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HomeMy WebLinkAboutDrainage Reports - 02/19/2003Off!1v-7?'.TY OF Final. �veu 1�� -ort FORT CODUNS �' al` Addendum - Final Drainage Report Harmony Ridge First Replat Lots 16-22 and Tract 7 Fort Collins, Colorado January 26, 2003 tMNORTHERN ENGINEERING SERVICES, INC. 11 Addendum - Final Drainage Report Harmony Ridge First Replat Lots 16-22 and Tract 7 Fort Collins, Colorado January 26, 2003 Prepared For Overland Homes 70 Dusty Sage Loop Road Fort Collins Colorado 80526 Prepared By Northern Engineering Services, Inc 420 S Howes Suite 202 Fort Collins Colorado 80521 Phone (970)221.4168 Fax (970)221-4159 Project Number HRO — 01 036 I M NORTHERN ENGINEERING SERVICES, INC. January 26, 2003 ' Mr Basil Hamdan Stormwater Utility ' City of Fort Collins 700 Wood Street ' Fort Collins, Colorado 80521 ' RE Addendum to the Harmony Ridge First Replat Lots 16-22, Tract 7 Fort Collins, Colorado Project Number 01-036 Dear Basil ' Northern Engineering Services, Inc is pleased to submit this Addendum to the Final Drainage Report for Harmony Ridge First Replat, Lots 16-22, and Tract 7 All issues from the design review comment letter dated January 7, 2003 have been addressed We understand that review by the City is to assure general compliance with standard governing criteria This report was prepared in compliance with technical criteria set forth in the Urban Drainage and Flood Control District (UDFCD) Urban Storm Drainage Criteria Manual and the City of Fort Collins Standard Design Criteria and Standard Construction Requirements Manual If you should have any questions or comments as you review thus report, please feel free to contact us at your convenience ' Sincerely NORTHERN ENGINEERING SERVICES, INC Roger A Curtiss, P E 27362 ": Project Engineer : c 1 , h' 'rSlriein�telo � 420 SOUTH HOWES SUITE 202 / FORT COLLINS COLORADO 80521 / 970 221 4158 / FAX 970 221 4159 [1' 1 1 1 1 'ILIRIWD W .ROAD RIE DCE D NE V/ W I 1 Final Drainage Report Northern Engineering Services Inc Addendum Harmony Ridge Fast Replat January 26 2003 Addendum to the Final Drainage Report for Harmony Ridge First Replat, Lots 16-22, Tract 7 Fort Collins, Colorado January 26, 2003 This addendum is necessary due to changes in the building layout along Dusty Sage Court Nine buildings will be constructed rather than the seven buildings shown on the approved plan The resultant unit count does not change from the original plan (36 units) However the imperviousness of three sub -basins, B2 B5 and C 1, does increase as a result of this change In addition the layout of the revised building requires that the storm sewer alignment be changed to avoid conflicts with a proposed building Table 1 below summarizes the change to the runoff coefficients for affected the sub -basins Table I - Runoff Coefficients Sub Basin C2 TST C2 New B2 078 082 B5 076 081 C1 038 043 The revised storm sewer plan and profiles along with the grading plan are attached for your review The calculations showing how the increased imperviousness was determined are also provided The intent of the design remains the same as noted in the approved report The slopes of the storm sewer pipes provide for a reduction in velocity of the stormwater at the outlet to mmunize erosion potential in the Cathy Fromme Prairie The following assumptions should be noted, • The sub-basm areas are not affected by the changes to the building geometry or layout • The increased imperviousness was divided equally among the three affected sub -basins • The time of concentration is not affected by the changes to the building geometry or layout • Current rainfall IDF curves were used to determine the peak flows Portions of the approved report as well as the original drainage plan are attached for your convenience Please note that we found an error in the peak flow calculations for the design point at the end of Dusty Sage Loop (DP 14) The wrong intensity was used for the 100-year storm (7 0 iph when it should have been 9 0 iph) The revised calculations include a correction to this error The correction did not affect the design The increased imperviousness increased the peak flow to the existing mlet at DP 14 to 13 93 cfs The existing inlet is adequate for the expected flow Prod No 01 036 Northern Engineering Services Basins By meo Harmony Ridge 1 4/17/2002 The following basins are affected by the changes to the budding ion Dusty Sage i Basin Area ac Note 1 C2 Note 2 % imp pervious Note 3 % pervious Note 3 C2 Note check Notes 4& 5 New C2 62 1 ill 0781 75 251 0 775 6 0 82 65 140 0761 73 27 0 761 7 0811 C 1 7431 0 38 18 82 0 376 8 0 43 Total 9941 Notes ' 1 Basin designations and Areas per drainage and erosion control plan and report by TST dated 1/20/1999 titled Final Drainage Report for Harmony Ridge P U D ' 2 C2 TST taken from Table 1 Hydrologic Calculations worksheet in report by TST 3 % impervious and % pervious taken from pages 4-5 of Appendix A in TST report 4 Impervious was assumed to have a C value of 1 0 95 per TST report 5 Pervious was assumed to have a C value of 0 25 per TST report ' 6 Contributes flow to open space east of units 7 Contributes flow to existing storm sewer inlet @ DP 14 on TST plan 8 Contributes flow to open space west of units Budding Count TST plan Buddinq Units SF Total 1 36 50976 Area of Each Unit on TST plan 64x18+44x6 equals 1416 sf Budding Count - Revised Plan Budding Units SF 1 4 9110 2 4 9110 3 4 9110 4 4 9110 5 4 9110 6 4 9110 7 41 9110 8 41 9110 91 41 8956 Total 1 361 81836 Areas of revised units taken from the plan prepared by Northern Engineering Services Increase in Impervious Area = 30860 sf affecting sub basins B2 B5 and C1 Assume increase in Imperviousness is shared equally by all basins Basin Area % of total Additional Addt I % ac Imo Imn B2 1 11 11% 3446 7% B5 1 40 14%1 4346 7% C1 7431 75%1 23067 7% Page 1 of 3 ' Prot No 01-036 Northern Engineering Services Basins By meo Harmony Ridge 4/17/2002 I 1 1 Assume Time of concentration not affected by revised building layout Assume basin areas are not affected by revised budding layout New New New Basin Area % imp % C2 ac pervious Dervious B2 1 11 82% 18%1 0821 B5 140 1 800/6 20% 0 81 C1 7431 25%1 75% 0 43 Note No additional design required for sub -basins B2 and C1 since flows are overland into open space Peak flows from TST report Time of Concentration 2 yr 100 yr min min 662 445 DP Area C2 C100 Intensity (iph) Qpeak (cfs) 2-yr 100 yr 2-yr 100 yr ac 14 140 0 76095 30 70 3191 931 Original Inlet Design Opening (h) Q100 = Theoretical Capacity Reduction Factor Required Length = 0 5 ft Depth of Water (yo) 0 5 ft 931 cfs yo/h = 1 1 1 cfs/ft from figure 5 2 085 per City of Fort Collins 9 96 ft say 10 feet Note The Intensity for the 100 year storm with a Tc of approximately 5 minutes is greater than 7 0 Revised TST Peak flows to show the correct intensifies DP Area C2 C100 Intensity (iph) Qpeak (cfs) 2 yr 100 yr I 2 yr 100 yr ac 14 140 0 761 0951 301 90 3191 1197 Corrected design Opening (h) 0 5 ft Depth of Water (yo) 0 5 ft Q100 = 11 97 cfs yo/h = 1 Theoretical Capacity 1 1 cfs/ft from figure 5 2 Reduction Factor 085 per City of Fort Collins Required Length = 12 80 ft say 15 feet This designed assumed that the curb would be the high point and be over topped This is not the case the high point is further back on the lot Page 2 of 3 Prol No 01-036 By meo Northern Engineering Services Harmony Ridge Revised Peak flows with revised C factors Time of Concentration 2 yr 100 yr min min 65 5 time of concentrate DP Area I C100 ac rounded to nearest 0 5 minutes Intensity (iph) Q 2-yr 100-yr 2 yr 100-yr Basins 4/17/2002 1 141 1401 0811 1001 261 995 295 ,-Aaz Note Current rainfall IDF values used which were adopted by Ordinance 3/16/1999 Design Design pipe and inlet for Q100 = 13 93 cfs Inlet Design Inlet installed already 10 ft long Opening (h) 0 5 ft Depth of Water (yo) 1 0 ft +/- based on proposed grading yo/h = 2 Theoretical Capacity 2 4 cfs/ft from figure 5 2 Reduction Factor 0 85 per City of Fort Collins Actual Capacity 20 4 cfs existing inlet is adequate Pipe Design Try 115 RCP Isame as approved plan C= 1 64 7 C= 1 486*A*R^2/3/n where n= 0 013 Q = CS^0 5 S = (Q/C)^2 Sreq d = 0 0464 ft/ft Sprovided= I 0 0553 ft/ft slope is reduced downstream to slowdown velocity to reduce erosion @ outlet into Cathy Fromme Prairie Conclude Design provides for same result of approved plan and profile Page 3 of 3 I NENORTHERN ENGINEERING SERVICES, INC. FORT COLLINS COLORADO 80521 PROJECT -JOB NO CLIENT G ���CALCULATIONS FOR MADE BY PYi DATE CHECKED BY DATE SHEET f - -- 2- zz _ T� I �_ � �..rr _ a� Pt_.a.,..► 1� � o �f".4a t 1�� dui a � s � - - - - --- - UK) I TS _ ----� i 74-a- -- - -- -- b- .�►� _ - - -_- - = : �� - _ a 11= � DI STU >✓� .zS aS �P mnn I T't. 4/ __ +I I t I r� G=-= I- 11.1 �- I G-��-5 S>✓=. -0 S I L I NE NORTHERN ENGINEERING SERVICES, INC. 1 November 5, 2002 Mr Basil Harridan Stormwater Utilities City of Fort Collins Water and Sewer Department ' 700 Wood Street Fort Collins, Colorado 80522-0580 ' RE Harmony Ridge Replat Lots 16-22 Response to City comments ' Basil, This letter is in regards to the Harmony Ridge Replat of Lots 16-22, and in particular to ' your comments regarding stormwater improvements This is based on comments we received dated 10-2-02 from Susan Joy, and specifically item 90 The first item is in regards to the severe slopes behind some of the units The gradmg plan has been revised to show 3 1 maximum for any slopes behind the units In those places where we had been showing slopes greater than 3 1, retaining walls have been indicated The second item is regarding an overflow path for the inlet at Dusty Sage Loop 100-year ' peak flows to this inlet were calculated to be approximately 13 93 cfs The high point between units 113 and 114 will beat elevation of 20 6 This section will act as abroad crested weir Using a weir coefficient of 2 7, a length of 20', and Q of 13 93, the low point, 5 feet from the high point should be at elevation approximately 0 40 feet lower, or at an elevation of approximately 20 2 The finished grade at these units is 210 ' The durd item is in regards to the swale adjacent to the bike/pedestnan path east of Dusty Sage Loop The original TST plan shows the swale located within the existing drainage draw, lined with 3' buried nprap protection With the replat a paved path will be placed ' in this natural draw area, with a 1' deep swale next to path I have attached a section that will be incorporated into the plans We calculate that this composite section will have a 100-yr WSEL approximately 1 5' deep, with a velocity of 5 5 fps Please call if you have any questions ' Sincerely, Roger A Curtiss, P E ' 420 SOUTH HOWES SUITE 202 / FORT COLLINS COLORADO 80521 / 970 221 4158 / FAX 970 221 4159 � i■r r r r r � r � � � r �r r� r� r �r �r r FG= 21 8 TF= 22 5 TW= 5 W �� I TW=8 0 g - 1`1 6- W-5 FG= 1 TF= 2 \ W=7 5 BS= �1 1 6 a , #--,21 8 S= O FG= W=7 0 , TF= 21�8 TW=10 5 FG= 21 C B �7 5 - -- — - -- - •Z ' BS=- 1 1 5 TF= 21 7 - _ O FG= 21 0 -'-- -BS= 10 8 W TF=-21-7- BS= 10 8 FG= 20 3- FG= 20 3- - TF=�21 0 TF= 21 0 WO o TA/RI\\ rr �r �r r� ■r �r r r it r� r r� r� r r r r� r r 5115 II TF= 22 3 I TW-2 © Bw=1 \ \ 1 \ II \ \ \ 1 I TF= 1\ 22 3 © \ \ 14 TF= 22 P1 bc FG = 21 \ \ + TF= 22 3 -\123 FG= 2118 /TF= 22 5` W \ r / l' BS=/ 1\1 5, FG= 21 0 / rl TF =� 2 t 7 BS= 1f1 5 FG= 21 0\ / I I TF= 21, 7 i BS= 115 it v i ' PROJEC P-4D6pMB NO ! 1 1 CLIEN � — A� �CALCULATIONS FOR MADE BY_P!!Ild DATE CHECKED BY DATE SHEET OF FORT COLLINS COLORADO 80521 — _ I - I 1 I f / i I 1 � -.-11T-�11 ti �' I i iT$Qli I iF r r� 'r T i- I -'1- - - - -- I----+-�-� - -} i --� - -I - - I I 1- - --`T`rPIC�„1_ SrEc�7o►.6_ � ,-�- �� 1-= I - �-' 1 - - I!(I I �- ---1- '- - 1 L I I I — I - -- L r l l 1 Q= She a%- ---- T 1 Q►�+ 3a% �sl f ( I 1 r IUd ye�;--- 1 rr S 4jsp . s l l ' I IIl ' Channel east of Dusty Sage Worksheet for Irregular Channel Project Description ' Project File c \haestad\fmw\profect1 fm2 Worksheet Harmony Ridge East of Dusty Sage Court Flow Element Irregular Channel Method Manning s Formula Solve For Water Elevation 1 Input Data Channel Slope 0 040000 ft/ft Elevation range 93 40 ft to 100 00 ft ' Station (ft) Elevation (ft) Start Station End Station 000 10000 000 1500 1500 9500 1500 4500 ' 4500 9440 4500 7700 4900 9340 5300 9440 t 5700 9540 7700 9740 ' Discharge 7564 cfs Results ' Wtd Mannings Coefficient 0 030 Water Surface Elevation 9487 ft Flow Area 1389 ft2 t Wetted Perimeter 3396 ft Top Width 3365 ft Height 147 ft ' Critical Depth 9502 ft Cntical Slope 0 013924 ft/ft Velocity 545 ft/s Velocity Head 046 ft ' Specific Energy 9534 ft Froude Number 149 ' Flow is supercritical '11/19/02 11 14 54 AM Haestad Methods Inc 37 Brookside Road Waterbury CT 06708 (203) 755-1666 1 Roughness 0 060 0 016 0 060 FlowMaster v5 13 Page 1 of 1 1.0 .9 .8 7 Ur L" f- w w U. .4 z r co z_ z .3 w a 0 2 15 12 i1 10 II LL s B 10 6 LL 9 0 4 a a 0: 3 i w z L . '� 2 Cs/ ° ci 7 Por1� , L5 1f 1e, � Exorn..� z r - z Ex 1.0 a 1'0 z - ---.8- w 5.5 a --- o- ui .6 w 5 i z 0 0 z .4 F ? w = 4.5 z ao 3 - w w _ 4 0 ,2 0 _ ~ z f z o 3.5 z z w w a .I o „JI 0 0 .08 0 .06 x 0 0 _z w o .04 2.5 = w w a .03 H } a r 3 a .02 0 a = 2 a X U a w .01 o L w 0 0 -� Yo 1.5 --- -- - -- -- < I -- 1.2 5 4 3 7 1.5 1.0 .9 .8 .7 .6 .5 .4 .3 .25 .2 Figure 5-2 NOMOGRPAH FOR CAPACITY OF CURB OPENING INLETS IN SUMPS, DEPRESSION DEPTH 2" Adapted from Bureau of Public Roads Nomograph MAY 1984 5-10 DESIGN CRITERIA FINAL DRAINAGE REPORT FOR HARMONY RIDGE P U D Submitted to CITY OF FORT COLLINS January 20, 1999 FIGURE 1 VICINITY MAP SCALE 1 = 2000 2 ' velocities to the minimum practical value (there is nearly 65 feet of fall across this basin) so that the existing eastern dramageway could be maintained in as natural a state as possible ' Basin B is approximately half the size of Basin A and also discharges to the existing eastern dnangeway at two locations Runoff from this basin is collected entirely from low points in the streets and conveyed directly to the existing dramageway via storm sewers Although it was not practical to route this basin through the water feature/quality ponds we were able to design the storm sewer outlets to reduce the flow velocities to manageable levels, again to provide as much ' protection to the existing dramageway as possible Basin C represents the western existing dramageway At this time there is only a small portion of ' Subbasin C1 that will be developed although it is possible that a future addition to this site could be extended into this area A water feature/quality pond is being installed in this subbasin but given the limited amount of development currently planned upstream this pond will serve ' pnmanly as a feature The results of the Rational Method Hydrologic Analysis can be found in Table 1 with the ' methodology of calculations shown in Appendix A Table 2 shows the results of the runoff attenuation described previously 1 1 1 31 0 J TABLE 1. HYDROLOGIC CALCULATIONS WOR1611EET 'MN AR UI ai sh §IW. "E N�IVD; VOVI4' UTTE'lc I� W Al 1 0.44 L00 1.25 100 23.00 530 270 120 A2 A3 A4 2 2 3 19 -i 10- 0.85 0.74 1.00 1.00 1.00 1.25 1.25 1-3 - 20 40 -2---- .00 10.00 5.00 1.34 1.41 2.71 0.54 0.68 1-59 0.71 AS 3 0.56 0.71 1.00 1.25 1.23 1.23 3-0 15 - 35 -3 .00 2.00 3.00 2.78 0.96 4.0% 1.49 -L-5 -I 0.38 520 - 430 590 A6 2 0.95 1.00 A A7 4 1-19 0.57 1.00 AR 10 0.32 0.60 1.00 1.25 - 1.25 1.23 35 50 50 20-W- L2-.00 4.50 2.06 2.97 4.02 2.99 1.44 2.11 430 65 30 - A9 - 5 -- IT43- 0-59 1.00 1.00 0 -1]- -7 -0(o -6--2-2 -O.Iii- -1.00 1.25 . .......... . . . 0 20.00 1.01 2.82 0.66 0 Al2 0.40 0.57 1-00 1.25 1.25 4-0 35 - 6.50 2.00 2.00 3.00 ---- 3.39 2 N 5 .92 2.47 1: � 120- 4.07 0 0 220 580 960 A13 -TI -4 9 0,50 - 0.78 1 14 0.78 ::00-00 1-25 33 80 35 1-25 - 1.25 131 II 13-7 0.60 -100 02 12 1.11 0.79 " `0 -100 3 -3-1 134 11 1.42 0-77 1.00 1.25 30 5.00 M.uu 2.09 0.91 580 D5 13 14 1.09 1.40 0.74 0.76 1.00 1.00 1.25 1.25 35 5-00 300 2.00 6.50 1 1.70 52 2.99 16.23 0.71 1.23 �13 2 14. 9 - 920 900 930 360 c CA C2 21 1-5 4- 33 --i-29- 038 0-25 -1 .00 1 .00 1-25 1.25 C3 C4 6 17 178 0-20 020 - I.00 1.25 -- 430 13.33 11.63 11.71 15.53 10. 5 14.67 230 00 1.23 Soo 200 9.71 6.50 17.77 9.13 - 16.79 �74 9 220 250 0 DI D2 31 32 - 084 0.64 0-46 0.90 1-00 1.00 1.25 1.25 D D-3 D4 33 -50 -0- .60 -7�. -3s 1.00 1.25 35 ISO 8.00 10.00 1.67 0.56 �37 360 IM 34 3-5 0.14 (F2-g -0 .49 .00 1.00 1.25 1.25 25 25.00 5.36 2.42 5 2.14 60 D6 D7 36 6.-14 -0 .95 1.00 - 1.25 70 25 2.00 2.00 7.59120 6.07 DR 37 39 0.37 0.28 0.49 0.75 1.00 LVID - 1.25 40 6.50 _116 1.25200 30 2.00 2.85 E EI E2 18 19 0.90 -31 0.20 0.20 1.00 1AM 1.25 Win -3 20 1.85 0.20 1.00.25 280 6 70 230 �30 0 TST. INC. CONSULTill ENGINEERS � b TABLE 1. HYDROLOGIC CALCULATIONS WORKSHEET Vr'ii'S 1 j IN 0ilN n 1� IP ;i, a dAY�RAG,&il hy�y tt y7TF i f CONCGNTRATIONg ))A RAS?N A. AI A2 2 5.50 3,70 3.84 5.48 2.30 0.82 6.68 2.16 5.95 AJ A4 2 3 4.16 2.12 5.91 4.15 0.34 2.09 1.75 4.80 1.36 L03 AS ne 3 2 2.20 4.00 4.23 5.70 1.70 1,73 0.48 2.59 3.57 3.21 A AJ AR - 4 10 350 6,67 7.07 4.23 2.34 0.26 6.42 2.30 A9 5 20.00 7.33 0.07 2.3I 3.04 1.70 1.70 A10 Al 6 7 0.00 0.00 0.00 0.00 0.00 0.00 4.02 2.18 2.82 Ail R 0.00 0.00 2.21 0.00 1 1.01 3.38 0.66 2.47 A13 9 0.60 A14 9 1.00 2.85 .66 3.39 4.49 6.21 2.76 4.49 UI 11 2.30 4.15 4.13 3.85 9.67 T93 U2 12 2.10 U 13 20 .. 4.51 .3 3.03 4.42 4.73 3.1561 7.74 UDdS 1 400 . 4.28 2.63 3.63 5.15 3.864 _ 6.62 4.95 C CI C2 21 15 9.00 4.JS 4.92 3.42 1.22 17.45 15.31 C7 C4 IG 17 4.55 3.50 I.12 LOS 12.83 16.59 11.97 15.72 4.00 3.29 1.27 19.05 18.06 -flbi- 31 32 0.00 3.33 0.00 5.20 0.00 9.13 7.49 D 33 J4 ).00 2.84 1.15 0.35 2.R2 3.71 L11 4.10 15 0.00 2.00 0.00 2.32 0.0o 0.86 z.az 2.14 D7 36 37 JR 18 19 2.30 2.00 I.IS 5.71 4.35 4.IS 2.32 329 3.92 /.44 I.09 0.12 6.46 2.22 533 3.94 8.95 6.93 0.64 4.35 2.41 8.47 DR El E2 I> E73 20 3.7J 2.99 2.99 1.12 1.67 13.58 14.SS 1-- 2.93 13.83 TST, INC. CONSULTING ENGINEERS TABLE 2. SUMMARY OF A1TF,NUATIi) RUNUFF d',5 �,"I'M .1 .!" I4^Il�f�y�ll �r�i lRAN ��"'lA°i�lh tf Ai AI�A•ai'�K. I • ,rEA1Cm41.11AI1r.Fgy. n\\1N ni•Ci'<I`7* IrnNP W�rr�)NYui��UTI :�� •bi�nnA.a'. � VQ„I��1:. •y All - Ail A1A 1.30 0.50 1.61 0.71 Im 0.71 IAO 0:71 1.5 1.5 1.5 1.5 6.21 1.4t _6.21 _].JA J.)A /,03 6.2i 6.43 4.A0 6.21 fi.13 LA6 6.42 216 6.12 6.Gt 6.63 J.13 .J.I6. 6.62 9.67 9.67 9.G7 17.15 17.45 . 19Os . wlii - 4.49 2.76 4.49 3A7 2.97 7.R 4.49 5.J3 J.37 e,ev 5..17 ).57 - --3I j 1.1G 3..12 5.95 4.95 l:Afi 1 95 7.93 7.9] 797 1531 15.7I I A06 Lss 153 6.93 6.9J 6.93 1.71 6. I 12I7I22S.14191)710 1J.1J -'-J.� 3.30 1.1A1 J.)n t30 )3J0 J.00 L95 JJn J.IA1 2.9,t J.N z93 3.10 2.95 J.00 J.00 3_I0 7_16 3.00 255 255 2ll,21 z0 bJI I90 7J0 2.70 270 123'6.75703 J0 2.7r3PASWO j 10 Y 7.0A 7.011 7.M 7.00 7.00 7,00 7.00 TOO 7011 7.IIf1 ],IAI 7.IIn 7m 7.00 7.11p 7.011 7.(q 7,00 7.M 7.00 7.M 700 tOD 5'90. 3.90 590U 5.50 7. O(m 7.0 7.O112 7.00 7.OpJ 7.0 7.0 472M 2 G'10 6�0 j 2.67 119 -___ .7.AA 0.75 1.22 3.17 fi.57 5.01 7.13 9.03 6.J9 14.74 0.53 15,21 19.30 _3.19 623�t 9.10 11.4 4.10 3.16 . 3 r5 6.79 7.72 9.01 0.60 0.99 . O.SU 171 Lfi9 2.70 3,53Il.11 3.70IA 31.93 211.37 iA,05 i110.3Yj7 wl� 7.79 1.4I ILI9 2.00 3.23 5.75 19.16 5.94 1J.25 30.M 76.75 Ifi.9] ! 71 J. 1 �l 43.12 56.A7 9.31 24.14 33.45 17.69 17.69 139tA021 30A 2U. 25.041, 21.45 1.390.@ i.filSA 1.20 1.63 4.23�3J A7 4.4A A.75 22.30 109.S 103.49 105.17 -_ All 0.10 LOD 037 1.00 •\ G 3 _4 l - __ _ '10 1^ _2 •7 AIO,DI' 1 AN. UP fi,DI'9 Ai - A4,A5 M, DI• i AA, UP .DPS A), A6_UI7 A1, AG DPS.DPI^ Ax Al, Al, Af., 171`5, DI'10 0.62 I.10 3.17 1.19 L14 J.49 4,61 2(4) 7.I1 0.19 7. 7 10.32 I.b z30 3.6t 5.01 337 J.J7 11.90 7.47 9,73 1203 037 0.31 0.39 I.00 0.60 Lot) 0.69 1.00 0.37 1.00 0.71 I.Op 0.6t LM 0.65 0.71 1.00 0.69 L00 1.00 0.15 1.a0 669 1.00 0.62 1.00 Q76 L00 0.76 1.00 076 0.76 too 0.60 1.00 0.60 1.00 0.65 L00 0.3 0.33 032 . 1 . .. 0.M . 1M 00 as$••15 1.00 1.00 1.23 1.33 I33 1.35 1.5 1.25 1.5 1.5 1.25 1, 5 L5 1.5 1.5 I25 1.5 I.5 L5 1.33 S 1. . 1.23 1 is7.)0 US t25 1.25 -- •2 ? Il I -14 AI, OP2 n5 Dl,D1 D2, DPU DPII IJA.SIN BASIN It fl DP 15 IJ - 1ff • ArtJ •IA <IS I 37 76 aDP35 DJ. DI.340.33 PD[ tiD WD.DIN, ,DI' 139 53)15 A. 1.46 1.46 .3 9..6.,.7 11.55 3 _1211^351 In 19 T.9'P, INC. CONSULTING UN➢INIIiaS ••-n.. . ___ 'Iodialc4 not oil haainc contributing. [] ' 3 2 1 Street Capacity Street encroachment criteria for the streets was taken from Table 4-1 (minor storm) and Table 4-2 ' (major storm) of the SDDC Runoff from Subbasms D6 and D7 will leave the site undetamed and join the flow on Harmony Rd Capacity calculations for Harmony Rd were performed to assure ' that this added flow did not exceed cntena All of the streets meet these requirements and will function below the allowable capacities The results of the Street Capacity Analysis can be found in Table 3 with supporting calculations presented in Appendix B 3 2 2 Storm Sewer Design ' Lines ST-1 and ST-2 will allow for most of the runoff from the eastern portion of Basin D to be intercepted and directed to a detention facility on the Harmony Ridge site where it will be ' detained and discharged to the Regency Park Channel The lines were analyzed with UDSEWER and pipes sized such that hydraulic grades remain at or below the flow line of proposed inlets so that inlet capacity is not effected An onfice plate was designed for the outlet of the detention pond (ST-1) to limit the flow to 2 37 cfs Lines ST-7 and ST-10 were also analyzed with UDSEWER The water surface at the ' downstream end of Line ST-7 was determined by the water surface in the downstream channel The down stream water surface for Line ST-10 was determined by the 100-yr water surface in the feature pond the line discharges to Lines ST-8 and ST-9 are simple culverts, which were analyzed with HY-8 In both cases the upstream ponding head was limited to allow for approximately one foot of freeboard and the ' downstream fixed water surface was determined by downstream conveyance facilities Lines STA ST-5, ST-6 and ST-1l represent the downstream most discharge points from the southern portion of the site to the Cathy Fromme open space As indicated earlier the design of these outfalls was to be such that outlet velocities from each of these pipes be reduced as much as possible to reduce the impact on the exiting dramageways Because of the incredible amount of ' vertical relief across this site we determined that the best way to flatten out the discharge pipes would be to use drop manholes at the upstream side of the discharge pipe This would allow us to convey the runoff efficiently over the length of most of the systems and then dissipate the energy to manageable levels at the outlet pipe We ran into two problems with our analysis We intended to use a UDSEWER model but needed to determine the correct loss coefficient to use ' for the drop manholes We researched this but were frustrated to find that an accurate coefficient was not available It was suggested that determining such a coefficient would be an excellent topic for a post graduate thesis but that did not help our situation now We discussed this matter ' at length with representatives of Lidstone and Anderson, Inc who are intimately familiar with this software They agreed that the idea of the drop manholes was the correct approach and in the absence of an accurate loss coefficient that we could run the model with no additional coefficient ' and simply let the flat slope (0 50%) of the outlet pipes dictate the outlet velocity This should produce results conservatively high but it was the only way we could get around the absence of an 10 I 1 1 [1 1 1 1 1 1 accurate coefficient When we initially set up and ran the model we began getting results that simply made no sense For instance when we ran the model it provided us with a recommended size for the pipe immediately upstream of the drop The pipe was very steep so the model recommended a relatively small pipe We were not happy with the velocity in this recommended pipe so we bumped it up a size and the model did not react well For some reason the model showed an increase in the HGL elevations of several feet 7 feet in one location This simply did not make sense We again consulted with Lidstone and Anderson and they are of the opinion that the model simply can not handle a drop situation where the HGL of the down stream pipe in the drop inlet is below the invert of the pipe at the upstream end What they suggested, and what we did, was test each drop It could be reasoned that if the HGL of the downstream pipe is below the invert of the upstream pipe that the pipes are hydraulically disconnected In that case it should be possible to accurately analyze the upstream and down stream portions of the system independently UDSEWER does not function vAth only one pipe in the system so those reaches would be analyzed with HY-8 If the HY-8 analysis showed that the upstream ponding was less than the elevation of the invert in of the drop manhole then the Hy-8 data was considered accurate The upstream portion of the system could then be analyzed with UDSEWER and the results of two analysis combined to get a hydraulic picture of the entire system This method worked for Lines ST-4 and ST-6 By disconnecting the upstream and down stream portions of Lines ST-5 and ST-11 we created two culvert situations so both these lines were analyzed exclusively with HY-8 The results of the Storm Sewer Analysis and Design can be found in Table 4 with supporting calculations and model outputs presented in Appendix C 12 TABLE 4. SUMMARY OF STORM SEWER DESIGN L11\L' Is , Yi"FRCOTMf� r i.,C y� OWN JMA" 1 Alvi) .µ. 1 � w,�,am', �e (h q .• k� kl P�1 III I I P k tik- A'"J`�� d tati � I DiA(MEy 'ER � aTes1=f V. I . , i ��rtmk t•I� RN.�Y 43AI� :k Itl d' 7 i�'S .I F'�S: .. i�•'/I4 Nei:1LA' IIP5 ...s..�l L j"» a� 3 '� Y Jk14 J{ ny,,.�,y C y`I �M." q- j j ST-1 EXISTING CHANNEL M H. MIA M.H.M1B M.H. MIA M.H. MIB POND j 2.37 2.37 2.37 15 15 15 RCP RCP RCP j ST-2 POND D j INLET 2A j INLET 2B INLET 2A j INLET 2B j DP 33 j 7.30 6.20 j 4.30 15 15 I5 RCP RCP RCP j ST4 CHANNEL M.H. M4A M.H. M4B M.H. M4A M.H. 44B INLET 4A 17.69 17.69 17.69 24 IS 15 RCP RCP RCP j ST-5 CHAR 1. M.H. M5A j )41-1 M5A j DPI 56.87 56.87 36 36 RCP RCP ST 6 CHANNPI. I Nil,.M M.H. M6B MH. M6B M.H. M6C M.H. M6A NCR M6B M= 6A NCH. M6C INLET 6B 33.45 33.45 24.14 9.31 9.31 30 24 15 15 15 RCP RCP RCP RCP RCP ST-7 CHANNEL INLET 7A MET 7B W=7A 1 INLET 7B j DP 2 45.12 1 43.71 26.79 36 30 24 RCP RCP RCP ST-8 DP 2 DP 4 5.94 18 RCP j T-9 POND DP 7 3.23 15 RCP rST-10 POND M.H.#IOA j INLET I OA M.H. M10A MET IOA INLET I OB 11.19 I1.19 7.78 15 15 15 RCP RCP RCP j ST-11 CHANNEL M.H.911A i M.H A'I ]A DP21 20.82 20.82 30.00 24.00 RCP RCP TST, INC. CONSULTING ENGINEERS 10/16/98 G00_hyd I .xls 7 32 12 TABLE 5. SUMMARY Of INLET ANALYSIS AND DESIGN Dl v.ai 0.7E 7.78 3.41 9.63 4.49 10 4 2.13 0.94 17.69 24.14 9 .J1 8.32 I aoi 9 1 I ._ NA LOS o.vv 10 150 10 00 10 �OS� —_— .Tf Z. 37 p % TST, INC. CONSULTING; ENGINEERS TST, INC. ' Consulting Engineers CLIENT JOB NO. PROJECT "[''�'l 2?:?G�= /�(/ CALCULATIONS FOR -'YvtiGFF MADE BY Gam[[ DATE /9-7 CHECKED BY DATE .y i / SHEET or i2o2F 3'3 c= SDDc. 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S t:/-S'6/.J ..-�-,•a.-= �-i/ :i'[e--: T,I;ic 4" G�=B -/� '- � - r GntiiLrL_ G�y G j G 77EA,5.%, =�. c.\ c a = -+ / _ .Ile_ ,iJ G✓.�'. %i'�F% F.%�.'- - _ u I/'I!✓. //.LFT LEI+'G' i'/= /t�rG) =' %�L�•' _i� C s4 S-c �•dg:•- :l_"S/GN ,/�i�.- // fi 't E•T: /Y�� /il // �.%•.� //✓L-T �C � �/ a /-� /Q f' �E2�£^7�.c�/��CFrilcr%Y c .�•.S� c:�Jri ' /✓. •''1 • i/✓L� LEiJC: l/ = r'. �`� •9i •:,5 - ,.2 -T1 C %-:Sc i -.n�, �_ ;/c=/u n: /s;/wT !Z /VLFT: /Y�'2.5 ",�%��G✓r:'j /IJE� �O T� Svc � �r/�u.= .�. 'Y•/`l C�S f_vr=c /-, Y - L l 1J 1 NOTE: ME TOP OF EOLNIWICN ELEVI.rMNs Sx M2 M MMM EIPIMICNS REgMIED Eqi PROTECT ENVY TINE IW-YF/R SIOR4. NNVN FM51ED FLUOR EIEVI.IION I F 111E IW-YEM Fl SURFACE S . CYAVNS'N. O ES. SSNNES. OR OTHER ORN FACALTIES, A AHII Hy P EN GRILM. PIAV ME ro BE BNOM1. „y>� _PRAIRIE RIDGE DRIVE] / j Ti 421 r / I tl41 O \ Now ARE� RO.. PC IF AN iFr__ /i 51 LEGEND: - EXISTING STORM SEWER D- - - - - - - BASTING STORM SEWER INLET PROPOSED STORM SEER F�� a"aaaa: PROPOSED STORM SEWER INLET — .H PROPOSED CONTOUR EXISTING CONTOUR - — -4920 - - EXISTING INDEX CONTOUR - PROPOSED CURB AND III - - PROJECT BOUNDARY — " — PROPOSED PORCINE PROPOSED GRACE EXISTING GRADE SILT FENCE - - GRADING & EROSION CONTROL NOTES: T— ME cm or FORT cauws sroxuwnreR DEPARTMENT EROSION CONTROL INSPECTOR MUST BE rvGDnEo AT LEAST EA noDRs PRIOR r0 MY coxsmucuory ON THIS SIT k ➢GAIN 1 ALL REQUIREDPERIMETER SILT PENCINU SHALL BE INSTALLED PRIOR TO ANY LAND AR TRQSTRIPPING, SENDING, E). DFpREWWEO 1 ENXOCONTROL MEASURES SNW BE INSTALLED THE APPROPRIATE P iNTTH UCTFON SEQUENCE n5 INDICATED N XE APPROVED gWECI Sri. IDS SCHEDULE CONSTRUCTION P4N5 AND EROSION CONTROL REPORT rH. 6 DI'0 D I'r PRE DMRB E KOBATpX SNMl BE PROTECTED AND RETAINED W EREVE POSSIBLE E [DISTURBANCE OF EXANG VEGETATION SAMI BE LIMITED TO 8'k ENE AREA REOLARED FOR NNEWTE CONSTRUCTION OPERATORS. AND FEW THE T OD o E AT ALL SOILS EXPOSED DURING LAND DISTURBING ACTMn (STRPPNC, GRAD IC uTLn xoTA T Ns STOCXPLNG. FILLING,RC.) SNK„ BE KEPT NA ROUGHENED 1S.9 CONDITION BY BMW OR DISKING ALONG LAND CONTOURS UNTIL MULCH VEGETATOrv. N OTHER PERMANENT EROSION CONTROL s STALLED SOILS IN O AREAS OUTSIDE PROJECT STREET RIGHTS of WAY SMALL RELLAN EXPOSED BY LAND pSTVRexG ACTNITY FOR MORE THAN THIRTY (30) NYs BEFORE REQUIRED TEMPORARY To I OR PERMANENT EROSION CONIRM (EO. SEED/MULCH MESCARNG ETC) 15 NSAL LT UNLESS OTHERWISE APPROVED By ME STORW4ER DEPARTMENTDIP �e'y1 ME PRyEIM SHALL BE WATERED Nq MAINTMNED ATylLIKES DURING CONI FOR ACTIVITIES SO n5 TO PREVENT WIND -CAUSED EROSION ALL LARD vY gSIVRHM10 KIM16 SNYL BE I44ENATELY DISCONTINUED WHEN EUGENE DUST IMPACTS ADJACENT PROPERTIES, S DETERMINED 8f THE CITY OF TOM COLLINS I ENGN MM DFYMLILEM. �. CH- i ALL Id0.YVR/ (SML'RIMI) EROERW Cg11ROL MEASURES SHALL BE INPROCIMID AND REPAIRED OR RECONSTRUCTED AS NECESSARY AFTER EACH RUNOFF EVENT IN PNKOAYNCE OF CIR 10 ASSUME WNI FUNCTION ALL PAt THOSE ON PAVED ROADWAY SURFACES SHALL. SE O LOCATION ED S LHEIRD EEASEXIT BE NYlm AND 06PoYD K N 1 YVNFA µ0 LIXRi ON SO AS NOT TO CAUSE INER RELEASE INTO An OPAIW.GEWPY. OFFAMY _... _ ....... NO SCl 9DUPILE SHALL. EXCFm TOM (10) REST N (GXI. ALL SOIL STOCxP LE`. SWLL BE PROTECTED FROM SEDIMENT TRANSPORT WE SURFACE RWGNENINO. WAIERMC. MID PERITEDER Ar MKM. Mn WE STOCKPILE RE"NNG ASTER ]D DAYS SHALL BE SEEDED ANC MULCHED. TYPICAL BUILDING DETAIL im MDE PPJMNIs THE R XM. DROPPING, OR DEPOSTING or SUITS OR ANY OTHER MATERIAL ONTO Hn STREETS BY OR FROM MY VMYt ANY WAiR1EM DEPOS(IED MATERUL SNVL BE CIFNIEO IMMEDIATELY BY THE CONTRACTOR. RESEED PER THE FOLLOWING RECOMMENDATION: ao _ SI Cemme:, Nam, Sr"I N,m Va,.L. I Ac..n./I I. .., M.. I. PIR/4 TI- PDT/ACCESSDUAL (CONCRETE) 15 DEEP (I00-YR. J WSEL ♦ ]]R) uLOPIh. 0.0< II/fl (4%) o', CIA O,� 1 .I]S - CFS OOwRy wsrl A- DEEP SWALE SECTION B—B IDEEP ALA '.IDE SLOPES ('HARMONY RIDGE PW PHASE I I �\ � �I / 0030 \/IhKK�\ TIP - - / m�,- sp ISF �J L NA7URALMH&A E, G YNOw5IF wv cxwTwa v� ecw.rn ANT rrar crorzva /MPpF¢vaNn Y 2500 ON ) SEE sM 4 owwnucroN ewuelcE aae¢ mT w ttwnm IF M ATE J e. Miss LD(/S7Y SAGE.., l \ \r} i, I AN ROWGRAPHIC SCALE: NORTH0 WAR M4W SU D To n IN TEES w) I lon- R :ii) OB City of Fort Collins, Colorado _. �. UTILITY PLAN APPROVAL - 8FSTEEL OR MPROVE p. _. a e[ pygn DWOOD Pas W) CHECKED BY ,E_ 77 CHECKED BY ®T ��I�1� nTR rApm pyM 1 CHECKED BY: part k ReereaLON -BUNFILLEF( G BY r Ton CollinsLoveland MatterDisfirl South Fort Collins Sanitation Oishict SECTION VIEW G OSIF ' ! a NOTE Too T OF DOWNS M. AIu N unED ro Dn Acas PEE / WW MOTOR[FEWDE pT EMN SICBL EVENT . REM MLN 1 ////�� J T1uTWr M:fYRLFRM_ Wa'� � � \ _ BASw M OMR B1FAC NFwS:REµ IL.PAxn TD A Timor - \- SIT FENCE ALONG TiiLBY LANQ TRILBY LATERAL IRRIGATION DITCH OTCN .wvaoNFD: src .,