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HomeMy WebLinkAboutDrainage Reports - 07/22/1992PROPERTY oF,., inal Approved Report FORT COLLINS Date 2/f,2 FINAL DRAINAGE REPORT for SPEIGHTS P.U.D. Fort Collins, Colorado June, 1992 prepared by NORTHERN ENGINEERING SERVICES , I NC _ 420 South Howes, Suite 106 Fort Collins, Colorado 80521 (303) 221-4158 ' Northern Engineering Services, Inc. ' June 18, 1992 Mr. Glen Schleuter ' Stormwater Utility City of Fort Collins 235 Mathews ' P.O. Box 580 Fort Collins, Colorado 80522-0580 1 re: Speights P.U.D. Final Drainage Report Project No. 9201.00 Dear Glen: Northern Engineering is pleased to submit this Final Drainage Study for your review. It represents a study of the existing and proposed runoff characteristics of the proposed Speights P.U.D.. Study of soil erosion and control at the site is also included in this report. Your assistance during the design phase of this project has been greatly appreciated. If you should have any questions or comments as you review this report, please feel free to contact me at your earliest convenience. Sincerely, NORTHERN FiNGINEERIVGSERVICES, INC. Michael F. JoE. 420 S. Howes • Suite 106 • Fort Collins, Colorado 80521 • (303) 221-4158 • Fax (303) 2214159 I IN A SCARF 1'=2000' VICINITY MAP Final Drainage Report for SPEIGHTS P.U.D. Fort Collins, Colorado June, 1992 I. GENERAL This report summarizes the results of a stormwater and erosion study conducted for the proposed development of Speights P.U.D., located in the Northwest quarter of Section 32, Township 7 North, Range 68 West of the 6th Principal Meridian, in Fort Collins, Colorado. The site has previously been platted as Timberline Subdivision. Methods outlined in the City of Fort Collins' Storm Drainage Design Criteria and Construction Standards were used in the calculations for the stormwater runoff portion of this study, while the City's Erosion Control Criteria was used as a guide in preparing the erosion control plan. Additional references were made to the Urban Drainage and Flood Control District's Urban Storm Drainage Criteria Manual as needed. Summary calculations and other supporting material is contained in an appendix to this report. The Rational Method was used to calculate stormwater runoff from the site, while calculations based on the Modified Universal Soil Loss Equation (MUSLE) were used in the erosion study. II. SITE DESCRIPTION The proposed Speights P.U.D. is located on approximately 2 acres of ground which is bounded on the west by Timberline Road, to the north by Fox Meadows P.U.D., to the east by Sunstone P.U.D. and to the south by an undeveloped tract of ground. Speights P.U.D. Final Drainage Report page 2 II. SITE DESCRIPTION (Continued) The land currently is occupied by a house and several small out buildings. The ground is covered by grass and gravel drives which access the house and other buildings and the site slopes gently downward from southwest to northeast at approximately two percent. A tract on the northern portion of the site contains a large drainage swale and a 24-inch storm drain which flow to the east. The site lies in the Fox Meadows Basin (Basin H) of the City of Fort Collins. The drainage swale on the north side of the site is included in this master drainage plan as the Sunstone Swale. On the east, Stony Creek Drive has been included in Sub -Basin I of the Sunstone Village Fourth Subdivision. III. HISTORIC DRAINAGE Slightly more than half of the site currently drains east to Stony Creek Drive. The remainder drains north into the Sunstone Swale. Sub -Basin H-1, shown on the attached Grading and Drainage Plan, flows onto the undeveloped property to the south and eventually into Stony Creek Drive. Sub -Basin H-3 drains northeast onto the developed Sunstone lot and on into the Sunstone Swale. Flows reaching Stony Creek Drive from the site currently flow south into a curb inlet, then back north in a storm drain which flows into the 24-inch storm sewer mentioned above. Runoff from Timberline Road to the west sheet flows across the site to the east. IV. PROPOSED IMPROVEMENTS Development of the site would place five single-family lots on the eastern portion of the site with access on Stony Creek Drive. Two commercial lots are planned on the west of the site with access off of Timberline Road. The northern of these lots will have a veterinary clinic in the existing house. Development of the southern commercial lot will occur with the second phase of this project. ri ' Speights P.U.D. Final Drainage Report page 3 IV. PROPOSED IMPROVEMENTS (Continued) Although Stony Creek Drive has been included in the Sunstone drainage plans, the portions of the project site which historically drain into the Sunstone P.U.D. were not included in the runoff calculations for that project. Drainage improvements for the Speights P.U.D. have, therefore, been designed to direct most of the stormwater runoff from the site into the Sunstone swale or into the 24 inch storm sewer on the north side of the site. A variance is requested from the on -site detention requirements to allow the peak runoff from the site to proceed downstream ahead of the basin's peak runoff. The lag time to the Sunstone detention basin (#210) is five hours and 5 minutes. The time of concentration for the 100-year peak flow from Speights P.U.D. to the pond is approximately one hour which is certainly less than the one half lag time for the entire basin. The percent of impervious area is assumed to be 40% in the 100-year storm runoff master plan study prepared by Engineering Professionals, Inc. (August 1989). An updated calculation estimates 34% impervious area to make the runoff slightly less than that given ' by the SWMM model used for the study. In addition, the area of Speights P.U.D. is small, and the required rate of release from a detention pond would be achieved using a small orifice at the ' outlet (radius = 1.8"). This would most likely result in maintenance problems due to clogging of the orifice. An area inlet is planned for each commercial lot, with a proposed 15-inch storm sewer to convey flows to the 24-inch storm sewer under the sunstone swale. The parking lot of the north commercial site will convey flows from that area through a vertical curb and gutter into the inlet at the northeast corner of the parking. Runoff from the north side of the site will be allowed to sheet flow into the Sunstone swale. In the event that the area inlets become clogged, the overflow paths will be as follows: from the area inlet at Lot 6 flow will be north to the Sunstone Swale; from the area inlet at Lot 7 the flow will be to the SE corner of the lot and along the development's south boundary into Stoney ' Creek Drive and into the inlet south of design point 1. Historic and developed flows are tabulated in Table A, attached. ' As part of the improvements to Timberline Road, a 15-inch storm sewer has been previously approved by the City to parallel ' the existing 42-inch line. This was necessary due to the 42-inch line being near capacity. ' Speights P.U.D. Final Drainage Report page 4 V. EROSION CONTROL tIt is anticipated that the proposed improvements for the ' Speights P.U.D. will be completed by the fall of 1992. Construction of homes on the residential lots would proceed shortly after that. Development of the veterinary clinic is expected to be complete by the end of 1992. Gravel dikes are to be placed in the street gutters as shown on the attached Grading and Drainage Plan and gravel filters are ' to placed around the inlets. These temporary gravel structures should be monitored by the developer during construction and maintained as necessary. ' After over -lot grading has been completed on the project, it is recommended that any areas of the project which are to stand longer than thirty days without further work be dry mulched to prevent wind and rainfall erosion. The mulch shall be of hay applied at a minimum rate of two tons per acre and adequately anchored into the soil. A'PPEPTID I X 1. Runoff Calculations ................................... 1 2. Tables & Nomographs used in calculations .............. 8 3. Erosion control ....................................... 15 4. References ............................................ 18 5. Excerpt from Timberline Road design by Engineering Professionals ................... 19 _ 4z,wnoff C&l c L-Ir.+jovi5 - Spitj khs F" . 0 �. Hisrop-Av GoiJDlr'or-,3-s - rz.\ w.o tr� 1. Sas, n I-Fi % A c- (Sre�ve I Dr iY2 — O. OS 4C. C' �• SO � 3 � 0.20 (o. S� r (o, zo)(o, ZO)�-a. 26 Z. R7ab,� f-fZ A = I. Z2 v, St►eee s : o. w ae- C = O. 9S c 33 8ldys : 0, 03 4c. G-0.9S �3) Dr,VQ5 . 0.Ol!&,,- G O,SQ c3) 6 va w, S- : o . 90 ac. G = o. ZO L 1 was,t n F,jIIAJS : V, O, 9S' C3I ja✓i\rCS; O.oZ C = o. SO j31 &roLAA.A: o �s� G= ZO [3) ' Coat,` = 4 P> K H4 : A str-et v,/ate C =n.gS C31 t3j = 0,51 f21 TL DCVGloPJ GoKol �f�c.ts 11 Tti► .4, �w.�o�� Coe IGle�al — 6/iS�9L I• i�- 6l.�5�h, �-L �rcr = 0.38ac. O Re no. /G urxS - D. Z4- [ 5 ] C= 14 ,(o,SS)t-(0.24.)(o.10•44 Cz] z. 5. R. t;)-Z Aror = V. SS c.c eie. = D, /3 4C L= 0.75* [ 33 o�v3xo.(O.746, 1S)J/-9• e5- = D, Z7 3. S.g• D-3 Qror ° o• 75- 0. k4=ae., Arvm+, hijI. = 0• 11 at, G _ o, tiS L37 G=�o•I,Q(o.�S)+ o,ll Co•95�l/0.75] = D.L7 CZ7 4, SOP. D 4 /tor — 0.3? 4c C=1(o•2B) 0.qS + (o,ii )0.15- )�D,3S s 5; -6 -,6as, h D-14 (111/5-Az, ATot a• Iz ac . ' Q � � = Q. /0 9s (era✓. a, oL 19, >/ bass/o DS ' A4G ' % fJrgCa �o-✓ )7e9igh P� � S C �IowPc,�%.-�.e-m. DZ cew{ro�s) 0•$S+ 0.4-Z = I. Z-7 1 (0 96xo.�5z70,34-6r 1 Ha.(riwat �av��CSc�.-(�G�ri% rw.PP/•I,owS I% b llt js , 100 A = 80 ' yr _ 2 . c.c 0. 8S6cL o� IOo[o.F3s(l.o)+' I.`14(o.O5)l arm- !o i rv�PQ✓r . a - -- - - 3416 Z 8 _ 4 DP L L = /34' 5 = /.9% S=Z�a 3. 6�k4.e., F-le,j fv L : 1`fo' i 70 bPtia. / G= o.9S a. SOAIe , 11rtgss L= Z3o , � v = is ff/5 L� S" L' 1 1 1 1 t 1 1 1 1 1 G . r25 ( f, DP 50. J �. 0�e1 I4�4 p, �veSS/ L = 4-a' L = 3S $ - 2.°io �•S fps MKS 3 - I , -F�r+ cc)1 t5 5t Dr. Z. DP1a -l-cz Use, io u,w �z : Z,S 3. DPZ tcZ = 18.0 �. DP3 +cz LZ 182 S D P`- +e Z h Q ice= Z,5 &. pp5 tcz- 20.3 L L L iZ= Z.IS t,00 _ Lioo" 5,8 /k✓ {��o =e4A I o 7. IS 11.3 +t too — I`j • 1 L too 5 • Z- i 1G too — 3 use to L,00 7. IS 1¢, o 11100 , ll ri.�7. 1 4 s CqI,$� 5.. 1 i ; tt I j ' egi, --�—� z ate• Z I., � � , . �� , . 1 Wom.k !G'akc-jtiu'anpS t•;-'o P„o.�. 7- F01.116 1 - so) = Oil - . ., - .. ;—' FR-�"` . 5=3') uJ;✓��--- o,Z o.s 0.7 o.s 1� z 0.5 0 0.4 x 0.3 Q c� z 0.2 0 i z 0 a- 0.1 ' 0.0 0 I 2 3 4 5 FLOW INTO INLET PER S0. FT. OF OPEN AREA (CFS/FT2) Figure 5-3 iCAPACITY OF GRATED INLET IN SUMP (From: Wright -McLaughlin Engineers, 1969) V. NYo6R..+DrZ4iN Ste, 5e4je.- - Lille. �5, /5" N-12 WDS ,p,P2 Sift otoo Q 100 � i I" CA n = 0. 012 5- 0. 170 0 S°37 0 Y s T'AF5/-e L TAaLs A T-ecl.ni,�, dote No. Z. �a9C8is� Low CgPA'r-y' Tea �, ilea ADS Spec. M4-,,kw/ Sr Z+00 �loo = 3-o2c�5 Mo rry Q = I. 5-$ r.e 5T� o 4t� Z+ o : y, = o, 5� VI_ 35 Q" 3.OZ �s STA Zi-oo tb Zr49: I osS coe4 : ke = 0. (�h �ra .. ( / C—at ..+, ) z z Z VI 571 L YZt 1.007- TABLE A ' STORNRATER RUNOFF Speights P.U.O. ' BASIN/ i OVERLAND i CUTTER/PIPE SNALE D.P„ AREA ; C L S tc2 tcIOO� L S V tc ; L S V tc ; TO Tcl00; i2 i100 ; C (ac) ; (ft)(8) (min)(min)I(ft) (1) (f/s(min)I(ft) (8) (f�s(min);(min)(min);(i�hlii�h) t-------- ------------------------------ ------------------------------------------------------ H 1 ; 0.26 10.10 160 1.9 17.2 16.2 ; i 117.2 16.2 12.00 5.80 10.29 ' H 2 ; 1.22 :0.20 310 1.9 23.8 22.4 ; 65 0.5 1,5 0.7 ; 124.5 23.2 ;1.65 4.75 10.36 H 3 ; 0.18 :0.20 160 1.9 17.2 16.2 ; ;17.2 16.2 12.00 5.80 :0.28 H 4 ; 1.06 :0.20 180 1.7 19.0 19.0 210 1.00 1.5 2.3 :21.4 20.3 :1.80 5.15 :0.31 1 ; 0.38 :0.15 134 1.9 16.7 16.0 ; :16.7 16.0 :1.95 5.80 :0.44 ' l.a 0.12 :0.15 4 2.0 2.8 2.7 ; 190 0,5 1.5 2.1 ; 4.9 4.8 :2.50 7.15 10.82 2 0.85 10.15 135 1.5 18.0 17.3 ; :18.0 17.3 11.94 5.50 :0,27 3 ; 0.75 10.15 182 2.7 17.2 16.5 ; ; 230 1.00 1.5 2.6 ;19.8 19.1 ;1.82 5,20 :0,27 ' 4 ; 0.39 :0.15 5 2.0 3.2 3,0 200 0,5 1.5 2,2 ; ; 5.4 5.3 :2.50 7.15 :0.72 5 1.27 10.15 135 1.5 18.0 17.3 ; 200 0.5 1.5 2.2 :20.3 19.5 ;1.82 5.30 10.34 5,a ; 0.42 10.15 75 2.0 12.2 11.7 205 0.5 1.5 2.3 114.5 14.0 ;2,15 6.15 :0.49 ' NOTES: 1. D.P. l.a represents flaw from the street portion of Developed Sub -Basin D1 2. D.P. 5.a represents surface flows entering inlet for Developed Sub -Basin D5. Q2 Q100 (cfs) (cfs) ------------- 0.15 0.55 0.72 2.51 0.10 0.37 0.59 2.12 0.32 1,20 0.25 0.88 0.45 1.58 0.37 1.32 0.70 2.51 0.79 2.86 0.44 1.58 I r TABLE A CALCULATIONS Table A is based on City of Fort Collins' criterai for calculating stormwater runoff using the Rational Method. Notes on each colimn contained in the bable appear below: 1. DP: Design Point. May be either a total contributing basin flow (e.g. HI or D2) or point flow at a Design Point (e.g. DPI). ' 2. Area: Area contributing flow to the Design Point, in acres. 3. Overland Flow: a. C: This is the runoff coefficient for the overland portion of the flow only. rb. L: Length, in feet, of flow path. Lmax = 500 feet. C. S: Average flow path slope, in percent. d. t,: Time of Concentration of the overland portion of the flow, in minutes. t,=[1.878(1.1-CfC)L121/S"' Where: Cf2=1.00 and Cf,00=1.25. 4. Gutter/Pipe and Swale flows: Channelled flow paths in either gutters, pipes or swales. May be undefined watercourses which occur naturally. a. L,S: As in 3.b and 3.c, above. b. V: Flow velocity from nomograph, attached. C. t�: Time of concentration, in minutes. t,=(L/V)(i/60). 5. Tc2, Tc,00: Total time of concentration, in minutes. 6. i2, i,00: Rainfall intensity, in inches per hour. 7. Q2+ Qioo: Peak runoff, in cubic feet per second. Q=CC,iA. No Text DRAINAGE CRITERIA MANUAL RUNOFF 5f 3C H 20 z W U It W d 10 z W Ix N5 W It co 0 0 2 x W I— I 5 1 2 3 5 10 20 VELOCITY IN FEET PER SECOND FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR USE WITH THE RATIONAL FORMULA. *MOST FREQUENTLY OCCURRING "UNDEVELOPED" LANDSURFACES IN THE DENVER REGION. REFERENCE: "Urban Hydrology For Small Watersheds" Technical Release No. 55. USDA, SCS Jan. 1975. 5 -1-84 URBAN DRAINAGE 3 FLOOD CONTROL DISTRICT tz A.D.S. TECHNICAL NOTE NO. 2.109 (88) FLOW CAPACITY June 1, 1988 gtrffwAAD ULRAJVAdmr�ADVANCED DRAINAGE SYSTEMS, INC. TABLE 1 Manning's "n" Value For Design (Sturm & Sanitary Sewer and Culverts), Pipe Type „n„ A.D.S. Corrugated Polyethylene Pipe 3 - 6" Diameter 0.015 8" Diameter 0.016 10" Diameter 0.017 12 - 15" Diameter 0.018 18 - 36". Diameter 0.020 A.D.S. N-12 — — — — — 0.012 ++� Concrete Pipe 0.013 Corrugated Metal Pipe (2 2/3" x -1/2" corrugation) Annular Plain 0.024 Paved Invert 0.020 Fully Paved (smooth lined) 0.013 Helical Plain 15" Diameter 0.013 18" Diameter 0.015 24" Diameter 0.018 36" Diameter 0.021 18 Spiral -Rib 0.012 Plastic Pipe (SDR, S&D, Etc.) 0.011 . 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LO W N t o cn t- O •-I N v W O W On OOO C; o N O NNt Nto W N N W W W O t v01 N v T W t W o t" O W W O W N t to 00. "to O .++N to n W W. ' 00000 vW O �Ittnpp�(n nNN to w-ftt- - W 0co aN O O•-IN Ntot ' 00000 to .+ W V W N N W W v v co 0 v CD t 0 O CQ co to W to In W -WknIm Nao - rti O O O.NrN O O' oo. NN10 t: 0; aye C 00000 N N II N mm W W -0 La On .•t Nt v W O MLn0 Wvv tNN v0 C OOOO.W-1 O 000 �+NN Wp 00000 N ' �Np C $4 t-Np W On -W w O W W .•1 tot cn .+ 0 tWOn W W O U!C? TWNOO cn Im N WN T cn in In vN wm ' W ONN W.M* NW cq-v0'N .~-I.t-IId. 0Ul to Nvto W co ONto co v t0 W N co M r.. .�.�.-I •� NN NM N v v ' Q v M i4 41 0 RAINFALL PERFORMANCE STANDARD EVALUATION PROJECT: QE16HT5 Pu.D - --------- STANDARD FORM A COMPLETED --------- ---- BY: ->, M -------- DATE: 6 i5 9Z DEVELOPED SUBBASIN + --------- ERODIBILITYI Asb I ZONE I (ac) I ---- Lsb I (ft) i Ssb (%) I Lb I Sb I PS --D4 .I(feet) I (%) I () I M i o.3g 1 134 1 1.9 i �'j4 i l 9 i 78.rp V 2 6.7S11 - 5 1 l .5 135' 1 I,5 -77, 2 182 1 ➢S 1 1 o.3g1 ZoS1 a.s 1 205 0.5 7Z,o1 1 a. 421 75 Z o 75- 1 z.o i78,41 1 I I I------------ HDI/SF-A:1989 EFFECTIVENESS CALCULATIONS ---------------------------------------------------------------------- PROJECT: STANDARD FORM B COMPLETED BY: TPAl DATE: (, /s Z i Erosion Control C-Factor Method Value A. ----------------------------- pe vtmewi 0. 0/ 8. See�Q/Mwl� 1. o. 06 C, -ILVe/ •F;/74Lev �. rr-S� Brats p.pg �si Ha mull 0.06 MAJO BASIN P-Factor Value Comment --------------------- /. 00 op /. oD --------------------- R PS SUB AREA (%) - ------ BASIN ----- (Ac) I CALCULATIONS 7 K ( D1 ------ 0. 38 -------------- ------- C, : (o. 1,w i- o. z*. g,)16, 3 8 0.14(0•o/)r0,Z4<0.OA)�� 3i5 = D, 04- 61 17, Z p Z c) cjel >(( 0.13 t A),-(o.7Z4c E)]/o, -0S o, oo 13. 0.0431 /o. w �Fr : [I — (o. o5 * o. g )i00 - �� a q _..._. Cy.�}'-L(f>,1)0t E.)'() 1(0 22 � fi !C�-75- I,O Ce, Src�SS,�1 00 - �S o 7Z.D P4 [0,11 E+ 0,,a9A =L(0,00-1 )4-(,003 PNET =V.g Ca.-.q I:14ev- ) EFF - C 1-(O.OZ4Xo,8)7 goo 72�.4' F1 r Ia,4z LET -L(O.IV4)i 0.2-4-(E)]/6, 4z= --------------------------------------------------------------------- I/SF-B:1989 CONSTRUCTION SEQUENCE ' PROJECT: Pk. Q. STANDARD FORM C SEQUENCE FOR 19 11:J:cNLY COMPLETED BY: -rPAA DATE: A1151fw. Indicate by use of a bar line or symbols when erosion control measures will be installed. Major modifications to an approved schedule may require submitting a new schedule for ' approval by the City Engineer. YEAR 1992- 1 �993 MONTH I fI A I s I D 1 N I D I -rl W OVERLOT GRADING ' WIND EROSION CONTROL Soil Roughening Perimeter Barrier Additional Barriers Vegetative Methods Soil Sealant Other 1 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 Nettings/Mate/Blankets Other i STRUCTURES: INSTALLED BY _ LGETATION/MULCHING CONTRACTOR LATE SUBMITTED MAINTAINED BY APPROVED BY CITY OF FORT COLLINS ON ' MARCH 1991 8-16 DESIGN CRITERIA 72�- Fe.rej c e.s M" T. It/R.�a 1251. 1 K�K� u�h/J 0T3v 1 1 1 1 1 1 i i 1 1 1 1 1 fn G�6� :24 2-1-Z2., • January 31, 1990 Mr. Glen Schleuter i Storm Water Utility City of Fort Collins P.O. Box 580 Fort Collins, CO 80524 r,}� RE: Sunstone Village - 4TH Subdivision Job No. 248.10 Timberline Road Design ' Dear Mr. Schleuter: The proposed storm drainage for Timberline Road Improvements from Caribou Drive north to the South Line of the NW 1/4 Section 32 is designed to adequately handle the 2-year and 100- year storm events. Consistent with the Sunstone Village - 4TH Subdivision drainage report, ' runoff from the east part of the Timberline Road right-of-way discharges at the Fox Meadows Drainageway located along the northern boundary of the site. The drainage area shown for Timberline Road, 1.7 acres, is less than the 2,51 acre Area "N" shown on the Sunstone Village 4TH Subdivision Drainage Exhibit. This is because the 700 feet south of Caribou Drive will drain into a pond located in the northwest corner of Timberline Farm and through a 42" pipe to the Drainageway. The "Sunstone swale" located along the north side of Sunstone Village has a capacity of 128 cfs with one foot of freeboard according to the calculations on page 5 of the Addendum to Storm Drainage Report, Sunstone Swale at Collindale Business Park, prepared by Stewart and Associates, Inc. June 15, 1989. Therefore, this channel will carry the 100-year flow including Timberline Road runoff. Drainage Area "I" on the Sunstone Village 4th Subdivision Drainage Exhibit includes a seven foot wide strip of the Timberline Road right-of-way with a runoff coefficient of 0.85. Foi the proposed grading, a 24.5 foot wide strip of right-of-way drains into Area "1" resulting in a 0.39. acre increase in the drainage area. The 2-year runoff increases by 0.22 cfs based upon the intensity used in the Sunstone 4th drainage report. Inlet calculations in the report indicate that the 15' CDOH Type R curb inlet, located in Stoney Creek Drive, has the capacity to take in this small additional flow. rAs shown on the attached calculations, the required pipe capacity for the 2-year storm for ultimate conditions is 4.02 cfs and 2.37 cfs for the proposed interim improvements. The capacity provided in the 15" pipe, 4.94 cfs, is therefore adequate. In addition, the hydraulic grade line is approximately three feet below the flow line of both inlets for this event. The required head on Inlet #1 is 0.42 feet which produces a ponded width of seven feet. The head on Inlet #2 is 0.19 feet and the ponded width is 2.5 feet. The 100-Year Storm Event is contained within the street right-of-way. Calculation of the ' hydraulic grade line indicates that water ponding in the sump of Inlet #1 will overflow the flow line high point elevation of 4947.40. Balancing the HGL and flows in the pipe and in the street indicates that 3.64 cfs spills over the high point at a depth of 0.40 feet (el=4947.80). Therefore, a berm will be constructed between the curb and sidewalk with a minimum elevation of 4948.00 to keep the flow in the right-of-way. I ENGINEERING PROFESSIONALS INC. ' 2000 Vermont Dr., Fort Collins, CO 80525 (303) 226-3852 Plcza of the Rockies, Ill South Tejon, Suite 300, Colorado Sprir.ys, Colcrado 80903 (303) 634-5006 I 11 [1 11 I I I r r r I 1 I Since the ponding depth at Inlet #2 and a future inlet (by others), located at the 1/4 section line, are higher than the flow line high point elevation 4946.58, then a joint ponding occurs over the two inlets. The calculations show that the ponding elevation is approximately 4946.96. The low point in the right-of-way at the future inlet is 4946.81. A very small amount of water will overflow the curb at this point and go into Sunstone swale. A slight berm will be constructed by Inlet #2. This will ensure that for some unusual condition (i.e., clogging of inlets or pipes), water will overflow from the street at the sag of the future inlet and into Sunstone swale. The 100-year ponded width at Inlet #1 is 23 feet leaving a 17 foot open lane. The ponded width at Inlet #2 is 15 feet leaving a 21 foot open lane. If you have any questions, please call. Sincerely, ENGINEERING PROFESSIONALS, INC. Michael J. Erion, E. Steven L. Kraushaai U I No Text ' 2 GUl 9-Z c - �3 1 91+LBL •RCUL' 26 X=Y? 51+LBL 92 76 EHTERt ' 82 R.AD 27 GTO 02 52 PI 77 2 03 'D 7 28 RCL 89 53 STO 10 78 ENTERI 04 PROMPT 29 RCL 04 54+LBL 93 79 3 05_ STO 60_ 39 - 55 RCL 10 ;p IN7 31 RCL 0? 56 ENTER.t 81 YtA PROMPT J? / `7 EI1-EF• 08 STO 81 3.3 ACOS 58 SIN 83 SpRT ' 34 2 59 - 84 10 PROMPT 35 * 68 8 85 RCL 95 2 11 .STO 02 36 STO IC 0 ! 26 37 f,TU C3 62 RCL 00 U 1.486 13 PROMPT 38+LBL 91 53 Xt? 88 la STO 93 3'3 PCL 94 64 • 89 RCl 03 15 "t ?' 4! RCL 09 65 STO 05 ' 16 PROMPT 41 - 66 RCL 10 91 STO 88 17 STO 04 42 RCL 99 67 2 u2 pq; 18 RCL 00 43 ! 58 ! 93 .p. . 19 2 44 ASIY 69 PCL pr y 4AR 92 a 29! 452 7C.+ AME 95 N E 21 ENTERI 46 * 71 ":T3 06 46 ST@P 22 STO 99 47 Pi 72 RCL 05 97 GTO •R.CUL' 23 RCL 04 48 + 73 RCL O6 9:3 END 24 X;Y? 49 STO 19 74 ! - 25 GTO 01 50 GTO 03 75 STO 07 ir -r s i u = d'r S I uy r- Z� �o A=.O CA-5��s,aL P- ti o D PZ= lk/p 1 . CURB 11 T EL SEE EEWOUL ON III %f" 111 III I II W I II III 0 I II II II < Ill IIllw III UU Ill JII II ar III UJI I Y m III) S III', � III I III n1 III 1I1 _ r III - III I u IIII lu AS INLET FILTER NAVEL E DETAIL ON DETAIL SHEET III Ear MIRE FOX MC 4•I'(' J!.j I -AL). NM1 J J ---------- 3F---��---->'--- -- -------fin- ------- ,- --.--_ b' VERTICAL CURB ACCESS E UTILITY ISEE DETA0.-THIS SHEET) IMST er IN sT4n nEM _ _ - - - - - p EASEMENT r n I] \ 1 MST W aTM wiWq - - _ - - - - AO L CONCRE E D/W PL PAD <� <i� BIMl»nMR1aSFTM aTv - _ Q9 _ Tr- T Rt IG.i _PAD FORT AREA CIOLLMBESTpITD-9 gW Y OF t -1 ', I'[ ce Fogr coLLus aD y< SUNSTONE DRAINAGE SWALE �- -- - - RP.0 1 _R 3 t MN s WM - 01SM-434 - - B.i - lR pS ISEE DETAIL SMEETI AA 7.0 NRT1 AM STN SEWER _ - - . , ,J li' WARPED SECTION ROD OF CURB 5 GUTTER _-- ___-_--- =----- S FULL OEPTH CONCRETE Mp 6' STOM IERW SECTION A -A 42 B `STANDARD 6- VERT CURB .................. --__...................................... ..... I WITH 10' GUTTER PER ...s................................................... - .......... 1■ COLLINS M ueR lY STANDARDISEE DEAIL AREA MET PEII CRY OF fi I SHEEOFFORTORT FORT COLIEM SrO. ON I M ELy.)1 l . a VERT CURS5 $0 FLC811 - PARKING LOT AREA INLET DETAIL ... 45 SEE CETAAU 1M b ET _ ...... _................ .........._. ... _ -� to yMi CURB R/r GUTTER r' � S UNIST v NIE_ `WTI E,^TOE- P.U.D.41 AID LOT 2 LOT I SCALE { = 20DRIVE ARKIN0STALL 1 NEW BUILDINOIRDDITION y 100 __ AB.Oo FF RB b 34 1 20 0 0 SO ]' CONCRETE GUTTER I e VERL cMW 0, Fa le.e F B.IB 1 _ LO�TJ 6 _- - _ � 4 EMWTN015' STORM SERE e. y ONCRETE 1 I ETINO BUILD] y ..... .... ..1 ... I I......t................. ...................................... ... w• CRUEHEDWAOOREOAIETBASE I +a.00 F.F. - .\ ......... ..... ' ..........._ ' 1IIII/................................................ SECTION B-B aiORn .... ...................... TTT IT BERM LIf 'A' do / yvaTc' - J L_L_ ____ __ TEE I MROfLE ; ( ulls SOEWALK WIDTH VARIES -___- ________ to 11 _-__-_-��-----.-�_ .__ �N -- -i. - BLDO. - DRIVE ITM ] GUTTER CURB a' vMnc.0 cm '"' "" """---'[ /i [••• ...................................... ° / STONE DRIVE FINISHES FLOOR OF FLOOR STANDARD CITY OF FOR' -- EXIST. BLDG. COLLINS B' VERT / 1 OF EXIST-`• RR MIN V .............. ........ / / e FINISHED SUN e' lR MIN SLOP VARIES a' VERT CURB V B auiTlow EA _ - AWSI , AREA /ma y SECTION C-C 3* ASPHALT CONCRETE WITH B coat GUTTED _ -- _ _ i i 1 .BA FO ' /%/ 10 CRUSHED AGGREGATE BASE 8' b _ _ LOT 3 wor II _ ofti_<s / 9fDAJN CONTROL NOTES. �� tl.^ ,ft < SST poIrTERS MARE 4 91 BE AM ORTHEs . L+.: °iftuot _� .w ed+/ri o. FIL ACED � NFI� �1 HEET n. ., .. let 1s11 oti xlD In sl11 Z _ __ Ir EaINR roWM IMj / ` 115 TI A1n1T LEGEND I PUT FAN° H 1. i } I , I 1 .J AFTER OVEILOT GRAM1r W COIPLETED. ANY �e ._. wl----- By 122 ; h� l ALAS OF THE PROJECT THAT AM TO STAIR) .�aft oftifteeft . Appeopet L. EXIST. CONTOURS Est �yP O I za n3 I 11 Lt wTHAN o�DY Yr�1Y PROPOSED CONTOURS STNM SEEM LK l ? , e =10J_ II APPIID AT A 1WH.M RATE IY 3 TONS/AC. II I H ADEQUATELY NILIIMED MO THE SQL. PROPERTY LINE SEE Son a FN mOPie? E LOT �4 ' +R.O O C^ NO \ i T f AMA IMEr Ia+M NAVE I r•millet -EXIST CURB. GUTTER d WALK 1 a; I sEE DETAR. ON OETAa sla \ II I I j - - - CENTERLINE OF ROAD Aft Reft I �`` 11 �'- -Spoleto oftit ....... -- HISTORIC BASIN BOUNDARY LOT 7 sr .•M ....... [ r1l, IIULI BR MFT rM mr s I r L .... - - i j i DEVELOPED BASIN BOUNDARY TOP CWLLRM m rN eMATEwx [ 1 1 O I ""----""----'-- ` ` - RUS DESIGN IOW DIRECTION F II I N Q DE POINT ......... _ - - i---_ _ 1 D II ,HIE I - �{ Y II to R4rNE 1EWr ��' O BASIN DESIGNATOR _ - _ _LOT 5 T 0' Lu 11 i ne,n1. r.e.R - - e.t BASIN AREA: AC H1 IS.�FO II I B'z - _ ■ U I 1 will MEMO I IRIM/IISI I WW - ED.: ME ; S I 1 tot LORD: S 1 I I< I I 1 1 M ; RI ,HN; N it" ; S E TIN � - ill t 1ST WON - t C II i-'-------------- ,.1 lfd -..... .. ........... :IMtlIMLIIIJUIiAI: aebl 1e61 ..................................................................._...... _............. .... ....... __....._.....M 5.01.:4 .6..._..55 I _ __ .._I......--- 1 1 1.11 R.II IN 1.1 1 14.I II.I 3.N Me ;1.11 ; 1.1f 1.f5 n' 1 tl1 1, 1 1 1 • •. I1 •••••••••••••••••••••••••••••••••.._........•...........•• •••••••• ~-I I : 0.M R. In LI N.l B.I Nis le 1., ; :SI.I 21,2 ll.n $10 N.n ; 1.n Lu J-� EI N I 11: 1.N;LN IN 1e 11.111.1; :11.lu.3 a.05.M;I.311.0 031 11 10.11 0.N 134 1.1 n.e TIES : : fll l.11 is L3 :".1 N.1 :I.N S.0 ;I.SI : I.SI I2.12 'll 1 I :I.11 :R1S u42.11L.1 N.1; : :I1.11Le ;Esl I.E N.11 11." At I Ir DO$M.15 Ile 1.11.1: M1s Ls 1.1; :1.I Ls lLsl LN;I.N:1.15 I.N TEMPORARY END PLUG 1 1 1 1.1f OLD DO I.1 ILA ILL; I ;IL^ I1.1 :1.f1 S.N :Lt1 ; 1.1f LN op,1 1 3 Ilas a.uml.l n.t us: :IM LMu vl:u. u.I a.N 511 :4.11 : I.n 1.n NDTEs: e P T NAVEL DM SEE DETAIL 4 : LH :4.15 5 2.0 3.1 3.0 : M 1.5 la 1.1 : : I 5.3 a.N 1.15 :0.n I lal t-0 ON CErna SIiEi. 5 : I.n :I.15 u5 IT Ill 13.3 : Mlls 1.5 t.l : :11A 1115 :1.M LW 'A.n : 0.11 l.N I. MANTENANWE OF ALL ON-STE MANAGE IMPROVEMENTS SHALL RE THE R vwi BMTY L J A11 ;1.1f ,S OF THE IUM& LOT OWIEis. 111n11 1.I. I.I Iqu1IIa free tot noet Nfol Of Mrtlgel $0 Hit 0 l 1. 1. LP. 5.1 uRneul spite f6n ntenu Itlrt to Develop" Sib -kill NORTHERN ENGINEERING SERVICES Project: ❑r lnt Date 9201.00 u ziant SPEIGHTS P.U.D. FY7 420 SOUTH HOMES SUITE 106. F7. COLLINS. COLORADD BoScale:5z1 RADING AND DRAINAGE PLAN 1303) EZI-415W Desl ner, MWK Checked b :MFJ Dr Dfl ennn MWK I D.... ..a.LBAD 1°°, EROSION CONTROL PLAN