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HomeMy WebLinkAboutDrainage Reports - 06/05/2001No Text [1 1 k zftw lZ & .14u0c, %KC. June 8, 2000 Project No. 0023 Mr. Donnie Dustin City of Fort Collins Stormwater Utility Department 700 Wood Street Fort Collins, CO 80522 P. 0. Vax 270852 57oat collars, e0 90527 (970) 493-2808 5o4X (970) 495- 9735 ' Dear Mr. Dustin: On behalf of our client we are submitting the attached Final Drainage Study for Mountain Ridge Farm P.U.D Fourth Filing. The purpose of this report is to evaluate and present the drainage impacts from the proposed Construction of the Mountain Ridge Farm P.U.D Fourth Filing. The drainage report will present the changes to the developed ' flow conditions and proposed improvements to resolve the impacts of the drainage flow condition. ' The Final Drainage Study for Mountain Ridge Farm P.U.D. Fourth Filing was prepared in accordance with the provisions of the City of Fort Collins Storm Drainage Criteria — revised January 1997. Loonan and Associates, Inc. es R. Loonan, .E. Registered Professional Engineer Colorado P.E.19195 IJ 1 Ll PROFESSIONAL ENGINEER'S CERTIFICATION I hereby certify that this Final Drainage Plan and Report for Mountain Ridge Farm P.U.D. Fourth Filing was prepared by me or under my direct supervision in accordance with the provisions of the City of Fort Collins Storm Drainage Criteria Manual for the owners thereof. Loonan and Associates, Inc. Registered Professional Engi State of Colorado No. 19195 Table of Contents I i I 11 I I �I Introduction................................................................................page 1 Existing Condition.........................................................................page 1 Drainage Impact...........................................................................page I Proposed Site Conditions Major Drainage Basins Offsite Basins Onsite Basins OffsiteRunoff.............................................................................page 3 OnsiteRunoff.............................................................................page 4 Conclusion.................................................................................page 4 Erosion and Sediment Control ..........................................................page 5 APPENDIX A Erosion Control Calculations APPENDIX B Final Drainage Study Calcs APPENDIX C Inlet Documentation (Final Drainage Study & Report for Mtn Ridge P.U.D. 3' filing) APPENDIX D Water Quality Documentation (Part of the Final Hydraulic Design Report for Regional Detention Pond 278, McClellands & Mail Creek Basin Fort Collins, CO) 11 'J FINAL DRAINAGE STUDY FOR MOUNTAIN RIDGE FARM P.U.D. 41" FILING intraductinn Mountain Ridge Farm P.U.D. Fourth Filing is a proposed residential subdivision in the City of Fort Collins, Colorado. The site is generally located on the West side of South Shields Street midway between Harmony Road and Horsetooth Road. The entire Mountain Ridge Farm development consists of the majority of the South ''/z of the Northeast '/< of the Northeast '/< of Section 34, T7N, R68W, Sixth Principal Meridian, Larimer County, Colorado. Mountain Ridge Farm, Fourth Filing consists of approximately 8 acres located in the Northwest corner of the above description. The purpose of this drainage study is to evaluate and present the drainage impacts from Mountain Ridge Farm, Fourth Filing on the approved final drainage studies. In the evaluation, a site description of the project and its relationship to the Mountain Ridge Farm P.U.D. development will be presented. The drainage report will present the changes to the developed flow conditions and proposed improvements to resolve the impact of the drainage flow condition. ' Existing Condition Description Currently the ground is gently sloping and covered with native grass and trees. The site is bound by Westfield Park PUD on the North, Seneca Street on the East, vacant land to the South and an existing development to the West. In the present state, the site slopes from the West to the East at approximately 2.0%. The current runoff drains East and South into a proposed detention pond to be built by the developers of Mountain Ridge Farm P.U.D. Third Filing. Currently in the proposed detention pond location there is a small existing pond. ' Seneca Street and the detention pond have not yet been completed for this filing. Both are planned to be completed before this filing is started. Drainage Impact Proposed Site Conditions Mountain Ridge Farm Fourth Filing consists of 36 residential lots. The proposed residential lots are accessed by two cul-de-sacs. Each cul-de-sac will begin from Seneca ' Street and extend to the West. The North cul-de-sac, Windcreek Court, will provide access to 23 lots. The lots will be located on both sides of the cul-de-sac. The South cul-de-sac, Westfield Drive, will provide access to 13 residential lots. These lots will only be located on the North side of Westfield Drive. The South side of Westfield Drive will remain undeveloped. I VICINITY MAP we Lnd kites t redo Cun St D Ct CCU - O, ar o� St Neat Ct 3 Ct c� Patterson Pattersona Enfield Churchill won r nford pr Q4 x � o < m — Caste% ors0 V H Or Ct rosiact c � P� Arbor Ctobti � Brook Dr � S p rt\ v 5Pointed € `\ Q^ t� e 75PU fa a Y �U 8 v u C Westfielc Dr U SITE J L yr Westfield Dr % ctes ay S e 12 Dr Cti Marble Dr W `m Lakeerest fi fT� els14 �y Green ate �'in a by Butte Pass Or c'.� -. Rd C r Brixton Rd me Lp r a m ew n9 e f f, • Dr a+ ,y m cn re m mg c` pp . Stoneflower y� 3 ��to Cti �akefn x io m . B A Cl o -e R h B CE J%Sb E Ct r 4 '..t m F e t WJ Harmony Rd. I. Westpotnt Ct S. Mwil wvien Ct g o 2 Prairkviev Ct 6. Glerw" Ct ,%AariPos 3. Cresbrim Ct 7. Shwvi" Ct °' 4. Cfiffaide Ct 8. V"Wint Ct v _ ---•P�7ye�bu J r N 1 inch = 1000 ft. I Maior Drainage Basins Mountain Ridge Farms 4"' filing lies within the McCelland-Mail Creek Master Drainage Basin. The offsite detention pond is a regional pond and was included in the Master Drainage Basin Study for McCelland-Mail Creek. Offsite Basins There are six offsite basins for this site. Three of these offsite basins are located directly West of the site. The three basins consist of the back portions of existing lots and buildings adjacent to Mountain Ridge Farms Filing 4. The fourth basin is located to the North of the site. This offsite basin consists of the ' South half of a cul-de-sac in the Westfield Park P.U.D. The fifth offsite basin is South of the site. The basin consists of the West half of Seneca Street. Onsite runoff drains through this basin and enters either the proposed curb inlet or the proposed storm inlet located at the low point of Seneca Street. ' The sixth offsite basin does not directly affect this site. This basin is the portion of the development west of this site that drains to the East end of Westfield Drive. Westfield Drive ends at the Southwest corner of our proposed cul-de-sac, Westfield Drive. All of the runoff that is produced by this offsite basin is conveyed to the South through two existing elliptical 24"x 36" cmp's. The runoff then enters an existing detention pond. ' Sub -basin OSA This is the offsite basin directly West of basin A. It consists of the back portions of existing lots and buildings located to the West of Mountain Ridge Farms filing 4. Sub -basin OSB This is the offsite basin directly West of basin B. It consists of the back portions of existing lots and buildings located to the west of Mountain Ridge Farms filing 4. ' Sub -basin OSC This is the offsite basin directly West of basin C. It consists of the back portions of existing lots and buildings located to the West of Mountain Ridge farms filing 4. Sub -basin OSD This is the offsite basin North of Mountain Ridge Farms filing 4. It consists of the South half of a cul-de-sac in Westfield Park P.U.D. together with the residential lots located south of the Westfield Park's cul-de-sac. ' Sub -basin OSE This offsite basin is on the South side of the site. It consists of a portion of the Western half of Seneca Street. 1 2 11 LJ I I 11 I 1 I L i I r Sub -basin OSF This offsite basin is part of an existing residential development located West of our proposed development. Please note the exhibit is in appendix C and calculations are located in appendix B. Onsite Basins Sub -basin A- This sub -basin consists residential lots and the North half of the North cul- de-sac, Windcreek Court. Sub -basin B- This sub -basin consists of residential lots and the South half of Wind Creek Court. Sub -basin C- This sub -basin consists of residential lots and the South cul-de-sac, Westfield Drive. OFFSITE RUNOFF The runoff from the three offsite basins to the West will enter this development on the West and be conveyed with onsite runoff into the street gutters. The runoff will then be conveyed East in the gutters of the two cul-de-sacs to Seneca Street. The West Seneca Street gutter will then convey the runoff to the South into one of two proposed inlets. The first inlet is a 6' curb inlet approximately 60' south of the intersection of Sennecca street and Westfield Drive. This inlet will intake some runoff and the remainder of the runoff will continue south and enter the proposed 15' Type R curb inlet (see Mountain Ridge Farm Filing 3 Drainage Report). A proposed storm sewer will then convey the runoff to Detention Pond 278 (see Mountain Ridge Farm Filing 3 Drainage Report). The runoff from the fourth offsite basin to the North drains to Seneca street and then South in a Seneca Street gutter to the Northeast corner of Mountain Ridge Farms Filing 4. The offsite runoff continues South combining with onsite runoff to one of the two proposed curb inlets on Seneca Street and ultimately into Detention Pond 278. The fifth offsite basin's(OSE) runoff combines with the onsite runoff and drains to the low point of Seneca Street. The sixth offsite basin's runoff will not impact this development. Existing elliptical 24"X36" CMP's will convey the runoff to the south of our development into a proposed concrete box culvert under Seneca Street. Sub -basin OSA The runoff generated by this basin drains to OS and eventually to DP1. Sub -basin OSB This runoff drains to OS2 and then to DP2. Sub -basin OSC This runoff drains to OS3 and then to DP3. 3 I Sub -basin OSE This runoff drains to the inlet located on the South end of this basin(DP 4). Sub -basin OSF This runoff drains to OS5 and then south to the proposed culvert under Seneca Street. ONSITE RUNOFF The runoff produced from the three onsite basins drains East to Seneca Street and then South in the West gutter of Seneca street to one of the two proposed curb inlets within Mountain Ridge Filing 3. Sub -basin A- This sub -basin will drain Easterly to the intersection of Windcreek Court and Seneca Street(DPI). This runoff will include offsite A. The runoff from the North offsite sub -basin will also be included at DP1. Sub -basin B- This sub -basin will drain Easterly to the intersection of Windcreek Court and Seneca Street(DP2). The runoff from DP1 will be included at DP2. Sub -basin C- This sub -basin will drain Easterly to the intersection of Westfield Drive and Seneca Street(DP 3). At DP3, all of the onsite runoff will be included from DP3. It will drain south and a portion of the runoff will enter the curb inlet while the remainder will continue to the proposed inlet at DP4.(Mountain Ridge 3) The first proposed curb inlet is a 6' curb inlet. At the inlet, the 2 year flow is approximately 8.78 cfs and the 100 year flow is approximately 39 cfs. For the 2 year ' storm, the inlet will intake 3.6 cfs and for the 100 year storm it will intake 7.38 cfs. This will leave the remainder continuing to the 15' inlet located at the low point. At this 15' inlet, the 2yr runoff from Mountain Ridge Farm Filing 4 is 8.45 cfs and the I00yr runoff is 37.3 cfs. Subtracting the runoff taken in by the upstream inlet gives a total of 4.85 cfs and 29.92 cfs for the 2 year storm and 100 year storm respectively at the 15' inlet. The runoff that cannot enter the inlet will overflow the sidewalk and run off into the proposed concrete box culvert on the west side of Seneca Street. The box culvert will then convey the runoff to Detention Pond 278. CK13ele) KIM [00 The runoff that will be produced by Mountain Ridge Farm Filing 4 has been accounted for with the design of Mountain Ridge Farm Filing 3. The runoff from this site will drain to one of the two proposed curb inlets in Seneca street and then to Detention Pond #278. Detention Pond #278 has been sized to accept this runoff and provides water quality for the runoff from this site. The Regional Detention Pond 278 Hydrology Re-evaluation, ' McClellands & Mail Creek Basin study completed by The Sear -Brown Group presents this information.(See appendix D) For documentation of the inlet and storm sewer on Seneca Street, see appendix C. 1 4 I I I I� L�J I I r I 1 r r EROSION AND SEDIMENT CONTROL This report describes methods which are recommended to control wind erosion, water erosion and sediment during and after the construction of drainage structures and site grading. Discussion The clearing and stripping of land for site grading, overlot grading, or for the construction of drainage structures, may cause localized erosion rates with subsequent deposition and damage to offsite properties. Uncontrolled, such erosion could destroy the aesthetic and practical values of individual sites, and cause damage to downstream property. In general, erosion and sediment control measures will consist of minimizing soil exposure, controlled runoff across exposed areas, and sediment control at drainage structures. Each of these measures is described below and should be utilized by the developer and/or the contractor during any construction activity that occurs at this site. GENERAL EROSION AND SEDIMENT CONTROL MEASURES Minimizing Soil Exposure: Where practical, the construction area and duration of soil exposure should be kept to a minimum. All other areas should have a good cover of vegetation or mulch. Grading should be completed as soon as possible after commencement. A temporary cover crop, a permanent vegetative cover crop, or other landscaping should be established in the disturbed areas. Re -vegetation may consist of native grasses, lawn grasses, or various winter wheat. Decorative rock, flower gardens, or shrubs may also be utilized in the final landscaping to cover the soil. Re -seeded areas should be mulched with straw or hay to protect exposed soil until vegetation is established. EROSION CONTROL PLAN The proposed erosion control measures are presented on the Grading and Erosion Control Plan located in the Appendix of this report. In summary, the erosion control measures consist of: 1. Temporary seeding on all of the land to be developed 2. Inlet protection at every inlet 3. Silt fences installed on the Eastern side of the development Vehicle tracking control I I I I I H, I I �1 I I 1 1 1 1 1 APPENDIX A Erosion Control Calculations I I EFFECTIVENESS CALCULATIONS ---------------------------------------------------------------1 PROJECT: l►l+�**•+R o�ja-�'"t r �`A y STANDARD FORM B COMPLETED BY: _ feljr DATE: iz q 9 I Erosion Control C-Factor P-Factor I Method --Value- Value Comment - -------- ---- T..p yaEi.^Jo U .44• .1.00 All I I S: I+ 0.ws�o All k5p4wx* / C�.aGW-L 0. OI /.O0 14/1 -------------------- !_ob .90 A // I ---------------------------------------I MAJORI PS SUB AREA I BASIN (a) (BASIN (Ac) CALCULATIONS ----- Qo. Iq A Z.3pjConcu►.. ACr+i = 94AC —94.3% I rA. + sxuk J— /.94 I O C 0.39 i = hi +<4 I I {f\ \ P. ( 9+� 1.99)+�I tE .3)�2.3 1 .S g0•I�I g zsN Pam Conte At.-o-= (`or.trc� IUDs �• W J C = C<< 4+1 aF . 0I� �• Z A`I '� .45�)� S� •. = 0. 3'I I w+d P 4 •I. 3.31 P.ocd k. ss= . 84 At = 2 si z.41 AC— I+ I`...•.� 5 E.eS,'on Cowl o� J�u3 1`1/ - 0.3y + (I.00 JF .�4���3.3)�: 5� ' 0•Ulo HDI/SF-B:1989 EFFECTIVENESS CALCULATIONS ----------------------------------- PROJECT: MrA1 R:� �y y STANDARD FORM B COMPLETED BY: Nt Q-r DATE: L A II Erosion Control C-Factor P-Factor --- Method -----------Value Value Cortmlent . -------------------- ------- -------------------------' MAJORS PS { SUB I AREA BASIN ----------- (a) ]BASIN I ----- (Ac) ------ ----------------------- ---------------------- CALCULATIONS ---------------------------------------- I S I /o e o�o O'j ------------- I/SF-B--------- fl a o � ` U I CPnIXt Lo aoi �co i lZf9 I99 y& -9.41 AIA17 " a c 0 5 a E cU) L o `O aa) _c rn o L5 1 t GroS:mtitrea.�' �o&+.EStri►2 Z+w.. Alo Dµen pfien Q4y link +- ! 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Ln ! CTOCta 1,,CO CO I�t�l�tp tp tO LnCCMMNN Ch tD C.--101 L0 3 1 . . . 1 1 O t O N N N N N N N N N N N N N N N N N N N .-+ e-+.••+.r O O 1 1 f� n n n n 1•.. f� f� 1 1 1 00 C O O O 1 t 0 C7 H 1 O O O O O O p O p O C 0 0 0 0 0 0 C= 0 t JZI.I_ 1 .--tNMC'Ln tO O *-t N MCtn LO f., C} 01 C Lo OtnCl!') 1 U- W v i 1 I O J ! •'•f .-� '-.� '•" '"� e-+ "" '-'• r-t .-•I N N M M C C L 1 1 ' TABLE 5.1 PAGE 24 ' Table 5.2 C-Factors and P-Factors for Evaluating EFF Values. ' Treatment C-Factor P-Factor BARE SOIL ' Packed and smooth . . . . . . . . . . . . 1.00 1.00 Freshly disked. 1.00 0.90 Rough irregular surface . . . . . . . . . 1.00 0.90 SEDIMENT BASIN/TRAP. . . . . . . . . . . . . 1.00 0.50(1) STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG. . 1.00 •0.80 ' SILT FENCE BARRIER . . . . . . 1.00 0.50 ' ASPHALT/CONCRETE PAVEMENT. 0.01 1.00 ESTABLISHED DRY LAND (NATIVE) GRASS. . . See Figure 1.00 C SOD GRASS . . . . . . . . . . . . . . . . . . . 0.01 TEMPORARY VEGETATION/COVER CROPS . . . . . . . 0.45(2) HYDRAULIC MULCH @ 2 TONS/ACRE. . . . . . . . . 0.10(3) SOIL SEALANT . . . . . . . . . . . . . . . 0.01-0.60(4) 1.00 1.00 1.00 1.00 EROSION CONTROL MATS/BLANKETS. . . . . . . . . 0.10 1.00 ' HAY OR STRAW DRY MULCH After pl.anting grass seed, apply mulch at a rate of 2 tons acre minimum) and -adequately ' anchor, tack or crimp material into the soil. Maximum Slope Length ' W (feet) 1 to 5 400 0.06 6 to 10 200 1,00 ' 0.06 11 to 15 150 0.07 1.00 1.00 16 to 20 100 0.11 1.00 21 to 25 75 0.14 25 to 33 50.. 1.00 0.17 > 33 35 0.20 1.00 .1.00 NOTE: Use of other C-Factor or P-Factor values reported in this ' table must be substantiated by documentation. (1) (2) Must be constructed as the first step in overlot grading. Assumes ' planting by dates identified in Table 7.4 thus dry or hydraulic mulches are not required. (3) Hydraulic mulches shall be used only between March 15 and May 15 unless irrigated. (4) Value used must be substantiated by documentation. CONSTRUCTION SEQUENCE '-. PROJECT:- MDV4.Kny STANDARD FORM C !MQUENCE. FOR 19 ONLY COMPLETED BY: DATE: z 9 ' Indicate Major modifications by use of a bar line or symbols when erosion control measures will be installed. to an approved schedule may require submitting a new ' approval by the City Engineer. schedule for YEAR -----MONTH_ OVERLOT GRADING 'WIND EROSION CONTROL Soil Roughing Perimeter Barrier ' Additional Barriers Vegetative Methods Soil Sealant ' Other RAINFALL EROSION CONTROL ' STRUCTURAL: Sediment Trap/Basin Inlet Filters Straw Barriers Silt Fence Barriers Sand Bags Bare Soil Preparation ' Contour Furrows Terracing Asphalt/Concrete Paving Other ' VEGETATIVE: Permanent Seed Planting Mulching/Sealant Temporary Seed Planting Sod Installation I Nettings/Mats/BlanketsOther ---------------------------- I. IS to Al lip ' STRUCTURES: INSTALLED BY MAINTAINED BY VEGETATION/MULCHING CONTRACTOR ' DATE. SUBMITTED APPROVED BY CITY OF FORT COLLINS ON )I/SF-C:1989 I 7 1 1 I 1 I 1 n 1 APPENDIX B Final Drainage Study Calcs a a L Cow posi�l. C = 4.N2) 6,95) �'�. Z3� �9S) +� Z(o . 95� 4". (Ijiu Z6 LO w` ►34s, n g , . tota�-. 1�'ckn-- = z..Y� . AC ; .. . Ptz' R'C. . iial.ks — 740' a(o.3y' W;d¢.. Asp1Ao.lL+ strL&. .. _ • 34 A...C. . CwtiOlsU�p�. (Gross). _ 1. 4C, ' Co..-.pc6.�L , C = 4Zs (LN) 95� + . 3(,) =0.Sy Bas:r1.. tc*ee .L Arw6. _ ..3.3 f %� L ' i s how&.Lz aL /(POD 13. �riXS .C' Asps-a9..� StcQ.ai- - �3 RCS . V) + G (a3) VS� + d�f /0k)-r 1211 199 I Fir/. nq y MOF ,. 1 E tU 1 Ci 4 �) C w` �S1 .1 I =I r IF I ul AC, - 90 p s .jla�L2S : /zoo iZ2 -. 0.. 2 (o G (E svo P't z =. 0. 11 �Ja111�. SFfU' @: (0,34;J,dC =0, OR.AC AsPV4-4.t SEraq,* ..O. Z5 Ac. w,p,rs Cow-pos,-Fe. .0 = (z(,) (ws)..'(.1q� �•'9S) + r! zsiwsj+(�•J�(.zS�-.. 01 %. D.=..Izo' 43. 15. M-A tom tt : L. S(o S' S = .l. l blo. �'qw+. 3 3 skews fit' (z.os 60 ..= 4.59: nn,tL 4. S9 . J �. `l - . l '7: O Al;k--q 04 4-L, E All asp..lL+ C= 9S #or, Ears. C.=_..95 A Z5, �C .1F kzs-;._. S= 2.074, . 1`p CZyr� 1.I I. M,J1.l .. touowf) . a.�4 i�,�...... 40r ais _ tt='�J,�� = y 38 wi•4, Tc Coy) . 6./Z pi.ri S.D.: /6u%✓ 99 /in y Tam _ eA l0 a o UZ a E 0 Basin N c _ Z. Oho rn ui Mot MIA /00`�l c, 16 rc(Z �r� = I4.I 4.'13 = fB.g3 fildt _I9.O.M•ti = = l8.OM;t'1,. L..= 9Z'' t3'1. 9,73_ 1'7. 83M•+'t. ;, _S• [ o,,51n Q f.� co :60) 0 . 7• Z.Q. M'�1 7c; (zir) = 13.Z + I ZO : Zo.y= Z0.0'/Ut,i(." .. 4 - �,la.t'1�-`/w•' T .(lUlLr�= IZ•Z + .7ZO = 9•y = I•g..0 h% ._...� S.�S �7+�+- : trfov = lS• 4_ Mtti U.= 2.Z5./S °_ ;.tt = (z.zs)(vu) S./O MA,/ U /S co+ S•!C — ZO.'1 - z I T� (/D�yr� = 14. S + S.10 - ! 9. (o = Z o WA-1 _ T . U P:.n t'FrµS y RW7- TNu Q fro +fin 110 _ .•. TC.. (Z.Lr) Tc.. (ioo.y-) Pw— /r. of M,v% a Z.°Z. = zo.oL 20.0,.. •40 Z `D Df. 3 �. L _ . Jr 9.O..�t. !. 5=0. Sf T`-CZ'ts� r DP.3 ZLO w„K + z.z(,o Al .= z :z�,; _ za • o w..A., Te 600,2,r) �... D pP3' = ZOO .,..n +_z..zcv..,a..K Zz.zb Pico Cv,, 3 = F D? 3.fc pP+l,. L - 3to_S $= 0.S-%, _. ro.. sa8' .. -rt T 1 ✓� Z3.0-f . �i.Bg = Z9.3g = Z'1, T IDS - A � Virg,....: [J�st o� B�s•n kj>. ' ' P.M 0.3q 4 . d TC- T.cU + C C .. E-Sh cr= I%/Zs �j to N on d C ( W u (�) - Z.0>, L=.75� "' ��: 3-3'.Shows 17s 7—C, (iavr) _ (8, Z(o 4-.44) = 910. - ( 14 rca . �Ua aF 04 B ac"ti $> ZZ AC-�.= SS S_ z.6). '(.ov (orl M.w fty S= Z.0% L..= '70 ^' �� 3-3SkawS �= Z.85 �t/5 tb= 70 Tc- C?J) z 1.36 + .4 1 Te- /oo = S.Ih + A z 9. dS.. pC �or fod� D= 50, 5= Z.O`�o f.ou�Zy+� ►-. = , 8.9Z M,-0 Lou � 8. Z6 L='70' ^'i 3. 3 ' li=. Z.85/s .^ tt =.� $ ) _ •yl W.�n, ' Te (tjr) = s3.9z+. y (_. 9. D ►arty c. (goo yr) 'go uo ...y.1 8. 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Cis 7- *************************************************** ***** FHWA URBAN DRAINAGE DESIGN PROGRAMS ***** ***** ROADWAY DRAINAGE DESIGN ***** *************************************************** DESIGNER: Mark DATE: 06-08-2000 PROJECT: Mtn Ridge PROJECT NO.: 1 INLET NO.: STATION: DRAINAGE AREA: Acres DESIGN FREQUENCY: 2 Years ROADWAY & DISCHARGE DATA Cross -Slope S , Sx n Q T ----------- (ft/ft) --------- (ft/ft) --------- ------- (cfs) --------- (ft) -------- Composite 0.005 0.020 0.016 8.78 17.94 GUTTER FLOW W Sw a Eo d V (ft) --------- (ft/ft) ------------------ (in) --------- (ft) -------- (fps) --------- 2.00 0.083 2.00 0.331 0.48 2.61 INLET INTERCEPTION Inlet Type LT L E Qi Qb (ft) (ft) (cfs) (cfs) ----------------------------------------------------- Curb-Opening 18.21 6.00 0.510 4.50 4.27 -------------------------------------------------------------------- Vl �i = (o.g��y•s�= 3.c0,0-ps *************************************************** ***** FHWA URBAN DRAINAGE DESIGN PROGRAMS ***** ***** ROADWAY DRAINAGE DESIGN ***** *************************************************** DESIGNER: Mark DATE: 06-08-2000 PROJECT: Mtn Ridge PROJECT NO.: 1 INLET NO.: STATION: DRAINAGE AREA: Acres DESIGN FREQUENCY: 100Years ROADWAY & DISCHARGE DATA Cross -Slope S Sx n Q T . ----------- - (ft/ft) - (ft/ft) --------- ------- (cfs) --------- (ft) -------- Composite 0.005 0.020 0.016 39.00 32.09 GUTTER FLOW Eo d V (ft) --------- (ft/ft) ------------------ (in) --------- (ft) -------- (fps) --------- 2.00 0.083 2.00 0.180 0.77 3.74 INLET INTERCEPTION Inlet Type LT L E Qi Qb (ft) (ft) (cfs) (cfs) ----------------------------------------------------- Curb-Opening 43.05 6.00 0.230 9.23 29.77 -------------------------------------------------------------------- = 9. 3e cps /z/91191 //(oK.tw,A- ice. rw ^.--� r -- D,,1,^ y I Afvr a,. Cross P96 .IPWOP3,.--9-46". 7-1 cc a _o _ /Crossp.� .. .... - E l` �$Trs CF .._4- I .... w • \ DMZ YI = .. O. O to Dom '0.33E.:. C r) cps� r C-S : XVA�.t R: ov- %r -,L r/,A? y I : '• � _ r/= o. 01�. Q��,= .3�.3 cis 5 U 1 Pt Lo CD TL&ot. h t&L Ce Pam QZ_ o.sc, (3tis� All. Z �cS a, �Qssw-- LI •'l o�s'-. OlL :. n owtA rtro ?S' ir =. Sr t To4'oQ.. Y4Cyxc ZsF�L c, t,.z eFs ok _ _. c gw IZizjgg flow,•-fVUK R I-dr., 44 ► L-S r.1,. y Arm ly, 0.., AcA ±.. Aim. IAd J�ofiti. ` olcwS,s.:. z (Jaa1- of mix Pa. 5 P','/" y C=... 95 =. K- E fin,'nq �3-3 0l' ' �t .�1/•as S+orUw. p�a'ti�,a..� . _ J toy= i8� ,I.� /(01.0.' Tc M, ti �N..9.,n y.0 /y,►t. rc =. g2L r?•n +. Iq::9 m•ti isct (ys) ,(i,y0�;'og)alco rwr ,,199 pal hti t4 Table 3-3 RATIONAL METHOD RUNOFF COEFFICIENTS FOR CCHPOSITE ANALYSIS Character of Surface Runoff Coefficient Streets, Parking Lots, Drives: Asphalt...................................... 0.95 Concrete..................................... 0.95 Gravel ....................................... 0.50 Roofs.......................................... 0.95 Lawns, Sandy Soil: Flat Averagege42 to 78.. 0.1 0.15 Steep>78.................................... 0.20 Lawns, Heavy Soil: Flat<28...................... 0.25 Average 2 to 7�.. ............... 0.2 Steep>78...................................... 0.35 3.1.7 Time of Concentration In order to use the Rainfall Intensity Duration Curve, the time of concentration must be known. The time of concentration, T,, represents the time for water to flow from the most remote part of the drainage basin under consideration to the design point under consideration. The time of concentration can be represented by the following equation. To = tov + tt Where: T- = Time of Concentration, minutes to = overland flow time, minutes t, = travel time in the gutter, Swale, or storm sewer, minutes The overland flow time, t,,,, ,can be determined either by the following equation or the "Overland Time of Flow Curves" from the Urban Storm Drainage Criteria Manual, included in this report (See Figure 3-2). r. 1.87(7.1-CC)d/2 f Tav= SI/3 Where: T,,.= Overland Flow Time of Concentration, minutes S = Slope, 8 C = Rational Method Runoff Coefficient D = Length of Overland Flow, feet'(500' maximum) C! = Frequency Adjustment Factor The travel time, t,, in the gutter, swale, or storm sewer can be estimated with the help of Figure 3-3. 3.1.8 Adjustment for Infrequent Storms The preceding variables are based on the initial storm, that is, the two to ten year storms. For storms with, higher intensities an adjustment of the runoff coefficient is required because of the lessening amount of infiltration, depression retention, and other losses that have a proportionally smaller effect on storm runoff. These frequency adjustment factors are found in Table 3-4. May 1984 Design Criteria Revised January i997 3-5 3.1.6 Runoff Coefficients The runoff coefficients to be used with the Rational Method referred to in Section 3.2 "Analysis Methodology" can be determined based on zoning classifications if the character of the surface is unknown. However, the final drainage study must calculate a composite coefficient using Table.3-3. Table 3-2 lists the runoff coefficients for the various types of zoning along with the zoning definitions. Table 3-3 lists coefficients for the different kinds of surfaces. Since the Land Development Guidance System for Fort Collins allows land development to occur which may vary the zoning requirements and produce runoff coefficients different from those specified in Table 3-2, the runoff coefficients should not be based solely on the zoning classifications. The runoff coefficient used for design should be based on the actual conditions of the proposed development. The Composite Runoff Coefficient shall be calculated using the following formula: n C = E (CiAi) / At i=1 Where C = Composite Runoff Coefficient Cs= Runoff Coefficient for specific area Al A1= Areas of surface with runoff coefficient of Cs n = Number of different surfaces to be considered At- Total area over which C is applicable; the sum of all Ails is equal to At Table 3-2 RATIONAL METHOD MINOR STORM RUNOFF COEFFICIENTS FOR ZONING CLASSIFICATIONS _ Description of Area or Zoning Coefficient Business: BP,BL..................................... 0.85 Business: BG,HB,C................................... 0.95 Industrial: IL,IP................................... 0.85 Industrial: IG...................................... 0.95 Residential: RE',RLP................................. 0.45 +�\ Residential: RL,ML,RP ............................... 0.50 Residential: RLM,RMP.. 0.60 Residential: RM,MM.................................. 0.65 Residential: RH..................................... 0.70 Parks, Cemeteries 0.25 Playgrounds........................................ 0.35 RailroadYard Areas ................................ 0.40 Unimproved Areas .................................... 0.20 IZoning Definitions _ R-E Estate Residential District - a low density residential area primarily in outlying areas with a minimum lot area of 9,000 square feet. R-L Low Density Residential District - low density residential areas located throughout the City with a minimum lot area of 6,000 square feet. R-M Medium Density Residential District - both low and medium density residential areas with a minimum lot area of 6,000 square feet for one - family or two-family dwellings and 9,000 square feet for a multiple family dwelling. R-H High Density Residential District - high density residential areas with a minimum lot area of 6,000 square feet for one -family or two-family �I dwellings, 9,000 square feet for a multiple family dwelling, and 12,000 square feet for other specified uses. R-P Planned Residential District - designation of areas planned as a unit i� (PUD) to provide a variation in use and building placements with a minimum lot area of 6,000 square feet. May 1984 Design Criteria Revised January 1997 3-3 0 DRAINAGE CRITERIA MANUAL so 30 t- 20 Z tL U W 10 Z W C. 0 5 in W c 3 O U 2 C LU H Q 1 RUNOFF t (I P II 1 I ice r c AZ' a v 3`` 130 1 A �� O h y, QT .. 1 1 1 1 f 1 1 I I 1 1 1 1 1 I 1 1 I t l I i 1 1 I I 11 1 I I I I I I I I I 1 I 1 1 1 1 1 I 1 I I I I I I I I I I i 11 I I I I I I I I I I Figure 3-3 .2 .3 .5 1 1 1.15 2 3 5 VELOCITY IN FEET PER SECOND ESTIMATE OF AVERAGE FLOW VELOCITY FOR USE WITH THE RATIONAL FORMULA. 10 20 ' MOST FREQUENTLY OCCURRING "UNDEVELOPED" LAND SURFACES IN THE DENVER REGION. REFERENCE:: "Urban Hydrology For Small Watersheds' Technical Release No. 55, USDA, SCS Jan. 1975. 5-1-84 URBAN DRAINAGE & FLOOD CONTROL DISTRICT No Text r t City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (5 minutes - 30 minutes) Figure 3-1a Duration (minutes) 2-year Intensity in/hr 10-year Intensity in/hr 100-year Intensity in/hr 5.00 2.85 4.87 9.95 6.00 2.67 4.56 9.31 7.00 2.52 4.31 8.80 8.00 2.40 4.10 8.38 9.00 2.30 3.93 8.03 10.00 2.21 3.78 7.72 11.00 2.13 3.63 7.42 12.00 2.05 3.50 7.16 13.00 1.98 3.39 6.92 14.00 1.92 3.29 6.71 15.00 1.87 3.19 6.52 16.00 1.81 3.08 6.30 17.00 1.75 2.99 6.10 18.00 1.70 2.90 5.92 19.00 1.65 2.82 5.75 20.00 1.61 2.74 5.60 21.00 1.56 2.67 5.46 22.00 1.53 2.61 5.32 23.00 1.49 2.55 5.20 24.00 1.46 2.49 5.09 25.00 1.43 2.44 4.98 26.00 1.40 2.39 4.87 27.00 1.37 .2.34 4.78 28.00 1.34 2.29 4.69 29.00 1.32 2.25 4.60 30.00 1.30 2.21 4.52 City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (31 minutes - 60 minutes) Figure 3-1b 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 1 0.83 1.42 2.89 60.00 1 0.82 1.40 2.86 I 2.0 r — i 10000 n ,s r000.411+ Cot.ncuwT t. •.rnrs .10 9000 10.r*L. .PP•OP•ult To .4Tt•4.1 .. 8000 SOr TOr O1 CNIONCL 1.0 7000 t Is PtCI—OC.L Co Ca"S SLOPE .08 8000 KIE.tit • . 0 PrOC[t*NGS .1.6 07 SO00 Plot 110 EC..TION *.) .80 06 4000 I` 70 EXAMPLE tact 0•8•E0 L,rtSI UP .05 3000 brew, S • 0.01 is .60 _ ' _• l =�w "200 N U. Y. 6o F .04 SO n • 021 U so � 2000 . • 0.22 to LL � 1.90: 0 • to cps _ .03 r .40 Z Z s —'-- Z 30 _ —' s _ 900 - — z .02 T Soo S a - --- - -- C 700 •+ raw � ' _ _ _ Soo o "•' z s 300 z s O 400 W x INSTRUCTIONS UI J OI Q 300 oT w N •i t CON.ECr I/n 0.140 ..I. SLOPE Ist Q x •N0 CO.NCCI o,sc.•.ac Io, .tr. U 07 Z .008 200 OAT. l.It NCIE r.0 LINES VS? .02 1NTt R1ICT At T.Pw..f LINE IM y, T .007 cONILETE SOLUTION Q .Ot U .006 2. r0* ""LOW , LL. .003 too ••1..N0 C...WEL 0 90 .S E.O.. USE NOracw•PN so 70 .;,. I Uj .004 60 IL SO Io • i , .003 I OEa..tNa �� 40 30 20 m From BPR POmON Or Cu.RI 1 1'—�7/ uorG a0,. •'. 1��S ��l OCIE..uE OEII. I 101 TO[.L DISC ... GE �+ tNT,rE SCCI.ON • Total USE .ON0*..1. TO OCT[•.•.t 0. .. SECT.*. • r0• DEPT. ra . TO OE r(.wIN[ O.ft...GE ' IN COMPOSITE SEC110. r0110...fr.UCTIe. I TU� r I� TO UST... sc..+cE .w —'1_. I ? m stcTIOo IF•T •asU.t0 oc1r. a 1 *Er... * 100 1,*.[ ..TI* 1. .NO 01.1. ! lot" 0, • 0� .0 .002 Figure 4-1 NONOGRAPH FOR FLOW IN TRIANGULAR GUTTERS (From U.S. Dept. of Commerce, Bureau of Public Roads, 1965) MAY 1984 4-3 I— Z Q. H ttJ a .08 t�+ W .07 0 06 Cr .OS (� .04 U 1— 03 Q ~r.L .02 ii W 0 Fox DESIGN CRITERIA U. 1.0 .9 .8 .7 .3 .2 I C s=060 f-08 . s=0.4% F=0.5 I I BELOW MINIMUM ALLOWABLE ' STREET GRADE 0 2 4 6 8 10 12 14 'SLOPE OF GUTTER (%) Figure 4-2 REDUCTION FACTOR FOR ALLOWABLE GUTTER CAPACITY Apply reduction factor for applicable slope to the theoretical gutter capacity to obiain allowable gutter capacity. (From: U.S. Dept. of Commerce, Bureau of Public Roads, 1965) MAY 1984 4-4 DESIGN CRITERIA ly r in ` 1r Mtn Flow one 3t r. • = ..� • . . • • �. •.� ♦ i -•vim.. ••-• ••••Ji0 I DRIVE -OVER CURB. GU KZS. 1 2'6v 4' u 6• s abo erbhe'wrb be 1 1& 4 OrSlope Sidewalk to mrb-1/eto 119" Per M cv •�.✓.� � :i• :'► .:fir ��.`�' '_; •. 4' Min. VERTICAL 6 INCH CURB C RTS. 1 EDGE SURFACE 1/8" R • . ' • 3/4�� Min : IL ' 4� ::.:.• A. ' NOTE: JOINT SHALL 8E CUT 1/4 THICKNESS OF CONCRETE INITIALLY MY JOINT FOR WALKS KTs AND SI 1 1/21' L4UZ 1" 1 U2�rR' a'• 2�R. T � N 1,6 OUTFALL CUR-8 AND GUTTER Il-es CURB AND GUTTER DETAILS 7 8-10 72 . Y OF FORT C0LLINS, COI.DRADO ENGINEERING DIVISION eoc nvrn �� REVISED 4-W wi n_ do 4 1] 1 1 APPENDIX C 1 Inlet Documentation i 1 11 1 1 1 1 1 1 1 11 1 91 II -{�-55oc►a.�es THIS FINAL STORM DRAINAGE STUDY AND REPORT FOR ' MOUNTAIN RIDGE P.U.D. 3rd FILING WAS PREPARED BY LAND DEVELOPMENT SERVICES USING THE CITY OF FORT COLLINS STORM DRAINAGE DESIGN CRITERIA AND CONSTRUCTION STANDARDS, dated May, 1984. ALSO, AN UPDATE TO THE 1984 CRITERIA AND STANDARDS PROVIDED BY THE CITY OF FORT COLLINS STORMWATER UTILITY, dated April, 1997 WAS USED. The results of this drainage study are reported in the enclosed text iand in the supporting documents, and shown in further detail on the Final Utility Plans submitted concurrently with this report. ' This Report is a revision of the initial Final Storm Drainage Report originally submitted by this office and signed on November 22, 1999. ' Signed this 29th day of April, 2000. I r^ Dennis L. Donovan, P.E. — L C7 . Land Development Services 309 W. Harmony Road Fort Collins, Colorado 80526 Phone: (970) 454-1972 I n 1 � 1 REVISED FINAL STORM DRAINAGE REPORT MOUNTAIN RIDGE FARM P.U.D. 3RD FILING CITY OF FORT COLLINS, COLORADO (April, 2000) PREPARED BY: LAND DEVELOPMENT SERVICES I. GENERAL INFORMATION MOUNTAIN RIDGE FARM P.U.D. 3RD FILING IS A PROPOSED RESIDEN- TIAL SUBDIVISION IN THE SOUTHWEST PART OF FORT COLLINS. THE SITE IS GENERALLY LOCATED ONE -QUARTER MILE WEST OF SOUTH SHIELDS STREET MIDWAY BETWEEN HARMONY ROAD AND HORSETOOTH ROAD. THE PROPOSED DEVELOPMENT PROJECT IS LOCATED AT THE NORTHEAST CORNER OF SENECA STREET AND TROUTMAN PARKWAY. BOTH ARE COLLECTOR STREETS WHICH ARE TO BE CONSTRUCTED IN ' CONJUNCTION WITH THE ON -SITE LOT DEVELOPMENT. A VICINITY MAP SHOWING THE GENERAL LOCATION IS PROVIDED AT THE END OF THIS REPORT. THE STORM DRAINAGE CONDITIONS IN THE AREA OF MOUNTAIN RIDGE FARM P.U.D. HAVE PREVIOUSLY BEEN REPORTED ON NUMEROUS OCCASIONS, BOTH BY THIS OFFICE AND OTHER FIRMS. LAND DEVELOP- MENT SERVICES STUDIED AND REPORTED STORM DRAINAGE SYSTEMS FOR THE MOUNTAIN RIDGE FARM P.U.D. PRELIMINARY AND MASTER PLAN APPROVAL, FOR THE SOUTH SHIELDS STREET IMPROVEMENT AND WIDENING PROJECT, AND FOR MOUNTAIN RIDGE FARM P.U.D. 1ST FILING. THE SEAR -BROWN GROUP, PREVIOUSLY R.B.D. ENGINEERING, INC., HAS PREPARED SEVERAL STUDIES ON THE STORM DRAINAGE CONDITIONS IN THIS AREA FOR THE CITY DESIGNATED MASTER STORM DRAINAGE ' BASINS IN WHICH THE MOUNTAIN RIDGE FARM P.U.D. PROJECT IS LOCATED. ALL OF MOUNTAIN RIDGE P.U.D. 3RD FILING IS LOCATED IN THE CITY'S McCLELLANDS & MAIL CREEK MASTER STORM DRAINAGE BASIN. ' ALL OF THOSE STUDIES REPORT THAT CITY WIDE REGIONAL DETENTION FACILITIES WERE, AND STILL ARE, NECESSARY IN THE MOUNTAIN RIDGE FARM P.U.D. DEVELOPMENT AREA. REGIONAL DETENTION POND #247 (AS IDENTIFIED IN THOSE STUDIES) WAS BUILT ALONG WITH THE MRF 1ST FILING DEVELOPMENT. THAT "REGIONAL" DRAI NAGE FACILITY HAS ALREADY BEEN CERTIFIED AS TO FINISH GRADES AND AS TO COMPLETION OF NECESSARY STORM DRAINAGE ' IMPROVEMENTS. THE CERTIFICATION OF POND #247 - AND ITS DOWNSTREAM STORM ' SEWER AND OVERFLOW SWALE - WAS A CONDITION OF THE CITY'S ACCEPTANCE OF THE M0UNTAIN RIDGE FARM P.U.D IST FILING'S STORM DRAINAGE IMPROVEMENTS. CITY ACCEPTANCE WAS REQUIRED FOR BUILDING PERMIT AND CERTIFICATES OF OCCUPANCY FOR THE HOMES CONSTRUCTED WITHIN THE 1ST FILING. REGIONAL DETENTION POND #278 FOR THE McCLELLANDS & MAIL CREEK BASIN WILL BE CONSTRUCTED WITH THE 3RD FILING DEVELOP- MENT. THE MOUNTAIN RIDGE FARM P.U.D. 1ST FILING DEVELOPMENT ABUTS SHIELDS STREET AND IS LOCATED TO THE EAST (DOWN -STREAM) OF THE 3`d FILING SITE. MUCH OF THE AREA TO THE EAST OF THE 3`d ' FILING, INCLUDING IMPROVEMENTS TO SHIELDS STREET, WAS DEVELOPED IN CONJUNCTION WITH THE EARLIER STAGES OF THE OVER- ALL MOUNTAIN RIDGE FARM P.U.D. DEVELOPMENT. ' THE 3RD FILING SITE CONTAINS 18.26 ACRES. THE LAND HAS A GENTLE SLOPE OF 1 TO 1.5 PERCENT FROM WEST TO EAST. THE PARCEL IS CURRENTLY VACANT LAND, WITH NO VISIBLE EVIDENCE OF PREVIOUS AGRICULTURAL USES. VEGETATION IS MINIMAL, WITH SPARSE GRASS - COVER, SOME SHRUBS, AND A FEW SMALL TREES. ' THE DEVELOPMENT PLAN FOR THE SITE INCLUDES 21 SINGLE FAMILY DETACHED LOTS, 29 TOWNHOME LOTS, AND THE CITY OWNED REGIONAL DETENTION POND #278. IN ADDITION TO THE LOCAL STREETS ' SERVING THE LOTS, THE ADJACENT COLLECTOR STREETS (SENECA STREET ON THE WEST AND TROUTMAN PARKWAY ON THE SOUTH) ARE TO ' BE CONSTRUCTED AS A PART OF THE 3rd FILING. DESCRIBING THIS SITE MORE SPECIFICALLY, THE PARCEL IS A ' PORTION OF THE SOUTH HALF OF THE NORTHEAST QUARTER OF SECTION 34, T7N, R69W OF THE SIXTH MERIDIAN, CITY OF FORT COLLINS, COUNTY . OF LARIMER, STATE OF COLORADO. ' THE PROPERTY IS BOUNDED IN ALL DIRECTIONS BY EXISTING AND PROPOSED SINGLE FAMILY RESIDENTIAL SUBDIVISIONS. ALSO, TO THE WEST (ACROSS THE PROPOSED SENECA STREET) THE SITE IS BOUNDED BY THE CITY OWNED WESTFIELD PARK. THE PARK SITE HAS BEEN PARTIALLY DEVELOPED. ' TO THE SOUTHWEST OF THE SITE IS AN EXISTING ELEMENTARY SCHOOL AND A JUNIOR HIGH SCHOOL — AS WELL AS ADDITIONAL EXISTING SINGLE FAMILY RESIDENCES. TO THE SOUTHEAST OF THE SITE IS VACANT LAND THAT IS CURRENTLY ZONED FOR MIXED USE MULTI- FAMILY AND SINGLE FAMILY USES. THE PROPOSED MOUNTAIN RIDGE FARM P.U.D. 3PD FILING RESIDENTIAL USES, AND THE CITY'S PROPOSED REGIONAL STORM ' 2 1] I DRAINAGE DETENTION POND Q278) ARE CONSISTENT WITH THE APPROVED MASTER PLAN AND PRELRvIINARY PLAT AND SITE PLAN FOR THE MOUNTAIN RIDGE FARM PLANNED UNIT DEVELOPMENT (P.U.D.). THE SITE IS BOUNDED ON THE EAST BY THE PLEASANT VALLEY AND LAKE CANAWV&LC) COMPANY IRRIGATION DITCH, WHICH SEPARATES THE 3RDFILING FROM THE PREVIOUSLY DEVELOPED I ST FILING AND THE APPROVED, BUT AS YET UNDEVELOPED, 2m FILING OF MOUNTAIN RIDGE FARM P.U.D. THERE ARE NO OTHER IRRIGATION DITCHES THAT ARE LOCATED WITHIN, OR THAT ARE ANTICIPATED TO AFFECT THE SITE. THE PLEASANT VALLEY AND LAKE COMPANY DITCH WAS REALIGNED AND LINED WITH FABRIC WITHIN MOUNTAIN RIDGE FARM P.U.D. - AND WELL BEYOND TO THE SOUTH - AS A PART OF THE FIRST FILING IMPROVEMENTS. AN EMERGENCY SPILLWAY WITH A CONCRETE HEADWALL WAS INSTALLED AT THAT TIME FOR STORM DRAINAGE CONTROL PURPOSES. ALSO, A HEADWALL STRUCTURE AND IRRIGATION WATER OUTLET PIPE WAS CONSTRUCTED IN THE DITCH. A 12 INCH IRRIGATION PIPE MEANDERS THROUGH THE 1ST FILING, CROSSES SHIELDS STREET, AND ULTIMATELY FEEDS THE DETENTION AND IRRIGATION POND WITHIN TROUTMAN PARK IN THE FOUR SEASONS DEVELOPMENT EAST OF SHIELDS STREET. 1 r ANOTHER MRIGATION WATER OUTLET WAS INSTALLED RECENTLY TO ALLOW DELIVERY OF IRRIGATION WATER FROM THE PV&LC DITCH INTO THE CITY OWNED REGIONAL POND #278 AREA. THERE A TEMPORARY IMPOUNDMENT AND PUMPING STATION WAS BUILT TO ALLOW DELIVERY OF UNTREATED WATER FOR THE IRRIGATION OF WESTFIELD PARK. THE IRRIGATION DITCH WILL BE CROSSED WITH SANITARY SEWER, A 12 INCH WATER MAIN, AND A 36 INCH STORM DRAIN WITH THE COMPLETION OF THE MRF 3RD FILING. ALSO, A 8 FOOT BY 4 FOOT CONCRETE BOX CULVERT WILL BE INSTALLED FOR THE DITCH CROSSING UNDER TROUTMAN, A TEMPORARY CULVERT THAT HAS BEEN USED FOR CROSSINGS OF THE DITCH WILL BE REMOVED, AND THE DISTURBED AREA WILL BE REGRADED AND LINED TO COMPLETE THE SYSTEM INTENDED TO MINIMIZE ANY DITCH LOSSES TO SEEPAGE. AS STATED ABOVE, THE CITY DESIGNATED "MASTER STORM DRAINAGE BASIN" IN WHICH THE 3' FILING IS LOCATED IS THE McCLELLANDS & MAIL CREEK DRAINAGE BASIN. A SMALL PORTION OF THE CITY'S "FOOTHILLS DRAINAGE BASIN" (AS ORIGINALLY IDENTIFIED) WILL ALSO DRAIN ONTO THE SITE. 3 I THE CITY'S MASTER STORM DRAINAGE BASIN STUDIES IN THIS AREA HAVE BEEN RE-EVALUATED AND UPDATED BY THE SEAR -BROWN GROUP OVER THE COURSE OF THE MOUNTAIN RIDGE FARM P.U.D. DEVELOPMENT. MINOR MODIFICATIONS TO THE MASTER BASINS HAVE BEEN PROPOSED AND APPROVED BY THE CITY AS DEVELOPMENT HAS OCCURRED IN THE AREA. THE MASTER BASIN STUDIES AND REPORTS AND THE SITE SPECIFIC DRAINAGE STUDIES FOR THE DIFFERENT PHASES OF THE MOUNTAIN RIDGE P.U.D., AS WELL AS ADJACENT RESIDENTIAL DEVELOPMENTS, GO INTO GREAT DETAIL IN DISCUSSING STORM DRAINAGE SYSTEMS WITHIN THE AREA. MOST RECENTLY, THE MASTER STORM DRAINAGE PLAN FOR THE McCLELLANDS & MAIL CREEK BASIN WAS RE -ANALYZED IN 1999 BY THE SEAR -BROWN GROUP TO REFLECT THE CITY'S DESIRE TO EVALUATE THE IMPACT OF HIGHER RAINFALL INTENSITIES THAN HAD HISTORICALLY BEEN USED FOR DESIGN PURPOSES. THE INCREASED RAINFALL WAS ROUTED THROUGH THE EXISTING _ AND PROPOSED DETENTION FACILITIES. THE STUDY FOUND THAT THE INCREASED RAINFALL INTENSITY CREATES A NEED TO PROVIDE LARGER STORAGE CAPACITY (DETENTION VOLUME) WITHIN REGIONAL STORM WATER DETENTION FACILITIES THAN ORIGINALLY ANTICIPATED AND WHEREVER POSSIBLE. THE EVALUATION ALSO PLACES SOME NEW RESTRICTIONS ON DRAINAGE BASINS CONTIBUTING TO EXISTING DETENTION POND #247. MORE ON THIS LATER IN THE REPORT. THE CONCEPTUAL DESIGN OF POND #278 BY THE SEAR -BROWN GROUP, AS DISCUSSED IN THEIR REPORT TITLED "REGIONAL DETENTION POND 278 HYDROLOGY RE-EVALUATION, MCCLLELANDS & MAIL CREEK BASIN, FORT COLLINS COLORADO, DATED JULY, 1999" ACCOMMODATED A LARGER DETENTION VOLUME WITHIN POND 278. THE SWMM MODEL USED IN THE STUDY SHOWED THE EXTRA VOLUME HELPED ALLEVIATE, OR AT LEAST MINIMIZE, ADVERSE IMPACTS ON EXISTING DOWNSTREAM STORM WATER STORAGE AREAS FOR THE LARGER RAINFALL INTENSITIES. HOWEVER, THE SIDE SLOPES OF THE MODIFIED DETENTION POND DESIGN (CONCEPTUAL) WERE PROPOSED AT A 3 TO 1, OR 33%, SIDE SLOPE. ' IT IS LARGELY ACCEPTED THAT A 4 TO 1, OR 25%, CROSS SLOPE IS THE MAXIMUM STEEPNESS DESIRABLE FOR ON -GOING MAINTAINANCE OF ANY LANDSCAPED GREEN BELT AREAS. THE CONCEPTUAL POND DESIGN WAS AWKWARD REGARDING NOT PROVIDING ADEQUATE FLAT AREAS FOR UTILITY INSTALLATION AND TOP OF BANK STABILITY ISSUES WOULD HAVE TO BE ADDRESSED. IT WOULD ALSO REQUIRE A MAJOR 1 4 MODIFICATION TO THE EXISTING IRRIGATION WATER DELIVERY SYSTEM FOR WESTFIELD PARK BY WORKING WITH CITY STAFF AND THE SEAR -BROWN GROUP STORM DRAINAGE STAFF, WE WERE ABLE TO FIND A SUITABLE CIVIL ENGINEERING DESIGN FOR POND 4278 THAT WILL PROVIDE ADEQUATE DETENTION VOLUME AND ALLOW FOR AN ATTRACTIVE, MAINTAINABLE (BY THE HOMEOWNER ASSOCIATION) GREEN BELT. THE NECESSARY DETENTION VOLUME AND DESIRABLE SIDE SLOPE FOR THE POND WAS ACHIEVED BY THE FOLLOWING PROPOSED DESIGN CHANGES FROM THE DESIGN ORIGINALLY PROPOSED IN THE PRELIMINARY PLAN AND IN THE INITIAL FINAL PLAN SUBMITTED: 1.. STEEPENING THE FALL FROM THE REAR LOT LINE ELEVATIONS AND NARROWING THE WALKABLE PLATEAU (SHELF) WIDTH FROM 10 FEET TO 8 FEET FROM THE REAR LOT LINE TO THE TOP OF BANK OF THE DETENTION POND. 2. MAINTAINING A 4:1 SIDE SLOPE FROM THE HINGE POINT 8 FEET BEHIND THE REAR LOT LINES DOWN TO 3 VERTICAL FEET ABOVE THE PERMANENT POND WATER SURFACE. POND #278 IS TO BE A "LIVE" POND, STORING IRRIGATION WATER FOR THE CITY PARK. 3. CONSTRUCTING A 2 FOOT IN 4 FOOT DROP OFF (SLOPE) ABOVE THE ELEVATION OF THE PERMANENT IRRIGATION (AND STORM DRAINAGE) WATER SURFACE ELEVATION (WSEL) AND AT THE TOE OF SLOPE OF THE 4:1 SLOPED BANK. THIS HELPS INCREASE DETENTION POND VOLUME LOST BY ADHERING TO A 4 TO 1 SLOPE, AND WILL CREATE AN AMENITY ABOVE THE POND SURFACE FOR THE NEIGHBORHOOD TO ENJOY. MANY DETENTION PONDS EXIST IN THE FRONT RANGE WITH THIS SAME TREATMENT CLOSE TO THE PERMANENT WSEL. 4. ELIMINATING THE "PARK LIKE" GENTLY SLOPING PLATEAU THAT WAS PREVIOUSLY DESIGNED FOR THE NORTHWEST CORNER OF THE POND. 5. SLOPING THE GRADES FROM THE RIGHT OF WAY OF SENECA STREET DOWNWARD TOWARD THE POND INSTEAD OF UPWARD FROM THE RIGHT OF WAY. 6. MOST IMPORTANTLY, AND WHAT IT REALLY TOOK TO ACHIEVE THE GOAL, IS THE INCLUSION OF APPROXIMATELY 800 LINEAR FEET OF VERTICAL STACKED BLOCK WALL THREE (3) FEET HIGH AROUND THE NORTH AND SOUTH SIDES AT THE TOP OF THE DETENTION POND. ' OVERALL, THE MODIFICATIONS LISTED ABOVE AND SHOWN ON THE FINAL UTILITY PLANS COMPENSATE FOR VARIATIONS FROM THE POND GRADING (i.e. 3:1 FROM PROPERTY LINE TO POND BOTTOM) THAT WAS ' ORIGINALLY PROPOSED IN CONCEPT BY THE SEAR -BROWN GROUP FOR THE CITY OF FORT COLLINS. 1 S I THIS OFFICE AND THE SEAR -BROWN GROUP WORKED CLOSELY TO BRING THE DESIGN INTO BALANCE, AND THEIR NEWEST REPORT TITLED "Final Hydraulic Design Report — Regional Detention Pond 278, McClellands & Mail Creek Basin — Fort Collins, Colorado — April, 2000" REFLECTS A SOLUTION THAT MEETS EVERYONES NEEDS. THEIR REPORT IS SUBMITTED SEPARATELY FROM THIS REPORT, BUT THE RESULTS DESCRIBED IN THE REPORT ARE COMPATIBLE WITH THE DESIGN DRAWINGS AND SUPPORT DOCUMENTS FOR THE 3' FILING. SHEETS A-1 thru A-5 WERE PREPARED BY THE SEAR -BROWN GROUP FOR EXHIBITS TO THEIR REPORT. THOSE FIVE SHEETS REFLECT THEIR CONSTRUCTION DETAILS FOR THE POND AND ASSOCIATED DRAINAGE FACILITIES. THOSE SHEETS ARE ALSO INCLUDED IN THE SET OF UTILITY PLANS FOR MOUNTAIN RIDGE FARM P.U.D. 3'd FILING. FOR THIS REPORT, LAND DEVELOPMENT SERVICES IS PROVIDING EXHIBITS THAT ARE SHEETS IN THE UTILITY PLANS AS WELL. THE '. FOLLOWING SHEETS FROM THE FINAL UTILITY PLANS FOR MOUNTAIN RIDGE' FARM PUD 3' FILING ARE FOLDED AND ATTACHED AS EXHIBITS A, B, C, D, & E AT THE END OF THIS REPORT: SHEET 3 (STORM DRAINAGE SUB -BASIN BOUNDARIES) SHEET 4 (STORM DRAINAGE AND EROSION CONTROL PLAN) SHEET 15 NEIGHBORHOOD GRADING AND DRAINAGE PLAN — NORTH) SHEET 16 (NEIGHBORHOOD GRADING AND DRAINAGE PLAN - SOUTH) SHEET 17 (STORM DRAIN PLAN AND PROFILES) SHEET 3 PROVIDES A COMPREHENSIVE OVERVIEW OF THE ON -SITE AND OFF -SITE DRAINAGE CONDITIONS PERTINENT TO THE 3' FILING. SHEETS 4,15 & 16 PROVIDE MORE DETAILED DESIGN INFORMATION. DRAINAGE AREAS (DA#'s, OR DA's) 1 THROUGH 16 HAVE BEEN IDENTIFIED WITHIN THE LIMITS OF THE 3RD FILING, AND DRAINAGE AREAS OSI THROUGH OS6 ARE IDENTIFIED AS SUBBASINS TO THE NORTH AND WEST THAT FLOW ONTO THE SITE AND IMPACT STORM WATER RUNOFF CALCULATIONS WITHIN THE 3RD FILING. DRAINAGE AREAS T 1, TR 1 THROUGH 7, AND SH 1 (AS WELL AS DA#'S AND 16) ARE SUBBASINS THAT CONTRIBUTE STORM RUNOFF THAT AFFECTS THE DESIGN OF TROUTMAN PARKWAY. THE REQUIREMENT TO DESIGN TROUTMAN PARKWAY GREATLY CHANGED THIS REPORT FROM THE REPORT SUBMITTED WITH THE UTILITY PLANS LAST DECEMBER. THE CITY IS REQUIRING THAT TROUTMAN BE DESIGNED AND BUILT FROM SENECA STREET TO WABASH STREET AS A PART OF THE 3' FILING DEVELOPMENT REQUIREMENTS. THE CITY POLICY IS THAT THE DESIGN OF THE STREET EXTEND AT LEAST 400 FEET TO THE EAST BEYOND THE WABASH CONNECTION. IN ORDER TO ADEQUATELY DESIGN THE 400 FEET OF COLLECTOR STREET, IT WAS NECESSARY TO DETERMINE HOW THE STREET NEEDS TO CONNECT INTO SHIELDS STREET APPROXIMATELY 700 FEET FURTHER TO THE EAST. TT BECAME APPARENT THAT AN ADEQUATE DESIGN OF TROUTMAN FROM SENECA TO SHIELDS WOULD BE NECESSARY, SO WE PREPARED ONE. ACCORDINGLY, DA#'s TR 1 THROUGH TR 7 WERE IDENTIFIED AS SUB -BASINS CONTRIBUTING TO THE TROUTMAN PARKWAY STREET AND STORM DRAINAGE IMPROVEMENTS. A SMALL SUBBASIN (TI) TO THE SOUTH OF THE 3RD FILING IN THE PROPOSED WESTBROOKE PUD 2r FILING CONTRIBUTES SURFACE FLOW ONTO TROUTMAN, AS DO DA's 1 AND 16 IN THE MRF 3RD FILING. A STUDY OF THESE SUBBASINS WAS REQUIRED TO ,j DETERMINE THE CHARACTERISTICS OF STREET SURFACE FLOWS AND STORM DRAIN CROSSINGS UNDER TROUTMAN. THERE ARE SUBBASINS SOUTH AND SOUTHWEST OF MRF 3' THAT CONTRIBUTE TO THE STORM SEWER THAT DRAINS THE REMAINDER OF WESTBROOKE 2ND AND THE SCHOOL SITE WEST OF SENECA IN A 36 INCH RCP STORM DRAIN UNDER TROUTMAN TO WABASH AND THEN UNDER WABASH TO POND #247. THE SUB -BASINS CONTRIBUTING TO THE 36 INCH STORM DRAIN WERE STUDIED BY TEAM ENGINEERING FOR WESTBROOKE AND THE SEAR -BROWN GROUP FOR THE CITY'S MASTER DRAINAGE PLAN. THE RESULTS ARE REPORTED IN THEIR INDIVIDUAL REPORTS. H. PROPOSED STORM DRAINAGE PLAN THE PROPOSED DRAINAGE PLAN IS CONSISTENT WITH PREVIOUS STUDIES, EXCEPT AS FOLLOWS: . A. MODIFICATIONS TO DETENTION POND #278 AS DISCUSSED ABOVE. B. MODIFICATIONS TO SENECA STREET, BORDERING THE 3' FILING TO THE WEST AND WESTFIELD PARK TO THE WEST, FROM THE ORIGINAL STREET PROFILE IN THE PRELIMINARY AND MASTER PLAN DESIGN. THIS MODIFICATION WAS NECESSARY TO ALLOW ANTICIPATED "MAJOR STORM" RUNOFF IN THE McCLELLANDS & MAIL CREEK BASIN TO �t EFFICIENTLY PASS THROUGH THE PARK SITE AND UNDER SENECA DRIVE TO POND. #278. ' THE PRELIMINARY DESIGN OF SENECA BY THIS OFFICE WOULD HAVE CREATED SPILLWAYS NORTH AND SOUTH OF THE NATURALLY OCCURING LOW POINT OF SENECA. THAT DESIGN WOULD HAVE MODIFIED THE EXISTING DRAINAGE PATTERNS AND ADDED SIGNIFICANT COSTS TO I THE CROSSING - AS WELL AS CREATED A NEED FOR A SIGNIFICANTLY LARGER DETENTION POND ON THE WEST SIDE OF SENECA STREET WITHIN THE PARK SITE. ' PREVIOUS DISCUSSIONS AMONG THE DEVELOPER, THE CITY PARKS AND RECREATION AND STORM WATER DEPARTMENTS, AND THIS OFFICE ESTABLISHED THAT POND #278 SHOULD BE THE MAJOR DETENTION ' FACILITY IN THE IMMEDIATE AREA. ACCORDINGLY, THE VERTICAL DESIGN OF SENECA WAS MODIFIED FROM THE PRELIMINARY TO PROVIDE FOR A MORE COST EFFECTIVE AND FUNCTIONAL CROSSING. ' C. MODIFICATIONS TO THE STORM DRAINAGE PLAN TO IDENTIFY THE DRAINAGE SYSTEM AFFECTING TROUTMAN PARKWAY AND PROVIDE FOR DESIGN TO ACCOMMODATE STORM RUNOFF WITHIN AND CROSSING THAT STREET. THE FINAL DRAINAGE PLAN FOR THE 3' FILING IS IN COMPLIANCE ' WITH THE CITY'S MASTER DRAINAGE PLANS AND WITH THE CITY'S STORM DRAINAGE CRITERIA. ALL OF THE SUBBASINS WITHIN AND AFFECTING THE 3'D FILING ARE IDENTIFIED AT EXHIBIT A, WHICH IS THE SUB -BASIN BOUNDARY DRAWING. EXHIBIT B, C & D PROVIDE INFORMATION ON THE STORM DRAINAGE AND EROSION CONTROL PLAN FOR MRF 3' ITSELF. WHERE STORM DRAINAGE RUNOFF FROM INDIVIDUAL STORM DRAINAGE BASINS COMBINE, A DESIGN POINT IS IDENTIFIED TO PROVIDE PERTINENT INFORMATION TO ADDRESS THE HYDRAULIC SOLUTIONS FOR THE COMBINED FLOWS. THE SUBBASIN DESCRIPTIONS AND DESIGN POINT DESIGNATIONS ARE SHOWN ON ALL OF THE EXHIBITS AND ARE GENERALLY DESCRIBED AS FOLLOWS: DRAINAGE SUBBASIN (DA)#1 WILL SHEET FLOW ONTO THE TROUTMAN PARKWAY STREET SECTION (DISCUSSION OF RUNOFF FROM ' DA#1 IS CONTINUED AFTER DA14 AND 15 BELOW). DA#'S 2 AND 3 FLOW TO A 10 FOOT INLET ON THE NORTH SIDE OF SAILCREST COURT, WHICH IS DESIGN POINT ONE (DP I). THE STORM DISCHARGE THEN FLOWS THROUGH A15 INCH HDPE STORM DRAIN CULVERT TO POND 278., RUNOFF FROM DA#5 WILL SHEET FLOW DIRECTLY INTO POND 278. ' DRAINAGE SUBBASIN DA#4 WILL FLOW OFF THE WEST END OF SAILCREST CT AND ALONG THE EAST SIDE OF SENECA TO A 5 FOOT INLET AT THE LOW POINT IN THE STREET PROFILE (THE INLET IS DESIGN POINT In. DA#6 AND DA#OS6 (OS STANDING FOR OFF -SITE) WILL FLOW TO AND ALONG THE WEST SIDE OF SENECA INTO A 10 FOOT INLET, WHICH IS ' DESIGN POINT (DP) III. 1 8 ' SUBBASINS DA#'S 7, OS3, OS4 AND OS5 WILL FLOW TO THE SOUTH ON THE WEST SIDE OF SENECA STREET TO DESIGN POINT III. SUBBASINS DA#'S 8 AND OS2 WILL FLOW ON THE EAST SIDE OF SENECA SOUTHERLY TO DP H. DUE TO THE AMOUNT OF STORM DISCHARGE ENTERING THE WESTERLY GUTTER OF SENECA FROM DA#'S OS3 AND OS4, IT IS NECESSARY TO ADD A 6 FOOT LONG "AT GRADE", OR CONTINUOUS GRADE, INLET AT THE SOUTH SIDE OF THE WESTFIELD DRIVE ' INTERSECTION WITH SENECA. FROM THE 6 FOOT INLET, WHICH IS DESIGN POINT VII, THE INTERCEPTED AMOUNT OF RUNOFF WILL FLOW IN AN 18 INCH RCP CULVERT AND DRAIN INTO THE 5 FOOT INLET AT DP U. THE REMAINDER WILL OVERFLOW THE 6 FOOT INLET AND CONTINUE TO FLOW SOUTHERLY ' IN THE GUTTER TO DP III. STORM RUNOFF WILL BE CARRIED FROM DP III EASTERLY UNDER ' SENECA STREET IN A 24 INCH RCP CULVERT TO THE 5 FOOT INLET AT DESIGN POINT II. COMBINED FLOWS FROM DESIGN POINTS II, III AND VII WILL BE CARRIED IN A 30 INCH HDPE STORM DRAIN FROM THE INLET AT t DP II TO POND 278, WHICH IS A RELEASE POINT FOR THE STORM DRAIN SYSTEM WE HAVE DESIGNATED AS DESIGN POINT VI. DA#9 WILL SHEET FLOW DIRECTLY INTO POND 278. STORM RUNOFF FROM DA#S 10, 11 &13 WILL FLOW TO AND ALONG WESTFIELD CT AND WESTFIELD DRIVE TO A FIVE (5) FOOT INLET AT THE END OF THE CUL-DE- SAC ON WESTFIELD DRIVE. THIS INLET IS DESIGN POINT IV. FROM THERE THE COMBINED FLOWS WILL BE CARRIED PARTIALLY IN A 15 INCH HDPE PIPE CULVERT AND PARTIALLY IN AN EARTHEN SWALE TO AN AREA INLET TO THE EAST OF THE CUL DE SAC. RUNOFF FROM DA#'S 12 AND OS 1 WILL FLOW ALONG AN EARTHEN ' SWALE (WITH A TWO FOOT WIDE CONCRETE DRAIN PAN AT THE INVERT OF THE SWALE) AT THE REAR OF LOTS 7 THROUGH 16 TO A CROSSING OF THE BIKE PEDESTRIAN PATH NEAR THE SOUTHEAST CORNER OF LOT 7. THERE THE RUNOFF FROM DA's 12 AND OS 1 WILL CROSS UNDER THE BIKE TRAIL THROUGH A 15 INCH HDPE PIPE CULVERT. ' JUST DOWNSTREAM OF THE CULVERT UNDER THE BIKE PATH IS AN AREA INLET, WHERE ALL OF THE OVERLAND FLOWS FROM THE END OF ' THE CUL-DE-SAC AND THE REAR OF THE LOTS ENTER THE STORM SEWER SYSTEM. THE AREA INLET IS DESIGN POINT V. FROM THE AREA INLET, ALL STORM DISCHARGE FROM SUBBASINS DA#'S 10,11,12,13 AND OS ARE ' CARRIED IN AN 18 INCH HDP CULVERT DIRECTLY TO POND 278. 1 5 r-- t I SUBBASINS DA#S 14 AND 15 WILL FLOW DIRECTLY INTO THE PV&LC IRRIGATION DITCH. SUBBASINS DA# I AND DA# 16, WHICH LIE NORTH OF TROUTMAN IN THE MRF 3RD FILING, AND SUB -BASIN TR 3 CONTRIBUTE STORM RUNOFF WHICH WILL FLOW TO AND ALONG THE NORTH GUTTER LINE OF TROUTMAN TO A LOW POINT NEAR CENTERLINE STATION 11+00. THERE THE COMBINED FLOWS WILL SPILL INTO A 5 FOOT INLET, WHICH IS DESIGN POINT TR II. SUBBASIN T 1 (WESTBROOKE PUD 2' FILING) WILL SHEET FLOW INTO TROUTMAN, COMBINE WITH STORM RUNOFF OCCURRING WITH FROM DA# TR 4 AND FLOW IN THE SOUTHERLY GUTTER OF TROUTMAN PARKWAY TO A 5 FOOT INLET AT THE LOW POINT IN THE STREET CURB AND GUTTER OPPOSITE DP TR II. THIS 5 FOOT INLET IS DESIGN POINT TR III. SUBBASIN TR 4 IS THE SOUTH HALF OF RIGHT OF WAY PLUS 9 FOOT UTILITY EASEMENT IN TROUTMAN FROM SENECA TO A HIGH POINT AT ABOUT CENTERLINE STATION 12+80. SUBBASIN TR 7 ALSO CONTRIBUTES STORM RUNOFF TO DESIGN POINT III. IF SUBBASIN TR 7 IS NOT DEVELOPED AT THE TIME OF CONSTRUCTION OF TROUTMAN PARKWAY (i.e. DEVELOPS AT SOME LATER DATE), STORM RUNOFF FROM THE EXISTING PASTURE/CROPLAND WILL SHEET FLOW OVER THE SIDEWALK WHERE EXISTING AND PROPOSED GRADES MATCH TO THE CURB GUTTER. THE STORM DRAIN UNDER TROUTMAN AT THIS LOCATION WAS DESIGNED TO PASS THE ENTIRE 100 YEAR STORM AT THIS LOCATION (i.e. A 24 INCH RCP CULVERT). THE INLETS WERE DESIGNED TO INTERCEPT THE DEVELOPED 100 YEAR STORM FROM THE STREET SUB -BASINS PLUS THE 100 YEAR EXISTING CONDITION FROM UPSTREAM SUB -BASIN TR 7. THE CULVERT IS TO BE PLUGGED AND BURIED AT THE UPSTREAM END UNTIL THAT AREA IS DEVELOPED IN SOME MANNER. SUB -BASIN TR 2 CONTRIBUTES STORM RUNOFF ON THE NORTH SIDE ' OF TROUTMAN TO A 5 FOOT INLET AT APPROXIMATELY CENTERLINE STATION 17+65. THIS IS THE ONLY SUB -BASIN CONTRIBUTING TO THE INLET, WHICH IS DESIGN POINT TR I. THE RUNOFF IS FROM THE NORTH ONE-HALF RIGHT OF WAY PLUS 9 FOOT UTILITY EASEMENT OF TROUTMAN FROM STATION 12+80 TO SOUTH SHIELDS STREET. ' SUB -BASINS TR 5, TR 6, AND SH 1 CONTRIBUTE STORM RUNOFF TO A 5 FOOT INLET ON THE SOUTH SIDE OF TROUTMAN, WHICH IS DESIGN ' POINT IV. TR 5 IS THE SOUTH '/2 ROW PLUS UTILITY EASEMENT FROM STATION 12+80 TO SHIELDS, SH 1 IS THE EAST ONE HALF ON THE ROW FOR SHIELDS FROM TROUTMAN TO A HIGH POINT APPROXIMATELY 600 TO THE SOUTH (WHICH DRAINS TO THE WEST AT THE SOUTHWEST CURB RETURN 1 16 AT THE TROUTMAN INTERSECTION), AND TR 6 IS THE UNDEVELOPED ' PROPERTY SOUTH OF TROUTMAN PARKWAY THAT DRAINS TO DP TR IV. AS WITH THE OTHER STORM DRAIN CROSSING UNDER SHIELDS, THE CULVERTS (i.e. TWO (2) —18 INCH RCP PIPE CULVERTS) ARE DESIGNED TO CARRY THE 100 YEAR DISCHARGE. THE INLETS ARE DESIGNED TO INTERCEPT DEVELOPED FLOWS IN THE STREET RIGHTS OF WAY AND ' EXISTING CONDITIONS FOR THE UNDEVELOPED PROPERTY TO THE SOUTH. AGAIN, THE UPSTREAM ENDS OF THE TWO PIPES ARE TO BE PLUGGED AND COVERED UNTIL DEVELOPMENT OF THE UPSTREAM PROPERTY. ' THE HYDROLOGIC CHARACTERISTICS FOR SUB -BASINS DESCRIBED ABOVE ARE INCLUDED ON THE FOLLOWING PAGE AS TABLE 1. THE STORM DISCHARGES FOR ALL OF THE SUB -BASINS ARE ESTIMATED USING THE RATIONAL METHOD, WHERE Q = CCf IA IN CUBIC ' FEET PER SECOND (CFS). THE "C" VALUE IS THE RUNOFF COEFFICIENT RELATIVE TO THE DEGREE OF IMPERVIOUS SURFACES WITHIN THE BASIN. THE C VALUES FOR THE SUB BASINS IN THIS STUDY VARY AS ' RECOMMENDED BY THE CITY'S STORM DRAINAGE MANUAL. WEIGHTED C FACTORS WERE DETERMINED BY THE AMOUNT OF ACTUAL IMPERVIOUS SURFACES PER SECTION 3.1.6 AND TABLE 3-3 OF THE REFERENCED DESIGN MANUAL. IMMEDIATELY FOLLOWING THE TEXT OF THIS DRAINAGE REPORT AND THE VICINITY MAP IS AN ADDENDUM WITH SEVERAL PAGES OF HAND WRITTEN SUPPORTING CALCULATIONS. THE FIRST INFORMATION IS A DESCRIPTION OF HOW THE C VALUE WAS DETERMINED FOR EACH OF THE SUB -BASINS. A RUNOFF COEFFICIENT OF 0.95 WAS USED FOR IMPERVIOUS AREAS, AND 0.25 FOR GRASSED AREAS. THE AREA OF STREETS, SIDEWALKS, DRIVEWAYS, AND ROOF TOPS WERE ESTIMATED IN EACH SUB -BASIN AND WEIGHTED AGAINST THE REMAINING AREA OF LANDSCAPED SURFACES TO DETERMINE THE APPROPRIATE C VALUE FOR THAT SUB -BASIN. ' Cf IS A FACTOR TO INCREASE THE RUNOFF COEFICIENT FOR LARGER THAN MINOR STORMS. THE Cf VALUE FOR A TWO YEAR "MINOR" STORM IS 1.0, BUT INCREASES TO 1.25 FOR THE 100 YEAR "MAJOR" STORM. ' WHEN FLOWS (I.E. STORM RUNOFF) FROM SEPARATE SUBBASINS COMBINE AND FLOW TOGETHER, THE C VALUE IS WEIGHTED FOR THE COMBINED AREAS (I.E. Al X Cl PLUS A2 X C2, ETC. DIVIDED BY TOTAL ' AREA). THOSE ESTIMATED VALUES ARE ALSO SHOWN IN THE FIRST SECTION OF THE ADDENDUM UNDER COMPOSITE C VALUES. C ' ii 1 1 TA E3LE 1 i 1 W N W O V M� Mto COO MCD N f�- OCR O W CA q C �(D M Ch M Mtn v) Nvtn V uir e-CV 01,: 0) CV CA CAM v V 0 o U. ' u C � � MW W W W Oto V'(O NCDMV VMI�NWNMW (DWO� Vt`O� iN d ci0f5000C 600 N0 N040 1 C C } �(DOON W nLf) W IT it) (DNf� V NNO� ti N (D01N� VN(DV N to V (O U7 V to G C) t` r, n (O (D (D (D (D to Co to f` n rl to to h (D LL M Z L M + C >. VOVOtoW M�NM.-WNOtD to tOW W M N N N" N N N N N N N N � N N N N N'- N (V NNit i o i 0 /�. rr Z ~� 10 W toM V (D V f-MO WCM f'-O CD �Wf-0 Vf, 1�V O a�0�OCO� ������.W-O CO ODOONV fl.C()OV CID tf)CO 1 ���♦♦ N`-' NNN� B 1 I.L 0 MOMV WW VNNONO"to MVCR CD (D SOD �(00 NwM Nto M MO OOM (D OV WNOW WO O to ���r ^�NNCN �D (S70t[)00(00 .- tee-Mom.-M(�J� ^ V N(D W to n(D WN(D NO V OLo W Wor,-m tD D> N0 (D f,- MW Wfl- M hflM W NN V 0V to NM CD�NtoNC �O W n(q (D (o M to V 1� WO(O�WONOW MmV W WOONW VI�Of WMOOVMV V i `Q V`ctto� W VI�IAf�f�Om� W W to�NCD(D W Df(-^OV V (ON Q 00000a 6ci6OOON co 00 M m 0 0 i C +� N CV) I Lo M V toto � QQQQQQQQ�����.-lnCAln(n(nln �O�DODO�oQQQQQQ000000 ___>» a.(L MC.aan. 1 H 1 1 1 i i i} OD ODOC)) -M T7 0)0 CR O�'q: V'CO'T'q:� fp O r-O�Nt`�f7U) C%4 O (O07O o U. u Cc G } VM^� O O00 M M m V D1N OO TNN'If)1-�.-N O)r- O NV V V iN i= } OOIT(0(O V V (D�������� •� C O n OD (O h (O (O f-: (O (O 1-: (O (O (O (O (O 4 V V .� 0 O LL Z VM�(O M M(O (O CO cv)fO M CO M a CV of N N N N N N N N(V N N 6 N �� �� �V i� a ^, Z LO O T7 CNN tr) T7 T7 O N T7 T7 T� IA(f)(f) LO O O O N V V 'T "T " , , M M M M •O '��/ ti (TZ_ MOOD O 0"n O 000D 0 to OD OD OD OD O OOO N N V Kr N V' V� V 0 � ���WOrr-O�����MMMM 7 O N W M(O(D N O W OD � V N VO .� (� . 1M 0 P- N �Nl�l�l�l�h(�I-h(1')(�I-hil-MMM V H OOV ODMMODI�(OODNQ)00�MOO.- iQa O O N O T-: T-: O O) Q O T-(DOD(000 oo¢¢¢¢QQQa�aaaaa�a N o cc Doc oO ap0 00-mmm O 1 i i J 1 1 1 1 1 1 u 1 1 L i 1 i i 1 "P' IS THE RAINFALL INTENSITY IN INCHES PER HOUR EXPECTED FOR THE DIFFERENT FREQUENCY OF STORM (i.e. 2, 5, 10, 25, 50, OR 100 YEAR EVENTS). THE RAINFALL INTENSITY IS DEPENDENT ON THE TIME OF CONCENTRATION, WHICH IS SHOWN AS Tc ON TABLE 1. THE TIMES OF CONCENTRATION WERE DETERMINED USING THE EQUATION FOR OVERLAND FLOW CONTAINED IN REFERENCES FOR THE RATIONAL METHOD AND ADDING THE TBAE OF CONCENTRATED GUTTER FLOW TO THE DOWNSTREAM END OF THE BASIN. OVERLAND FLOW IS CALCULATED AS Tc = [1.87 (1.1-CCF) D1/2] / S1/3, AND CONCENTRATED GUTTER FLOW COMES FROM FIGURE 3-2 "ESTIMATE OF AVERAGE FLOW VELOCITY FOR USE WITH THE RATIONAL FORMULA" FOUND IN THE "URBAN HYDROLOGY FOR SMALL WATERSHEDS" TECHNICAL RELEASE NO. 50, USDA, SCS JANUARY, 1975. CALCULATIONS FOR TIMES OF CONCENTRATION FOR EACH SUB -BASIN IS SHOWN IN THE ADDENDUM FOLLOWING THE INFORMATION ON COMPOSITE C VALUES. THE SUBBASINS WITHIN THE 3RD FILING STUDY AREA ARE RELATIVELY SMALL, AND THE LONGEST TIMES OF CONCENTRATION ARE 20.4 MINUTES FOR BASIN DA#OS3 AND 19.0 MINUTES FOR DA#12. A FIVE (5) MINUTE TIME OF CONCENTRATION IS THE MINIMUM USED. THE SHORTEST Tc IS 6.9 MIN. FOR THE 2 YR STORM AND 6.3 FOR THE MAJOR STORM. RAINFALL INTENSITIES (I) ARE FOUND FROM FIG. 3-2 OF THE DESIGN CRITERIA MANUAL TITLED "RAINFALL INTENSITY DURATION CURVE". THE "I" VALUES FOR THESE SUB -BASINS VARY FROM 1.8 TO 2.9 INCES PER HOUR FOR THE MINOR STORM AND 5.2 TO 7.8 FOR THE MAJOR STORM. AS CAN BE SEEN ON TABLE 1, THE ON -SITE FLOWS ARE SMALL. DA#2 AT 1.8 CFS DURING THE MINOR/INITIAL STORM AND 6.5 FOR THE MAJOR (100YEAR) STORM ARE THE LARGEST FOR ANY INDIVIDUAL INTERNAL SUBBASIN. OFF -SITE SUBBASIN OS4 (WHICH WILL BECOME THE FOURTH AND LAST FILING TO BE APPROVED IN THE MOUNTAIN RIDGE FARM PUD) IS ESTIMATED TO CONTRIBUTE 7.8 CFS AND 27.8 CFS RUNOFF AMOUNTS TO SENECA DRIVE AFTER DEVELOPMENT. III.DESCRIPTION OF STREET FLOWS AND DRAINAGE IMPROVEMENTS DUE TO THE RELATIVELY SMALL AREAS OF THE SUBBASINS THAT WILL CONTRIBUTE STORM RUNOFF WITHIN THE 3RD FILING, STREET FLOWS WILL BE MINOR. DA#S 11 AND 13 WILL HAVE THE LARGEST CONCENTRATED FLOW WITHIN THE INTERNAL STREETS JUST NORTH OF I IL I I I i 1 I I 1 1 DP IV. THE 2YEAR INITIAL FLOW THERE WILL BE ONLY 2.5 CFS, AND THE 100YEAR FLOW WILL BE ONLY 9.1 CFS. IN SENECA STREET ADJACENT TO THE 3PD FILING, DA#'S 7, OS3, OS4 AND OS5 COMBINE ON THE NORTH SIDE OF THE 15 FOOT INLET, WHICH IS DP III. THERE, THE MINOR FLOW IS 10.4 CFS AND THE MAJOR 100 YEAR FLOW IS 36.0 CFS. CITY CRITERIA REQUIRES THAT INITIAL STORMS IN ALL CATAGORIES (LOCAL, COLLECTOR AND ARTERIAL) NOT OVERTOP THE CURB, WHICH IS 6 INCHES ABOVE THE GUTTER. ADDITIONALLY, TABLE 4- 1 OF THE OF THE DESIGN CRITERIA MANUAL FOR STREET RUNOFF ENCROACHMENT STATES THAT THE FLOW SPREAD MUST LEAVE AT LEAST ONE LANE WIDTH FREE OF WATER DURING THE MINOR STORM. ACCORDING TO FIGURE 4-1 OF THE CITY DESIGN MANUAL, THE ALLOWABLE FLOW IS DETERMINED IN THE CASE OF THE STREETS AS FOLLOWS; CROSS SLOPE OF THE CURB AND GUTTER FOR LOCAL STREETS (i.e. DRIVEOVER CURB AND GUTTER = 7.64%, A RECIPROCAL OF THE CROSS SLOPE (Z) = 1/0.0764 = 13.09 ROUGHNESS COEFFICIENT (n) = 0.016, SO RATIO Z/n = 818 PAVEMENT CROSS SLOPE = 2.0% MINIMUM, SO RATIO Z/n = 3,125 SLOPE OF CURB AND GUTTER = 0.5% MINIMUM USING THE NOMOGRAPH AT FIGURE 4-1 AT AN ALLOWABLE DEPTH OF 6 INCHES OR 0.5 FEET, DISCHARGE (Q GUTTER) = 4.8 CFS AND AN ALLOWABLE DEPTH OF 0.38 FEET IN THE TRIANCLE ABOVE THE PAVEMENT, DISCHARGE (Q OUTSIDE GUTTER) = 8.0 CFS TOTAL Q = 12.8 CFS. A RATING CURVE WAS DEVELOPED FOR THE DRIVE OVER CURB AND GUTTER PARTICULAR TO FORT COLLINS. THE DETAIL AND RATING CURVE ARE IN THE ADDENDUM IN THE SECTION ON STREET CAPACITIES. THAT CURVE SHOWS A DISCHARGE OF 9.5 CFS AT 0.5 FEET DEEP. THE MORE CONSERVATIVE VALUE OF 9.5 CFS WAS USED. THE REDUCTION FACTOR (F) FOR ALLOWABLE Q (FIG 4-2) IS 0.65 FOR A LONGITUDINAL SLOPE OF 0.5 PERCENT. ALL OF THIS LEADS TO A MAXIMUM ALLOWABLE FLOW IN THE STREETS WITH THESE MINIMUM SLOPES OF 6.2 CFS. THE INITIAL STORM CRITERIA IS MET FOR THE LOCAL STREETS, SINCE THE MAXIMUM 2YEAR FLOW IS 2.5 CFS. ADDITIONAL INFORMATION IS PROVIDED IN THE SECTION ON STREET CAPACITIES. 13 n tTHE MAJOR STORM ALLOWS A DEPTH OF 6 INCHES OVER THE CROWN FOR LOCAL STREETS. THIS WAS NOT CALCULATED, BUT WOULD BE MANY TIMES THE 9.1 CFS MAXIMUM 100 YEAR STORM RUNOFF THAT IS ESTIMATED. THE LOCAL STREETS ALL MEET CITY CRITERIA. FOR THE COLLECTOR STREET (i.e. SENECA STREET AND TROUTMAN PARKWAY), THE VARIATION FROM LOCAL STREET CRITERIA IS THAT THE GUTTER IS SHAPED DIFFERENTLY AND ONE LANE MUST BE LEFT OPEN. THE STREET CAPACITY INFORMATION IN THE ADDENDUM GOES INTO DETAIL, WITH THE CROSS SLOPE OF THE VERTICAL CURB AND GUTTER BEING 8.33 PERCENT, Z = 1/0.0833 = 12.0, Z/n = 750. BY LEAVING THE TOP 6 FEET OPEN ON EACH SIDE OF THE STREET (12 FOOT LANE TOTAL), THE MAXIMUM DEPTH IN THE FLOWLINE IS 0.51 FEET (0.17' IN THE GUTTER PLUS 17'X2% = 0.34' AT THE LIP OF THE GUTTER). FROM FIG.4-2, AT A DEPTH OF'6 INCHES, THE DISCHARGE ABOVE ' THE VERTICAL CURB AND GUTTER IS 4.8 CFS AND Q ABOVE THE 17 FEET OF PAVEMENT IS ABOUT 6.2 CFS. AGAIN, RATING CURVE FOR THE VERTICAL CURVE WAS PREPARED WHICH SHOWS THE CAPACITY TO BE ABOUT 10.5 CFS. WITH A 65 PERCENT REDUCTION FACTOR, THE ALLOWABLE FLOW IS SOMEWHERE BETWEEN 6.5 AND 7.1 CFS. ' THE ADDENDUM SHOWS THAT TROUTMAN PARKWAY MEETS CRITERIA FOR MINOR STORMS, BUT IT IS NECESSARY TO EXTEND THE STORM DRAIN SYSTEM TO THE SOUTHWEST CORNER OF THE SENECA INTERSECTION TO REMOVE FLOW THAT HAS REACHED 10 CFS TO REDUCE IT TO LESS THAN 6.5 CFS. THAT EXTENTION IS SHOWN ON THE UTILITY PLANS. THE BACK OF THE SIDEWALK FOR MINIMUM CROSS SLOPES IN THE RIGHT OF WAY AND ATTACHED 9 FOOT UTILITY EASEMENT IS ONLY 0.85 FEET HIGHER THAN THE FLOWLINE. ALLOWABLE DEPTH OF 0.5 FEET ABOVE THE CENTERLINE IS 0.63 FEET PLUS 0.5 FEET, OR 1.13 FEET ABOVE THE FLOWLINE. WITH THE GRADE DROPPING AWAY FROM THE STREET ' OUTSIDE THE BACK OF EASEMENT WEIR FLOW WILL OCCUR AND NEVER LET THE DEPTH REACH 1.13 FEET. THE COLLECTOR STREET CAPACITY CRITERIA IS MET FOR MAJOR STORMS. STORM DRAINAGE IMPROVEMENTS, OR FACILITIES, INCLUDE THE ' FOLLOWING: A 10 FOOT INLET AND A 15 INCH STORM DRAIN LINE (HIGH DENSITY POLYETHELINE PIPE CULVERT) FROM SAILCREST COURT TO POND #278; A SIDEWALK CULVERT AT THE EAST END OF WESTFIELD DRIVE. THE TEN (10) FOOT INLET WAS CHOSEN TO CAPTURE ALL OF THE 100 YEAR STORM 1¢ I AND ALLOW NO FLOW TO OCCUR IN THE EMERGENCY OVERFLOW SWALE. THAT WILL PROTECT THE 4:1 SIDE SLOPE OF POND# 278 DOWNSTREAM. A 10 FOOT INLET AT THE LOW POINT ON THE WEST SIDE OF SENECA STREET; A 5 FOOT INLET AT THE LOW POINT ON THE EAST SIDE OF SENECA STREET, AND A SIX (6) FOOT CONTINUOUS GRADE INLET ON THE WEST ' SIDE OF SENECA SOUTH OF WESTFIELD DR. A 30 INCH HDPE STORM DRAIN THAT DRAINS THROUGH THE 4' BY 8' BOX CULVERT WINGWALL AT POND 278 AND EXTENDS UP TO THE 5 FOOT INLET. A 24 INCH RCP CULVERT WILL EXTEND BETWEEN THE TWO INLETS ' AT THE SAG IN SENECA, AND AN 18 INCH RCP CULVERT WILL EXTEND FRON THE 5' INLET TO THE 6' AT GRADE INLET. A 5 FOOT INLET AT THE EAST END OF WESTFIELD DRIVE AND A TWO FOOT BY TWO FOOT (INSIDE DIMENSION) AREA INLET APPROXIMATELY 140 FEET EAST OF THE STREET INLET. A 15 INCH HDPE STORM DRAIN CONNECTS THOSE TWO INLETS, AND AN 18 INCH HDPE STPRM DRAIN CARRIES STORM WATER FROM THE AREA INLET TO POND #278. THE PONDING DESIGNED TO OCCUR ABOVE THE INLET WILL CAUSE THE ENTIRE 100 YEAR STORM TO BE CARRIED TO POND 278 IN THE PIPE CULVERT. THIS MINIMIZES THE CHANCE FOR ANY CONCENTRATED FLOWS TO OCCUR OVER THE STEEP BANKS OF THE POND IN THAT AREA. A 15 INCH HDPE STORM DRAIN WILL PASS STORM WATER UNDER THE BIKE/PEDESTRIAN TRAIL JUST NORTH OF THE AREA INLET THAT HAS COLLECTED IN THE DRAINAGE SWALE WITH CONCRETE PAN THAT WILL EXIST ON THE REAR OF LOTS 7 THROUGH 15. ITS FLOWS ARE ALSO INCLUDED IN THE 18 INCH STORM DRAIN TO POND 278. "FINAL ALSO, THE HYDRAULIC DESIGN REPORT — REGIONAL DETENTION POND 278, MCCLELLANDS & MAIL CREEK BASIN, DATED JUNE 1998" BY THE SEAR -BROWN GROUP PROVIDES THE DESIGN CRITERIA AND DESIGN DETAILS FOR THE 8' BY 4' REINFORCED CONCRETE BOX CULVERT CROSSING FOR BASIN'S MAJOR DRAINAGE CROSSING UNDER SENECA. THE DETAILS OF THAT CROSSING ARE PROVIDED AT SHEETS A 1 THROUGH A 5 OF THE UTILITY PLANS. THERE ARE TWO STORM DRAINAGE CROSSINGS PROPOSED UNDER TROUTMAN PARKWAY — A 24 INCH RCP AT STATION 11+00 AND TWO 18 INCH SIDE BY SIDE RCP's AT STATION 17+60. A TOTAL OF FOUR 5 FOOT INLETS DRAIN INTO THE STORM DRAIN CROSSINGS — ONE (1) EACH AT BOTH SIDES OF THE TWO SAG CURVES. A DRAINAGE SWALE WILL DRAIN (DAYLIGHT) EACH OF THE TWO CROSSINGS TO THE NORTHEAST CORNER ' OF THE PROPERTY THROUGH WHICH IT EXTENDS EAST OF WABASH STREET. 1 15 I A 36 INCH RCP STORM DRAIN WILL BE EXTENDED FROM WHERE IT EXISTS ON THE WEST SIDE OF WABASH TO TROUTMAN PARKWAY AND UNDER THE IRRIGATION DITCH CROSSING TO WESTBROOKE DRIVE. IT WILL BE EXTENDED SOUTHERLY INTO THE WESTBROOKE DRIVE ' ALIGNMENT WITH THIS PROJECT SO THAT IT CAN BE COMPLETED WITH THE WESTBROOKE 2ND FILING DEVELOPMENT. A 4 FOOT BY 8 FOOT CONCRETE BOX CULVERT WITH WING WALLS WILL BE CONSTRUCTED FOR THE IRRIGATION DITCH CROSSING UNDER TROUTMANT PARKWAY. THE STORM DRAINAGE INLET CAPACITIES ARE DETERMINED BY USING FIGURE 5-2 OF THE CITY'S DRAINAGE MANUAL. A SECTION OF THE ADDENDUM ON INLET SIZING FOLLOWS THE SECTION ON STREET CAPACITIES. THE 6 FOOT CONTINUOUS GRADE INLET WAS SIZED AND EVALUATED USING BOTH FIGURE 5-2 AND 5-6. THE AREA INLET WAS DESIGNED USING A COMPUTER PROGRAM DEVELOPED BY THE SEAR - BROWN GROUP. THE RESULTS ARE INCLUDED IN THE ADDENDUM. A MAXIMUM OF 6 INCHES OF GUTTER FLOW DEPTH IS ALLOWED ADJACENT TO THE INLET (Yo) DURING A 2 YEAR STORM. THE STANDARD HEIGHT OF THE OPENING (h) IS 6 INCHES FOR BOTH THE 5 AND 10 FOOT INLETS. REDUCTION FACTORS FOR CLOGGING OF THE OPENING, ETC. ARE 0.80 FOR THE 5 FOOT AND 0.85 FOR THE 10 FOOT INLET. USING FIG. 2-5 AT Yo = 6" AND h = 6", A MAXIMUM OF 1.25 CFS PER FOOT OF OPENING IS THE THORETICAL FLOW ALLOWED. WITH A 80 PERCENT REDUCTION FACTOR FOR THE 5 FOOT INLET, THE ACTUAL FLOW ALLOWED IS 1.00 CFS PER LINEAR FOOT (1.06 CFS PER FT. FOR A 10 FOOT INLET). THE 2 YEAR STORM RUNOFF AMOUNTS AT THE SIX (6) 5 FOOT INLETS DO NOT EXCEED 4.4 CFS, WHICH IS AT DESIGN POINT DPTR-IV-U IN TROUTMAN PARKWAY. THE U STANDS FOR UNDEVELOPED CONDITION FOR THE UPSTREAM PROPERTY DRAINING TO THAT LOCATION. WHEN THE PROPERTY IS DEVELOPED, THEY WILL ACCESS THE STORM DRAIN STUBBED OUT OF THE RIGHT OF WAY AT THAT LOCATION TO ENSURE THAT THE RUNOFF AMOUNT TO THE INLET AT THAT LOCATION DOES NOT EXCEED CITY CRITERIA. AT THE TWO (2) 10 FOOT INLETS, THE MAXIMUM DISCHARGE DURING A 100 YEAR STORM IS 9.1 CFS AT DP I. A 10 FOOT INLET WAS USED THERE TO KEEP OVERLAND FLOW THROUGH A SWALE FROM CARRYING ANY FLOWS TO THE STEEP BANKS OF POND 278 IN OTHER THAN UNUSUAL SITUATION (i.e. EMERGENCY CONDITIONS). 1 16 CONSIDERABLE DETAIL IS PROVIDED REGARDING INLET SIZING IN THE. ADDENDUM FOR INSTANCE, DP III. ON TABLE 1 LISTS A 2 YEAR DISCHARGE OF 10 CFS. THAT IS WHAT IT WOULD BE EXCEPT FOR THE INTERCEPTION OF FLOWS IN THE 6 FOOT AT GRADE INLET AT DESIGN POINT VI, WHICH REDUCES THE 2 YR. FLOW AT III. TO 4.8 CFS. THE ADDENDUM ALSO SHOWS DEPTHS OF PONDING AT THE INLETS DURING PEAK FLOWS. DURING A 100 YEAR STORM, THE LARGER FLOWS WILL POND TO A HIGHER ELEVATION, UNTIL THE DEPTH EXCEEDS 0.7 FEET. AT THAT DEPTH WEIR FLOW OCCURS OVER THE BACK OF EASEMENT, AND FLOWS WOULD "WEIR" OVER THE BACK OF EASEMENT TO THE DOWNSTREAM DRAINAGE FACILITIES. THE SITUATION AT DESIGN POINT III IS EVALUATED IN SOME DETAIL IN THE INLET SIZING SECTION OF THE ADDENDUM. ' A FIVE FOOT INLET MIGHT HAVE BEEN USED AT DP III, SINCE LESS THAN 5 CFS IS ANTICIPATED DURING A MINOR STORM AFTER THE PARTIAL INTERCEPTION OF FLOWS AT THE 6 FOOT INLET. A LONGER 10 FOOT INLET WAS CHOSEN TO ALLOW MORE RUNOFF INTO THE PIPE SYSTEM TO AVOID SIGNIFICANT WEIR FLOW TO POND 278 OVER THE GROUND SURFACE TO THE STEEP BANKS THERE. A WEIR FLOW VERSUS ORIFICE FLOW ANALYSIS FOR THAT 10 FOOT INLET SHOWS THAT ABOUT 17 CFS WILL BE ENTERING THE INLET AT A DEPTH OF 0.8 FEET, WHILE ABOUT 4.5 CFS WILL BE WEIR FLOWING TO THE PARK SITE. AT DPH, 8.5 OR SO CFS WILL BE ENTERING THE 5 FOOT INLET AND 4.5 OR SO CFS WILL BE WEIR FLOWING TO POND 278. THE OTHER 10 OR SO CFS THAT LEAD TO THE TOTAL DISCHARGE TO POND 278 AT DP VI (43.7 CFS) COMES BELOW THE STREET SURFACE IN AN 18 INCH STORM DRAIN BETWEEN DP H AND DP VII. THE HYDRAULIC CALCULATIONS FOR ALL OF THE STORM DRAINAGE CULVERTS ARE PROVIDED AFTER THE INLET SIZING IN A ' SECTION CALLED CULVERT DESIGN. THE RESULTING HYDRAULIC GRADE LINE ELEVATIONS AND ALL OTHER PERTINENT INFORMATION ARE PLOTTED ON PLAN AND PROFILES AT SHEET 17, WHICH IS EXHIBIT E. THE LAST SECTION OF THE ADDENDUM IS INFORMATION REGARDING THE DRAINAGE SWALES WITHIN THE PROJECT LIMITS, SUCH AS CROSS SECTION SHAPE, RATING CURVES ESTABLISHED USING MANNING's EQUATION, FLOW VELOCITIES, ETC. THE CROSS SECTIONS AND DEPTH OF FLOWS ARE DRAWN ON SHEET 4/EXHIBIT B. IN SUMMARY, THE PROPOSED STORM DRAINAGE PLAN FOR THE MOUNTAIN RIDGE PUD 3' FILING AS REFLECTED ON THE ENCLOSED 17 EXHIBITS IS CONSISTENT WITH THE MASTER PLAN, AND THE RESULTING IMPROVEMENTS SHOULD ADEQUATELY PROTECT LIFE AND PROPERTY ON THE SITE. I I I I 1l Ll I 1. I r 11 I V I C 11J t-`f Y M A P 1 /'I OUNTAIIM RIDGE FARM .1 UO 3 t"9 F I -L I N6 SCALE I THIS FINAL EROSION CONTROL PLAN REPORT FOR MOUNTAIN RIDGE P.U.D. 3rd FILING WAS PREPARED BY LAND DEVELOPMENT SERVICES USING THE CITY OF FORT COLLINS ' EROSION CONTROL REFERENCE MANUAL, for Construction Sites, dated January, 1991. The results of this erosion control study are reported in the enclosed text and in the supporting documents, and shown in further detail on the Storm Drainage and Erosion Control Plan submitted concurrently with this report. This Report is a revision of the initial Final Erosion Control Plan Report prepared by this office and signed on November 22, 1999. Signed this 30th day of April, 2000. �1 Dennis L. Donovan, P.E. Land Development Services 309 W. Harmony Road Fort Collins, Colorado 80526 ' Phone: (970) 454-1972 i I 1, MOUNTAIN RIDGE FARM P.U.D. THIRD FILING FINAL EROSION CONTROL PLAN PEPORT ' THE EROSION CONTROL CONCEPTS AND GENERAL DESIGN CONSIDERATIONS FOR MOUNTAIN RIDGE FARM P.U.D. 3RD FILING ARE OUTLINED IN THE FOLLOWING PARAGRAPHS AND SHOWN IN FURTHER DETAIL ON EXHIBIT B. THE EXHIBIT IS THE SAME AS FOR THE STORM i. DRAINAGE REPORT, AND IS TITLED "STORM DRAINAGE AND EROSION CONTROL PLAN". THE CITY REFERENCE MANUAL AND WIND ERODIBILITY ZONE MAP SHOW THAT THE ZONE FOR BOTH RAINFALL AND WIND EROSION IS MODERATE FOR THE SITE. THE AREAS OF CONCERN FOR THE EROSION CONTROL PLAN AND THEIR PERTINENT BASIN CHARACTERISTICS ARE AS FOLLOWS: ■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vIIZE SEDIMENT. LIKEWISE, DA#'S 9THROUGH 12 WILL FLOW TO POND 278. A GRAVEL M FILTER AT THE SIDEWALK CULVERT IN WESTFIELD DRIVE, STRAW BALES WHERE THE MAJORITY OF THE STORM RUNOFF FROM THIS AREA ENTERS THE NORTHEAST CORNER OF THE DETENTION POND, AND A TEMPORARY CROP COVER OVER THE ENTIRE DISTURBED AREA WILL BE PROVIDED TO MINIMIZE SEDIMENT TRANSPORT FROM THIS AREA. DA#'S 14 AND 15 WILL FLOW DIRECTLY INTO THE PV&LC DITCH AFTER GRADING. A PERMANENT VEGETATION CROP WILL BE PROVIDED FOR THOSE SMALL AREAS. I DA#'S 4,6,7 &8 WERE IDENTIFIED SEPARATELY AS A BASIN FOR EROSION CONTROL MEASURES BECAUSE 70 PERCENT OF THE AREA WILL BE PAVING AND SIDEWALK SURFACES. THAT ALONE MEETS THE EFFECTIVENESS CRITERIA, ALTHOUGH THE DISTURBED AREAS OUTSIDE ' THE IMPERVIOUS AREAS WILL ALSO BE COVERED WITH PERMANENT OR TEMPORARY CROPS. DA#'S 16, T 1, AND TR 1 THROUGH TR 4 ARE RELATED TO THE DEVELOPMENT OF TROUTMAN PARKWAY. MORE THAN 70 PERCENT OF THESE SUBBASINS ARE TO BE PAVING AND SIDEWALK SURFACES. THE PERVIOUS SURFACES WILL BE COVERED WITH PERMANENT OR PERMANENT CROPS. "EFFECTIVENESS CALCULATIONS" FOR THE FOUR AREAS OF CONCERN ARE PROVIDED ON STANDARD FORM B AFTER THIS TEXT. THE EROSION CONTROL MEASURES THAT ARE RECOMMENDED ARE COMPATIBLE WITH THE CITY'S STATED GOALS IN THE EROSION CONTROL ORDINANCE AND SUPPORTING DOCUMENTS. TO MINIMIZE WIND EROSION AND AIR -BORN SEDIMENT TRANSPORT FROM THE SITE, IT IS RECOMMENDED THAT A SILT FENCE BE INSTALLED ALONG THE EAST SIDE OF THE PROJECT NEAR THE PV & LC IRRIGATION DITCH BANK SILT FENCE SHOULD ALSO BE PLACED ON THE SOUTH SIDE OF TROUTMAN PARKWAY IF THE WESTBROOKE PUD 2ND FILING IS NOT BEING DEVELOPED CONCURRENTLY WITH THE MRF 3RD FILING. ' THE EASTERLY BERM OF THE IRRIGATION DITCH IS TWO FEET HIGHER THAN THE SITE AND THE WESTERLY SIDE OF THE DITCH, WHICH SHOULD PROVIDE A BARRIER AGAINST SEDIMENT TRANSPORT TO THE EAST OF THE SITE. WE STILL RECOMMEND THE SILT FENCE NEAR THE DITCH BANK TO ASSIST IN CONTROLING AGAINST AIR BORN TRANSPORT AS WELL AS SURFACE DRAINAGE SEDIMENT TRANSPORT. ALSO WATERING OF HAUL ROADS AND OTHER AREAS LIKELY TO CREATE DUST PROBLEMS SHOULD BE A STANDARD ON -GOING OPERATION. THE ANTICIPATED CONSTRUCTION SCHEDULE FOR THE PROJECT IS TO BEGIN GRADING IN JUNE OF 2000. THE FIRST PHASE OF DEVELOPMENT IS TO INCLUDE SANITARY SEWER INSTALLATION AND EXCAVATION OF THE DETENTION POND AND FILLING OF THE LOTS AND INTERNAL STREETS. CONSTRUCTION OF SENECA STREET SHOULD OCCUR CONCURRENTLY. TROUTMAN PARKWAY WILL BE CONSTRUCTED TO ITS INTERSECTION WITH WABASH AT THIS TIME ALSO. FA I COMPLETION OF THE REMAINING INFRASTRUCTURE IMPROVEMENTS WILL PROBABLY OCCUR BY NOVEMBER. STANDARD FORM C FOLLOWS AND GIVES A ROUGH ESTIMATE OF THE TIME FRAME FOR THE INDIVIDUAL EROSION CONTROL IMPROVEMENTS. I It 11, I I I I I RAINFALL PERFORMANCE' STANDARD EVALUATION PROJECT:.MovwT*w R106a F4#zm PUD -31"Fii. Ipj(?TANDARD FORM A COMPLETED BY: OLD DATE: - DEVELOP ED.ERODIBILITY. SUBBAqINS ZONE Asb (ac) Lsb (ft) Ssb M Lb (feet) Sb M PS M MODERATE Lh 4-5 51+0 .1.2 "713 o Lk MICIP5RATE 0,6 `7 -3. 5+ 1066 1,0 -le.3 16)TRZ,3) 006 1,6 .76.6 DTI MARCH 1991 8-14 DESIGN CRITERIA I Y 0, I I I I a EFFECTIVENESS CALCULATIONS PROJECT : 0 V r4-rA I N R 1 PC, E FAR M PUP — 3 F 1 1 N G STANDARD FORM B COMPLETED BY: ,0419 DATE: Erosion Control C-Factor P-Factor Method Value Value Comment ROA95 /tA/ALKS 0,61 I,0 GRAVEL FILTE-R 5 1,6 0.8 5-rR*w 6^LE S ISO D,$ PERmAonTCRop 6,007 1.0 '>`MPoRAAgCRoP O.tS 1,0 MAJOR PS SUB AREA BASIN ($) BASIN (Ac) CALCULATIONS 11213,5 78 •�{ 4.4-5 ROA173 = 15010 N4:4-5=6.c7,c7 PERMarlr-N-r CROP-6.81AC.) �15 TEMP CR6P=2.g7AG )GPAVeI rrr 1lTER)SEDIME/JTIRA VVTo C =(a.67 Ko.c I t 6,9114 0.67 t 2.97><0.�t5)/+�,1f5 =0.31 W-rp P= 0.5to•8= 0-T E17F=(1-0,31xo.1IL)X160 =87.(, b 73,5 2,73 R6ko5= 1.°IZAc NVASuRtD) wrD c=(.92�0.01+o.�Zx1,o)�Z.73 =d.31 WTo P EFF "(i-0.31 XO,5)gIDv 84-.6 O K q�'IZ y /8,3 6,53 ROADS= 1S4%.i6,53y10-59AG TeMPCRv1"= 5,55 Wro C = (6,18 0-01 + 5.55X 0,'f 5)16,53 = 6,36 Wra I°= 6. 5 9 6.9 =6,`t 6 OFF=�I-0.38X0,4-)Y100 = g '� QK 16,T11 -7 ROAPS =657. y t.OZ= 2.�I Ac. TEIMP COROp Cr(Z,61XO,U1 EFF MARCH 1991 8-15 DESIGN CRITERIA A PPENO U M To . STORM ORAIVAGE R /Al RP 5 6- 14. j 5� .. �.. .1 & I M T Y 5trt 4 L 6D 1-66 i t o.56 � I OPP-; W6 f 6. .56 0,71 Z TP LZ 960 278):5 6) �o 0 ; -pr 1, v C-s. + O,V A 0.67 f6 TN s @ 4-66 10.1 SA CK6,q 6 + 6,7.4.4 51 OfM Eo,3.5,,xo.15+ —%. m 6.75 0,37 0.86 7 - 0.72 FR; 366 s f" n 5f re -a+ 4 5W Lo. c 5 ic 6.9 5 + 0.0 7y 0! F 511. + &7 9 0170 -7 sf IA 54, e4+ A: �5w )148 0 �K ol 5 0 75.�. :`1- 0,78. E4,12x - - -- -- ----- -0.73 @71 56 IL_1 - xQ,g5+:0,�4-x0.25]�-d.;1.3, oii � �, �,�q' .-.`t9c 1b,Qrir��7�0.s�j r ,.;_��'/•o%nes@'/OVIsF'v�b -Eq N- 'i -F, 9" i 99� s •/ _- ' �i 5vb�a5i 11' ftrei� J/e 5G f ►P�tr - - = tl � r D :i2 1.9� `,1� orics ?:900s ;Concr�14-R,`n@?�i�9c�' , " 13 1.18 -f µm►� s C l �00 s �I' r� Yes@156sf �,i-reeSHI@.1�730; De� Sw�J 2ZDsf �. C0.51 x0:95t0,6.7d,i5] 1.t8 0:5`5 I�- 0,89 La►nc�ScaP�'v� D<Z5 15 0,56 Lco,JScaP►`n� 051 0, 50 Pe r A pProve-j Wes4i e l d Ra rk Puo 0,7(o 65 6,IZ Co.G7X 6,5 + 05x0,Z5J^D,l Z 0,6 Z 5 a, 053 Z,Z8 Per ApPrmveJ Vesf-gi'eW Pork f UD Oq-7 05*1 8.6q- Per IIRF1 .4` F; 1 t`nc, 0.5.E b55 0.G7 ParOcpadl- Lah4smpilp t 0.25 v YrrOS6 0,99 5014C GDnCM4iiel-T:FPaveme + i E04-Z46,g5 tb,-79 u02s] -; 6,99 039 . 1%l 6' ;., a130 5f-r, ee -Side Waal k e�-6 I lac.:; i wI s r A C? 3o yJtand� tn� ,o ., .5- '/0: @ D, q5 2,5 /a0.5 i r t '>> 7R. p,58' .. C13.F5���`f3_�) �:0.25',+-:129,'S; TR3 = L,I3�E=Eo.55 r xio.. ;58;�M 1► �1 l0 , rR��.27 h' , IPA S4';8, 73 75: �I itl I� D4'S 653� 13,70 DA $, 052�Us3� US^/'f�U55 3.bQ Co,73x0,72+ 1,09 X0,701 1.1$X a,55] -3;0 Z3`Oxo,65+ +0,50v6,%]_5.L4- l1.64� [4.72XO.98+2,Z8 x0.4.7+ R.6`f-x0.53] =-11,6It =0.5'f ts.�3 [1,073x6,7`Pf-13.70y0.5-g15,f3= 0.5t ,. PN. )ZO..52 z.z i �` ,O:FF S�T� J�N'nf✓:� TR7 I9Pi VT PUD3;r d 5ubs►n (ver�en_c� F�o'w __ t✓'onte�t'1rae_ F�oW, 8TgL ' �. � -D►srANce 5rc�� C' `TcZ T��, 1D� � ; YA�6, T a-.. I N5 a --p�-r S0 - Z,Z r..:6.:25 ti,3 t0,5. 3 - .SD �► � ,► 8,9 8,3 _320:1;3 2;2 ; .Z.� . _ �: �(,3 _:.�a,?_ 4� 10 11,1 Lo' 6:7 ..106. - . 4-t 5 76 ►, to, 6 Its. 6;3 7 860 0.5 I,`t 10,2 I.? - 8 30 ,, d;3't 6;Z 5,5. 760 0,5 f;4- 9,0 15,Z N5 9 t Q ri 025 132 18,3 13,Z M 3 10 pro ;, {�► 8,0 74 360 0,6 1$5 t0 140 I1,L . 74- 650 6.6 I, 5 7, 2 15, 2 1'1 6 i Z 70 3111 g;+ 78 890 6,5 let 1a ,6 1-9.0 118-# . 13 65 2,1 R5 380 0,6 r, 5 'f,2 I3,q- IZ,7 I't 85 007 16,5 153.: )5 66 18,3 9.6 6 051 CO 4.2 >> '+48 't1t 30b j;2 2,2 05 Z 50 200 8,9 83 40 0.5 t,Lt .6,5 9,`1 S.S p 5 3 ► 0 Z 5 „ I'S 1 I't6 5" , 0.9 1:9 'Z0,4' Iq,3 � To DP1 - 0,2 1, '+ �t lo.. .3 �8 ._, � �.9.7 ." 0,:6 q-� 4-i4 a D53 So,m�osj Lo i P UO - '-AJ n- 3, - -- ----- -- 90 ubbasfn F%` 5 U. C. -056 0166 "0.3 - .7 0 0.71 1515. 240 5­ Offl. 0031 110.6 qO 8 2.5 72 0,8 3# 0 7 11.8 23 6.7 1.5 5,3 8 0,16 0'.15. 15'2 14.5 &1 6.1 5.1 9 638 0136 .1-3.2 R3 ZZ C, 5 -616 23 )o 0.73 0.12. .. lz 6 11 It 2.3 G, 8 112 �. 5 lj ) 1 )101 0070 4152 )1�.6 0.) G. 1 1.6 5.8 12 1.9 ' 63+ 0.6 18'� 1.9 5.1f 1.3 4�' 5 13 1.18 0.55 13,� 1 V 22 6.5 1, q 5.3 I 1t Ok8l 0.25 16.5 15.3 Z. 0 .5t6 04' 1.6 #VA 15 0.56 6.?5 1013 9; 6 2.5 7,2 D. 3 1,1 Ot J_ 0,50 ON 7.1 6.7 2.9 1.7 0,1 2.2 052 0,12 0 G6 9.9,8 2.6 z 0,711- 055 2628 0'+7 2641fi 15,3 1-8� 52 ...3 05 It -SAT 0.53. .2018­ 17'7._'119 17,61 1: It055 0.0 02.5 130G D 5 6ir Op - 18-b 17J, :&0 in 64- 2.0 59- I--- Vq tZ.: -9 43 L�-V­ p -if _1 '.- ST PfM K :_ _� � /'?uVn� tn��►' _ F rM,PUI� 3�d_F'izl�►�:� _f7LD _ ,4 I I 1! 1 < I �• f 5`,u bbos t Z o "to 'CAc). dot i 6: • :0,30 _ 0,50 � 11l3 { _ ►6,5•_;� ` Z't .-av:-��;o! = Yo ��: � :'.'I l� , F�f4.1 d,3D 0'!Z.d 5 n=;3. �,0... 0.,3 6,:8 TRZ 5 0,58 073 818' 815 Z;6 7R 30 1.13 0.16 IZ}5 I? 'Z 9#3 6.6 2.0 71 T66 9,V 0.79 Its R1 111 152 55,1 f TR7 1;9 0:78 I'tS 1q,1 Z,1 6.1 7.6 27.7 DP 0,58 6.73 9.8 .6 N I, l 3,9 DP 191 1.9Z 0.57 1Z.5 12,Z ZL3 6.6 2,5 9,0 DP TRTZ 6,01 0.75 I1.8 i'�.I Zl I 6,1 906 3�;$ DP 7613 10.58 0.78 IM Pf, I Z L 1 6.1 17.3 6VI PP TRj 11,16 6►78 ► S 1`H Oil 6,1 1913 UH PP TqZ 8.81 0,71, 1t$ 11t,1 Z41 6.1 11,9 y30,f DPTR 1T-C'u�'t 01 o.3T 3to c�� 31.5 1,3 t.,1 16.6 P TR 0.3 Z 0 11 t 17,y- �rpP"TR-g-u 11,16 0.v �► 4,9 1q,Lk ' i?P 77Z[-0 u1 roo . 31., Lz) DP,�R cJ �s wta11+G � f' : UND�VFLORGQ - -, , > pP TR. -U i s ;wµr�� 014- ,V t5 V�/r-a VEL ©p� v h ' � ' 4 I ` 1' r 1 1 5 1 { ! J 1 1 1 1 W 1 1 1 Movn+wn RiJc�� Farm PUP rd Fr �f1":U UAL Gf . . (OY•TICY: O• O.fa Ill f1 J ti , 10000 n ,t IOYewNESS C941I14:7101 IN e•..I,a .10 9000 fee. A •PPee.elelt TO .•TENI•L „ 8000 NOTTOY Of C.•NIIEL 7000 t If Itar.oC•. ON c.osf fort .08 1.6 6000 .taNE.0 .. a .Ioct[e..at .TM. .07 5000 I.O[ IM tOwTNI1, Oq 80 .06 4000 .70 EXAMPLE ITct o•awto u.Efl .OS 3000 a1.[•, f . a.ol 1Op .60 [ , 2. 70 :/nltoo n.J .!0 �„� .04 2000 .a[ I • O.ta (j 30 1L .50 FIND i a • 2.0 CIS 20 In .40 1000, .30 900 — ?_,_Noo W �� 02 T C' _ 600 Cr = 7 s N 500 .20 O 400 .' lJ l .2 Z Q300 CTIONS 01 0 x 07 1. t/n a.T10 w Iy. EL CONNECT A. .( is) Q .OS .e0 CONNECT 011C."at la, Ir zO' 'z , DOB 008 200 *CPT. III T.Ef[ TWO L ES .Y$1 U IN .a2 Q I^ IN,t4s1CT .T T..NI.a LIME 100 Cn .10 cor.0 Tt sDLmloN V .006 11.) :.+oN aw•uor ' Ili • 100 .-a.•rte cwawect U- .005 W .0707 90 O so .s 3.0.0 USE .o.ace•Iw r-" t ' i .004 .06 TO [a t 60 2 .05 SO a la ocrtwNE —• r' 0 .003 ro117104 of E.... r1 I --t (i) 30 ..N,.c r10Tw .: I��.�.I OCTEN,INI SEPT. a IO. TOT•L 11,...1, ,. [all.[ SECTION a 1N411 YSt •OYOOaarw 10 .002 •03 20 or+t•r1.t o, IN SCChD, a roe at". Q • TO OtTtNr1.( MSC.•ec( r�R. IN cowosrtt stcrm. .. I . • 101c0N oft OVChO. 1 I �•}� n. .02 IO 0 TO O eTUN OISC«NNct 10 7 t i .001 SECTION a AT •SfY,te • E-I f-i 1 .. 09-7. a; 041.04 o 100 From BPR SLOPE RATIO 1, AND 0E01. i 1.,, a, • D, . D, Figure 4-1 .01 NONOGRAPH FOR FLOW IN TRIANGULAR GUTTERS (From U.S. Dept. of Commerce, Bureau of Public Roads, 1965) MAY 1984 4-3 DESIGN CRITERIA 1 1 1 I 1 1 1 1 1 MAY 1984 w We 9 e 7 .3 2 /'IoUAIT'A114 tDGE �.4RM PUJ 3F,%Ilfm STR ��T 'CA- ��4GcTf ES MM mill", M. Elm 11 =,III 11LINE11mil Emil till BELOW ALLOWABLE STREET MINIMUM GRAOE .0 0 2 4 6 6 10 12 la SLOPE OF GUTTER Figure 4-2 REDUCTION FACTOR FOR ALLOWABLE GUTTER CAPACITY Apply reduction factor for applicable slope to the theoretical gutter capacity to obtain allowable gutter capacity. (From: U.S. Dept. of Commerce, Bureau of Public Roads. 1965) 4-4 III DESIGN CRITERIA I Y ' T �!'1ou�'a'i n R►'c�3','1 f I ' r 1 // /J/j11►. ,. ; � ; . ; , � ; ,� �SiTR�.�`r' 1\/./'si- Ph G. t T► � 5 � _.. 3 7 (�q�./1 Si'reer{-s , Drive _O�rer Cur G�- -er c� c e j t 7 n - t �es�� flo;�r occurs. negr IiP T from OA Z where f�ti� i nb ►- S i-o r in '1: t u`ci;o n Fac �'c:ti'' Cs =0, 5/° p ;.. , D,65':- Fro,,) �e enc:tosed Ra%ll Curve; �eP�� 4,33 f eei �OV-Q=Z,Bc� ' sump-r�'on �'s -�,'e J cond,'�-,'or�s resri'c-� Flow so Aa+ 1.8.c�'-5 vvi)1 reiuire cLn..etcv4l clePfh. a ii` I'm ches. r11�//er.l�4n-.3%: Incke5.1-P Aere. were- n0 adVer.se-' - eld cinnIX.jtrlec $ 1 I I I The L.4uaI �)avj rare allowable (al (owab/e lu++er -f low) for f A e In i -J-,'a. f 5-6 r jn 5freY,- 4 Ru n o t -F En c roac � m e-n 4- 4 Gi 1/4 inches i-s 10, 5 c-Ps X D,65 = 6,8 c�s . Mrta,or 5%orin S+ree.�'- Pvv\6F-V Encroaev mcft ' allows a deI04 upfo 6ihckes over 4e' crowv/t 6�4e 5frcIef, 414.0014. re-5+ri`c+ec% �f-o n a i )'nnuAda�e bui�c ih ,5 a-%-��ie roumCF. IOe,- I.rte Iar% s� lot) year 4 i`.sc�ct�- e. is 6.5 cps o c Ql s OY-c :�-s� o- c� i n -Pro m p� Z Eve rt w ►A k-e; 65 1� �_" x ' � r;_' l[7bU►1�7•a'irl, I�'fack� t F V -. "_ STRE�"r C/k�+4ClT�Es ,rt necc. S ..ree: (Con n5?'rucr,on�}'aret-erM} n.i c�i`sGilcir. n C, 1 qq posy+e 5ec-�-icri ��w,'r1 1 o0.boVe:�-.he `..I` 510 e - OJ-7 ; 2� _. 8,5%�' 1=.'ReGi coca, D-� Cra "0:�8.5 = ll.%6 5 1�ai-1'o ' �h --735 From Fi��re. �'f'-]� �'orY=-8.17/Q`0,Z'f'cr, 1 y = 6. 3 5 c-Fs ` 0, S ' Q = �}.Z c7Cs Z; S reei-'F�ow oui si a c� u4+er - rwclx.4 Gerc er ie "- 1 5=6.5%' n=01016 'Gross e Slo =2 ' =50 71ri -3 IZ5 From F►` ure �-1��or Y=O�IZ`(0,3'1-�aLoJe)�(,�=1,©c�s� 1 y � . 0.33 C0.5' 01 ve Ft), 1 3. Compos 4a Flow CQ►+QZ> \1=0,I7�, Q=O,Z4-+o=a2�t '! = Y=6,5O,)Q=Y.2+-6,0 =102cez 1 For S =D,5� Rii!Juc�ion roc, �or S 1v✓h itc% rS .�'11 e �c'I•t1cU � Iow �.��-owe , s ,I's less 4an 4 h.e IU,� cFS, s6 -the s�cor.m.MI.P1 1 , ,sysem.-Nlu5i" 6e.�X. ene v�- co rPS�r'e sarY1 . .CortrnUauS 1 Ya 1 nleT- �O;Gedt a-1-.f.tie .soufirtweG � e rive O.v1 yen ��ow b a-1- �s:f,►' cFs s , Y . _ __ a f<{'vw5o�ui rCZY 41'l , kFl o w s a're less � h c� 6, G c Fs a 1 0lpjc- %� , 1r..�ore 5e S+�reet ees ✓�y r ,Q , a Vl cCt V7 Mr�ir'ni�-Qi ` !ul I.r'4 1 f 1 J— i 1 T1 u' s f r,e� b'�s r',n is un:d �,ve �c ecQ' o cc u rs a ' e s`fp ea, 5 i cd 56ine+h"iw�.:.:Ie.sS,t�i/i's'c�teA-r �5TeYrv1 ' runa�� t�e Cdn i�ro:vls .Font �ow i'✓I' Tro'u�-n�avl czre..11cf eni-r'caJ�:..,. � n c ✓`h� e- n'h r'n4um�©c�`-�Td�� s16p�.a..-F lwc oAn Ac--r,uALE5t-I'Ma4-d Ptow ©-��. 4-•o6(AiLi. eF41Uj re'5Yv�5 cL eorer caI4.JT101\ Pcic�or O( Prorn Pt, Ur-eo t 0 e- AICIL.V, l .�:Q r+�iZ ' from e Pd-� Ik\ Curve herei'h aeO SI( Ql+4z=ID•Sc 's, *�c W o.; �•O dP5 I0CCUpQ. �1 f I .� Allt Icv.Js on T VIe t�o►� S crr� I►1 ►'du�i��sY1 . are I$s 5 ��a.h �v, 2•X'0;651% £3.c 's .There �ore� T�-eDti n" t� -re e+- �oVJ m C. 745.. C1r�-Y Gri�}-eNtr�. ( I z I t 1 f i ' ' c s I i E ..., I ,...r.., .. �.•. F..—.N - : _ u...e.,:.� .t I ry ' f 7 4 } r —x 41ix 0 Z rm 6 91 A.Tc, 4-RGr CCFS) 10 I ` i(No-r �op'of 6:5 Percen� A //ow�6 ��e. F/ow Realuc on Fac4-oris D;(.�� VeHncRL CURB Anly GUTTER; 07 1 T r - i 1 : _. s _ ....". .. i 1 r I ti + ,�L .i t }�S L` � '+ 7 f,, i O A, �$ J 1 _I f.� -- - ------ ----------- . ........ -------- --- 61 ---4 .......o,99...,A. z (f 0, 2-3m. /16 3 q S 6 16 59 =61t2SV77 ........... ... . .. ....... --------- . ............ ...... ..... . --- ---- - --------- - ------- --- .... .... ........ - ---------- ----- Ho Z8 13 1,171 LnosA t r, r b3333! .. . . L9-5 AA --f e Form PU `3R°F�`II`K� •S �•• ••� i N• •: �•�. ' DRIVE-01 1 u S K Slope sidewali �: ,;ate• •!'� :-•i:.-: �i• �= i.n. V. VERT ICAL 6 INCH CURB, GUTTER N TS. EDGE SURFACE 1/8" R • ' • 3/4Min A. A. NOTE: JOINT SHALL BE CUT 1/4 THICKNESS OF CONCRETE INITIALLY AMY JOINT FOR WALKS ' N.TS. a curb it•shaft be above the curb. to curb—U$to 1J2' per & Qq pig! _ / �d rZcf SI . OUTFALL CURB AND GUTTER H.T.S. Il-gs CURB AND GUTTER DETAILS ' Y OF FORT COLLINS, COLORADO - REVISED a -as ENGINEERING DIVISION Moun�`ain i c�e RarrA FU1) 3. h 10 .9 II 8 10 6 F 8 0 L 0 �. T U. W 8 .6 T E*' .5 �! 5.5 W W 5 W U. .4 z ? 4.5 z r _ r 4. r. � z O z w '3 3.5 w Q. 0 a 0 U. 00 .25 3 U. c� c� W W 2.5 .2 .15 1.5 a n�ey� z z _ _e Part a I 0 z L W a 0 6 u_ O O z z .4 W = o_ 0 .3 W x u_ ►- � O z T W J .I W 0' .08 ~o .06 0 0 z U. - w .04 W W o. .03 a a .02 0 a x a � c� o. W 01 U. 4O O Yo a 5 4/L-pv.8 = f,1 O.Ck =2,2 4 .3 .25 .2 .IS .10 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 MTERIA o.:v:n 'a►`n....f ,`d-`�e 1=arn►:p.U� 3r pi'�r.'vt�. �nle-� 5.�'3►h� — - ss un�e__�0rt 04 _ l _ ' -- - I _G._o_a_). n_.�_e-c�..1-u r-- ►��. ram.-1:_0_CCe:. c_� -E-a rn1_s o-- i n-o:__..o-ve 78 -- -- RedUGA-1.0 n. 7` .... _ 0,7 t� =615 8. C� J�6 R e u G� i o n roc,-6 r I:n .i ............. . ®/ear .5+o rm o:Un`�-ainI' e.. farm QU�?.3`Ii'r� �. � DLO -- . ---- - _Q►ov_ �" 9;_4=:G�s:. � z Z.�O_:c-�s;. _.�A-Ss��r m_e__�..��_1��- _ 3 G U 5 �0.4..'kocc.U_ r .QR Y:vaY, _. c.ps. A l l cwc`b_ f CL�oye ._. __..._._.. )ai-';wl1).bc. 5:4-1n e,vt�4-k �Tye.�..� _.. o_(L"i-eL,-_ F ro m_►'-2� Pep4 �o r 9,'f Cis TA rd re-i I'_cc 9,'+ o ,Pao _ 11,75 c% w►-II.._re�c.h__�.P-1-�__w_h_.ere _-------v�t_:.e.i_� _� �Sa_uw___.r_ a c4_c.�__ _.�1 _,_'�. ��s_" --_ h_l_a ►re_-__o t2_� � � s_..._-- __.__-= San e !lao o cf5 me ----- _ �-------- --- ' Gaal n t'e rGepr 2 �I.I?a v �' ( ► n o r..5-6.rm cVi_0. �e rem We. `e. J::.. P6- r. (� , cwt t. i�loUn�-a-crr f-FIJF4r!►+ 1Dt D: -- 1 �, s_c.�__►�s� u_s_se a( __a b D..V__�� _ ���--1� 0_c� �.�'_c�_�o wQ _f �_-- _.. � r 2 �s.__�sc�...__ ...... Pe p.4, dv rreT'tc0 iG. :� _!►!�..e,. � r. -low b e. t n 5 M . t o Q,.7 d e_ f-e_r_ rn 1. n.e d -ra n� c©_n� ►� e /c w r.n-o Tn i ---- _.._.� -. j. S.: cS VJ__ T7©h ►_!\ _. __ 0.10o v.t� __ ` _ Fte O..l._ �..1..11-�5 .�±._,. fc �l �.1-� ✓l s 1 , - -=- - 0--5_► ` 2 `t._... - Th l's--c c-US-_ c, f s-d::_ F L o w_c'„ - - - - -- ;"k .4_r`DP.._�-o__'Qd7-0 -- _.__ ....__ -- ---- - _ !�.- Q roo =.25,Z cs..rs. `oi`n 1.0.2c-s_e_� 1'v e.re._. J i/ +_h_e.5 �v� -eat{"evc_..... 4-o47.� Q g oo = 3�, .c-f' ._ : Yc�:r►1 DP .__._. ��:.5.9 t5..5-f-5,5 _ 47#0 c�S vs 4-367 a 5�0wYt-�orVPf 2 ffM !).0 0-171-a" rni W-r- Fdr�tPOP 33. r_� 1,; F) A Lh A7 A.G,�::7�L'N.FdRA 4-T16 Z7+06 5-1-k -r 16 ta (FT) �;IeapA Le, n5A 0 =- C L �f (c =3 1 6) 0 0 30 60 0, 51,3 i IYo%e pe�f {6 is oveF-'.. f3ac�toF Wo-lk whllc_� I'z 0,7-P,,,J bo:e F)6 w I'VI a OKA5": AB VE7k_ Sw rvG�I. r7 c+­ 24M D, AF : rl �iG-, FL ...... .. ...... -1:)NZ L E7r,l fi AY ��L e--T: rN L-E-T tj 5,-j 41 L L I I Zoo 4� ,n 5.p 60 .:. . vi5c,#A-RG.E.`(! F5� ' COA INED ThILE.T AIL IR FL&W FLOW 04 15&5. T 51FLOW d(J WosT 51DP De �� O-Sg.,T Qv.I61R TbTkL- 0-1AJLr=T Qwr-IR(W) QwEfR(E-) LiTD7'ki- 1 6' Ii,3 (�,8 8.2 Z.8fi1,� ' ��,►� 16,�I- I,`�' I,'t 11.8 ' an S;8 610 1+.8 16,9 6.0 2Z.9 37,7 LEY -r Pon�J►NG 1=LEv o- VJt 4TOZle- -Z 61,751- --5 --- ------ ------- ...... .. ..... .......... ........ . - --- --- ---------- . ....... . ... ..... ...... — ... . ... .... ..... ------------ .... . ..... .......... --------------- .. . . ..... ....... — .. .... 4, ZCA ........ ... ....... 16 e+.--*.Lt, 5-c .. cx IA AQ 5 16 -+, 8 st. --slit 1pt+a- e+. 5,4 — — -- — — ------------ - -------------------- OYC ---- --------- ---- - --- ... .... ---- - .... .. A: ..... --- -... _. _....._.. .. _._ .... �, rn ...---------------------__.-------__.__...-._--- 3� . A•1 '� �Qi:7i.1 1�llT'o 111��J . _. 1 Z•� 37 `t fQ.2_Z7.2 i 1 _�lt-,�----=----...---- 53D/0_ = 13,30 _t5 _3 x ��x 6.•61I Z -- D,.]-00-35-..__.- �.%, o--=- ------ ��$4--- 0,Ito. _----_ _- ;-s°: ArT__�— �. Its +o: DP.ZL _ nTM f t47, i P LD DY) lb..... ......... 50 ... 01,16-0 .... .. 0fog Tf e-.e k ....... ... ---- ---- ------ .......... . ...... � _ F_ _�__n _I_�.�- �.+- ._ _D �_ _� _ C,� ram.. _�_�_� �.�-_ �� 5 �-_Q �_ � P.t.�. _ - - ---------- - t nc-l/ tv� cl te4 --r CA- 56. Vol, La-6-o-ye.. cA -reAx, tvde� --U,V7.(A OK LL PO IJ �P SOL4 56.1 -7 Illustrating R-3402-E R-3403 Al :Gutter Inlet Frame and Grate Heavy Duty Total Weight 445 Pounds F4wi F 1 rid• zs Cl a --23 333�j �--25}, 3* I F R-3403-F Gutter lnlet,F.cme and Grate Heavy Duty. Total Weight 485 Pounds44LN \ 1 a 1 •�N � / �33 42—I F'-2533} -I� 3 R-3404-5 Gutter Inlet.Frames and Grates :., o. vv.► Heavy Duty I� 14r -�• Ov ��� �► va c E Catalog Dimensions in inches wt. No. A B C I D I E I F I G IH lbs. R-3404 21'hx21'/z t'fz 205ix2054 I22/kx22Ys 30%x30% 5'/a 2x2 13/i6 2" ' R-3405 235/ex233/e t'/z 22x22 243/4x243/4 323/4x323/ 6 2byx2'-y 1 345 -R-3405-A 23%x23%a 2 22x22.__.. 241/sx24%6 32''x32'% 65¢ 2'/4x2Ya 1'A, 460- Illustrating R-3405 R3405-B 23%x23% 2 22x22 24%x247/9 32'/ax29 6'ib 2'/x2'/4 1'/6 440-• - .Same as R-3405-A except base flange on 3 sides only. .*Also available with Type L grate. See R-35884. 1FF The Sear -Brown Group Westfield Park -- Pond 278 Area Inlet Grate: Neenah R-3402-E Open length, L = Open width, W = Clogging, c = Weir equation: Qw = C Lc H^1.5 C = 3.0 Lc = 2.8 ft ! H Qw Qo (ft) (cfs) (cfs) - ------------ 0 10 ' 0 00 0"00m 0.00 p sir 3.48 I 0 20' � dim 4.93 0 30 ' 13 6.03 0.40 . _ 2.14 6.97 0 50 ;i 2 99 7.79 0.60 3.93 8.53 0 70 t. 4.96 9.22 0.80 _ 6.04: 9.85 0.90 -- " r 10 4 1.00 - �0 ,2 ,g _ 6 6 A 2 0 1 0 0. 1 504-023 1.6 ft 1.8 ft 20% Orifice equation: Do = C Ac (2gH)^0.5 C = 0.6 Ac = 2.3 ft2 Q(100) = 16 cfs d(100) = 1.71 ft SEL = 5098.51 ft el 04 06 08 1 Head (1) -�-Weir-+-Onfce �Cmuolling 12 31-Mar-2000 t I Maun+ain R,'dte.Farm IUD 3rdF�'1�nq Enle+ j;�,'nI DLD Wllbq� Goa, Be covsec�uri'r) �11e m i_n-or .5+6rm eXcee rallowalle s�re.e' CCa O-C'. once runitr o_�ro►Irt l_-------- Was�Tie-IA-Drive. we-s Or Sene.ca.. eVil`e-r,5 r�+ S l° n e cGl_ 54-r e e4', i 4- 1' ,5 n ece 5 sa.v'y �o a 4 l c- Coni-r'nuou-s Gra�e T-nlc- SDA o� +fie. in�er- 5ec+jon --o reduce Ui- er �(ouJ on }�,e wes4 s1de o--5e-►iee soujkI-rI �I, D , y f' rt Wc-S 6L5Su 05 ik r) �ic, ure- �-5 anc( 5-(o �rom +fie c,ri�-erica rv�civtuc�(� _U_ - 5k=o,o2 ) 15)T-2=13 5=6o05ff/ffjn=�.01�6 _ _ �,� Sy�T:Z)Ql[/Q - D.rjS ,L+L./Q•� V �� K { O GTS - �(',8G1/"""5 X �OO/D1(1\CdUG�'10_I� 4- IhCrea-se. t'or C Of�1 pOUnd 5+ree-+ c�ur(Iriq ---- �- flow as5e-5 �h h i' �h T 15 �r1 �rG rou a_----- 5 h'Cfo 49 . Th e re mai Ain con+('►.0 'e o T)6vi n 4 e To RPUT l 1 Vurin I cL MaJ `or- �or-m) wt44 'a [ar- e-r- s�r�i 1 = a55 to,t1d�w =D;02 X (Z3�=0,�{'6 -a4d Us1'R �=11,7.E r J I eore� (\-C-aj X80°10 =q,Oc�s I,135 = %�,2cis ackaIly �`n �erc/e�a�e 1' duri Ac 101�f'year 54-o rrm , lie remc� cn l`n5 Z5.9 �+5 �.,nn��t��1PS nYi tO PP 7FF. No Text 30 2.0 1.0 0.8 0.E 0.4 a, a Lol c - �z�.-�.� • per• eta �o�im� ����av,�.______—�-_-- T 0 O.OI U.UG uua V.v�- CROSS SLOPE, Sx FIGURE 556 INCREASE IN INTERCEPTION OF COMPOUND STREET SECTION FOR W = 2 FT AND GUTTER CROSS -SLOPE = 1 : 12 SCURCE, URBAN CRAMAGE ANO FL000 C6NTROL*01STRIM REFERENCE CARL RZARO, FL000 NAZARO NEWS U0 AND FCO, JUNE, 19TT MAY 1984 5-14 DESIGN CRITERIA 1 � V1c��1 p U ►1�Jllrl _'�j � f'.lf�rwt_ I! JV LLD n (- a% '� I i�_ - w(Sa _►';� bra u'rv+�n Par` �%rf way - - 1 rl 0.ETS a Q.21 5 C!t-5 ._C.A_3.5 U GTJ_ C70(3, ZV i- erc+ef? .i.. °lViI nor.;�i-c Y'►v� ctY at a� �ov✓ /"jai es v" 1 V� l t S Ter rvj... l_o ..ov a r. t- ICD %Kj a G �Z D.:r 9 / lJ �7 I i Ccse�ec�f cJv4c arc er - 0�0a.. Ocv'O55 Va_caK- ' p ►4 e,r-�- n o y:/ ,,1 VL:=0,c2 c�C51 LF FYDM ril ure. 'S�Z Rio = OI�g yo = Z Tn Ie�a+ 2P TRITU(Scq_ in Tr-cu�Mrxh — Sou�-� slcle A 1 my = 0, C Js ; Q z Z7 c Ps C 5' Th I e.-0 Go QJ avid Q/L allow a.(o)e, (Sawne- as F) r2e..P.. � h �or 7c�5 ® 018 3,39 c�s / 1t = b, 68c,�s LX Fra1 rn F1'�ure:5-2,yo/h-a,720 1 f Y4o =613G' PP TR 1-U �Sa�in Tv-bUTrnam e Sau�h 571'Ge)..: 17c�s Ie ��►� >° Goal, e�� _ _: �eI1or ff FS--bS-'5..5cs 1j h,--If 6 O 1 &,'-$5 �f,ui`'i`o.p,0yerj aj-L'- 1,7: ` I, ji- 1 ' r IA e'.'- be_a�tn s, _ . r - J I DRAINAGE CRITERIA MANUAL INLETS & CULVERTS 0.ih Rid eF-amrfl 3r4Fiiling ISO veofoD�si n ,. PR 168 8,000 EXAMPLE (1) (2) (3) 156 6,000 D•42 inches (3.5 fest) 6. f44 5,000 0. 120 efs 6. 5. 4,000 Hwe Hw 6. S. 132 o feet 120 3,000 (1) 2.5 8.8 5. 4. 4. 2,000 f2l 2.1 7.4 108 (3) 2.2 7.7 4. aD in fast 3. 96 1,000 3• Soo 84 ---+ -- 600 / 2• 2- 500 m 72 400 / 2. v 300 1.5 ? U. / s Z 60 v 200 c 54 LA)48 / W 100 > / so 60 x f 42 a 1.0 1.0 o rn So Hw SCALE ENTRANCE G W 40 p TYPE cc U.1 I.0 W 36 30 (1) Severe edge with at 9 .9 33 hoodwall 3' .9 Q C G 20 (2) Groove end with Q W 30 headwall x .13 8 (3) Groove and •8 27 projecting . 10 24 8 .7 7 .7' 6 To use scale (2) or (3) project 21 5 horizontally to scale (I), then 4 use straight inclined line through 0 and 0 scales, or reverse as 3 illustrated. .6 '6 „6 IB 2 IS 11.0 -.5 .5 5 '.2 HEADWATER DEPTH FOR CONCRETE PIPE CULVERTS WITH INLET CONTROL FIGURE 10-10. II-+5-68 Denver Regional Council of Governments DRAINAGE CRITERIA ANUAL INLETS & C LVERTS Mov n a-i n .(��lt� te, Farm PU,D 31 FIt�irt Culver-f-Paz(V� 2000 — — M 11� = irM I -+ 1000 LIILKICl) WHIT CM IT ftMM4 FML 6 r Soo 120 . r..nr� r w�W. �wr w• A 6 r11rN dnwftd a Y MI' 600 106 500 96 400 64 300 72 s6 too 60 54 u _ 91 e.w W 49 77 o 100 = i- W 4t i ��O _ as 3s � w 60 r 33 W SO MA -30 40 � 0 t1 30 24 20 1 ep �t s 6 • ) r 10 16 L t0 10 15 s 6 It 5 4 From 8PR HEAD FOR CONCRETE PIPE CULVERTS FLOWING FULL n a 0.012 FIGURE 10-13. II-15-68 Denver Regional Council of 6arornmont/ P4■■■■e■■■■■■■■e■■■■ .eO■■■■■■■■■■■■■■■■■■ . . . . .. . .. . :. .. .. 7 w 6 w V. t� 9 5 " x F a w p 0 100 200 300 400 500 600 700 800 900 1000 J UDISCHARGE (0) C.F.S. F- 14 oc U 12 10 8. 6 4 U r. 0 1000 2000 3000 4000 DISCHARGE (0) C.F.S. Figure 7.4:3— 4 CRITICAL DEPTH CIRCULAR PIPE ( From : U.S. Dept. of Commerce, Bureau of Public Roads, Dec. 1965) �i 7.4--15 ■■e■e■■■■■■■■e■■■eo■_ ■■■■■.�■■■■■■■■■■■■■ ■■■ M■■■■■■ ■ ■■r`M■■■■■■■■■■■■■■■■ ■PO■■■■■■■■■■■■■■■®■ CLIENT: Project No: THE SEAR -BROWN GROUP I LJ I i I I I I 11 I I Project: 74z*tW al 79 Checked By: By: Oido44— Date: -31Z--Z- Sheet: Of,: 1 1 1 1 1 1 i 1 1 1 1 i 1 1 1 1 1 1 i DRAINAGE CRITERIA MANUAL 44. IzA �V) wL z = F O W Q H ~ G p � I J W --q V S^^�l 4- L u z o v) t � O �+ � z O W z .� C OJ p H V Q J p ac a } INLETS 8 CULVERTS =—SOMEONE M N y H H •N v N1110Y1N0� N W •J < i = e W W V Z R d, y s tV 1 IW < 1 J J W O Q O L + � = c to a 3 ; ~ lO I tj it J cc (h 11 11 W 1- H Z +� zz 3 M — Q o Q ` Lap flo0= o ¢ �V N W W No a w Y 0 z it C9 W W � y at WW g = N 3 3 cc w Flo au'- z W HI �_ N fi O z u N a L W S a S C u ZO : C a J W 3 11011 N e �� o a 1= d V JC a Oy > Qu CIW = OS FIGURE4-4. DESIGN COMPUTATION FORM FOR CULVERTS 11-IS-se Do wr ftowwl Comil of Goww" no al D DRAINAGE CRITERIA MANUAL INLETS & CULVERTS r dl W ;k O C�a 1-4 - 3 ti 1 to aC CX 1110012A Lri vi W J •M MI110111M0� r In = z Y Y H \ ~ IU U Z V J z o W W< j O W W 7 0 ; 0 M tl ' W W V Z I z - z J r < x W O 22 -oilN = (YM Ul O �- 4 CSO J �- . z L YI ^M Qj V L v I W H Q C + Z It II- < z zz00 a �, ltl O D W W It o N J J cc W W do._+ = ' -i3 OO Q cc Y W yN ~f• _ < < W pz = 2 W p O O z 4f � Y = O W Ct W z i - 2 O 2 WO t-O 11 tl N } O CC C 0 O }_ W a Q 0. i Ay H H rrom t" FIGURE 4-4. DESIGN COMPUTATION FORM FOR CULVERTS 11-IS-68 Do~ fte4o.l CwIro11 of as r i me is (� N w :E O 4 I JIO ~ Q � list t 1 J O �µ I ' 0 w �3 j I I / 1311110 w M u n v Z W } U U O O Y NIll Ol11NOD l 3 x _ Ld W a fa.. - i fn In w w > > 0 0 u n J W a a V w Z s �- V . �, In J a X� w 0 Q Q � 22 O J _ J = J O e t o Q, V o 0 -.1 ~ N N S D: w m F C�6 N o M Z 11 11 F Z p N lV p O O Z Z 3 U _oo o a W N pj F' Q O kf O J J o 0 1� a Z W W o n Ui �� >.o Y O O 7 (Z'S Q J a > w w w Ina z _ V, Z as Wy $ _ '� -+� a 3 3 cc—}- 0 Z =I� m QD v O ►- } H= Z w >> Z c N Z N O d W UuU w C� w 4A 0 LIJ F- O c U -i Ix W . 7 0 flail N ix 7 N Oix O Z i '„ � r Q Z. } wa LW a = JC Oy F Uw > S Figure 6-1 DESIGN COMPUTATION FORM FOR CULVERTS 1 1 1 1 W N Q LAJ . x o 0 o T w CL L, u J H JII AAIDOl3A • iviin0 W n n Uoz z U W F- LLJ o O gP110a1NOD - N ►- ; w a Y~ N N W W N I > > x E1D ^ J a Q W = V o W z ~ F ; N N v�V G J z Q X W �1 O'er W Q _ N n z 1 J W O t (�Q F M p a „ 3 ; Q d U J 0 M O U '^ _L W U z II 11 F z z y, Y £ QI O O O �� O UUl L in Q — O f F— 0 Q W W � �. o ly a> o = J N -- uJw O ,r, o J J 7 ° 2 M LIJ N Oo s z w w N o — 0 LL } 0 Y Q c z a s W g 2 �i z = 3 3 x� o -� V1 U Q Q S a E �i ~ ~ N QQ z W is y Q o _N N N W q.O U u 0 p C9 In w W = 0 4 U F- O O U W LLl .'� O 11011 .N a: ?N O 0 z W a Q c f.0 a = JCC ` cr- a 7N � V W z O� O D U' W 1 Figure 6-1 DESIGN COMPUTATION FORM FOR CULVERTS DRAINAGE CRITERIA MANUAL INLETS a CULVERTS 1 1 1 1 - b � 0. ocs = V a �- �- At a � kD o -� - �0 a ? Fi D c FO V A110017A W I 1]11fl0 ♦� n a V 2 > Y ~ • N Z0� V MI110Y1N0� N _ W W Q to U) U > > O O L1 a a ¢ Ir . '� < s C W S V O I F 0: t(1 � y 3 S N = v J < X W = J Lii J M _. W 0 + Q F = 4 �' i cc cc Z 11 11 < C 1 9 Cn Q O 2 2 O O O 3 < V W LL < Wcc < a x N U.I 6J cc O J J n o or �► z W W a �C-S rr Ix Y Y Q r N yJj WW a< W N g= M lV z Z W o_ 0 _ o O W __ Z o Q /J N W (� Y c9 w = o W H O o K �•� W 11 a N O O O O �� F� d -JIf C VW = 3 rrom WOK FIGURE4-4. DESIGN COMPUTATION FORM FOR CULVERTS II-IS-68 comes neow"l Caeail of Off 0 -.m. DRAINAGE CRITERIA MANUAL to INLETS & CULVERTS H � ~ w o � I ® lu ao t lz c it H.+ C-N i C O a N O VO Q W I I �A.00013A cc Q 1i11no Z N M �O fH •" Lcl (n W Y ~� J rnloyallo� W Q H ���9 > ; S �J < i = p� � 11� Cl o N T' �- L Lr J wx w = N I i 7 = J J a O J O_ o ¢T 0 Q1 Q W ~ L + wo W F y 0 2 220 t W H O J F = �W v0 N N o �14- cc Y o a W W W y N N z s V) z 3 3 w W 8 } N O d i = J J¢ =lo m N H N Z o W Y � U V y W w C IL p 000 0 0 IL > s .J V < V W = O ruwn or-M FIGURE 4-4. DESIGN COMPUTATION FORM FOR CULVERTS II-IS-68 Denvw ftow n.I C'"mil o1 Govm as M I I I I 1 r DRAINAGE CRITERIA MANUAL INLETS a CULVERTS -- I � � A O U1>j ~ r H 4a W 3 S ti vmJJ' ( 2 Uou 4- a } o p� T c C £ V -,I Q I, O v- A110017A Q _ W (4-('J' O 1i1100 V {� AM MI110iI1N00 N � W 1Y1 V y Y A. f 1h V 3 Z W t~ G G d ■. • J h V7 W r� W W V Z v � �... J 11 f/f j J t x -�{-. W40 am J �. _N h s = W z °+ o Q Cn a- 0 M k c) CM o W z H M Q 1^ v! Z II 11 < C 9 N v 00 c < < o < _ W ' p -W W 0 W It U. W W N - N N N 0 Ccc y 9 W W '� a O � W N N a< W z g s ui tY' zc - n Z W 3 3 d , � C� Qa ux 1.1 z s l0 C70 M N N _ H l;91 ~ ~ q to Z w O N H usO �v z C N W O O 4 V H cv01 zz w -� ¢ N? N v aN ILz > a rrom e*t FIGURE4-4. DESIGN COMPUTATION FORM FOR CULVERTS ' II-i'5-68 Do w► a If I COM1011 of OMrmMAI� DRAINAGE CRITERIA MANUAL INLETS & CULVERTS I I �l 11 I n [1 I N H � I W � 1Q^ M tO.i u10 Q(L O o 3 J , W A119017A ,11 Q 1711no = / C9 W < � wI110i11 dw (� W Q Y j H y >> `,Z W Itx V =q11,, ~ � W c d z x J 4 x J L,L w O !� z e J x yJl ° c t x ! o -►- i _ N u J ~ O + N I I ¢ W ¢ H Q Q) 2 11 II Q C o Q� 00 �� oIOU tz _ Lo � O W W � o x q)m ¢ O o W (V v z W W N Z H —t i § Y y w W W a4i y of =O ! W $ _ _s W Z 3 3 d-� _ =�J � J ric M H �, y t� a Q x< ~ ~ z W O H 2 � O Y N - 0 W W= O H O co � W 0 O o�n iv O O C13 C : ... w a cc w. _ a i s >CC a 7y rrom c" FIGURE4-4. DESIGN COMPUTATION FORM FOR CULVERTS ' 11-IS-68 DMww "**WWI C&OW11 of se"m nl� DRAINAGE CRITERIA MANUAL INLETS & CULVERTS 1 1 1 1 i i 1 1 1 1 1 1 1 1 1 1 1 q O I z W 0 a� CLOP a �' a a 1-a A410017A .� Q W I r r Azuno snloarA/loo Q� W v c ~ W VV~ Y < O O W Q N > W C = > W o: zi.i itCQ �i Q lJ N M i x W Q a s w J J 1^ M 0 W C e c J (d + x c (T N iz- QL 4 N 3 s ~ (� I I V cc J ¢ z 11 II W F I..y z +� p Qc O z z �- 0 0 �\ P; 10, p F F Y q N w >: z W W q- a A�i . `�. Q fc } F- 1- `p sn N Q<1...�r1iW z = z = u 3; �I t= $ W -- o :3 In _HF-jyu z w } rt� 41 sz Y H N Q' > c� V o O � OW z O ti o W � ,W Oz Nn a �o p O Z �_ cr a = it >¢ V Q V W i p co r__ nrb FIGURE4-4. DESIGN COMPUTATION FORM FOR CULVERTS 1I-IS-68 comw Mbnw1 Cwnall of so 9 1 olo t DRAINAGE CRITERIA MANUAL INLETS a CULVERTS q r_ rp cn W I IA417017A 0- A3lAflO "1110w1"0� a = W W Q Y t J N > > � G ■■ t N + L J 49 I = N 4 E70 No. J W _ O C t J cf c u � L cc W w fa ill II O H 3 Z u I? 11 L -- Z 2 0 0 —_ N 0 = w = oo O >ci a W J 0 UJ O N >c ^'O tJ W WIN _� �o ` J ti � � fl i } Q i s {� W "' tv W N 1t Z to.�-1- = W 33wW $ o -4- a a g < _ j> t—~Q. Z y1 a O �vviy W U 4 L Fri U > t9 ZW i c M ti t\ c0i ovoN � Nn n E o a'e�.� z : a 2 a } W w Ix -J < rrom t" FIGURE4-4. DESIGN COMPUTATION FORM FOR CULVERTS 11-15-68 0wwww► ftowwwl Cwwmil w1 aw.wrw■iwwl. If%s ,j}� ; unialn Ric i10 rg��ra}�'cPaac L ->- L e FarM_. 3 rd "1 okS E. ST o.F W..sSTFriE f J i ! i 51 B 3.0 EL EV.CFT� 5103,0 =uJS�L �I FREE BoAR1 (Q =4Z2.3cfs. ZZ5 wi5EL c�( iov(ggicF� 't0 5 0 5l03' GRD55 SECTION Z, t Li L Frame i _ � r I ! t ^r m l r A h ' f (r - - , w�-rH_- 1 ] No Text s 1',nrd�e r 1ouni-�►n'R;ci. �ariri �VD�3r,FI'(ri �LD - m, _ 400 i I 1 Concne�e Pin i 1 I 10 'f „) 2 0 30. GROSS SECTION T, %�a�'Inq lnforPla�'tort Q, l9eP�-h VW P AlRr- (Pc,n(FT) (LFi (FT , �n'o1o16 �erP411�011��'(=orGr4ss�S=0,5%] , fr44 R'�3 '1%ioc►�►D�S��RR�>✓ siZ_6,s$�(Po+� 1,756&ra, 6136 LZ I - 't3 Z QZ 1 _ ; - V ;J I;d Z'>` 2d10 � t�F18�61 1156 31,1 i - i ' r 1 , 1 I 1 I I I - I — — : I 1 I I 1 1, r � k � 1 i.ix • - #%ctJ'f1�r R j h GI �1 r ! r e _ car q�. 1 Freebo0.4 13,7c e 56 Cr^o s s Se cf I k 0 n F- I !? ai tin � Cvrrve. CY'055 Sec�tloV1 C"• � � C�`r l rVo/'�•l� a7� Sc�i�cvr�5�l..�' I 5 Jot. E LS Y Cat) 5103� ; Node •:�oer. e�c� �vCtr'.�oW _ _ 1 20, V i. t f F T� , I 1 _ , I I I 1 -1, : '. -; -4 T rU, i .-. ...... --t -A-P U- ra SLI LEI - �2�73 V.-! 56 Ices 85: 5 4-6,9 5 = 516 0 RO:5-T - sr=C7 ( ON 0 F P� R l< VJ A Y -m I . . VV A L e- F: R 6 Al 6 J TIM r. J.� . .... ... Ji .. ......... J.. -.1- ------ . ..... I I 1 APPENDIX D Water Quality Documentation Final Hydraulic Design Report � Regional: Detention Pond 278, I i 1 I McClellands & Mail Creek Basin Fort Collins, Colorado April 2000 THE SEAR -BROWN GROUP Standards in Excellence It V. SENECA STREET STORMWATER CROSSING The drainage culvert crossing Seneca Street was originally proposed with the Westfield Park drainage study (Sear -Brown Group, 1997b). For this final design, the previous culvert design was lowered in the ground to meet the following objectives: ► Reduce the size of box culvert from 1 Vx4' reinforced concrete box culvert (RCBC) to 8'x4' RCBC. Reduce areal extent, aesthetic effect, and cost of grouted riprap rundown from drainage culvert into detention pond 278. ► Reduce burial depth of the 12-inch waterline which is to be relocated within Seneca Street. With the proposed depth of the storm drainage culvert, the relocated waterline can be located 18" above the RCBC. and another storm pipe (designed by others) leaving approximately 16 inches vertical clearance on both sides of the pipe. The upstream end of the culvert crossing Seneca Street terminates in an improved inlet. The inlet is designed to pass the peak stormwater discharge without exceeding detention freeboard requirements adjacent to Seneca Street. The downstream end of the culvert crossing Seneca Street will connect to detention pond 278 at the maximum irrigation storage elevation (5088.02). The outlet will include a grouted riprap rundown within the irrigation storage portion of the pond to prevent undercutting. As required by the Stormwater Utility, a grating to bar unauthorized access to the box culvert (i.e., by school children) has also been proposed for the downstream face of this structure because of the large size of the box culvert. A trashrack is also proposed for the upstream face of this structure for similar reasons. VI. STORMWATER QUALITY To enhance stormwater quality, the regional detention pond will be comprised of a grassed zone above the irrigation pool to allow for settlement of suspended solids. The Mountainridge regional detention pond 247 design report (RBD, Inc., 1996) indicated that 2.76 ac-ft of water quality capture volume (WQCV) should also be provided in detention pond 278. Note that this WQCV is based on the entire tributary area of the drainage basin and storage within a normally dry water quality pond. As directed by City of Fort Collins Stormwater Utility staff, the outlet from pond 278 will be modified to restrict "first -flush" outflow while still passing the 100-year stormwater discharge. Pond 278 is considered to be a wet pond because of the irrigation storage volume below the stormwater outlet. Therefore the water quality outlet has been designed to release the WQCV within this pond over a 12-hour duration (UDFCD, 1992). The water quality outlet consists of a flat plate m mounted on the proposed drop inlet to the existing outlet pipe. The dimensions and spacing of the holes in this plate have been designed in a manner consistent with the UDFCD standard riser pipe. A steel trash skimmer screen is to be mounted outside of the water quality outlet plate; sizing of the trash screen is also consistent with UDFCD guidelines. VII. EROSION CONTROL The overall erosion control for the regional detention pond 278 is included with the Mountain Ridge Farm P.U.D., 3rd Filing report and construction drawings. Construction of adjacent improvements, including the proposed residential lots both north and south of detention pond 278, will need to design appropriate energy dissipation and erosion control measures for any associated surface or piped outfalls into the pond. Erosion control for the Westfield Park area includes the installation of a permanent erosion control blanket in the channelized approach to the culvert. VIII. CONCLUSIONS The proposed grading for detention pond 278, in conjunction with Westfield Park, provide sufficient capacity for stormwater detention and is consistent with applicable master plans and reports for the McClellands and Mail Creek Basin. The outlet structure for this pond will be a drop inlet incorporating a water quality outlet. The emergency overflow for pond 278 is located west of the PV&L Canal but will cross the PV&L Canal, then overflow through the weir notch on the east bank of the canal which was constructed with detention pond 247. From there, any overflow will follow the previously -established overflow path into detention pond 247. The Seneca Street culvert crossing will be composed of approximately 165 feet of 8'x4' RCBC, an improved inlet structure with wingwalls and a trashrack on the upstream end, and wingwalls and an access grate (as required by the City) on the downstream end. The irrigation diversion from the PV&L Canal will connect the irrigation storage component of pond 278 with the existing headgate structure constructed during Spring 1998. Stormwater quality issues are addressed by using the bottom 2.61 feet of detention pond 278 to satisfy the remaining 2.76 acre-foot WQCV requirement for the tributary basin. W �1 �RBD, Inc. 504-009 `WATER DUALITY CAPTURE VOLUME QC : Percent impervious: Tributary Area Impervious Basin (ac) N -------------- 77 -------------- 26.3 ---- 45 78 74.7 37 81 82 24.4 30.0 45 65 83 33.6 35 ' 84 22.2 75 177 11.5 41 178 11.7 14 179 13.9 67 180 29.8 40 181 182 16.2 17.8 45 45 400 2.8 75 ---- —Total - - 314.9 Aver--------w-;�� o Average „::;.::.w /o Required storage: 0.19 In 1QCV (UDFCD Fig. 5-1) = (Required storage)(Area) _ (0.19 in) / (12 in/ft) * (314.9 ac) 1QCV = 4.99 ac-ft failable WQ volume = 2.23 ac-ft Remaining WQ volume = provided in Pond 247 2.76 ac-ft to be provided in Pond 278 1 r 10/12/94 DRAINAGE CRITERIA MANUAL (V. 3) 0 0,�9 0. 05 a . . C 9.1-1992 UDFCD STORMWATER QUALITY MANAGEMENT 5 ,Extenc 0-1-10 ed De r Drai entior time Basi (Dry) /000000/ 000/f D 1 tent! -Hour n Ponl Drain s (W rime t) v iv cu Ju 40 150 60 70 so 90 100 Percent Impervious Area in Tributary Watershed Source: Urbanos, Guo, Tucker (I sag) Ncte: Watershed inches of runcff shall app!y to the entire watershed tributary to the 6fdP Facility. FIGURE 5-1. WATER QUALITY CAPTURE VOLUME (WQCV) DRAINAGE CRITERIA MANUAL(V. 3) STRUCTURAL BMPs r from �owCi ,MokrctA nni�9Z C �Iv�1 1vo�� "?4-7 11,�alysl s a.c� --F r✓ Fiovr\ t—'otiw( Z ✓� n. C kAr't t o. 8. 6. 4. 2. 1.0 0.8 0.6 m E 0.4 E CL Lj 0.2 ca a m 0.08 0.06 0.04 0.02 0 0 0 o 0 0 0 EXAMPLE: DWQ= 2.0 ft X000 0 WQCV = 2.1 acre-feet SOLUTION: Required Area per Row = 16.5 in? I 0 I — 4101 1 or QJ a� r r I O�Q OeQ I JF i 0.01 0.2 0.4 0.6 0.8 1.0 2.0 4.0 6.0 8.0 10 11 Required Area per Row (in? ) Lu 40 cu 2 irurce: Douglas County Storm Drainage and Technical Criteria, 1986. r FIGURE 6-3. WATER QUALITY OUTLET SIZING: ev. 3-1-1994 WET EXTENDED DETENTION BASIN RETENTION POND UDFCD WITH A 12-HOUR DRAIN TIME OF THE CAPTURE VOLUME DRAINAGE CRITERIA MANUAL (V. 3) STRUCTURAL BMPs Threaded Cap Removable & Lockable Overflow Grate for Larger Storms Stiff Steel Water Quality Capture,: Screen for Volume Level Trash Skimmer Y Open on Top t— Perforated Holes •� �;•: Y• & Bottom Above Permanent Pool '•` Permanent Pool Level I RQ 2 feet Permanent Pool / Trash Skimmer .'' ,:°,• Rs2 4D of Riser 41� See Detail ` '' :' Pond Bottom Drain Valve Water Quality Access Pit Outlet Pipe—► Riser Pipe (See Detail) (min. 3 ft) Notes: 1. Alternate designs are acceptable as long as the hydraulics provides the required emtying times. 2. Use trash skimmer screens of stiff green steel material to protect perforated riser- Must extend from the top of the riser to 2 ft. below the Permanent pool level. Notes: 1. Minimum number of holes = 8 2. Minimum hole diameter = 118- Dia. -112" diameter Air ent in Threaded Cap Water Quality Outlet Holes Ductile Iron or Steel Pipe FER QUALITY RISER PIPE NOT TO SCALE Size Base to Prevent OUTLET WORKS Hydrostatic Uplift NOT TO SCALE Maximum Number of Perforated Columns Riser Diameter Hole Diameter, inches (in.) 114" 1.'2' 3; 4• 1 4 8 I 8 -- 6 12 12 9 8 16 16 12 8 10 20 20 14 10 12 24 24 18 12 Hole Diameter Area (in.) (in. 2) 1/8 0.013 1 /4 0.049 3;8 0.110 112 0.196 5i8 0.307 3/ 4 0.442 7/8 0.601 1 0.785 FIGURE 6-2. WATER QUALITY OUTLET FOR A WET 9_1-1992 EXTENDED DETENTION BASIN UDFCD he Sear -Brown Group estfield Park 504-023 ater Quality Outlet Riser Columns Hole Hole Hole Area Remarks Diameter `J Diameter Unit Area per Row (in) M (in) (in2) (in2) tingle Riser Trials: 4 8 0.50 0.196 1.571 6 9 0.75 0.442 3.976 8 8 1.00 0.785 6.283 10 12 10 12 1.00 1.00 0.785 0.785 7.854 9.425 ual Riser Trials: 2x8 8 1.00 0.785 12.566 2x8 12 0.75 0.442 10.603 2x10 2x10 7 13 1.00 0.75 0.785 0.442 10.996 11.486 .Zlvflate Trials: 24 7 1.00 0.785 10.996 3" O.C. 28 13 0.88 0.601 15.634 2" O.C. 48 31 0.50 0.196 12.174 1.5" O.C. 11, f u 04-Apr-2000 I Worksheet Worksheet for Circular Channel Worksheet PVC WQ DutletT _. ..H Flow Element Circular Channel Method Manning's Formula Solve For Full Flow Capacity Input ata annings oe Icient 0.010 G Channel Slope 0.0069 ft/ft CSarnc Diameter 12.00 in esu is Depth 1.00 Discharge 3.85 cfs Flow Area 0.79 ft2 Wetted Perimeter 3.14 ft Top Width 0.00 ft Critical Depth 0.83 ft Percent Full 100.00 Critical Slope 0.006699 ft/ft Velocity 4.90 fus Velocity Head 0.37 ft Specific Energy FULL ft Froude Number FULL Maximum Discharge 4.14 cfs Full Flow Capacity 3.85 cfs Full Flow Slope 0.006900 ft/ft 11 ,'4Cj I a 5 1115, P, Sim pe o >n Qi�aP rnlc-r-;- i -gyp Pass Z \N!�!'•/ 17`/ PVG c� �-t A/[.e-T' `A ,- — / ✓C d.Ic Imo. n is �� I Vi c4 l ( --> 10/98 57:37 PM The Sear -Brown Group, Inc. FlowMaster v5.12 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 '1 _—_�v'3 do do .+.-......4c�'� a 4_. a y 1 de 4 oLf (' / J 1 •.eJM5J6L'S I:.. C �i T?S �. ,1'P•8!1 Po•rf �w 1 - tel: S /.A _ V 2 ♦} � • � ems'. s.r+. -- � il . r'_ r. �. F 4 =� r t _ ) Si - ` - Y 1 b� Iy \ GJV. _ w, l ! o >m • - lac— , _. F di F. r W. r ` '.iS. Lod dim. - Iwo dr�do1+.►��. l� VMI rd did a.... 91 S( ! y VIi �N i m • ;�tr-.-� ) . -"° I �J'� S i ytf;*n1.% Lod L o �l"'7 >�=•_�_3-,...�n'L�`L tl y do Iddidood 1.°. f iL �'L..r r ..T 14 T. did333 � a � of do - F ^.sTS7■'��r ■ Wdr 3 J. JILI ew tp4 IHN s I T„ r , ,L I ri � I+'. MEW oil— ild. . dd­ CONTROL NOTES 1. IT IS THE CONTRACTOR AND THE DEVELOPER ARE RESPONSIBLE FOR MAINTAINING ONSITE EROSION AND SEDIMENTATION PROTECTION FOR OFFSNE PROPERTY DURING CONSTRUCTION. THE CONTRACTOR SHALL ANTICIPATE LOCAL AREAS WHICH ARE VIILNERASU TO EROSION AND SHALL TAKE NECESSARY MEASURES TO PROTECT ONSITE AND OFFSRE PROPERTY. 2. THE CONTRACTOR SHALL INSTALL A SILT FENCE ALONG THE SOON AND EAST LIMITS OF THE PROPOSED DISTURBED AREAS PRIM TO BEGINNING ANY OVERLOT GRADING. THE SILT PENCE SMALL BE MAINTAINED TO PROTECT ADJACENT PROPERTY FROM SEDIMENTATION. THEY SHALL NOT BE REMOVED UNTIL THE CONTRACTOR HAS COORDINATED WITH AND OBTAINED APPROVAL FROM THE CITY OF FORT COLLINS. 3. MEASURES SHALL BE UNDERTAKEN TO LIMIT THE OFF -SITE SOIL TRACKING OF MUD AND DEBRIS SPILLAGE FROM VEHICLES LEAVING THE SITE. MUD AND DEBRIS SMALL NOT BE TUCKED ALONG ROADWAYS AND/OR PAVED STREETS. !. ALL DISTURBED AREA HOT IN BUILDING. SIDEWALK. PARKING OR ROADWAY SHALL BE DRILL SEEDED WITH DROUGHT TOLERANT NON -IRRIGATED TURF. S. INSTALL STRAW BALE BARRIER AT THE START OF CONSTRUCTION. COORDINATE WITH THE CITY OF FORT COLLINS FOR REMOVAL 6. GENERAL EROSION CONTROL CONSTRUCTION PLAN NOTES, CITY OF FORT COLLINS. JULY 1996. A. THE CITY OF FORT COLLINS STORMWATER UTILITY EROSION CONTROL INSPECTOR MUST BE NOTIFIED AT LEAST 24 HOURS PRIOR TO ANY CONSTRUCTION ON THIS SITE. B. ALL REQUIRED PERIMETER SILT 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 APPROPRMTE TIME IN THE CONSTRUCTION SEQUENCE AS INDICATED IN THE APPROVED PROJECT SCHEDULE, CONSTRUCTION PUMS, AND EROSION CONTROL REPORT. C. PRE -DISTURBANCE VEGETATION SHALL BE PROTECTED AND RETAINED WHEREVER POSSIBLE. REMOVAL OR DISTURBANCE OF EXISTING VEGETATION SMALL LIMITED TO THE AREA REQUIRED FOR IMMEDIATE CONSTRUCTION OPERATIONS. AND FOR ME SHORTEST PRACTICAL PERIOD OF TIME. D. ALL SOILS EXPOSED DURING LAND DISTURBING ACTIVITY (STRIPPING, GRADING. UTILITY INSTALLATIONS, STOCKPILING FILLING. ETC..) SHALL BE KEPT IN A ROUGHEN CONDITION BY RIPPING OR DISCING ALONG LAND CONTOURS UNTIL MULCH, VEGETATION, OR OTHER PERMANENT EROSION CONTROL IS INSTALLED. NO SOILS IN AREAS OUTSIDE PROJECT STREET RIGHT OF WAY SMALL REMAIN EXPOSED BY LAND DISTURBING ACTIVITY FOR MORE THAN THIRTY EROSION 3CONTROL (E.G.RSEED/MIDAM BEFOE REQURED TEMPORARY OR PERMANENT ULCH,, LANDSSWING, ETC.) INSTALLED. UNLESS OTHERWIS APPROVED BY TIE STORMWATER UTILITY. E. THE PROPERTY SHALL BE WATERED AND MAINTAINED AT ALL TIMES DURING CONSTRUCTION ACTIVITIES SO AS TO PREVENT WIND - CAUSED EROSION. ALL LAND DISTURBING ACTIVITIES SHALL BE IMMEDIATELY DISCONTINUED WHEN FUGITIVE DUST IMPACTS ADJACENT PROPERDES. AS DETERMINED BY ME CITY OF FORT COLLINS ENGINEERING DEPARTMENT. F. ALL TEMPORARY (STRUCTURAL) EROSION CONTROL MEASURES SHALL BE INSPECTED AND REPAIRED OR RECONSTRUCTED AS NECESSARY AFTER EACH RUNOFF EVENT IN ORDER TO ASSURE CONTINUED PERFORMANCE OF THEIR INTENDED FUNCTION. ALL RETAINED SEDIMENTS, PARTICULARITY 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 DRAINAGEWAY. G. NO SOIL STOCKPILE SHALL EXCEED TEN (10) FEET IN HEIGHT. ALL SOIL STOCKPILES SHALL BE PROTECTED FROM SEDIMENT TRANSPORT BY SURFACE ROUGHENING, WATERING, AND PERIMETER SILT FENCING. ANY SOIL STOCKPILE REMAINING AFTER 30 DAYS SHALL BE SEEDED AND MULCHED. H. CITY ORDINANCE PROHIBITS THE TRACKING. DROPPING, OR DEPOSITING OF SOIL OR ANY OTHER MATERIAL ONTO CRY STREETS BY OR FROM ANY VEHICLE. ANY INADVERTENT DEPOSITED MATERIAL SHALL BE CLEANED IMMEDIATELY BY THE CONTRACTOR. EROSION CONTROL LEGEND OVEMNYE TRACKING CONTROL ® TEMPORARY SEEDING/MULCH OPERMANENT SEEDING OSILT FENCE © INMT PROTECTION N NON -IRRIGATED SEEDING: A. DRILL SEEDING AND HYDRO MULCHING: 1. DRILL SEED ALL NON -IRRIGATED GRASS SEED BY MEANS OF MECHANICAL POWER DRAWN DRILL SEEDERS (NOT MILLION SEEDER) FOLLOWED BY PACKER WHEELS OR DRAG CHAINS, SEED AT THE RATES SHOWN, SEED IN TWO PASSES AT RIGHT ANGLES TO ONE ANOTHER, SOW HALF THE SEED IN EACH PASS, PROVIDE MARKERS OR OTHER MEANS TO ASSURE. THAT ME SUCCESSIVE SEEDED STRIPS WILL OVERLAP OR BE SEPARATED BY A SPACE NO GREATER THAN THE SPACE BETWEEN THE ROWS PUNTED BY THE EQUIPMENT BEING USED, DO NOT SEED DURING WINDY WEATHER. 2. IN NON -IRRIGATED TURF AREAS. DO NOT SOW SEED IN TREE OR SHRUB WATERING RINGS. MULCHING(REQUIRED FOR TEMP. SEEDING): MULCH FOLLOWING SOIL PREPARATION. A. HYDRO -MULCH ALL AREAS WHICH HAVE BEEN DRILL OR BROADCAST SEEDED. MIX INGREDIENTS TO FORM A HOMOGENEOUS SLURRY. USING THE COLOR OF THE MULCH AS A METERING AGENT, SPRAY THE SLURRY MIXTURE UNIFORMLY OVER THE DESIGNATED SEEDED AREA. B. THE MIXTURE SHALL BE APPLIED AT A RATE RECOMMENDED BY THE MANUFACTURER. C. HYDRO -MULCHING SHALL NOT BE DONE IN THE PRESENCE OF SURFACE WATER OR HIGH WIND, THOROUGHLY CLEAN OVERSPRAT AREAS AND SITE AMENITIES AFTER MULCHING. CONSTRUCTION SEQUENCE PROJECT: MOUNTAIN RIDGE FARM PUG FOURTH RUNG STANDARD FORM C SEQUENCE FOR 1999 ONLY. COMPLETED BY: MIST Indicate by use of a bar line or symbol when erasion control measures will be Insfalled. Major modification to a approved schedule may require submitting a new schedule for approval by the City Engineer. YEAR CONSTRUCTION Month J F IJ A M J J A S O N D OVERLOT GRADING WIND EROSION CONTROL Soil RppMning PxWaler Barrier AddOWnai Barriers Vegetative Methods Solt Banlonl Other RAINFALL EROSION CONTROL STRUCTURAL: Sediment Trap/Bails Inlet Filters Straw Barriers Sin Fence Barriers Sand Bags Bare Sail Preparation Contour Furrows Terracing Asphalt/Concrete Paving Other VEGETATIVE: Permanent Seed Planting Mulching / Sealant Temporary Seed Planting Sad Installation IIII / Mats / BlonNah NOTE: FOR EROSION CONTROL DETAILS, SEE EROSION CONTROL DETAIL SHEET. GRAPHIC SCALE Me o ss w Rea IV F¢ I I ImN - eD IL City of Fort Collins, Colorado UTILITY PUN APPROVAL Dlnalar of outlawry DM CHECKED BY: wabr ! wemawer wish Dme CHECKED BY; f,wrvow U., DM CHECKED BY: Pwaa ! ponchos pole CHECKED BY: CHECKED BY: E O m� o W! a V U v DATE: 4/10/00 SCALE: 1"=50' DRAWN: GSF CHECKED: MWT APPROVED: JRL W O Q D C J F a a U � J az O L. J_ EC 0 ~ Z_ W Z > o= p r U K IY W > z O Z 0 Z V) o � O 0 0 a Lee i LLJ woo" PROJECT N 0023 SHEET 5 No Text LEGEND PRroosD siORN MWER AREA INLET O ♦ AREA ME STORN %WER YMIXIXE 0 SOEWALX CULVERT D wmE cucvvT ORANP.GE YBBAIRN BOUNDARY MMMMMMMMMMMMM ORANAGE WBBASN DAS OFFVT CRANAGE 91YABN OSZ ELISTNG CGNTWR sm--------- FLOW ARROW CURB NUT D TPE_R WAFT PROPOSED CONTO.a BOA PRCPOSEO WT OXVADON Y p5 MGX PONT A 04](HP) LOW PONT • 04.NV) MNGN PONT ® (POLAR NUMERAL) GRADE BREAK L 0 PRCFOSED GRADE 2.0 R 110 a ® X�/estbrooke � W�WUD of offoil / too2nd Filing ®' .IN Oil eft ®\ t CALL UTILITY NOTIFICATION CENTER OF COLOIRADO 1-800-922-1987, w 5LL34Vy-[ 6W7�500WDU�R BEf0 Y PB556 . OR ryGwSE iM NENB@ MLMEES. RA am 'IZ: HOR1' _100' ®a� UTILITY PLAN APPROVAL CITY OF FORT COLLINS. COLORADO APPROVED: OW.eb el E�pin.wN pal. Y Ja CMECIEED BY: wtw see won..nw uunE wL. CHECKED BY: stwm.olw MINE Me CHECKED BY: Pam P.B RwRWPMn pots CHECKED BY: CHECKED BY: DM. MOUNTAIN RIDGE FARM 3RD FILING SHEET 3 OF 2T STORM DRAINAGE SUB —BASIN DR 13 c: WRAwrICWNF-]Rp\wEJ-ro-1 m.m..Dw APRL ta. 2000 ExHZBIT l� LEGEND PROPOSED STORM SEWER 41aa�mmb AREA INLET a . YF/' MF STORM SEWER MANHOLE 0 SIDEWALK CULVERT 0 mEWAK CUL.xRT_y DRAINAIi SUBBASN BWNDAY MmmmmmM DRAINAGE SUBBA9N Al LTyTE DRAINADC SUBBAyN ADj' EXISTING CprtWR - 92m FLOW ARROW CURB INLET D rool INLET PROPOSED CONTaR —I— PROPOSED Brot ELEVATION X 92.5 HICH PONT X 04 C(HP) LOW PONT X OL.NLPI DESIGN POINT ® (Foal wANwU) GRADE RR AK X OR 2.0 a Hydrologic CharacterisUc9 C. (ACT -Cie iy Tr RWIxI MImx1Y OI.muP INS IN IWHN Keel SYR INYe SM IN" M-0 aK on 113 lab 24 ].I 03 L1 b 2 I W ON Ro 17.120 56 Is 65 o6J ON ON 113 102 2e 70 09 - 32 OM 0.)1 025 ne 15,5 20 59 09 39 Ow5 ON 032 106 9a 25 n 00 36 MA ON age e9 43 28 26 10 3f M9 on on I2A Ila 23 67 15 13 Pia ON a35 152 N6 21 Be 1e 61 br9 0m 0m 13.2 1" 22 Bs 0" 23 Will Bm on 120 ILA 23 as 12 46 W11 100 am 152 16s 21 at Is se 001-12 195 ON 19A 1114 Is Be 13 46 111,I3 1.1e am 134 II] 22 a5 14 63 M-ta ON Om t 6 No 20 56 Da Is W15 am am Its Be 26 72 03 11 a i 0m BOB 21 63 20 n 07 22 radial 012 ON 9e sa 26 7e 02 or oAOs3 225 Bn 204 193 is - 52 Is To D6054 ON Om ms I97 Is 52 e2 no Os033 067 an Me no 17 50 03 90 NI on on ISO Ile 21 61 0" 29 \\ OR ISo ON too RI 2A 56 26 91 \\\\ OR 11 173 DA 164 165 20 a9 26 Be VA AA\ WIN 1370 DR me 297 1e 62 100 971 V A\ MTV 3m 0WE 152 Ae 21 6n 41 149 \ \U\ OR 544 052 too ia. 19 54 5e 191 0P v1 1Se3 ON To SO I 4 4 z 117 ur m I \ \ MN IIM aN mA 2SY I9 5e 100 '!1 �m halt'\ \ \\\ DIP 224 ON ls0 Al 1954 17 01 Is If Alp If If I/ IN / e 5 11• _ Wass if 0 7 i `�1 ` 9 IF is IT IF F'// i r q0 33 �v Palma aim IRWIN CROSS SECTION Al — Al 4mw.um qGs `q POND 276 - 100 YEAR STORM / WSEL 701.96 VOLUME EQUIRED 29.2 Al VOLUME ROVIDED : 29.97 AC -FT RELEASE DISCHARGE : 102.1 CFS IT i No IF how / Low m. -m es xe 4.4 v 5,026 CROSS SECTION C1 — C1 4m TO. aI o Hydrologic Characteristics 9m5min Me "C' VYw T Tm R 1,14InYmlry q.mu4e W) IVA IN41 (1"0) ICe91 2IS ban 2M IN" WIO ON am 143 106 24 30 04 I! MT9 ON 025 5.0 &a 32 s.0 03 as MM-1 214 an Ae Iet 2t 31 v as MIA Dm Om 6e 95 2e 2e 11 39 mmB t13 am 126 122 23 9s 20 71 MT".. 113 am rzs 122 23 9a 20 1.1 MT95 Om 325 Be 95 26 21 11 29 MTRB 32r on 145 I4,1 21 Sd ..I52 Set DI 4GO Om 146 141 21 a 35 2r.2 OPTIM Om aTo a9 55 26 2e 11 as CPIR4 152 057 125 122 24 55 25 90 MIR at 609 075 1Ee 141 21 64 96 ys MTR.N elm 0m 1E8 w 21 at 173 n9 MTR.a ilia old 148 141 21 51 103 04 MTRA 601 a71 its 141 21 61 119 ue OPIR-5W 5IN ON No M5 13 e1 27 106 MRm T--V low an ON 31.5 13 II ee 174 00,711,11) 1116 aN no 315 13 61 49 194 DWR-0I11 BN am 31.0 315 13 41 42 yl. T.O.F. w Represents Engineers recommended mNYnum Top of Foundation wall Nehallon. Minimum elevation far lowest Voting in any home shall insure that no storm drainage y';mmmm runoff will flow Into the Nesidence. En99lnew, recommends that all f rlahed four elewtlMs should ee J Now the sidewalk a5 o WM al Ilia. Devhtlm of EruM Control Mmurex MOTE' 1 At Nxueee Ma, IP M neeeaed. omos, Me, to how a..maml Pam wd g 1 wade Few elm ee YItlmN q. 0.1m DIN and owdot vmEog Me to how twYMMY wMA R het M. wain "Per elm M w hist3 z. mAWN aimuMUW a w noMlwewmll the had, Oar m'rk &IN the we, lief, Igea elm ae o1 the pMWF Cawl IRBIM she iM YJeI. f Smneet Coon and Whomed o2w and No 1M Neis at the eq a1w i1 6MW[a SORL 3 stem boF FNIe and aMN athlete Rm how FIAT Nos, 'nVoted thah 45p 2. Ses Met E17 rw SIM, Call Roam the mslm[I41 911aw Me OF m[mweY aft" the side If the eeweamml Re 3 Ile ] Sat Met AS AN Rip-R© ashes Or We mMMd F we dmM t aFa t). ., pnMa l at We" No (5) felt a a Mbtmy e. AN!1 Mel ff meoYee Ow ORYIgMe4 uetnM xMb 1fo3m dew Mamm Me NINUMA aRmeNorth"n Ma Sum at at raises mMNL ewrNtry. R02' Sw'EFM HydwINNNI [ DMOn N owns, Beh- Draholoo orl PRa , C MNSman6, 6 Mar ham BmW-Eat CY 0 carvaa0-Mrr. - L saw e.mm GwP b 011wm MaM1aq 514-BaMna �\ h A `\ D he \ \\\ N N\ INNN p N yo \ \11` to Y/ IN IN IN —' It' i�ai ,�� .•`: ��`` y 1 / he s' a ;"Aj Ar .l..i ire d 9aa I a / / /a so / / aJ / *• \� 6? he r m m A No IN HORIZ: 1e = 60' UTILITY PLAN APPROVAL CITY OF FORT COLLINS. COL-0thoo tW a ^� m� // ` APPRO\2D: CAYMAN W Eh9Mew'^9 OW. 1, ♦ NECKED BY: ' wmr wM 6eM...t. aunt' pal. CALL LrFUY NOTIFICATION CHECKED BY: CENTER OF COLORADO ebmwtr. MMRY wit 1-800-922-1987 CHECKED BY: M 534-670ONIRm0 "'°""�'""" Nt' m [1 IN EAOW CHECKED BY: —� FOR M MaalS OF UmflpRp.ND rSLMw munEs. CHECKED BY: mt. MOUNTAIN RIDGE FARM 3RD FILING STORM DRAINAGE AND EROSION CONTROL PLAN SHEET 4 OF 27 ' Q\ORAMNG\M T-yin\MRF3-OP.Ino Y9,22000 '(' R [�F, M 6'-7 l r' r Cmtm..m 37. 6 • ��J A ,� ads \I I \ 1 I I \ I s \ PO 9N;`I\' \ SECTION AA \ CROSS SECTION ACROSS POND 278 \\x I80e. yi �• _\� \ ' \ \vl y E i \X-u • ♦ /Ja TORSI Psi Ito � � ll a sw �____L_ _ ♦ I 1 RT s e _ \ \\ Ew A61,74 to e, ,emmed—�+ `\ \ `ow 'a 1 1 , DIRE) I I STA . IWIG7 \ w ° �� Ds. \Q\ EXIST. ION SMON •'eN w I \ \\\\ E IER90N STRUCTURE ` \ \ § I I / II �+ \ / ' � �♦ � M) � \ \\ \ \\\ EXISTING INV. 945,95t 0+W.62 — DROP MH \ \ V (° it 1 \\ OR 354 �s)) FILEASANT VALLEY AND) LAKE CANAL (Icw Aucwcx0 vE E%IST. FES TO 0 TRUCi DROP INLET TY .0 - ts' •(0,0�4-� V e 9 - EPa >.� ♦ �I1141FR WNItt R 1xRu a3.00 \ \ \ CB a ad T W. art' k... - \\���\ fl R w.nERGENCY OVERFLOW /mow]% SIR STA I e' \ O EMg]py // CENTER � COLORADO _-51w_____-\\\\\ \\I \ w ���— I i Ij i ����'_� 1-800-922-1987 It,(I w.� N — t _ erg_ b IIl/ a534-6700 \\ �_° gl iIF— / 55 \ \ �� m� 117. 3 If 5- N/ 1. smE&' FOR THE �w� � \ \� \\ \��Ia. e� s� \ � � n � i�i � / i ii [xnP IDLRxzp LEGEND PEDGouD saw SloR4 ueeR "1 e SIE'"MA 1 soAI LARI FLOW clw IAI DeE-R,u. .M.�M caDDD. VMAELD SWf a NITION R Bid HIGH) x xa. LOW ROM x Le OE bM Y (N MMM) aRUE MW x us T.O.F. = Represents Engineers recommended minimum Top of Foundation wall elevation. Minimum elevation for lowest opening in any home shall insure that no storm drainage runoff will flow into the residence. Engineer recommends that all finished floor elevations should be } above the sidewalk as a general rule. n n$ >o HORIZ: 1' =p 50' goo UTILITY PLAN APPROVAL CITY OF FORT COLLINS, COLORADO APPROVED: Director Dt EngEnI set, CHECKED BY: gat• and wo.le•oter trust, Date CHECKED BY: StoDeM• unity one CHECKED BY: >x, and R.o..eM -M CHECKED BY: CHECKED BY: Dale MOUNTAIN RIDGE FARM 3RD "LING SHEET 15 OF 27 NEIGHBORHOOD GRADING AND DRAINAGE PLAN (NORTH) WY I1.. 2aW a\osAwxcWs-aW000 xa �tlff16l% C WESTBROWE DRIVE LEGEND P,aPo noxr SURE, .--n---.-�—a roar ,Fw, rMxaEE swwx c.xwM a swawx axvn� r.r«wE srSEWSNex.aw, MWOMMMMMENSOMM � RS x,a a ww, Wx ED <anwP � � Ewvx,ax x n.. Pa«. x rP. LON ROW X LP ttWN MM Y PW", nYWI Ga.w xrax . a,. T.O.F, w Represents Engineers recommended minimum Top of Foundation wall elevation. Minimum elevation for lowest Opening in any home shall insure that no storm drainage runoff will flow into the residence. Engineer recommends that Oil finished floor elevations should be 3above the sidewalk as a general rule. r9 Ss a » >e w HORIZ: 1` w 50' UTILITY PLAN APPROVAL CITY OF FORT COIUNS COLORADO APPROWD: sH.mw a E.q*wHa sm. NECKED BY: wow and wow..ww wmp o CALL UTILITY NOTIFICATION CENTER OF COLORADO NECKED BY: Sk, m ff WIRY Me 1-800-922-1987 CHECKED BY: Fan, ww e.v W Oct, m534-67000DA�t vUR"u'vov' eAmURioi. oa rxaw FOR THE KWOER �LMErcRCMuxo CHECKED BY: r CHECKED BY: ow. MOUNTAIN RIDGE FARM 3RD FILING NEIGHBORHOOD GRADING AND DRAINAGE PLAN (SOUTH) SHEET 16 OF 2] c\ORAwxaWRF-=WRF] Wow: LXIiZ81T No Text