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HomeMy WebLinkAboutDrainage Reports - 09/24/2006FILE:05-036.05 August 24, 2006 r11 City of Ft. Collinsykpprc#ud Plans City of Fort Collins MMYVWBy. ALI &2=6� Stormwater Utility 70o Wood Street Fort Collins, CO 80521 RE: Colorado State University Summit Hall Parking Lot Expansion 2310 East Prospect Fort Collins, CO 80525 ph:970.484.7477 fa:970.484.7488 www.tec-engrs.com To Whom It May C/eansion : a3(fl70 1 CSU is planning aof the parking lot at Summit Hall on their main campus. This expansion wise the number of parking stalls by 88 spaces and increase the pavement by 2,63 yards. In order to mitigate the increased imperviousness, a detention and water quality.pond are being proposed south of the proposed parking lot. This facility will provide extended detention for.water quality control per Urban Drainage and Flood Control District criteria and detain the 100-year developed runoff, releasing at the 2-year historic runoff rate. Historic drainage patterns on the proposed site are from west to east. This pattern is generally maintained with the construction of the proposed parking lot and the construction of a detention pond to the south of the parking lot. The detention pond releases through a 15-inch CMP to an existing detention pond. This was done in order to reduce the number of utility crossings and storm sewer structures. The main effect of releasing runoff from a detention pond into another existing detention pond is the tailwater effect of the existing detention pond during the I00-year storm event. The as -built spillway elevation for the existing pond is 5021.4.5. All storage volume in the proposed pond below this elevation was neglected during the I00-year storm. This way, if the existing pond is full, the proposed pond still has the capacity to detain the I00-year event and release the allowable discharge to maintain the hydraulic design of the proposed pond. Calculations have been completed in order to determine the runoff from the proposed site, required storage volume, pond outlet structure, and erosion protection to safely construct the proposed improvements without causing harm to downstream properties. Calculations show a required water quality capture volume of 0.02 acre-feet and a detention storage requirement of 0.17 acre-feet for a total storage volume requirement of 0.19 acre-feet. The proposed plan accomplishes this storage with a I00-year water surface elevation of 5023.50. City of Fort Collins Stormwater Utility August 24, 2006 Page 2 . ' Erosion control will be provided on site through the use of silt fence, sediment traps, and vehicle construction entrances. These measures are designed to limit the overall sediment yield increase caused by construction as required by the City of Fort Collins. Silt fence shall be used to control sediment from leaving site along the eastern property line. Runoff from all other edges of the property is directed to the center of the property. A sediment trap will be constructed in the proposed pond by over -excavating the pond during the construction phase. Vehicle construction entrances will mitigate vehicle tracking onto City streets as much as possible. The contractor will be responsible for keeping sediment from migrating to City streets via vehicle tracking. All other erosion control measures will be adhered to as specified in the City of Fort Collins Storm Drainage Design Criteria. ' Sincerely yours, I, Amber Kauffman, P. . Project Engineer The Engineering Company enc. Rick R. Pickard, P.E. Principal The Engineering Company Icc: Jim Stoddard, CSU Facilities Management I 11 1 W w N ? U Q Q 7 � W O N � 0 o in rn u� a 0 w N U O Q o c r N U N C N U O O U o 0 m d � N N Q C � cJ 16 a a N_ N O o ►`-' N =a c _m c N O v a 0 RUNOFF COEFFICIENTS & % IMPERVIOUS LOCATION: Summit Hall PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Ktafinan DATE: 711812006 Recommended Runoff Coefficients from Table 3-3 of City of Fort Collins Design Criteria Recommended % Impervious from Urban Storm Drainage Criteria Manual Streets, parking lots (asphalt) Sidewalks (concrete) Roofs Lawns, Undeveloped Runoff % coefficient Impervious C 0.95 100 0.95 96 0.95 90 0.20 0 SUBBASIN DESIGNATION TOTAL AREA (ac.) TOTAL AREA (sq.ft) ROOF AREA (sq.ft) PAVED AREA (sq.ft) SIDEWALK AREA (sq.ft) LANDSCAPE AREA (sq.ft) RUNOFF COEFF. (C) % Impervious Historic 1.22 53,265 0 0 0 53,265 0.20 0 Proposed 1.22 53.265 0 23,679 0 29,586 0.53 44 Equations - Calculated C coefficients & % Impervious are area weighted C=E(Ci Ai) /At Ci = runoff coefficient for specific area, Ai Ai = areas of surface with runoff coefficient of Ci n = number of different surfaces to consider At = total area over which C is applicable; the sum of all Ai's Drainage and Pond LL } N Z O F Q N N Z 0 W 00 00 a U 0 LL a O N cW G_ N Y !r Q s W K J N « Ip z E Z O C E N h m ° v u 0 « Y N v V C F-- u N � U � O y O N J LL E J Z d O � O N Z Q_ > m z y o O U K O C O O O W � Ill O r r � d a^ w t r J W � � iza, M M Q J v � r r .. O O d n � n h � fn K J W o N N � J O O Q W U � H � z� d d � N N N N N Z u y 1p N a NO ;, N 2 Z 70 m Q Z Na 0 N N >N L J U Y LL U L U 0 C y al E 0 0 N N C � t0 � E c In � II � G `0 E E z E C E U 0` O O r Z O N N ~ Z ¢ W o(L) LL Z 00 a U LL O N WW C F N Y K Q W K J r N Vi ai U Z E O 4 nj y � E v mU Y N a WZ J a m u 7 U i r N 3 20 N r mo p J LL J O z m N 2 rn N m U O O O C C C J O O Q W m O � N O t=9 0 o m w M M J L f m � O o N N m L O m N r J U 10 r Cl! m cc O z Q J U K W o c > N O O Q U M F W Z f d � N N N N N N Z U � N Q O a O = o 00 7 a N Z � F Q OD Fa W O a N O p Z J U U LL N 0 Uw O C N N r m E .a- 0 N N N 7E C In � I I `o E E E_ C E u U RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 2-Yr Storm) LOCATION: Summit Hall PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffinan DATE: 7/18/2006 2 yr storm, Cf = 1.00 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Design Point Tributary Sub -basin A (ac) C Cf tc (min) i (in/hr) Q (2) (cfs) from Design Point Q (2) (cfs) Q(2)tot (cfs) 1 Historic 1.22 0.20 16.2 1.79 0.4 0.4 0 1 Proposed 1.22 0.53 11.1 2.13 1.4 1.4 Q=CfCiA Q = peak discharge (cfs) C = runoff coefficient Cf = frequency adjustment factor i = rainfall intensity (in/hr) from City of Fort Collins IDF curve (4/16/99) A = drainage area (acres) 1= 24.221 t (10+ tc)°'tea Drainage and Pond RATIONAL METHOD PEAK RUNOFF (City of Fort Collins, 100-Yr Storm) LOCATION: Summit Hall PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffman DATE: 7/ 18/2006 100 yr storm, Cf = 1.25 DIRECT RUNOFF CARRY OVER TOTAL REMARKS Des. Point Area Design. A (ac) C Cf - tc (min) i (in1hr) Q (100) (cfs) from Design Point Q (100) (cfs) Q(100)tot (cfs) 1 Historic 1.22 0.25 15.7 6.36 1.9 1.9 1 Proposed 1.22 0.67 9.2 8.02 6.5 6.5 Q=CiA Q = peak discharge (cfs) C = runoff coefficient i = rainfall intensity (in/hr) from City of Fort Collins OF curve (4/16/99) A = drainage area (acres) i = 84.682 / (10+tc)0.7975 Drainage and Pond WATER QUALITY CAPTURE VOLUME SUMMARY FOR EXTENDED DETENTION PROJECT NAME: Summit Hall JR PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffman DATE: 7/18/2006 Guidelines from Urban Strom Drainage Criterial Manual, September 1999 (Referenced figures are attached at the end of this section) Use 40-hour brim -full volume drain time for extended detention basin Water quality Capture Volume, WQCV = 1.0 * (0.91 * i3 - 1.19 * i2 + 0.78i) Design Volume: Vol = WQCV/12 * Area * 1.2 MAJOR BASIN Trib. area (acres) Impervious Ratio, la %Impervious i = Ia1100 WQCV (watershed inches) Design Volume, Vol. (ac-ft) Design Volume, Vol. W) Proposed 1.22 44 0.44 0.19 0.02 1020 Drainage and Pond,7/19/2006,9:42 AM [1 i I I I I I I I I Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility POND A Project Name: Soderberg Trailhead Designer: A. Kauffinan Submitted By: ASCE NCB Date: DATE 1. Basin Storage Volume A) Tributary Area's Imperviousness Ratio (i=la/100) la = 44 % i = 0.44 B) Contributing Watershed Area (Area) A = 1.22 acres C) Water Quality Capture Volume (WQCV) WQCV = 0.19 watershed inches (WQCV =1.0-(0.91'13-1.19'i2+0.78i)) D) Design Volume: Vol = WQCV/12 ' Area 1.2 Vol. = 0.02 ac-ft 2. Outlet Works A) Outlet Type (Check One) x Orifice Plate Perforated Riser Pipe Other: B) Depth at Outlet Above Lowevst Perforations (H) H = 1.8 ft C) Required Maxiumum Outlet Area per Row, (Ao) Ao = 0.07 square inches (Figure EDB-3, Ao=WQCV/(6.013-H2+0.22'H-0.10)) D) Perforation Dimensions (enter one only) i) Circular Perforation Diamter OR D = 15116 inches, OR ii) 2" Height Rectangular Perforation Width W = inches E) Number of Columns (nc, See Table 6a-1 for Maximum) ne = 1 number F) Actual Design Outlet Area per Row (A,) k = 0.69 square inches G) Number of Rows (nr) nr = 5 number H) Total outlet Area (At) A.( = 3.45 square inches 3. Trash Rack A) Needed Open Area: At = 0.5 ' (Figure 7 Value) ' kt At = 117.3 square inches B) Type of Outlet Opening (Check One) x < 2" Diameter Round 2" High Rectangular Other: C) For 2", or Smaller, Round Opening (Ref: Figure 6a) 1) Width of Trash Rack and Concrete Opening (W, c) Wconc = 6 inches from Table 6a-1 ii) Height of Trash Rack Screen (HTR) HTR = 19.6 inches = H - 2" for flange of top support iii) Type of Screen Based on Depth H) x S.S. #93 VE Wire (US Filter) Describe if "other" Other: iv) Screen Opening Slot Dimension, x 0.139" (US Filter) Describe if "other" Other: v) Spacing of Support Rod (O.C.) 3/4 inches Type and Size of Support rod (Ref: Table 6a-2) #156 VEE Drainage -ftc - alk DETENTION VOLUME CALCULATIONS Rational Volumetric (FAA) Method 100-Year Event LOCATION: Summit Hall PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffman DATE: 7/18/2006 Equations: Area trib. to pond = 1.22 Developed flow = Qo = CIA C (100) = 0.67 Vol. In = Vi = T C I A = T Qp Developed C A = 0.8 Vol. Out = Vo =K QPo T Release rate, QPo = 0.4 storage = S = Vi - Vo K = 0.9 Rainfall intensity from City of Fort Collins OF Curve with updated (3.67") rainfall acre acre cfs (from fig 2.1) Storm Duration, T (min) Rainfall Intensity, I (in/hr) Qn (cfs) Vol. In Vi (ft) Vol. Out Vo (ft) Storage S (ft) Storage S (ac-ft) 5 9.95 8.1 2434 118 2315 0.05 10 7.77 6.3 3799 237 3563 0.08 20 5.62 4.6 5499 473 5026 0.12 30 4.47 3.6 6558 710 5847 0.13 40 3.74 3.0 7318 947 6371 0.15 50 3.23 2.6 7910 1184 6726 0.15 60 2.86 2.3 8394 1420 6973 0.16 70 2.57 2.1 8803 1657 7146 0.16 80 2.34 1.9 9159 1894 7265 0.17 90 2.15 ' 1.8 9473 2130 7343 0.17 100 1.99 1.6 9756 2367 7389 0.17 110 1.86 1.5 10012 2604 7408 0.17 120 1.75 1.4 10247 2841 7406 0.17 130 1.65 1.3 10463 3077 7386 0.17 140 1.56 1.3 10665 3314 7351 0.17 150 1.48 1.2 10854 3551 7303 0.17 160 1.41 1.1 11031 3787 7243 0.17 170 1.35 1.1 11198 4024 7174 0.16 F777TTC�- 1.29 1.1 11356 4261 7095 0.16 Required Storage Volume: 7408 ft3 0.17 acre-ft Drainage and Pond,Det-FAA-Opt. B I�x \Il()N 111%, ),I I ( I V( ). 0AIPUTAIIUNti 11) DAI[ DETENTION VOLUME CALCULATIONS Rational Volumetric (FAA) Method 100-Year Event Summit Hall 0;-U36,0) A. Kauffman 7 15 2006 12000 10000 8000 � I E 6000 6 4000 2000 0 0 50 100 150 Storm Duration (min) t Inflow Volume Outflow Volume 200 Drainage and Pond,Det-FAA-Opt. B LOCH"LION: PROJECT NO: COMPUTATIONS BY DACE_ :111 7000 6000 5000 E 4000 0 > 3000 2000 iI1I1I1ll 0' 0 DETENTION VOLUME CALCULATIONS Rational Volumetric (FAA) Method 100-Year Event Summit Hall A. Kauffman 7 IS _'(lf)O 50 100 Storm Duration (min) t Storage Volume 150 200 Drainage and Pond,Det-FAA-Opt. B Proposed Detention Pond - Stage/Storage LOCATION: Summit Hall PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffman DATE: 7/18/2006 V=1/3d(A+B+sgrt(A'B)) where V = volume between contours, ft 3 d = depth between contours, ft A = surface area of contour Pondlnver Discharge Pond WSEL 100-yr WSEL- Spill - top of berm - Stage (ft) Surface Area W) Incremental Storage (ft) Incremental Storage (ac-ft) Total Storage (ac-ft) Total Storage (ac-ft) Actual Storage (ac-ft) 5019.65 0 5020 100 586 0.00 586 0.00 0.00 5021 1209 1943 0.01 2529 0.01 0.00 5021.45 2957 1304 0.02 3833 0.03 0.00 5022 3495 2169 0.04 1 6002 0.07 0.04 5023 4506 4236 0.09 10238 0.17 0.13 5023.5 5041 2381 0.05 12620 0.22 0.19 5024 1 7292 1 2516 0.07 15136 0.29 0.26 5025 Required Water Quality Capture Volume: Required 100-Yr Detention Volume: Total Required Volume: Volume Provided: (ft) ac-ft 1,020 0.02 7,408 0.17 8,428 0.19 15,136 0.26 IDrainage and Pond l_J Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility PROPOSED POND OUTLET STRUCTURE LOCATION: Summit Hall PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffman DATE: 7/18/2006 1. Basin Storage Volume A) Tributary Area's Imperviousness Ratio (i=la/100) la = 44 % i = 0.44 B) Contributing Watershed Area (Area) A = 1.22 acres C) Water Quality Capture Volume (WQCV) WQCV = 0.19 watershed'inches (WQCV =1.0`(0.91-i'-1.19'i'+0.78i)) D) Design Volume: Vol = WQCV/12 ' Area ' 1.2 Vol. = 0.02 ac-ft 2. Outlet Works A) Outlet Type (Check One) x Orifice Plate ' Perforated Riser Pipe Other: B) Depth at Outlet Above Lowevst Perforations (H) H = 1.8 ft C) Required Maxiumum Outlet Area per Row, (Ao) Ao = 0.07 square inches (Figure EDB-3, Ao=WQCV/(0.013"HZ+022-H-0.10)) D) Perforation Dimensions (enter one only) i) Circular Perforation Diamter OR D = 15116 inches, OR ' ii) 2" Height Rectangular Perforation Width W = inches E) Number of Columns (nc, See Table 6a-1 for Maximum) nc = 1 number ' F) Actual Design Outlet Area per Row (Aj Ao = 0.69 square inches G) Number of Rows (nr) nr = 5 number ' H) Total outlet Area (A,,) Aot = 3.45 square inches 3. Trash Rack A) Needed Open Area: At = 0.5 ' (Figure 7 Value) ` Aot A, = 117.3 square inches ' B) Type of Outlet Opening (Check One) x < 2" Diameter Round 2" High Rectangular Other: C) For 2", or Smaller, Round Opening (Ref: Figure 6a) - 1) Width of Trash Rack and Concrete Opening (Wco .) Woo c= 6 inches from Table 6a-1 ii) Height of Trash Rack Screen (HTR) HTR = 19.6 inches = H - 2" for flange of top support iii) Type of Screen Based on Depth H) x S.S. #93 VE Wire (US Filter) Describe if "other" Other: iv) Screen Opening Slot Dimension, x 0.139" (US Filter) Describe if "other" Other: ' v) Spacing of Support Rod (O.C.) 3/4 inches Type and Size of Support rod (Ref: Table 6a-2) #156 VEE IDrainage and Pond I I 71 J J r 11 I I f 1 I I I ,11 DRAINAGE CRITERIA MANUAL (V. 3) STRUCTURAL BEST MANAGEMENT PRACTICES Table 6a-1: Standardized WQCV Outlet Design Using Circular Openings (2" diameter maximum). Minimum Width (W,P,,,i,,g) of Opening for a Well -Screen Type "trash Rack. Requires a minimum water depth below the lowest perforation of 2'-4". See Figure 6-a for Explanation of Terms. Maximum Dia. of Circular Width of Trash Rack Opening (Ww J Per Column of Holes as a Function of Water Dept H Below Lowest Perforation Opening (inches) H=2.0' H=3.0' H=4.0' H=5.0' H=6.0' Maximum Number of Columns < 0.25 3 in. 3 in. 3 in. 3 in. 3 in. 14 < 0.50 3 in. 3 in. 3 in. 3 in. 3 in. 14 < 0.75 3 in. 6 in. 6 in. 6 in. 6 in. 7 < 1.00 , 6 in. 9 in. 9 in. 9 in. 9 in. 4 < 1.25 9 in. 12 in. 12 in. 12 in. 15 in. 2 < 1.50 112 in. 15 in: 18 in. 18 in. 18 in. 2 < 1.75 18 in. 21 in. 21 in. 24 in. 24 in. 1 < 2.00 21 in. 24 in. 27 in. 30 in. 30 in. 1 Table 6a-2: Standardized WQCV Outlet Design Using Circular Openings (2" diameter maximum). US Filter TM Stainless Steel Well -Screen' (or equal) Trash Rack Design Specifications. Max. Width of Opening Screen #93 VEE Wire Slot Opening Support Rod Type Support Rod, On -Center, S acin Total Screen Thickness Carbon Steel Frame Type 9" 0.139 #156 VEE %" 0.31' /8"x1.0"flat bar 18" 0.139 TE .074"x.50" 1" 0.655 %" x 1.0 angle 24" 0.139 TE .074"x.75" 1" 1.03" 1.0" x 1 /2" angle 27" 0.139 TE .074"x.75" 1" 1.03" 1.0" x 1'/2" an le 30" 0.139 TE .074"x1.0" 1" 1.155" 1 /4"x 1 Yz" angle 36" 0.139 TE .074"x1.0" 1" -T. 155" 1 /4`x 1'/z" angle 42" 0.139 TE .105"x1.0" 1" 1.155" 1 /4"x 1'/z" angle US Filter, St. Paul, Minnesota, USA DESIGN EXAMPLE: Given: A WQCV outlet with three columns of 5/8 inch (0.625 in) diameter openings. Water Depth H = 3.5 feet above the lowest opening and 2'-4" feet below the lowest opening. Find: The dimensions for a well screen trash rack within the mounting frame. Solution: From Table 6a-1 with an outlet opening diameter of 0.75 inches (i.e., rounded up from 5/8 inch actual diameter of the opening) and the Water Depth H = 4 feet (i.e., rounded up from 3.5 feet) above the lowest perforation. The minimum width for each column of openings is 6 inches. From Fig's 4 and 5, the total width of concrete opening is W,on,. = 2x3" + 6" = 12 inches. Total minimum height of the rack structure (adding 2-feet below the lowest row of openings and adding a total of 2 inches for top and bottom support channel flanges (i.e., 3'-6" + 2'-0" + 2") is 68 inches. Total trash rack dimensions, including the mounting frame, are 14 inches wide x 68 inches high (net trash tack dimensions within the frame are 12 inches wide x 66 inches high). From Table 6a-2 select the ordering specifications for an 18", or less, wide opening trash rack using US Filter (or equal) stainless steel well -screen with #93 VEE wire, 0.139" openings between wires, TE .074" x .50" support rods on 1.0" on -center spacing, total rack thickness of 0.655" and'/" x 1.0" welded carbon steel frame. ' Rev.6-2002 Urban Drainage and Flood Control District SD-10 DRAINAGE CRITERIA MANUAL (V. 3) 10 6. 4. 2. 1.1 d 0.61 t a, 0.4( E m 0.21 U T R 0 0.0E 0.0' 0.0E STRUCTURAL BEST MANAGEMENT PRACTICES I EXAMPLE: DWQ = 4.5 it WQCV = 2.1 acre-feet - — SOLUTION: Required Area per Row = 1.75 in 2 EQUATION: WQCV a= K 40 t t in which, K40=0.013DWO +0.22DWQ -0.10 i/Z 10 t rb i Oe Q�r t Qr 1 -- O� -Z_Z agoam u.u4 U.vb u.iv u.ru U.4U U.6U 1.0 2.0 4.0 6.0 Required Area per Row,a (in.2 ) FIGURE EDB-3 Water Quality Outlet Sizing: Extended Detention Basin (Dry) With 40-hour Drain Time for Capture Volume Rev. 6-2002 S-43 Urban Drainage and Flood Control District ' DRAINAGE CRITERIA MANUAL (V. 3) STRUCTURAL BEST MANAGEMENT PRACTICES Orifice Perforation Details 7.1AJ WPlate — WConc + 6 inches (minimum) Structural Steel Channel 0— Formed Into Concrete, To Conc. �W (see below) Span Width Of Structure. See Figures 6—a, 6—b Circular Openings: WC°ne.Obtained From Table 6a-1 Rectangular Openings: WConc_ = (Width of Rectangular Perforation W) + 12" Rectangular Openings: Wopening (see Figure 6-1b) Obtained From Table 6b-1 S�, see S=, see figure 5 Figure 5 W :-00- : 0 [C) 00 o O OO O 000 0 0 0 0 0OOo o o 0 0 000 o O O O O 000 0 O O O 000 0 0 0 0 0 0 0 o C6 0 Example Perforation Patterns Note: The goal in designing the outlet is to minimize the number of columns of perforations that will drain the WOCV in the desired time. Do not, however, increase the diameter of circular perforations or the height of the rectangular perforations beyond 2 inches. Use the allowed perforation shapes and configurations shown above along with Figure 5 to determine the pattern that provides on orea per row closest to that required without exceeding it. Urban Drainage and Figure 4 Flood Control District Orifice Details for Drainage Criteria Manual (V.3) Draining WOCV File: V3-0utlel Deloilsdwg Figure 4. Orifice Details for Draining WQCV. Rev. 6-2002 SD-6 Urban Drainage and Flood Control District STRUCTURAL BMP DETAILS DRAINAGE CRITERIA MANUAL (V. 3) Orifice Plate Perforation Sizing Circular Perforation Sizing This table may be used to size perforation in a vertical plate of riser pipe. Hole Dia. (in.) Hole Dia. (in.) Min. S, (in.) Area per Row (sq. in.) n= 1 n= 2 n= 3 1/4 0.250 1 0.05 0.10 0.15 5/16 0.313 2 0.08 0.16 0.24 3/8 0.375 2 0.11 0.22 0.33 7/16 0.438 2 0.15 0.30 0.45 1/2 0.500 2 0.20 0.40 0.60 9/16 1 0.563 3 0.25 0.50 0.75 5/8 0.625 3 0.31 0.62 0.93 11/16 0.688 3 0.37 0.74 1.11 3/4 0.750 3 0.44 0.88 1.32 13/16 0.813 3 0.52 1.04 1.56 7/8 0.875 3 0.60 1.20 1.80 15/16 0.938 3 0.69 1.38 2.07 1 1.000 4 0.79 1.58 2.37 11116 1.063 4 0.89 1.78 2.67 11/8 1.125 4 0.99 1.98 2.97 13/16 1.188 4 1.11 2.22 3.33 11/4 1.250 4 1.23 2.46 3.69 15116 1.313 4 1.35 2.70 4.05 13/8 1.375 4 1.48 2.96 4.44 17/16 1.438 4 1.62 3.24 4.86 11/2 1.500 4 1.77 3.54 5.31 19/16 1.563 4 1.92 3.84 1 5.76 15/8 1.625 4 2.07 4.14 6.21 111/16 1.688 4 2.24 4.48 6.72 13/4 1.750 4 2.41 4.82 7.23 113/16 1.813 4 2.58 5.16 7.74 17/8 1.875 4 2.76 5.52 8.28 115/16 1.938 4 2.95 5.90 8.85 2 2.000 1 4 3.14 6.28 9.42 n = Number of columns of perforations Minimum steel late thickness 1/4" 1 5/16" 3/8" Designer may interfere to the nearest 32 no inch to better match the needed area if desired. Rectangular Perforation sizing Use only one rectangular column whenever two 2;inch diameter circular perforations cannot provide needed outlet area. Rectangular Height = 2-inches Rectangular Width = Required Area per Row / 2" Rectangular hole Width Min. Steel Thickness 5" 1/4 " 6" 114 " 7" 5/32 " 8" 5/16 " 9" 11/32" 10" 3/8 " >1O" 1/2" Figure 5-WQCV Outlets Orifice Perforation Sizing. SD-8 Rev. 10-2005 Urban Drainage and Flood Control District DRAINAGE CRITERIA MANUAL (V. 3) STRUCTURAL BEST MANAGEMENT PRACTICES C8a18.75 American Standard Structural Steel Channel. Trash Pock Attached By Welding 3or4 1f— H Varies C 2'-0" U.S. Filter' Stainless to Steel Well -Screen 6'-0" (or equal) Per Tables 6a-1. 6a-2 Micro Pool W.S. C8x18.75 American Standard Structural 2•-4 Steel Channel Formed Minimum Into Concrete Bottom And Sides Of W, . Trash Rack Altachetl .Il By Intermittent Welds. Boll Down or Lock Down / Tubular rash Rack —i On 6" - - 4 Centers Section A —A. Rack Swivel Hinge Optional Flow Control Orifice Plate Sleet Perforated Flow Control Plate 4.. I Outlet Pipe 18" Min. 3" Minimum From Figure 6, Circular Openings Only Well -Screen From Attached To Chann By Intermittent Weld Steel Perforated Flow Control Plate W� I Flow Trash Rack Attached By Intermittent Welding All Around 6' Min. Section B—B — Plan View From Figure 6, Circular Openings Only Limits for this Standardized Design: 1. All outlet plate openings are circular. 2. Maximum diameter of opening = 2 inches. 'U.S. Filter, St. Paul, Minnesota, USA Urban Drainage and Flood Control District Drainage Criteria Manual (V.3) Fae: V3-0uuet oeloas.o«g Stainless Steel Support Bars No. 93 Stainless Steel (U.S. Filter' or Equal) Wires Flow �- 0.139" 0.090" Section C—C From Figure 6, Circular Openings Only R Value = (net open area)/(gross rack area) = 0.60 Figure 6—o Suggested Standordardized Trash Rack and Outlet Design For WOCV Outlets With Circular Openings Figure 6-a. Suggested Standardized Trash Rack and Outlet Design for WQCV Outlets With Circular Openings. Rev. 6-2002 SD-9 Urban Drainage and Flood Control District I Proposed Pond 100-yr Event, Outlet Sizing LOCATION: Summit Hall ' PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffman DATE: 7/18/2006 Submerged Orifice Outlet: release rate is described by the orifice equation, ' Qo = C,A, sqrt( 2g(h-Eo)) where Qo = orifice outflow (cfs) Co = orifice discharge coefficient ' g = gravitational acceleration = 32.20 fUs Ao = effective area of the orifice (ft`) Eo = greater of geometric center elevation of the orifice or d/s HGL (ft) h = water surface elevation (ft) Qo = 0.40 cfs outlet pipe dia = D = 15.0 in Invert elev. = 5019.60 ft (inv. "D" on outlet structure) ' E. = 5021.45 ft (downstream WSEL for existing pond) h = 5023.50 ft - 100 yr WSEL Co = 0.65 ' solve for effective area of orifice using the orifice equation Ao = 0.054 ft` = 7.7 in` orifice dia. = d = 3.13 in ' Check orifice discharge coefficient using Figure 5-21 (Hydraulic Engineering) d/ D = 0.21 kinematic viscosity, v = 1.22E-05 ft2/s ' Reynolds no. = Red = 4Q/(rcdv) = 1.60E+05 Co = (K in figure) = 0.65 check ' Use d = Ao = Qmax = 3.13 in = 0.053 ft` _ 0.40 cfs 3 1/8 in 7.69 in ` ' orifice - 100yr, Drainage and Pond Existing Pond 100-yr Event, Outlet Sizing Modification LOCATION: Summit Hall ' PROJECT NO: 05-036.05 COMPUTATIONS BY: A. Kauffman DATE: 7/18/2006 ' Submerged Orifice Outlet: release rate is described by the orifice equation, ' Qo = C,A, sqrt( 2g(h-E,)) where Qo = orifice outflow (cfs) Co = orifice discharge coefficient g = gravitational acceleration = 32.20 ft/s Ao = effective area of the orifice (ft`) Eo = greater of geometric center elevation of the orifice or d/s HGL (ft) ' h = water surface elevation (ft) ' Qo = 1.34 cfs (0.94 cfs previous report release rate + 0.4 cfs additional release to pa: outlet pipe dia = D = 15.0 in Invert elev. = 16.81 ft (inv. "D" on outlet structure) Eo = 17.34 ft (downstream HGL for peak 100 yr flow - from FlowMaster) h = 21.45 ft - 100 yr WSEL Co = 0.65 ' solve for effective area of orifice using the orifice equation Ao = 0.127 ft` = 18.2 in` orifice dia. = d = 4.82 in ' Check orifice discharge coefficient using Figure 5-21 (Hydraulic Engineering) d/ D = 0.32 kinematic viscosity, v = 1.22E-05 ft2/s Reynolds no. = Red = 4Q/(ndv) = 3.48E+05 Ca = (K in figure) = 0.65 check ' Use d = Ao = Qmax = 4.81 in = 0.126 n` 1.33 cfs 4 13/16 in 18.17 in ' orifice - modification, Drainage and Pond Worksheet Worksheet for Circular Channel Project Description Worksheet Proposed Pond C Flow Element Circular Channel Method Manning's Formu Solve For Channel Depth Input Data Mannings Coeffic 0.013 Slope 007000 ft/ft Diameter 15 in Discharge 0.40 cfs Results Depth 0.23 ft Flow Area 0.2 ft' Wetted Perime 1.11 ft Top Width 0.97 ft Critical Depth 0.25 ft Percent Full 18.4 % Critical Slope 0.005372 ft/ft Velocity 2.58 ft/s Velocity Head 0.10 ft Specific Energ 0.33 ft Froude Numbe 1.14 Maximum Disc 5.81 cfs Discharge Full 5.40 cfs Slope Full 0.000038 ft/ft Flow Type supercritical Project Engineer: The Engineering Company f:\...\eng data\culverts.fm2 The Engineering Company FlowMaster v6.1 [614o] 07/19/06 09,44:43 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1 Worksheet Worksheet for Circular Channel Project Description Worksheet Existing pond out Flow Element Circular Channel Method Manning's Formu Solve For Channel Depth Input Data Mannings Coeffic 0.013 Slope 003000 ft/ft Diameter 15 in Discharge 1.34 cfs Results Depth 0.53 ft Flow Area 0.5 ft' Wetted Perime 1.78 ft Top Width 1.24 ft Critical Depth 0.46 It Percent Full 42.7 % Critical Slope 0.005273 ft/ft Velocity 2.68 ft/s Velocity Head 0.11 ft Specific Energ: 0.65 ft Froude Numbe 0.74 Maximum Disc 3.81 cfs Discharge Full 3.54 cfs Slope Full 0.000430 ft/ft Flow Type 3ubcritical Project Engineer: The Engineering Company f:\...\eng data\culverts.fm2 The Engineering Company FlowMaster v6.1 [614o] 07/19/06 09,44,53 AM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1 J Ico N }o�O O O QIO O N N O N m y 7 LO O c> O c0 2 to� = —°y c•N �i- �-N�- 3 � N Q O O N c O N a co oa �� 0 O o E Qa cLo 0 N O 0 0 R C O O U N -C O N N tK C y Y O y y 'Q m :t: .y N a r w a O c a� 2 0 O co -a c O U > N N a C . C N O @ w U z C O O y O U C o a)o 0 0,m r E @ 3 3 `o m m m 0 LO o a m ��ir d QUU u u u > a ct cc C c c .o 0 U Q ~ ) O (D OJ o c �L 0� CL V R = C C E c V] C J IO O N O O N -= w N O N 6 u C � l0 ++ N N (O M � �^, v 11 ± � � � J Z 11 O r � O � Q N C 0 E O L n $ G I, r) a �l�QQN M, A'� L6O r N T U N M ON O U7 _ > > Q L 42) N ci N O (a O O U. R a a m y CO 9 O M O N c C (0 L U C C co N C O a c o p U N C a) N c L _O i O cu o o 3 U > N w N C c N criN C N f0 O U� O c N N i (6 a 0 0 c 0 0 7 o Na) a")U r 0) o 0 LL CU co In 34�- cLi m 3 4-� rn 'p 'Ip O O Lo @ II @ r--: ui Q � II U II II II II O 3 w c co Q) U :� p L W o � Li G J IC +t+ p In00 a J 0. M C Di O O ` O M N _Q a c 0 a M a� rn m c 0 9 9 I NOTES: 1. THE CITY OF FORT COLLINS STORM WATER DEPARTMENT EROSION CONTROL INSPECTOR MUST BE NOTIFIED AT (EAST 24 HOURS PRIOR TO ANY CONSTRUCTION ON THIS SITE. POND SUMMARY TABLE DRAINAGE SUMMARY TABLE 2. ALL REQUIRED PERIMETER SILT FENCING SHALL BE INSTALLED PRIOR TO ANY LAND WOCV KCVD = 0.02 AC -FT BASIN AREA(a,) CA GIN Bayp Ie'u9ND ! M 9ANWN DISTURBING ACTIVITY (STOCKPIUNC, STRIPPING, GRADING, ETC.) ALL OTHER REQUIRED WOLY PROVIDED = 0.02 AC -FT HISTORIC 1.22 U.20 0.25 16.2 15.7 0.M 1.9 EROSION CONTROL MEASURES SHALL BE INSTALLED AT THE APPROPRIATE TIME IN THE 100 YR MENTION VOLUME REQUIRED = 0.17 AC -FT PROPOSED I.22 0.53 0.67 11.1 9.2 1.4 63 L CONSTRUCTION SEQUENCE AS INDICATED IN THE APPROVED PROJECT SCHEDULE. TOTAL VOWME PROVIDED = 0.20 AC -FT CONSTRUCTION PLANS, AND EROSION CONTROL REPORT. IN YR RELEASE KITE = 0.4 CPS '�^��+>•.���..�..�-�. _,�,�_ .�-_ V ORIFICE DIAMETER 3. PRE-DISTURBACE VEGETATION SHALL BE PROTECTED AND RETAINED WHEREVER IN YR WSEL = 5023.5 ---- -- --- - --- -3UILD _ POSSIBLE. REMOVAL OR DISTURBANCE OF EXISTING VEGETATION SHALL BE LIMITED TO THE SPILL ELEV = W24.0 -f-B AREA REQUIRED FOR IMMEDIATE CONSTRUCTION OPERATIONS. AND FOR THE SHORTEST PRACTICAL PERIOD OF TIME. TES d 2' CGNC IEwY%YEMofWAtll� �� „LY \ 1 V� �- X. ALL SOILS EXPOSED DURING LAND DISTURBING ACTIVITY (STRIPPING, GRADING, UNLLTY TO E%ST PAI Ly ----- IXSTALLATIONS, SOCKPILING, TILLING. ETC.) SHALL BE KEPT IN A ROUGHENED WND910N -- -- -- ---- -- x BY RIPPING OR DISKING ALONG LAND CONTOURS UNTIL MULCH, VEGETATION, OR OTHER �yUP PERMANENT EROSION CONTROL IS INSTALLED. NO SOILS IN AREAS OUTSIDE PROJECT I\i j!wV eyi 9T J1ai STREET RIGHTS OF WAY SHALL REMAIN EXPOSED BY LAND DISTURBING ACTIVITY FOR MORE THAN THIRTY (30) DAYS BEFORE REQUIRED TEMPORARY OR PERMANENT EROSION CONTROL t --- ---- /-'{L (E.G. SEED/MULCH, LANDSCAPING, ETC.) IS INSTALLED, UNLESS OTHERWISE APPROVED BY I I \ \./-B"DI F�LWE § ! / !� LINNva T4 BSnS THE STORM WATER DEPARTMENT. ��� \ `\ ! It .'� LL I rvl S. THE PROPERTY SHALL BE WATERED AND MAINTAINED AT ATINES DURING § ��� \� � � CONSTRUCTION ACTIVITIES SO AS TO PREVENT WIND -CAUSED EROSION. ALL LAND..� DISTURBING ACTIVITIES SHALL BE IMMEDIATELY DISCONTINUED WHEN FUGITIVE DUST` �___---tea\- �\ \ -� ��-��_�_-_� •� -- _ _ ___ IMPACTS ADJACENT PROPERTIES, AS DETERMINED BY THE Cltt OF FORT GOWNS \ �� ~ ENGINEERING DEPARTMENT. / 6. ALL TEMPORARY (STRUCTURAL) EROSION CONTROL MEASURES SHALL BE INSPECTED \ \ \\ AND REPAIRED OR RECONSTRUCTED AS NECESSARY AMR EACH RUNOTF EVENT IN C ORDER \ TO ASSURE CONTINUED PERFORMANCE OF THEIR INTENDED FUNCTION. ALL RETAINED ¢ - SEDIMENTS. PARTICULARLY THOSE ON PAYED ROADWAY SURFACES, SHALL BE REMOVED b \ 5 ECNN: VAULT AND DISPOSED OF IN A MANNER AND LOCATION SO AS NOT TO GUSE THEIR RELEASE \ I '1 INTO ANY DRAINAGE WAY T. NO SOIL STOCKPILE SHALL EXCEED TEN (10) FEET IN HEIGHT. ALL SOIL STOCKPILES1\\\\ u 11/ SHALL BE PROTECTED FROM SEDIMENT TRANSPORT BY SURFACE ROUGHENING, WATERING, AND PERIMETER SILT FENCING. ANY SOIL STOCKPILE REMAINING AFTER 3O DAYS SHALL BE \\ 15' RCP STORM DRAIN SEEDED AND MULCHED. \ SEE SHF CIS FOR PUN I X 6. CITY ORDINANCE PROHIBITS THE TRACKING. DROPPING, OR DEPOSITING OF SOILS OR EXISTING PARIONG LOT \\ ` \ �� \\ ANC PROPI ANLE ANY OTHER MATERIAL ONTO CITY STREETS BY OR FROM ANY VEHICLE. Y INADVERTENT ANi \ \ DEPOSITED MATERIAL SHALL BE CLEED IMMEDIATELY BY THE CONTRACTOR. \ �V § mi ALIE rm I k :oil \ \ twl' ni I I _1411- d § vLw ss \ ;'Ei ✓ I EuDID c IIAL 1 0 1020 SO ® \ % LN � I_ Scal. 1 = 20 EX w7.43 \ I I EX w2R61� uri I -RECALL3a Damn ��6-� d � ` � rl ---{. _ � EX xz2a Ex &ELIM:MEN I I, LEGEND x IX Wa.3 aDIED.'A \��� ' \I_ I1_-- \ IX3M2� ma.eo q ■ Ea MEASIN BOUNDARY Y\\a DID Y ` `d _I I i I I I .. I I `I Ati�xu. I _ +PI ) FLOW ARROW I I P bOPnOIA9 _ vt- y�_�-iYs - ` /- _ - _ ` - _ _ _ _ __69r Ex ¢1 bP E mselbo �...i �NRR;aR' � Ex eaPal� � BASIN 10 law \ _ I I - I ZI ZZZ HI m'� .� �. _�{�-w r z-��z-.r.l %.X% Y.Y COEFFICIENT FI RUNOFF ■ I COEFFILIENi ■ GRCH ADE A \ / / 1. ' , =4 �C I BASIN AREA (00) GRADE BREAK, > i-UpPTJi3 veo / / I .�I d GMEROUTFLOW WRB 3m w -I /x ' � / / I I I SF SILT FENCE JYM 1 W1T.6E :� ( Y o5T� I 4 Aoo HIGH PT SENSE. .M >DT.s V A umm I i I 503\ N SO2U041D ORAOE B { ST SEDIMENT TRAP "':TA,..•� FAS•]!T!T tr 5• it IJ.:h11. 1 ALL,f ,:� I x I _ _ _ _ - - _ - 1 - - I - - - - _ - - _ _ ` � � VTC VEHICLE TRACKING Aty ¢wcN'i 1 Y I CONTROL \ \ wmn \\ 3' L'ONC vALLEr I \ so I' PAN l OUMIJORN CURB 1 " °U^s" CITY OF FORT COLLINS, COLORADO UTILITY PLAN APPROVAL PROVED \ 1 n � -_ CNY fX41NCfR 5019. ~ I �A CHECKED BY: I\ LY2 0.0 1 DETENTION PoND \ f 1 $T EMO.BB� I SST WATER AND SLIVER NI \' `LAAAXE \\ �� ) 1 •„ I CHECKED BY: TRIBESI___ 1 _ __ __-- n - -�I' 9r0RU WATER Umm - *X� \X x -x-xi'z-z-z-X-z-z z�z-z-z-z�-z�X•�1F�z TzyhzTal s-x�.�XX-•-•-c-a �L-%-s - _ sm-tea 'x-x '- X _*�3X- - �! = uLIL d _ Iv IBc NEW -wlce tHa I Ln 2 BGAFD rTNEE d 1r xMlsE I g III- aAw�uxX TFxa SLOPE Po 0 SEE WATER QUALITY Ig BOTTOM O u STRUCTURE A SHEE1 CB - E: 2005 Pr09UM 05035.05 CIO DRAINAGE PLAN.dwa L6d Saw@ ] 31 2006 10:20 AM AufaCad WT: 16.25 US TECH 7TE� N0. TE REVISION BT / SHEETS SHELL DRARN JWL De31CN60 RRP DATE Mar OB The Engineering Company CSII SU13'IMCI' PAR 'I�B`IG LOT IT NO x L CBECEED RRP 2310P TTRAIAX NOREI, S1dmB FwLCDDID3,CO6Ds25 DRAINAGE &.EROSION CONTROL PLAN ADJu 10 C) SCALE I'=20' APPROVED WHM PROM. NO.05-036 COLORADO STATE UNIVERSITY TBIB s@JH, DTING (rro) a6aTm W W W.TCOaaaR.cDo, scel.es .ccaRDlxGfY