proposed multi -stage outlet structure will be constructed at the inlet ' to the proposed 8-inch diameter HDPE storm drain. The outlet structure will incorporate a perforated steel orifice plate to allow for a 40-hour drain time of the WQCV. A steel plate with an orifice opening will be installed ' over the outlet pipe to act as a flow regulator for the detention area during a 100-year storm event. 1 1 f. The 100-year maximum release rate from the Detention Facility will be 0.22 c.f.s. (Equal to the historic 2-year storm event of the area being developed). Based on this outflow rate, the detention facility will require 6,330 cubic feet (3,333 cubic feet of storage + 2,997 cubic feet of WQCV). g. Proposed rip rap at the pipe outlet will reduce erosion and scouring along the side of the ditch. . h. In the event the outlet structure or storm pipe becomes blocked, the detention area will overflow at the 100-year Water Surface Elevation through an emergency overflow spillway and discharge to the natural drainage course offsite. i. The 100-year Water Surface Elevation (5071.00) is more than 18-inches below the lowest Finished Floor Elevation (5083.00). V. Erosion Control: A. General Concept 1. Temporary erosion control measures will be implemented during the construction of this project. These measures will include: a. Silt fence along the east, and south property lines. b. Wattle Inlet Protection installed around the proposed outlet structure. 2. Long term erosion control measures will be implemented after the construction of this project. These measures will include: a. Landscape planting and seeding. ' b. Surface treatments for parking areas, sidewalks; and structures. ' c. Rip rap lining the area surrounding the outlet pipe. 3. Maintenance of all erosion control devices will remain the responsibility of the ' developer until the completion of the project. 4. Wind erosion measures, other than watering down of the site during ' construction, have been neglected due to the relatively small size of the site. ' VI. Conclusions: A. Compliance with Standards ' 1. All drainage design conforms to the criteria and requirements of the City of Fort Collins Storm Drainage Criteria and Construction Standards. 2. Proposed drainage improvements generally conform to the concepts and ' recommendations of the City of Fort Collins Master Drainage Plan. 3. Proposed erosion control measures conform to the recommendations of City of ' Fort Collins standards and generally accepted erosion control procedures. B. Drainage Concept ' 1. The final drainage design for the Whitman Storage Facility - P. D. P. is effective for the control of storm water runoff with little or no effect on the City of ' Fort Collins Master Drainage Plan recommendations. 2. The lowest Finished Floor Elevation (5083.00 feet), is more than 18-inches ' above the computed 100-year Water Surface Elevation of 5071.00 feet in the storm water detention facility to be constructed on site. ' 3: Emergency overflow beyond the limits of the 100-year High Water Elevation will spill offsite. ' 4. With the implementation of the proposed detention facilities and controlled release rates, the development of this site will not result in an increase of runoff ' compared to the historic rates. The total released runoff during the 100-year storm events will equal the 2-year historic release rate as prescribed by the City of Fort Collins Storm Drainage Criteria and Construction Standards. 6 VII. References: A. City of Fort Collins Storm Drainage Criteria and Construction Standards B. City of Fort Collins Master Drainage Plan C. City of Fort Collins Development Standards D. Soil Survey of Larimer County Area, Colorado w I 1 1 [1 1 1 i EXHIBITS 1 [] WHITMAN STORAGE FACILITY - PDP Ij O U DUNN J J Q m UR=DRIVE SATURN DRIVE UNRAVEN ST. MICHAELS O N OD SKYWAY DRIVE N = U O In _ < N SITE z c m )0� c N CHERYLEN STREET VICINITY MAP SCALE: 1 "=500' 209 East Skyway Drive (Lot 1, Block 1, Lynn Acres Subdivision) Fort Collins, Colorado I Existing 7.5 ltility Easem n I` I I II E 'sting �" Y Uri Ity Eapsement R I\V X \ verrient� - _- -� 1 i 1 Existing L�wn�Area i 1 iExisting� � iGorogel i �\ i I � Existing Existing i �uiEding ; House / 1 \ 1 E is in T. i 1 Exisitin Lawn ea i t E se ent i g �� y IL- — — — — —J L_= __ 7 ExistJ'6 Go ge I 1 \ / h / 1 3.01 ac. J � Utility Easement I I I I N 12.5 50 0 25 75 1" = 50' \r / —5012— - Typically Indicates Existing Ground Surface Contour 1 _ Drainage Basin Limit Identifier Typically Indicates Drainage Flow Direction Concentration Point Identifier \ / l #4 Basin 'B'-- .Design Point, Basin Number Area of basin in Acres 3.4 6.7 Q1o0c.f.s. Q10 C.f.s. u m m C C w U t/] 7� p F d . '...� A 0 iR �kq�V m IV � �U woWWw z� w ''j J U DATE: Mqy 26, 2009 SCALE: AS NOTED DRAWN: D.A.R. CHKD: D.R.M Project No. GRD-587-08 1 of 3 7.5' Drainage Utility Eoseml S/Ik /� %� klY MW I Existing Lown A eo I e I IExisting� -rL,- z \_ IGaragel I J I Existing_ , Building ENergency _ � Is Easement � A Prop I sed R )rao Stru ur( •-P Io osed G J Utility Easement � S Existing F House Exist ng Lawn A e __lam/_1_ M CI i J ! D N S IXY ET AL (RL) L�rajhag� aggg Iidic tes / O Dt Voci J c� / e'� 3.01 ac. 1.3910.7 0.99 ac' %zni Boundary se doAi • 12.5 50 0 25 75 t" = 50' Y) o 0 In b a •� A:0dO W 0 Hui � m a"- CO O U !�+ Q I� p I� � I� IG I� (I III ® w Q o Il 1 o k. 5012 Typicolly Indicates Existing r-I GGround Surface Contour o —5o12— Typically Indicates Proposed a u Finish Surface Contour ULi F Drainage Basin Limit Identifier Typically Indicates Drainage DATE: MSa 26. 2009 Flow Direction SCALE: As Norm �♦ Concentration Point Identifier DRAWN: DAR. #4 Basin B��Oesign Point, Basin Number �� CHKD: MR Area of basin in Acres Project No. GRD-587-00 Q100c.f.s. SHEET Q2 C-f.S. 2 of 3 40 . i S 1 1 � w 0 K Y W A Y D R I IV w Existing -WM1113 ' Building J _ + Q 4P —� w -�� 4.00 ac U — Existing w Building Z t .1� J "SD— ——30"SD— J O (!7 L Building U D at Ob 9 Xisti ulldl M 25 100 0 50 150 I" = 100, 14 a O L] X 'o W 0 v 0 40 U n q � N lV y y MU t,wW� O O t. f O 0 N ® - 5012 Typically Indicates Existing z Ground Surface Contour U U H Drainage Basin Limit Identifier RT piColly Indicates Drainage DATE: May 26, 2009 Y IOW Direction SCALE: AS NOTED Concentration Point Identifier DRAWN: DA.R. #4 Basin 'B'-` Design Point, Basin Number CHKO: D.R.M ProjectNo. GRD-58-587-08 Area of basin in Acres 5.23 ac. Q1GOC.f.s. 3.4 6.7 SHEET % Imperviousness 3 Of 3 Slope Proposed Sidewalk ® 12:1 to Match Existing Aspohalt Drive to West r 4988.96/ I ! I I, I � !� l I I I I I, 7.5' Drainage & f I Utility Easement I �I I 1 I II II i I IWI I to �o I id- I rn I I� II i I ! , j ll i ' 1 I � I S K Y W A Y D R I V E 89.00/ 68' RoW '5' Sidewalk "= �2_ _ Existing° e r m6 Parkway .83.38x x V- \ Display Area / I �� x 15' Drainage & V -x I- / � 85.06 �Existing Asphalt 7 ® I \_ - Existing Rock , - r' r= _�� - r7 \\ - _-- \ I 20\ I Landscaped Area I %' ---__, Existing mergenc - - - - - - - -ILandscaped Area\ \ \� 986.60 Proposed Recycled Asphalt \ - _ - _ - _ - ~ 4- Access I \ f-- �� ------ �- /- - / ----` - / \_ Easement I l ' \ \ 1 I n' 1 \ �m i 86.41 \ I I I I \ \ Typically Indicates Existing Tree d 86.73 I ___ _; _________ � � I I Existing Lawn Area ExistingCo -- 1 _86.4 Repair Shop [� - F.F. Elev=4984.2 86.2 -0 �' I I \ I �% I I I Existing I i Q!I Existin"Repair Sh-- I' iOffice/ Io o g op � I Retail Sales, 0) - F.F. Elev.4987.0 1I \ tI F.F. Elev. w °I=4985.8 Proposed 6 Cedar Fence i \ 85.42 84.97 .a °_ a e� f' ` �/I I / �\ ' 86.25 I a a :1 -'`a 1 Existing Residence �> % i I 0/ a n n'.. -" ° I I Existing Concrete° Pad a.1 F.F. E►ev.=4985.8 o \ - O ° I (� ° a . ° ° I 9 101 I COMMERCIAL (C) a . ° - li n al I :-MARIE MATCH EXISTING 100-YR. W.S.L. 4 -.r 4986.28. �< �'--------- - - - - -- i I I 84:$6/_' c"Jn + .' a- I I III X LOT 1,I I 7.5' Drainagen�, 0a GRASSED SLOPES (TYPICAL) Utility Easemen& w t o 83.63 0 U Io a in9qo °9 Stora9e Build F.F. Elev.=4987.0 83.48 �84.5I Proposed Asphalt �g3.33 Existing Lawn Area i I 1 LOW DENSITY RESIDENTIAL (RL) I \ I 06 ------------- Compacted - -� - Gravel LOT 2 Surface I Existing Fenced Area - I ' I o '- - - - - - - - - - - - - - ,� � / a / �, i 82.8 _82_48_=_//----------=/,-- -----1 r ° \ Co o ` Co _, � � � _ � - e Indicates Zoning Boundary & Lot Line a Proposed Gravel Swaler4986°'�' I Existing IExisting/7Existingi Garden Patio °� � Garage I � �- 1 81.85 r d- - 4985 of �r--4987(E)-4988(E) 4988(E) - O- ---= 4987E 4984 Natural Feature Buffer o j Compacted Gravel Surface 4 4 4985.6 ' f 98 I 86 (IV- 2- 1 I 9; ��' C / I I I ��If I� I / /VL � r o I° Q N I UJ � � ! ��� �- " i� LOT 3�� A �v; d- ; ra Lo / I Proposed Enclosed RV C) % COMMERCIAL (C)/ ' Storage Structure v i 4 Q -� J i F.F. EIev=4983.00 v, i TRACT A _„li � o/ o E �( I / ate, _ / i U ° ° �' Existing Gravel %l 1 � f ---- --- ; i - ------ - �M4 C srg8 81.20 0 2 A9,o_0 0 4982 i ---[ 4981 ern^ ' rn Proposed Gravel Swale J Il 6.00 f \ J-_;;Z�aoo� oo0c_498000Dt�499p0P 497800-oP -ao o Existing Gravel f Flowline of Existing Swale / �LF1 _J / $t,41i' , - - -- --- 4977(E) - i (V) - XI �_x X-- - - =499L2 �Y O dO P 9� -0 O O O O D 0 0 0 D 7.5' Drainage & \ Utility Easement i T.III� v /-4 4974(E) 4971(E)= I - �i 0L 7 Proposed Detention Pond 100-yr. HWL=6,330 cu.ft. ® EIev.=4971.00 Outlet Inv. EIev.=4968.00 - - _ 7 4970- 0 0 o-b__ 491 ^ a u CALL UTILITY NOTIFICATION CENTER OF COLORADO 1-800-922-1987 OR 534-6700 IN METRO DENVER CALL 2-BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES 4 GRAVEL - 11=111=111 III. I I I= TYPICAL CROSS SECTION OF GRAVEL SWALE NOT TO SCALE 4% O O Q, m? V) Z O oci E c W ° o C" CU U (n � n C IL D Of FL _ ' VARIES- - VARIES -►I j N � N 0 I r� vJ 5° 5' 5072.00 5071.00 C %i 44 4 c \\\� 4 MATCH o 00 U EXISTING n 6' °' O L Co O TYPICAL SECTION A -A W N.T.S. 0 0 rt 0 a� J E c o ° N d %%%' 0 Vim6 L'-I - cn U � � N Q) CD CD W 10' 40' 0 20' 60' 1" = 20' Q) 1~ Q � o RS co a b - - �012- - - Typically Indicates Existing rn Ground Surface Contour Ztu W 5012- Typically Indicates Proposed a, Finish Surface Contour (� 00 99.11 Typically Indicates Existing x Surface Spot Elevation 98.00 Typically Indicates Proposed Pavement Surface + Elevation or Flow Line of Gutter ° �p Typically Indicates Drainage Flow Direction W F= - Typically Indicates Existing ,- Curb & Gutter U City of Fort Collins, Colorado w 0 UTILITY PLAN APPROVAL v APPROVED: City Engineer Date DATE: May 20. 2009 CHECKED BY: SCALE: AS NOTED Water 8c as ewater Utility Date DRAWN: D.A.R. CHECKED BY: Stormwater Utility. Date CHKD: D.R.M. CHECKED BY: Project No. Parks &Recreation Date GRD-587-07 CHECKED BY: SHEET Traffic Engineer Date CHECKED BY: 3 Of 9 Date - - I 7.5' Drainage & Utility Easement 3o"SD- 'SD— — 68' RoW )isplay Area Existing Asphalt 'A' 0.99 53.4 -5' SidewalkS K Y W A Y D R I V E 6' Parkway Existing Berm ° d ° i l 15' Drainage &- 11 firitv Easement Existing Rock ' �,_ -_� , 0 Landscaped Area %`� ,' Existing h'�il 6 N/ p 11 i / ' b 1� 6 �� o �1, Landscaped Area Proposed Recycled Asphalt I ( i r------- - --L-- 1-----------1----- - - -- \� -- /---��/-------- Typically Indicates Existing Lawn Area Existing Tree Existing 1 �✓ i 000 I 1 ; I I Repair Shop" 1 1 71�---// I I Existing71 v a Office/ / hA o Existing Repair Shop„ Retail Salesi '� v O a. e L U I 1 0 1 ( I DETENTION BASIN SUMMARY TABLE Water WQCV 100-yr. 100 yr. 100-yr. Quality Water Required Water Maximum Detention Capture Surface Detention Surface Release Facility Volume Elevation Volume Elevation Rate (cubic feet) (feet) (cubic feet) (feet) (cfs) #1 2,997 4969.75 6,330 4971.00 0.22 RUNOFF SUMMARY TABLE Design Point Contributing Basin(s) Contributing Area (acres) 2-Year Runoff (cfs) 100-Year Runoff (cfs) #1 A' 0.99 0.79 4.68 #2 B. 3.01 1.39 10.68 1 Proposed 6 Cedar Fence CALL UTILITY NOTIFICATION 1 CENTER OF COLORADO 1 ° I o a' , Existing Residence I _ / i / 0 1-800-922-1987 OR Existing Concrete Pad t i o o I c 1 I '� g d I 534-6700 IN METRO DENVER o I a °. 1 COMMERCIAL C) e e , d_ a�, 1 v d CALL 2—BUSINESS DAYS IN ADVANCE o rna.° #1 --— — — — --� d.. ' Q � — — — — — — _ — ,,° .. e. r� );. d '',/, I BEFORE YOU DIG, GRADE, OR EXCAVATE d 0 ° e FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES 1 1 1 d e Q w o ;i I LOT 1 I a.. / 7.5' Drainage & to c I I I � Utility Easement 0 I °<..e� L--'1 �". ter-'\ 0 U //II e.>y Existing Storage Building I Proposed Asphalt �". . o a I I "ee Existing Lawn Area ' LOW DENSITY RESIDENTIAL (RL) 1 1 I / Easement Compacted - - - - - - - - - - - - - - - -I �.v Gravel o 10' 40' o Surface I Existing Fenced Area LOT 2 0o I �_ I o L - - - - - - - - - - - - - - I � o - f Indicates Zoning Boundary & Lot Line 0 20' 60' (o I I Existing 1 Existing AllExistingi / -- - - -) 1" = 20' o Proposed Gravel Swale I Garage _ I v� _Garden r. Patio i I Natural o Feature / ' Io Buffer o v 0 o 3.01 36.8 / Proposed Detention Pond o IW,Q.C.V.=2,997 cu.ft. i ,/09 100-yr. HWL=6,330 cu.ft. I TRACT A I �I osed Straw Wattle Inlet Filter Application Proposed Straw Wattle Inlet Filter Applicatio C Proposed Gravel Swwale / / C 0 0 0 > 000C�000 F a c/t> 000P 0 0 0 > 00P la � II °O Existing Gravel I Flowline of Existing Swale M o Proposed 36" Dia. HDPE Storm Drain / OOOOOOG OOOP - 000�='Q00� 000P�-000P 0 0 0 > 77- 7.5' Drainage & Ili Utility Easement ° I O e O U ° v o 11,00 0 C 0 3 Q I� O o � e. o N v I 0 o 0Q o o o a I b e e �p Dmpacted Gravel Surface 1 a' o. / 1 �a LOT 3 / 1 L Proposed Enclosed RV Storage Structure ci COMMERCIAL (C) / ) / 0� a / / Existing Gravel tl ,U #2 (1 �l O O O D 0 0 0 D 0 0 o D � SF Proposed Silt Fence Appliacation Along South & East Property Line —a o 0 0— Typically Indicates Flowline 4% 0 o O ; m¢ CD z� o E > C w o v +1 Q a U U L C) �I N N N I r7 O O � 0 h c rn a v c o o U 00 t,) rn C .L � O 00 0 C w � 0 c a) o o E 0 O O N C w o U C o 0 In 0 _ > in � 0) N _C •C Uj w O of Ditch or Swale SF —SF— Typically Indicates Silt Fence Typically Indicates Wattle Application o O rd 39.96 Typically Indicates Existing q X Pavement Surface Elevation 0 0 or Flow Line of Gutter Cd t-I 39.96 Typically Indicates Proposed 0 Pavement Surface Elevation o or Flow Line of Gutter W Typically Indicates Drainage rn O co Flow Direction 4-) Typically Indicates Existing 0 0' o 0 1 Curb & Gutter co — - -- ---A -A-- Ba-s+n--D�-signation -- Q) Q B I B = Area in Acres I = % Imperviousness p D = Design Point Designation i;_i H City of Fort Collins, Colorado w 0 UTILITY PLAN APPROVAL v APPROVED: City Engineer Date D DATE: May 20, 2009 CHECKED BY: SCALE: AS NOTED Water & Wastewater Utility- Date DRAWN: D.A.R. CHECKED BY: Stormwater Utllity Date CHKD: D.R.M. CHECKED BY: Project No. Parks &Recreation Date GRD-587-07 CHECKED BY: SHEET Traffic Engineer pate CHECKED BY: O q Date — 9 No Text r , LOW DENSITY RESIDENTIAL NO 0 /Indicate Indicates Extent I 1 % I �i 4971 (E) 4974 7.5 Drainage & 4o LOT 2 Utility Easement/ ----- 1 7.5' Drainage & Utility Easement P R6POSED 8 DIA. H PE CULVERT 3. qA972.0C. 4972 100-yr. V.S.L. Elev. ® 4971� 1 0 e II I) 4971 _ III�II IIIII _ AtLic-1, y ��° Ililll 4970 4967 a> L E +' o a o 4965 L o+ °;ern 00 L m Zu>,+ o+,o a_— O ap 00 mom+ ! 0 0: IZ 00 Opp jl 4964 �oU) � a-UJ(A ! 0+00 0+10 0+20 0 0+40 4972 4971 4969 4967 4965 I••I I STORM DRAINAGE NOTES 1. The City of Fort Collins shall not be responsible for the maintenance of storm drainage facilities located on private property. Maintenance of onsite drainage facilities shall be the responsibility of the property owner(s). / 2. All recommendations of the final drainage and erosion control study for Campus West Redevelopment Dated June 2006 by Messner Engineering, Inc. shall be followed and implemented. 3. Prior to final inspection and acceptance by The City of Fort Collins, certification of the drainage facilities, by a registered engineer, must by submitted to and approved by the Stormwater Utility Department. iCertification shall be submitted to the Stormwater Utility Department at least two weeks prior to the release I of a certificate of occupancy for single family units. For commercial properties, certification shall by submitted to the Stormwater Utility Department at least two weeks prior to the release of any building II permits in excess of those allowed prior to certification per the Development Agreement. GRASSED ggag(E) SLOPES _-4968(E) (TYP.) 3" MIN. 4972.00 S\ 44( — V� 4972.00 II II II � h . I 1 OVERFLOW SPILLWAY DETAIL N.T.S. 5' -0' 0 10' 30' 101 Trash Rack Attached by Intermittent Welds All Around Flow Control Detail SECTION A —A Scale: 1 Yz" Thick Steel Plate I 12" I Stainless _ _ Steel Bolts 8" Dia. O Outlet Pipe t 1 8" 6 Ot �O 4 69.00 ORIFICE PLATE #2 DETAIL Scale: 1 "=1' 4" Thick Steel Plate l 12" I Stainless Ij�I Steel Bolts O O 4" O.C. 21" 1 Columns of 4"0 1%6"0 Openings (3 Rows) ORIFICE PLATE ##1 DETAIL Scale: 1 "=l' 3" Wide x 12" High Johnson VEE Wire (or equal) Stainless Steel Screen with #93 VEE Wire, #156 Bolt Down or VEE Support Rod and %"xl" Lock Down Flat Bar Carbon Steel Frame 100 YR W.S. EL.=4971.00 No. 3's @10" O.0 Toe Wall STANDARD EROSION AND SEDIMENT CONTROL CONSTRUCTION PLAN NOTES 1. The erosion control inspector must be notified at least twenty—four (24) hours prior to any construction on this site. 2. There shall be no earth —disturbing activity outside the limits designated on the accepted plans. 3. All required perimeter silt and construction fencing shall be installed prior to any land disturbing activity (stockpiling, stripping, _grading, etc. All other required erosion control, measures shall be installed at the 'iapproprlate time in tfie construction sequence as indicated in the approved project schedule, construction plans and erosion control report. 4. At all times during construction, the Developer shall be responsible for preventing_ and controlling onslte erosion including Ikeepin the property sufficiently watered so as to minimize wind blown sediment. The Developer shall also be responsible for installing and maintaining all erosion control facilities shown hereon. 5. Pre disturbance vegetation shall be protected and retained wh rever possible. Removal or disturbance of existin vegetation shall be limited to the areas) required for immediate construction operations and- for the shortest practical period of time. 6. All soils exposed during land disturbing activity (stripping, grading,, utility installations, stockpiling, filling, etc. shall be kept in a roughened condition y ripping or disking along land contours until much, vegetation, or other permanent erosion control BMPs are installed. No soils in areas outside project street rights—ot—way shall remain exposed by land disturbin ctivity for more than thirty 30 da s before required temporary or permanent erosion control .g. seed/mulch, landscaping, etc. is installed, unless otherwise approved by the City of 4rt Collins. 7. In order to minimize erosion potential, all temporary (structural) erosion control measures shall: a. Be inspected at a minimum of once every two (2) weeks and after each significant storm event and repaired or reconstructed as necessary in order to ensure the continued performance of their intended function. b. Remain in place until such time as all the surrounding disturbed areas are sufficiently stabilized as determined by -the erosion control inspector. c. Be removed after the site has been sufficiently stabilized as determined by the erosion control inspector. 8. When temporary control measures are removed, the Developer shall be responsible for the clean up and removal of all sediment and debris from all drainage infrastructure and other public facilities. 9. The contractor shall clean up cny construction materials inadvertent deposited on existing streets, sidewalks, or other public rights of way, and make sure streets and walkways are cleaned at the end of each working day. 10. All retained sediments, particularly those on paved roadway surfaces, shall be removed and disposed of in a manner and location so as not to cause their release into any waters of the United States. 11. No soil stockpile shall exceed ten (10) feet in height. All soil stockpiles shall be protected from sediment transport b urface roughening watering and perimeter silt fencing. Any soil stockpile remaining after thirty (30) days shall be seeded and mulched. 12. The stormwater volume capacity of detention ponds will be restored and storm sewer lines will be cleaned upon completion of the prof ct and before turning the maintenance over to the City of Fort Collins or Homeowners Association �HOA). 13. City Ordinance and Colorado Discharge Permit System (CDPS) requirements make it unlawful to discharge or allow the discharge of _an pollutant or contaminated water from construction site Pollutants ipclude but are not limited to dis arded building mcter'ia s, concrete tuck washout, chemicals, oil 'and gas products, litter anT sanitary waste. The beveloper shall at all times take whatever measures are necessary to assure the proper containment and disposal of pollutants on the site in accordance with any and all applicable local, state and federal regulations. 14. A designated area shall be provided on site for concrete truck chute washout. The areo shall be constructed so as to contain washout material and located at least fifty (50) feet: away from any waterway during construction. Upon completion of construction activities the concrete washol_It material will be removed and properly disposed of prior to the area being restored. 15. To ensure that sediment does not move off of individual lots one or more of the following sediment/erosion control BMPs shall be Installed and maintained until the lots are sufficiently stabilized, as determined by the erosion control Inspector. a. Below all gutter down spouts. c. Along lot perimeter. b. Out to drainage swales. d. Other locations, if needed. 16. Conditions in the field may warrant erosion control measures in addition to what is shown on these plans. The Developer shall implement whatever measures are determined necessary, as directed by the City of Fort Collins. 0.09" Stainless Steel Support Bars CALL UTILITY NOTIFICATION CENTER OF COLORADO < 0.139" 1—800-922-1987 OR #93 Stainless Steel (U.S. Filter 534-6700 IN METRO DENVER or Equal) Wires CALL 2—BUSINESS DAYS IN ADVANCE BEFORE YOU DIG, GRADE, OR EXCAVATE FOR THE MARKING OF UNDERGROUND MEMBER UTILITIES Flow SECTION B—B Not to Scale 6"1 3'—O" 6"� 9" I•: ` .I ©10" O.C. 21 No. 4's .o o. ..: .... <I• f `I l @8" O.C. 6" •— _ _ °1 6" - Toe Wall FRONT VIEW Tubular Trash (—Rack 6" O.C. B ,l I Swivel Hinge 8" HDPE Outlet Pipe Flow Control Orifice Plate #2, See Detail Ua u.r'- —Steel Perforated Flow Control Orifice 7.5' 2,5' Plate #1, See Detail r� SECTION VIEW Trash Rack Attached Steel Perforated Flow Control by Intermittent Welds Orifice Plate #1, See Detail A I" I: y_6" 1. L..-....^.6" Flow Control Orifice'', . I Plate 2, See Detail c< A 7, 3 r (- WATER QUALITY OUTLET STRUCTURE #1 DETAIL Scale: 1/2--1' 1 a M o i rn 00 V) z o c E W O U ry a2 U U m (D v I Q) 1 N N N I 0 c rn o U) C Q) t- o U 00 (3, C •c 0 o 00 OU 04 C W C 0 o a� c a)J > C o O .> N C W O C _0 cn 6 > �L N (D N c .0) Li C_ o 0 Ld J F— �- U City of Fort Collins, Colorado w 0 UTILITY PLAN APPROVAL _D � U � APPROVED: City Engineer Date DATE: May 20, 2009 CHECKED BY: SCALE: AS NOTED Water & Wastewater Utility Date DRAWN: D.A.R. CHECKED BY: Stormwater Utility Date CHKD: D.R.M. CHECKED BY: Project No. Parks & Recreation Date GRD-587-07 CHECKED BY: SHEET Traffic Engineer Date CHECKED BY: 8 of g Date — I 1 .1 .1 1 1 APPENDIX I ' DRAINAGE CALCULATIONS 1 1 1 1 1 1 11 Area -Weighting for Runoff Coefficient Calculation Project Title: _ Catchment ID: Illustration 209 E. Flow Du: Flow D;rection cacmm®cSubauL3LBoumdmy Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C" CA input input input output Undevel. 0.41 2.00 0.82 Pavement 0.38 90.00 34.20 Gravel 0.10 40.00 4.00 Roof 0.10 90.00 9.00 surn:1 0.99 sum: 4� 8.02 I AreaMeighted Runoff Coefficient (sum CA/sum A) = 48.51 "See sheet "Design Info" for inperviousness-based runoff coefficient values. I 1 L 1 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Existing Conditions-Sub43asin'A' (2 Year Storm) I. Catchment Hydrologic Data Catchment ID = A' Area = 0.99 Acres Percent Imperviousness = 48.51 % NRCS Soil Type = D A. B. C, or D II. Rainfall Information I(inch1hr)=C1'P1/(C2+Td)"C3 Design Storm Return Period, Tr = 2 years (input return period for design storm) C1 = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 0.82 inches (input one-hr precipitation se Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient C = 0.33 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 0.39 Overide Syr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration � `� owtlod 8ewh 1 Ilea Rewh3 L F Flaw Dnerdn NRCS Land 11 Type Hea W Meadow Tilla e/ 9 Field Short Pasture! Lawns Nea rly Bare Ground Grassed Swales/ Wete Paved Areas 8 Shallow Paved Shales Sheet Flow Conv nca 20 Calculations: Reach Slope Length 5-yr NRCS Flaw Flux ID S L Rmroff C--y- Velocity Time Coeff ante V Tf fl/fl R C-5 fps minutes input input output input output output Overland 0.0385 130 0.39 N/A 0.23 9.37 ' IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 2.18 inchmr Rainfall Intensity at Regional Tc, I = 2.07 inchlhr Rainfall Intensity at User -Defined To, I = 2.18 ineh1hr Regional Tc User -Entered To Peak Flowrate, Op = 0.71 cfs Peak Flowrate, Op = 0.67 cis Peak F wrate, Op = 0.71 cis I 1 1 1 1 1 11 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Existing Conditions-Sub43asin'A' (10-Year Storm) I. Catchment Hydrologic Data Catchment ID = A' Area = 0.99 Acres Percent Imperviousness = 48.51 % NRCS Soil Type = D A. B. C, or D II. Rainfall Information I(inchlhr)=C1'PI I(C2+Td)AC3 Design Storm Return Period, Tr = 10 years (input return period for design storm) C1 = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) Pi= 1.40 inches (input one-hr precipitation see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment ' Runoff Coefficient, C = 0.45 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C-5 = 0.39 Overide Syr. Runoff Coefficient, C = (enter an overide C.5 value if desired, or leave blank to accept calculated C 5.) Illustration �"-�x oaedned Bexh 1 flow 8es43 t .) Flow Diaerdin E- Cetehmeat NRCS Land r Heavy Tillagel Shod Neady Grassed Paved Areas d Type 11 Meadow Field Pasture/ Bare Swalesf Shallow Paved Swales Lawns Ground Wete Sheet Flow Comeyance I2.5 7 10 15 20 Calculations: Reach I Slope I Length Syr ID S L Runoff Coeff Poll ff I CS Overland ' IV. Peak Runoff Prediction Rainfall Intensity at Computed To, I = 3.73 inchllu Rainfall Intensity at Regional Tc, I = 3.53 inchRtr Rainfall Intensity at User -Defined To, I = 3.73 InGJhr Canvey- I Velocity I Time ance V Tf fps minutes Regional Tc = 11.89 ' User -Entered Tc = 10.40 Peak Flowrate, Qp = 1.67 cis Peak Flowrate, Qp = 1.58 cis Peak Flowrate, Op = 1.67 cis CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Existing Conditions - Sub-13asin'A' (100 Year Storm) I. Catchment Hydrologic Data Catchment ID = N Area = 0.99 Acres Percent Imperviousness = 48.51 % NRCS Soil Type = D A, B, C, or D 11. Rainfall Information I (inch/hr) = C1 • Pt /(C2 + Td)"C3 Design Storm Return Period, Tr = 100 years (input return period for design storm) - C1 = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) Pi= 2.86 inches (input one-hr precipitation —see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.60 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C 5 = 0.39 Overide Syr. Runoff Coefficient, C = (enter an overide C5 value if desired, or leave blank to accept calculated C5.) Illustration aaerlmd ltexh 1 9av 3 C.tirhment B..Aary NRCS Land Tillage/ Shod Nearly Goosed Paved Areas 8 ]FHeavy Type Meadow Field Pasture/ Bare Swalea/ Shallow Paved Swales Lawns Ground Wat Sheet Flow 11 Co nce Calculations: Reach Slope Length Syr NRCS ID S L Runoff Convey - Coal antefttft Nk R C5 IV. Peak Runoff Prediction ' Rainfall Intensity at Computed Tc, I = 7.62 inchmr Rainfall Intensity at Regional Tc, I = 7.21 inch/hr Rainfall Intensity at User -Defined Tc, I = 7.62 inch/hr Flax Flow Velociy Time V Tf fps minutes Regional Tc User -Entered Tc Peak Flowrate, Qp = 4.52 cfs Peak Flowrate, Qp = 428 ofs Peak Flowrate, Qp = 4.52 cfs F[= Area -Weighting for Runoff Coefficient Calculation Project Title: _ Catchment ID: Illustration 209 E. Skvwav Drive Flow Direction s Subama 3 cazmm mr Boundarg Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C" CA input input input output Undevel. 2.48 2.00 4.96 Pavement 0.23 90.00 20.70 Gravel 0.14 40.00 5.60 Roof 0.16 90.00 1 14.40 sum:l 3.111 l Sum:l 45.55 l Area -Weighted Runoff Coefficient (sum CAlsum A) = 15.17 `See sheet "Design Info" for inperviousness-based runoff coefficient values. 11 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Pmject Title: 209 E- Skyway Drive Catchment ID: Existing Conditions - Sub-Basin'6 (2 Year Storm) 1. Catchment Hydrologic Data Catchment ID = B' Area = 3.01 Acres Percent Imperviousness = 15.17 % NRCS Soil Type = D A, B, C. or D II. Rainfall Information I(inch/hr)=C1'P1/(C2+Td)"C3 Design Storm Return Period, Tr = 2 years (input return period for design storm) C1 = 28.50 (Input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 0.82 inches Input one-hr precipitation-eee Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.14 Ovedde Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0.24 Overide Syr. Runoff Coefficient, C = (enter an overide C-5 value If desired, or leave blank to accept calculated C-5.) Illustration Reach3 LEGEND hit Her ftrAng Catcl.et lio.wilax, NRCS Land Type Heavy H Mention Tilla of s Field Short Pasture/ Lawns Nea dv Bare Ground Grassed Swales/ 'ate Paved Areas S Shallow Paved Swales Sheet FI Con nos 2.5 5 7 10 15 20 Calculations: Reach Slope I Length I S-yr ID S L Runoff Coeff Pofl It G6 L��I-.i1TE1 ' IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 1.55 inch/hr Rainfall Intensity at Regional Tc, 1 = 1.99 inch/hr Rainfall Intensity at User -Defined Tc, I = 1.99 inch/hr 1 Convey- I Velocity I Time ante V Tf fps minutes Computed I = Regional Tc = User -Entered Tc = Peak Flowrate, Qp = 0.66 cfs Peak Flowrate, Qp = 0.85 cfs Peak Flowrate, Qp = 0.85 aft; I CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Existing Conditions -Sub-Basin'B' (10-Year Storrn) I. Catchment Hydrologic Data Catchment ID = B' Area = 3.01 Acres Percent Imperviousness = 15.17 % NRCS Soil Type = D A. B, C, or D II. Rainfall Information I(inchlhr)=C1•P1 I(C2+Td)"C3 Design Storm Return Period, Tr = 10 years (input return period for design stomr) 01 = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 1.40 inches (input one-hr precipitation —see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.33 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 024 Overide 5-yr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Reath Reath 3 L Illustration J_ Rexh I 9er Catenseat NRCS Land Type Heavy Meadow Tillegel Field Shod Pasture! Newry Bare Grassed Swalesl atenvaysSheet Paved Areas d Shallow Paved Svrales Flow Conveyance 2.5 5 �7 10 15 20 Calculations: Reach Slope Length Syr NRCS Flov Flow ID S L Runoff Convey- Velocity Time Coed I ante V Tf 11M 0 CS fps minutes input input output input output output Overland 0.0350 400 0.24 N/A 032 20.61 IV. Peak Runoff Prediction ' Rainfall Intensity at Computed To, I = 2.65 inchlhr Rainfall Intensity at Regional Tc, I = 3.39 inctrlhr Rainfall Intensity at User -Defined To, I = 3.39 inclVhr Computed Tc = Regional Tc = User -Entered To = Peak Flowrate, Qp = 2.59 cis Peak Flowrate, Qp = 3.32 efs Peak Flowrate, Qp = 3.32 cfs 11 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Existing Conditions - Sub-Basin'B' (100 Year Storrs) 1. Catchment Hydrologic Data Catchment ID = B' Area = 3.01 Acres Percent Imperviousness = 15.17 % NRCS Soil Type = D A. B, C. or D II. Rainfall Information I(Inchfhr)-C1'P1/(C2+Td)-C3 Design Storm Return Period, Tr = 100 years (input return period for design storm) - C1 = 28.50 (input the value of 01) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 2.86 inches (input one-hr precipitation —see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.54 Ovedde Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C•5 = 0.24 Overide Syr. Runoff Coefficient, C = (enter an overide C-5 value it desired, or leave blank to accept calculated Gb.) 6each3 Illustration Reach I g� f LE ce&b..st Madas NRCS Land ]F—H..WTilla Type Meadow gty elAP..tZrr.1 Field Nea Bare Ground Grassed Swales/ Wate Paved Areas 6 Shallow Paved Swales Sheet FlowConve nice 2.5 510 15 20 Calculations: Reach Slope Length Syr NRCS Flow Flow ID S L I Runoff Convey- I Velocity I Time I Coeff attics V Tf ffm fl CS fps minutes Overland 3 IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 5.41 inch/hr Rainfall Intensity at Regional Tc, I = 6.93 inch/hr Rainfall Intensity at User -Defined To, I = 6.93 inch/hr Regional Tc User -Entered Tc Peak Flowrate, Qp = 8.85 cfs Peak Rowrate, Qp = 11.33 cfs Peak Rowrate, Qp = 11.33 cfs IFArea -Weighting for Runoff Coefficient Calculation _�: Project Title: _ Catchment ID: Illustration Flow nirec[:an s ~— Strbatea 3 Catchimeot Bouodagr Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output Undevel. 0.00 2.00 OAO Pavement 3.35 90.00 301.50 Gravel 0.10 40.00 4.00 Roof 0.55 90.00 1 49.50 Sum:l 4.00 I SuM:I 355.00 Area -Weighted Runoff Coefficient (sum CAlsum A) = 88.75 *See sheet "Design Info" for inperviousness-based runoff coefficient values. CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Existing Conditions-Sub-Elasin'OS-1' (100-Year Storm) I. Catchment Hydrologic Data Catchment ID = B' Area = 4.00 Acres Percent Imperviousness = 88.75 % . NRCS Soil Type = D A. B. C. or D II. Rainfall Information I(inchmr)=Ct"P1/(C2♦Td)"C3 Design Storm Return Period, Tr = 100 years (input return period for design storm) C1 = 28.50 (input the value of CI) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 2.86 inches (input one-hr precipitation -see Sheet "Design Info' III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.82 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C-5 = 0.73 Overide Syr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C-5.) Illustration / Reach 1 �) LEGENDglaning ca,hd Yes NRCS Land F—HeevIe Meadow Tina d Fed Shan Peslure/Swalesl LawnsWale MI GraPaved Areas3Type Shallow Paved Sheet Flow Conveyance 2.5 0E 70 15 tCalculations: Reach Slope Leng ID S L 11111 Itin ' input inpu Overland 0.0350 40C 1 2 ' 3 4 5 ' Suml 40C IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 8.10 inchthr ' Rainfall Intensity at Regional Tc, I = 7.12 inctvbr Rainfall Intensity at User -Defined To, I = 8.10 inch/hr Runoff I Convey- I Velocity Time Coeff ante V Tf C-5 fps minutes Regional Tc User -Entered Tc Peak Flowrate, Qp = 26.63 cis Peak Ram -ate, Qp = 23.41 cis Peak Flowrate, Op = 26.63 cis 11 Area -Weighting for Runoff Coefficient Calculation Project Title: _ Catchment ID: Illustration Subaaa 3 209 E. Skyway Drive A Conditions -Sub4 aJfie' L S ,s s Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C* CA input input input output Undevel. 0.34 2.00 0.68 Pavement 0.48 90.00 4320 Gravel 0.00 40.00 0.00 Roof 0.10 90.00 9.00 Lawn 0.07 0.00 0.00 Flow Direction i Catchm eint Boundary Sum:l U.99 , Sum: 5i 2.83 J Area -Weighted Runoff Coefficient (sum CAlsum A) = 53.41 *See sheet "Design Info" for inperviousness-based in coefficient values. I CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E Skyway Drive Catchment ID: Proposed Conditions - Sub-Basin'A' (2-Year Storm) I. Catchment Hydrologic Data Catchment ID = A Area = 0.99 Acres Percent Imperviousness = 53.41 % NRCS Soil Type = D A, B, C, or D Il. Rainfall Information I(inchPor)=C1'Pt/(C2+Td)-C3 Design Storm Return Period, Tr = 2 years (input return period for design storm) C1 = 28.50 (input the value of Cl) C2= 10.00 (input the value of 02) C3= 0.786 (input the value of C3) P1= 0.82 inches (nput one-hr precipitation —see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.36. Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C5 = 0.42 Overide Syr. Runoff Coefficient, C = (enter an overide C5 value If desired, or leave blank to accept calculated C5.) Illustration amdmd Rmh I flow f3each3 L Flo®D mrtisr Ces,h.w NRCS Land Type JMeadow Tillage! Field Shod er Nearly Bare Ground Grassed Waterways Paved Areas d, ; les Shall (Sheet Con nce 2.5 00 10 15 20 Calculations: Reach Slope Length 5-yr NRCS Flow Flow ID S I L I Runoff I Convey- I Velocity 1 Time I Coeff ante V Tf nM ff C5 fps minutes t IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 2.21 inchthr Rainfall Intensity at Regional Tc, I = 2.07 inchthr Rainfall Intensity at User -Defined Tc, I = 2.21 inchlhr Regional Tc User -Entered Tc Peak Flowrate, Op = 0.79 cis Peak Flowrete, Qp = 0.74 cis Peak Rowrate, Qp = 0.79 cis h 11 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Proposed Conditions -Sub-Basln'A' (10-Year Storm) 1. Catchment Hydrologic Data Catchment ID = A Area = 0.99 Acres Percent Imperviousness = 53.41 % NRCS Soil Type = D A, B, C, or D II. Rainfall Information I (inch(hr) = C1' P1 /(C2 + Td)-C3 Design Storm Return Period, Tr = 10 years (input return period for design stone) C1 = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 1.40 inches (input one-hr precipitation —see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.47 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C-5 = 0.42 Overide 5-yr. Runoff Coefficient, C = (enter an overide C 5 value if desired, or leave blank to accept calculated G5.) Illustration � v � Bexa t flow C. h.wt NRCS Land Type Hea Y Meadow Tilla el 9 Field Shon Pasture) Lawns Nea Bare Gmund Grassed Swales/ Wale �� Paved Areas 3 Shallow Paved Swales (Sheet Flow Conveyance 2.5 5 � 10 15 20 Calculations: ID S L 0m itu ' in u[ in Overland 0.0385 13C 1 0.0286 21C 2 ' 3 4 5 ' Sum 34[ IV. Peak Runoff Prediction ' Rainfall Intensity at Computed Tc, I = 3.78 inch8tr Rainfall Intensity at Regional Tc, I = 3.53 incltlhr Rainfall Intensity at User -Defined Tc, I = 3.78 inchlhr Runoff Convey- Velocity I Time Coeff anoe V Tf C3 I I fps minutes Regional Tc User -Entered Tc Peak Flowrate, Op = 1.77 cfs Peak Flowrate, Qp = 1.65 cfs Peak Flownde, Op = 1.77 cfs CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: _ _ _ _ 209 E. Skyway Drive Catchment ID: Proposed Conditions-Sub43asin'A' (100 Year Storm) I. Catchment Hydrologic Data Catchment ID = A' Area = 0.99 Acres Percent Imperviousness = 53.41 % NRCS Soil Type = D A. B, C. or D If. Rainfall Information I (inch/hr) = C1 "P1 1(C2 +Td)AM Design Storm Return Period, Tr = 100 years (Input return period for design storm) C1 = 28.50 (Input the value of C1) C2= 10.00 (input the value of C2) C3= 0.786 (Input the value of C3) P1= 2.86 inches (input one-hr precipilatiorr•-see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 6.61 Override Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C5 = 0.42 Overide Syr. Runoff Coefficient, C = (enter an overide C5 value If desired, or leave blank to accept calculated C-5.) Illustration -tea medmd Beach I /1w Reach NRCS Lend Type HWW Meadow illa Te/ e Feld Shod Pasture/ Lawns Nw rN Bare Ground Grassed Swales/ I Wate(Sheet Paved Areas 6 Shallow Paved Swales RoM Conveyance 2b 5 7 10 15 20 Calculations: Reach Slope Length 5qr I NRCS Flow I Flow ID S L Runoff Convey- Velocity Time Coetf ante V Tf RM 0 C 6 1 fps minutes IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 7.72 inch/hr Rainfall Intensity at Regional Tc, I = 7.21 inch/hr Rainfall Intensity at User -Defined Tc, I = 7.72 incWhr 1 c;omplaed Ie= Regional Tc = User -Entered To = Peak Floverate, Qp = 4.68 cfs Peak Flowrate, Qp = 4.36 cis Peak Flowrete, Qp = 4.68 cfs Area -Weighting for Runoff Coefficient Calculation Project Title: _ Catchment ID: Illustration Subazea 3 S 209 E. Drive -Suh-F s VA Instructions: For each catchment subarea, enter values for A and C. Subarea Area Runoff Product ID acres Coeff. A C' CA input input input output Undevel. 1.00 2.00 2.00 Pavement 0.36 90.00 32.40 Gravel 1.15 40.00 46.00 Roof 1 0.34 90.00 1 30.60 Lawn 0.16 0.00 0.00 Flow Ditecaon i Catchment Bormdagr Srnn:l 3.01 I sum:l 111.90 Area -Weighted Runoff Coefficient tsum CA/sum A) = 36.88 "See sheet "Design Info" for inperviousness-based runoff coefficient values. [1 CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Proposed Conditions -Sub-13asin'B (2-Year Storm) I. Catchment Hydrologic Data Catchment ID = B' Area = 3.01 Acres Percent Imperviousness = 36.88 % NRCS Soil Type = D A, 8, C, or D II. Rainfall Information I (inch/hr) = C1' P1 /(C2 +Td)-C3 Design Storm Return Period, Tr = 2 years (input return period for design storm) Ct = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 0.82 inches (input one-hr precipitation —see Sheet "Design Info") III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.26 Overide Runoff Coefficient, C = (enter an overide C value it desired, or leave blank to accept calculated C.) 5-yr. Runoff Coefficient, C-5 = 0.33 Overide Syr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C5.) Illustration �� merls.d @exh 1 flw, Reach 2 F Flow Dhrxtim NRCS Land Heavy Tillage/ Shon Nearly Grassed Paved Areas 8 Type Meadow 11 Field Pasture/ Bare Swales/ Shallow Paved Svrales Levms Gmund Wat Sheet Co nce 2.5 5 7 10 15 20 Calculations: Reach Slope Length 5-yr NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff ante V Tf JIM 0 C-5 fps minutes input input output input output output Overland 0.0250 200 0.33 N/A 0.23 14.44 1 0.0238 335 15.00 2.31 2.41 ' IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, 1= 1.76 InchRtr Rainfall Intensity at Regional Tc, I = 1.99 inch/hr Rainfall Intensity at User -Defined To, I = 1.99 inch/hr Computed Tc = Regional Tc = User -Entered To = Peak Flowrate, Qp = 1.39 cis Peak Fkiwrate, Qp = 1.57 cis Peak Flowrate, Qp = 1.57 cfs I 1 F CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Proposed Conditions-Sub-Basin'B' (10-Year Storm) I. Catchment Hydrologic Data Catchment ID = & Area = 3.01 Acres Percent Imperviousness = 36.88 % NRCS Soil Type = D A. B, C, or D H. Rainfall Information I(inchlhr)=C1'P1 I(C2+Td)^C3 Design Storm Return Period, Tr = 10 years (input return period for design storm) C1 = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 1.40 inches (input one-hr precipitation —see Sheet "Design Info' III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.41 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C-5 = 0.33 Overide Syr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated C3.) Illustration v O°� egboitalf ftam�— ay Rmh I fl Ca hmeat Eeazh3 t_ NRCS Land Heavy Tillage/ Shod Nearly Grassed Paved Areas h Type Meadow Field Pasture/ 11 Bare Swales/ Shallow Paved Sviales Lawns Ground VatenvaysSheet Flan Ca nce 2.5 0�7 ig 15 2n Calculations: Reach Slope Length Syr ID S L Runaff Coefi Will it C-5 input input output Overland 0.0250 200 0: 3 ' IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 3.00 inch/hr Rainfall Intensity at Regional Tc, I = 3.40 inch/hr Rainfall Intensity at User -Defined Tc, I = 3.40 inch/hr 1 NRCS Flow Flow Convey- Velocity Time artce V Tf fps minutes iGkGl Regional Te User -Entered To Peak Flaiv ate, Qp = 3.66 cfs Peak Flovmate, Qp = 4.14 cfs Peak Flowrate, Qp = 4.14 cfs CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD Project Title: 209 E. Skyway Drive Catchment ID: Proposed Conditions -Sub -Basin B' (100-Year Storm) I. Catchment Hydrologic Data Catchment ID = IT Area = 3.01 Acres Percent Imperviousness = 36.88 % NRCS Soil Type = D A, B, C, or D II. Rainfall Information I (Dnchfhr) = C1 . P1 /(C2+ Td)AC3 Design Storm Retum Period, Tr = 100 years (input return period for design storm) 01 = 28.50 (input the value of C1) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 2.86 inches (input one-hr precipitation —see Sheet "Design Info') Ill. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.58 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C-5 = 0.33 Overide Syr. Runoff Coefficient, C = (enter an overde C-5 value if desired, or leave blank to accept calculated C.5.) Illustration Rmk 3 LEGEND Begbining Ciiti,h e B,noull n NRCS Land Type HeaW Meadow Tillage! 8 Feld Shod astur Lawn Nearly GrBare oin Grassed WSwaIW Paved Areas 8 Shallow Paved les oot Flow) Con ca 2.5 00 10 I 15-E 20 Calculations: Reach Slope Length 5-17 NRCS Flow Flow ID S L Runoff Convey- Velocity Time Coeff aru»e V Tf gm It C-5 fps minutes input i input output input output output Overland 0.0250 200 0.33 WA 0.23 14.44 ' IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 6.14 inch/hr Rainfall Intensity at Regional Tc, I = 6.94 inch8rr Rainfall Intensity at User -Defined Tc, 1 = 6.94 mct✓hr Regional To = User -Entered Tc = Peak Flowrate, Op = 10.68 cfs Peak Flowrate, Clip = 12.07 cfs Peak Flowrate, Op = 12.07 cfs 11 Area -Weighting for Runoff Coefficient Calculation Project Title: _ Catchment ID: Illustration Subarea 3 209 E. Skvwav Drive s Insb actions: For each catchment subarea, enter values for A and C. Area Runoff Product acres Coeff. A C* CA k in ut in ut out ut 0.00 2.00 0.00 0.23 90.00 20.70 0.00 40.00 0.00 Roof 1 0.17 90.00 1 15.30 Flow Direction catcdmeor Bo*mAazy Sum:J OAO sum:J 36.00 Area Weighted Runoff Coefficient (sum CA/sum A) = 90.00 *See sheet "Design Info" for inperviousness-based runoff coefficient values. CALCULATION OF A PEAK RUNOFF USING RATIONAL METHOD ' Project Title: 209 E. Skyway Drive Catchment ID: Existing Conditions - Detention Pond #1 (2-Year Storm) I. Catchment Hydrologic Data Catchment ID = Pond #1 Area = 0.40 Acres Percent Imperviousness= 40.00 % NRCS Soil Type = D A, B, C, or D It. Rainfall Information I (inchlhr) = C1 • P1 /(C2 + Td)AC3 Design Storm Return Period, Tr = 2 years (input return period for design stone) C1 = 28.50 (input the value of Cl) C2= 10.00 (input the value of C2) C3= 0.786 (input the value of C3) P1= 0.82 inches (input one-hr precipitation —see Sheet "Design Info') III. Analysis of Flow Time (Time of Concentration) for a Catchment Runoff Coefficient, C = 0.28 Overide Runoff Coefficient, C = (enter an overide C value if desired, or leave blank to accept calculated C.) Syr. Runoff Coefficient, C-5 = 0.35 Overide Syr. Runoff Coefficient, C = (enter an overide C-5 value if desired, or leave blank to accept calculated CS.) Illustration a.edud Reazht am Caa M.,i,t NRCS Land Nea ryType Paved Areas 3 ]IF--H;Wvy--IFTTiiiii—a—ge/7[S..t. Meadow Field Bareja Shallow Paved Svrdtes Ground Sheet Flow Con nce 2.5 00 10 15 20 Calculations: ID S L Rm it ' input in u Overland 1 0.0350 1 20C 1 2 ' 3 4 ESUIE20C 5 ' IV. Peak Runoff Prediction Rainfall Intensity at Computed Tc, I = 2.01 inchthr Rainfall Intensity at Regional Tc, I = 2.13 inch/hr Rainfall Intensity at User -Defined To, I = 2.13 inch/hr Runoff Comev- Iv Veloci Time Coeff ance V Tf C-5 1 1 fps minutes Regional Tc User -Entered Tc Peak Flowrate, Qp = 0.22 cfs Peak Flowrate, Qp = 0.24 cfs Peak Flowrate, Qp = 0.24 cis MAJOR DETENTION VOLUME BY FAA & MODIFIED FAA METHOD (See USDCM Volume 1 Runoff Chapter for description of method) in (Note: for catchments larger than 90 acres, CUHP hydrograph and routing are recommended) The user must till In all of the blue calls for these sheets to function. ian Information llnout): mont Drainage hgaMouaess .no Drabage Area nvbpned NRCS Soe Caaq n PaloO to Daianlbn CadW d Carcmta0on N Walerste0 doe Um Release Repo (See Tede A) tar predldaee in Rainfall OF Formula I•CPP1/(C2•Tcr idenf Om ast Tao dea Thee I,= 90.00 percad A= 0.C31 eves Type. D A, 6, C,arD T- 1W yeas(2, 5, 10, M. W. a' IN) To. 13 .metes' q= am ds/ave Cf • 28.50 CL= 10.00 Cy • 0.79 Fluor CuefBard C= ow hdbw Peak RlaMf C". 217 ds Peak Udllow Rob mod• 0.22 ds RmboorOPadL7pin RaBo• 0.10 Determination of MAJOR Detention Volume Using FAA & Modified FAA Method 10 c FNer Ramat Usage none nveese Vale Here fee 5 farS Meeks Randal Usage rmalaa� (WA) RaWal Ire oty nrles/tr (Cuout) Inflow Volare adcfact (output) Average 0u0bw (FAA ds) (outun Udllgw Vc/ne (FAA cf) (cut") Storage Valme (FAA d) (ozut) Aquslrcnl Factor (Modred) (out") Awraga OW10. (Moo. cis) (cutpu) Cutlb4 Vdmn (Mad. d) (OU04) Stooge Vohs (Mod cn (0,41put) 0 &W 0 OW 0 0 ow &W 0 0 10 7,57 1,519 0.12 72 1.447 1.W 0.22 133 1.386 20 6.0 2,205 D.12 143 Z062 093 0.18 219 1985 30 4.W 2,635 0.12 215 2,420 0.72 0.15 286 2,349 40 3.67 2,945 0.12 286 2,659 0.68 0.16 353 2,593 50 3.18 3.188 0.12 358 2,830 0.0 0.14 419 Z,70 SO 2.81 3,W7 0.12 430 ZW 0.61 0.13 486 2,W1 70 253 3.5M 0.12 5D1 3,055 0.59 0.13 552 3,W4 W 231 3,7W 0.12 573 3,130 0.68 0.13 619 3,W W Z12 3,833 0.12 644 Mae uS 0.13 685 3.10 1W 1.97 3.950 0.12 716 3234 0.57 0.13 752 3,198 110 1.64 4,056 o12 788 3.:?M 0.66 0.12 818 3.236 120 1.72 4,154 0.12 859 3295 0.55 0.12 885 3269 1W 1.0 42" 0.12 of 3,313 0.M 0.12 951 :i q3 140 1." 4,328 0.12 I= 3,326 am 0.12 1.018 3,310 IN 1.46 4.W7 0.12 1.074 3.333 0.64 0.12 1,084 3,M 1W 1.40 4.481 0.12 1,146 3,335 0.54 0.12 1.151 3,330 170 I'M 4.5W 0.12 1,217 3,333 0.54 0.12 1217 3,333 180 1.28 4.617 0.12 1,2W 3, 0.54 0.12 1,284 3,333 1W 1.23 4,660 0.12 I= 3,319 0.53 0.12 1,350 3,329 ZW 1.18 4,740 0.12 1,432 3,308 0.53 0.12 1,417 3.323 210 1.14 4,7W 0.12 1,504 3,294 0.53 0.12 1,483 3,314 Z20 1.10 4.13W 0.12 1,575 3,2T7 am 0.12 1.550 3,3D2 230 1.06 4,905 0.12 1,647 3,258 0.53 0.12 1,616 3.289 240 1.03 4,956 0.12 1,718 3237 otKf 0.12 1.683 3,M 250 1.W 5,W5 0.12 1,790 3,215 0.63 0.12 1,749 3256 260 097 5,052 0.12 1.&M 3,191 ow 0.12 1,816 3,Z36 270 094 5,098 0.12 1933 3,165 0.52 0.12 I'M 3.216 260 0.91 6,142 DA2 zoos 3,131 0.52 0.12 I'M 3,10 2W 0.09 5,185 0.12 Z076 3,109 0.52 0.12 Z015 3.170 3W 0.87 6,227 0.12 2.148 3.079 0.52 0.12 Z082 3,145 310 0.85 5,267 0.12 ZMD 3,048 0.52 0.12 Zia 3,119 320 0.M 5,we 0.12 2,291 3,015 0.52 0.12 2.215 3,092 330 0.81 5,345 0.12 Z,363 Z982 0.52 0.12 2281 3,063 340 0.79 5.382 0.12 Z434 2,948 0.52 0.12 Z348 3.034 3W 0.77 5,418 0.12 2506 2,912 0.52 0.11 Z414 3,004 3W 0.75 5,454 0.12 2578 2,876 DS2 0AI 2,481 Z973 FM Major Stomp Vulture (cubic R) a FAA Major Skonrya V.I.(acr.A)- 3,385 Mod FAA Major Storage Voluma(cubic R)a Mod FAA Ma)or Storage Volume (acwk)• 3,333 0.0768 0.070 it=rviivn vv��mr=�aiimninvv rrvnmm��n veram� 2.G2, R.i..."i aa.iay cvur U0.Detordm Der Pad t.ds, Modred FAA 121122W6, 9:M AM OW mliiiiiiiiiiiiiiiiiiiiiiiiiiiiiillillilillilI | k a STAGE -DISCHARGE SONG OF THE WEIRS AND ORIFICES (INLET CONTROL) I ho%sl: lMa ML AroRNE m w er w 0 wxaR.mx1.. nw.lauxax Wmea omx..x rr..nxa1 wr n.nv Suea9n a Oxen oepn agYlxtra166 GOm LwIFYrrn ne9 W M Peet iLTw a.sN am a o.ap� Dew o0r9xadanteOrrpeu) 6m CedOya NMrY tYlCxOa My. L�PiCxx Mbx sysq See. Ne Pa15+La.1nR Fl..xe TT.IAiYpnn PYxe) i.pa e...xn r pp o Beer r pw PnxLI o-ennrwexerww iaxm p.r Fle.Tbwe/eaeeu raWlVtaalat CAM Ont,O M• SJ. ne .b• A M ye yL m VYdL/aMbllfb• Ii'LS 1.M• a.n xa T• Ln�x • LvwL1 F1x I'r anw py• A.twm M1 a• ra T o.ww �i La ylw.t L- x3w J=•...� rwa.r we. NWxWnrM M OpMs: Won On Out lxNn~-x Odeel pxuaAtrape...IW nAA- 'MYCMkYa arh. EYvmnwoeexM WIM CalsNalbn olaaMeem CmsRx na CArNMee InvT Semo Reeg. WwPNbtlel Cperq/ua PxF.rr Wrvver Lny. Lxi9. nlWb. RIWC nWM1 RWM1 OY. M1xt W ]w ay p. LSX• xm aw e. Sy . EOm 1wm i C�• a.65 a65 C.• tm E�• L98Lm ♦%a.w Tap 9xaM rVNl4rghLaeeip.TW• M®m a. AaxEMYxrVWaIQh.Opxiq,Cse L9nq n Ro1AIng b: 3In91. Stag. - Water Dora ti mu9h W plate And H hoduntal opening Into M VeNlool opening. This flow, will be uee. Iv w]Lv.wv. Lrp9p WS nerve wax Hulse DWaNI C vxaev nw. nr. WeF dao tbx M N Is, nr. AS . WY 4he Flew ibx N W AWM1 a¢vw. Tr Cnnae aapsq re T.oava.ex bWOCV.Mm. LMp9ry vume b PYMOs FlM nl COram CWMV, Rt Clthx Cpry a< Me,.15 am aw cow aw a.w am o.w CA Qr 4909.00 0.. 0.0 om a.w om .m om AM am 49maz 0.01 3.75 TJn om O.w Am ow AM 49411.50 om WA, uM om om om em GAS M00.15 cm MA$ n.n em om o.w om CA a .m om MA SIA om om pa. om Lu Lm9.x5 ow .'AA Jo.0 nm em ..n om .1 11,11 SO III M.n vet om om C." om kit WYCKNI 4909.15 o.tx nM AS. om om au om au oQ! WDrOO o.0 COM se. om .m CA$ o.w aO 491a25 tna Ltm om CA CIA om uL 41T0.50 nee, Mm om om ..% am Its 1910.75 tMAI MAI om CA o.11 .m e17 r.4071.00 MCA 41M Cw .m a.0 pw kit um pm .m ov om .11 URIM 01. om om Cis em UL w.w ow om CM em Fnebeen! "MOD 5A.n om om 0s om ar see tNa1 tNe1 ow MCA Anse Cmom LwA Anw rw om LWA I w+w Ln+. «w ww ew ww RA OWO L1M An!n om Lww AnA NA AnA AA om MA ww Anon AnA alA om LwwAnA AnA An1n om LNLL Mn AnA Nn Anln om Y9A nW M01 Mn LTA om LWM WIn Mn nln om MA See LWL wA AnA eA om LWw WA ►A WA. Mn WA om A9A Mn wA MA wA AnA om Aet W1M vA An!N WA pA om LWA Ww WA AnA wA eA om nuw RLM MA MCA Anse LWL om LWw wA wA WA wA wA om ruw !A O1n LWM wA AnA .m 49A wA AnA WA Mn eA o.w WA WA fA Anse MM RA om MCA Mn WA wA wA RA o.w WA Ow 1!M RA LIa11 wA om WA Anal One, mi AA Anal wA WA On. WA om ww UPDrrN.n Dr PWW lr , Oalr 1mMN100, 10AM I [1 1 APPENDIX II . CHARTS, GRAPHS, FIGURES AND DETAILS I 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 Runoff Coefficient vs. Watershed Imperviousness Based on Runal CoaRkJent estimatitq equation published by Urbmms, eta]. (MO) &WEF (1998) Basic equation for MRCS Soll Noes C & D: Cm =Lm + R"'i' - 0.7964' + 0.7741+&N) Basic equation for NRCS $911 Noe A Cs=La +(lllY'•lA1Y'+1.135 •/-0.12) Iew aawNoesfs Cs>0 in which: r - 1.1100, imperviousness ratio 1. =watershed imperviousness in percent CA w RuwffCoeffiaad fm NRCS Soil Type A KA=ComcBmt aYm fm CA when to stem rNmr peuodie gtrsterden 2-y Cuy - RwoffCoedxdon 9e NRCS Sod Types C and Key- Cmrechen(ecru for Cyo v the stem anon period is l9eata dm 2-yea NRCS Vshes ofCOMCfi nF*e1nn Kraa LA Sumn Reovn Period sea 2- 5-w 1a 'sw 50- 100- C&Dj aos 1 141"+aIllnrnw.v nnvwa axsvao. o" A I om [aesYY+aos]I [nr .nj 1[aurwa4]1 [s.xxv. 2q I [nu,+ oq Weim OfRxumffCoeff=etC Vehreof RmioffCot imdC Oep rv. Rmm 1 0.00 0.04 OA5 0.25 0.37 0.N 0.50 -OA2 .0.03F0,20 0.12 OAS 0.20 0.05 008 0,18 028 0.39 OA6 0.52 .0.07 0.02 0.18 0.20 0.24 OAO 0.11 0.21 0.30 0.41 OA8 0.53 -0.02 0.08 0.20 0.24 0.28 0.15 0.14 0.24 0.32 0.43 OA9 0.54 0.02 0.10 0.23 0.27 0.30 0.20 OA7 0.26 034 0." 0.50 0.55 0.08 0.13 0.28 0.30 0.33 0,25 0.20 0.28 038 0.48 0,52 0.58 0,09 0.10 0.29 0.32 0.35 0.30 0.22 0.30 0,35 0.47 0.53 0.57 0.13 0,19 0.31 0.34 0,37 0.35 0.25 0.33 0.40 OA8 0.54 0.57 0.16 0.22 0.33 0.W 0.39 0.40 0.2B 0.35 0.42 0.50 0.55 0.58 0.19 0.25 0.35 0,38 0.41 0.45 0.31 0.37 0.44 0.51 0.56 0.59 0.22 0.27 OX 0.40 0.430.50 0.34 0.40 0.48 0.53 057 0.80 0.25 0.30 0.40 0.42 0.45 0.55 0.37 0.43 am 0.55 0.59 0.62 0.29 0.33 0.38 OA2 0.45 0.47 0.60 0.41 0.48 0.51 0.57 0.81 0.63 0.33 0.37 0.41 OA5 0.47 0.50 0,65 0.45 0.49 0,64 0.59 0.63 0.65 0,37 0.41 OA5 0.49 051 0.53 0.70 0.49 0.53 0,57 0.62 0.66 0.68 0.42 0.45 OA9 0.53 0.54 0.58 0.75 0.54 0.58 0.62 0.06 0.69 0.71 0.47 0.50 054 0.57 0.59 OA1 0.80 0.80 0.63 0.60 0.70 0.73 0.74 0.54 0.58 0.80 0.83 0.64 0.86 0.85 0.88 0.68 0.71 0.75 0.78 0.79 0.61 0.83 0.88 Oso 0.70 0.72 0.90 0.73 0.75 0.77 0.80 0,83 0.83 0.69 0.71 0.73 0.76 0.77 0.79 0.95 0.80 0.82 0.84 0.87 0.89 0.89 0.78 0.80 0.82 0.84 0.85 0.88 1.00 0.89 0.90 0.92 O.N 0.98 0.98 0.89 0.90 0.92 O.N 0.95 0.98 ,.�. em rypeq emu, ux ue svemge ...I a .". When the RunoffCoeffuimnm above able is <0,ux 0. When cong)M1b ig the RunoffCeeffi snd fm diffaen sod IyMose Poe table vehm above ngaeAee ift ey m <O. Runoff Coefficient vs. Imperviousness Runoff CoAnclem vs. Impeavlousness NRCS Hydrologic Solis C & D NRCS Hydrologic Soil A 1.00 0.9D 0.80 • 0.70 0.00 0.50 0.40 030 a 0.20 0.10 0.00 1.00 F19ax 0.90 r 0.80 2}yr 2 0.70 -1ayr I E' D.eo •-"-5.x 1 - 0.50 -`2-W 1 ✓i 0.40 § 0.30 rc 0.20 0.10 0.00 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.0 0.1 0.2 0.3 0.4 0.5 0.0 0.7 0.8 0.9 1.0 Watershed Impervious Ratio Watershed Impervious Ratio .1oo-yr ,max +1ayr + Syr -�z-x ftpr DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table 110-3—Recommended Percentage Imperviousness values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family Multi -unit (detached) 60 Multi -unit (attached) 75 Half -acre lot or larger Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off -site flow analysis (when land use not defined) 45 Streets: Paved 100 —Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 0 Lawns, clayey soil 0 See Figures RO-3 through RO-5 for percentage imperviousness. CA = KA + (1.31i' —1.44i 2 + 1.135i — 0.12) for CA >: 0, otherwise CA = 0 (RO-6) CcD = K , + (0.858i' — 0.786i2 + 0.774i + 0.04) (RO-7) CB = (CA + CcD)12 2007-01 RO 9 Urban Drainage and Flood Control District Recommended Values for Manning's N in Overflow Bank Areas in Composite Channel Grass Type Grass Length 0.7 ft <De th<1.5 ft De th>3.0 ft For Minor Runoff For Major Runoff Bermuda 2-inch 0.0350 0.0300 Bermuda 4-inch 0.0400 0.0300 Kentucky 2-inch 0.0350 0.0300 Kentucky 4-inch 0.0400 0.0300 Any Grass Good Stand 12-inch 0.0700 0.0350 Good Stand 24-inch 0.1000 0.0350 Fair Stand 12-inch 0.0600 0.0350 Fair Stand 24-inch 0.0700 0.0350 Assumed Manning's N vs. Depth for Composite Channel and Low -Flow Section Design .070 .065 r.r .055 m .. 2 .045 .040 n = 0.0018 .035 0.0206(Y) + 030 2 n = 0.000, (Y') - 0.0025(Y) + 0.050 3 4 5 6 7 Depth of Flow Y, in Feet 8 9 10 UD-Channels_v1.04.xis, Design Info 4/3012008, 10:50 AM