Loading...
HomeMy WebLinkAboutDrainage Reports - 03/14/1989STORM DRAINAGE REPORT COLLINDALE BUSINESS PARK MARCH 14, 1989 PREPARED FOR K. BILL TILEY STEWART & ASSOCIATES, INC. /L 214 NORTH HOWES FORT COLLINS, CO 80521 STORM DRAINAGE REPORT• COLLINDALE BUSINESS PARk• Collindale Business Park is within the Fox Meadow Drainage Basin. The property is located on the west side of Timberline Road and extends west to the Union Pacific Railroad. The property begins 1330 feet south of Horsetooth Road and runs south approximately 1700 feet to the top of a ridge. The Tiley property covers only the north 1330 feet, and the property to the south belongs to Tom Chandler and Don Chadwick. The gross area of the property, including the Chandler and Chadwick properties, the west z of Timberline Road, and the East z of the Union Pacific Railroad R.O.W. is 44.5 acres. There is no offsite run—off onto the site. The south boundary is a ridge from which the drainage goes southerly to the Chandler sump. Flows from the west are blocked by the Railroad embankment. The north boundary is the low point and drainage flows east along this north line. There is an irrigation ditch running east parallel to and about six feet north of the north line. This ditch belongs to Bob Shields. The ditch can.carry irrigation water from Warren Lake across the golf course, under the railroad and along the north property line. Historically, this ditch has carried storm drainage under the railroad from the golf course and from .the railroad right—of—way. This flow from the golf course, according to the Fox Meadows report is Q2=1.0 c.f.s. — Q10=3.0 c.f.s. — Q100=9.0 c.f.s. per page 12 of the report. We propose to not distrub this ditch or alter the flows which it now receives. The attached map shows the entire 44.5 acres divided into 10 sub —basins and a detention pond area, which are shown as parcels 1 through 10 on the map. We propose to provide detention for parcels 1,4,6,7,8,9,10 and the pond area. The total area being detained in the pond will be 44.5 acres minus 5.7 acres in Parcel 2, minus 1.3 acres in Parcel 3, and minus 3.1 acres in Parcel 5, which equals 34.4 acres. Detention shall be provided on site on parcels 2 and 3 for the difference between 2 year undeveloped run—off and 100 year developed run—off. -Parcel 5, the'Chadwick property, has a 10 year undeveloped run—off of 1.4 c.f.s. which will be carried through the proposed drainage system to the detention pond, area. Future detention must be provided on Parcel 5 when and if its present use is changed. The undeveloped 10 year out —flow from Parcels 2 and 3 was used to determine gutter flows because it is greater than the future allowable out —flow when the Parcels are developed and on —site detention is provided. These out —flows are shown on sheet 14 of this report. The proposed detention pond is located at the northeast corner of the site. The outfall from the pond will drain under Timberline Road to the east and then into the Sunstone swale. The new pipe under Timberline Road is per the design plans of the Fox Meadows Business Park Drainage Channel. We plan to carry the storm runoff by overland flows to the detention pond. The majority of the flow will be carried to the pond by a drainage swale which runs to the north along the west side of Timberline Road. Storm Drainage Report Collindale Business Park March 14, 1989 Page 2 The Collindale Business Park will be developed in phases. The first phase will be the streets, Parcel 1, the drain swale along Timberline Road, and the detention pond. The detention pond area will be used as a settling basin for erosion control during the first phase construction period. No outlet shall be connected to the Sunstone Swale before the streets and grading on Parcel 1 are completed. At the time of connection, erosion control may be needed to protect the outfall from sedimentation. A concrete pan is to be placed in the drain swales to prevent erosion. Flow capacities of these pans are calculated on sheet 13 of this report. The attached calculation sheets show the run—off calculations from each of the parcels, the allowable gutter flows, the allowable outflow from the detention ponds, the required detention, and the volume of the pond. Also, there are run—off computation sheets showing flows at design points. These design points are shown on the attached map. Out —flow from the detention pond will cross under Timberline Road in a 24 inch pipe which empties into the Sunstone swale. This 24 inch pipe will also carry out —flow from the W.W. Reynolds property located directly north of the Collindale Business Park. The W.W. Reynolds out —flow is approximately 5 c.f.s. There will not be a property owners association for this development, therefore we propose that the .City of Fort Collins maintain the detention area and channels. A 2 year or 2 growing season time period is required, plus, acceptance by Stormwater Utility, prior to assuming maintenance. Should the adjacent property owners desire to place more intense landscaping in the detention area and channel than that required by the City, they shall become responsible for placing and maintaining this additional landscaping. All landscaping in the detention area and channels shall be subject to approval by the Stormwater Utility, City of Fort Collins. Office of STEWART & ASSOCIATES, INC. o(f•.+...,,.� 3�/S1dr9 Phillip I. Robinson, P.E. & L.S. �G\ST Ei?F�;�iji 4502 2 COMP,UTATIOW> ., James KIStewart & Assoc. j Fort Collins, Colorado t I I By: PIF Date 116 8 Client: f ill' 7— ey Sheet No. 3 of f 4- Chkd By: ' Date Project: ( 0&1701a4e 3051'nes5 Bark Job No. Subject 'S�Orrg rair'laae Calc(Aot4-ior)J f offal Gr-w /4ra.a. = ¢4-. S acres inel• ;/Z JZ��/ro��%z%i �Serlier4 chadwic�c) 14i,s4ciric G= 0.20 — -57 = O:SB� /.e7 Cl.►-.zoo �e oO I ^ t QZ - G)lor �0 20)�0.6)�¢¢.5) z 7. I Z cts ALLoV,l/t4-13LC- oUTr-14LL /Ir) Per acre 7,1Z 44+.5 = 0.J6 cfs J ac. Deve1a��� CGh i 7 1 0�' S. Fi-UwI zonins SlvPe off- Stree{� -use o.¢� �r �e✓�fa� e� la-�S i • i i i l✓o%vMe 0�PO cz�e�En Jon I E )e ✓ai-1 o i O 4-Z I �-500 3 `/ Oo 0 l0Z000 l 26 OA �q�q vo0 reOirec/ I Z.3/3Z00 i i j, ' Uglv.�e i /300 z1750 .. z 70t06 Tor^+- UolvMe 130(I Z30 0 w 7 s�'-o J 37 500 345050 i 'r COMPUTATION James WStewart & Assoc. ' Fort Collins, Colorado i By: P1IS Date Client: k% !3i i % lIey Sheet No.4—of Chkd By: Date Project: Co%l� �g�P 6vs Pu F'a�f Job No. , cL ir-�� i Subject et i l/1 ci inar! '.e cct cc'l k:2kI5 7-0fa1 Deb en�lo� J���Vl eC — /�rea� �To�kl� —(Are4, oP Por-eels z, 3 � s) M.�zs DIArrrz�.rl NMET+tG� _ 44.5-- l0,1 = .3¢,4- acres T 10 zo 30 ¢U FG 90 1Z0 too ,300000 zorXioo 100000 z 7.3 15-06 7? S.z 34.¢ z►4-C,SC �, /S I ZSC9 G8 3.5 ; 268R66 z. G I.Bs 1.05 33 35-y13� 3100q� : CbM . PUTATIONO STEWARI -Z, OCIATES Consultirr g Eq3ineers and Surveyors 214 N. Howes St. Ft. Collins, CO 80521 (303) 482-9331 By: PI R Date Client: 13ill T IPY Sheet No. -5 of Chkd By: Date- Project: CO CIO Ie 3 V5 i h ely Subject -S-h rpn D 0'-\ 1?e e / v n 7arc�If 2, 3 #!;' I -t57 5" <45 14W-011" D, ei r,�No V1 0�- 0. p tiv ��° ( lij� b RO T II, 0-0 0 I F k-J ! G(� I'(" � • I3 h: 1 ! ) �� Cre ! � i ! I ' s lee r-k /'.5 �O e I 0()�Wow L7e4� V, die 9 TL 37 nt/ 3.7 a. zz 1 SFr- �, PAR CE[ r 0/4 U 11-5k 1 bee- 13 7 I f V r 5- e ! I ! � L/O lv 01) f -3 01 e p' r��'�'� ,✓ I ti Ic ,� _ �� u p m�^ r y v• �• EO cr I v m�jU� yov^� l c v ti L 1L11� U L 30.vdj troy w CL o V M 'tuL O�� Q poi O O M+ �t pv Mt Mt ul fli col c M O V M ri rJ t nl N r-1 M N N ti N �i rM t} [i- (�j w N � M r,\ (\j C) rJ- �} M u u u `% N � VJ � a b r M N V �� s M N1 r' 0 -4- v U p c 0 � r rl ? o a 41 w O W E a C cam;. y � J � � n _ L o,� mom} C � � • r � r rO ON 1 r. E r _ O N •` 1s W Q ■ u l9 1n w V u O r�j p 00 a. Cy'• g ►� M , � N a 'L ll L o`er o r1i o ti N C �I u a -4 C `U CI J W > p > ` O � � L �v O l L �• i"1 + � M } � �T } o- n VZ gz o d j r d- M M u r1i w �9 a d M Op. CO e lr V - u co o o p 0 0 o O n lr a � Lr� a o- e r o N o a rw;o C r w 0 W u a N i J W p ` = v V C 6 0, a Mz� r• ^'� M M d J th + M t i- + .... Q M �i l7 r, 1 w w M � 2 p Na 'J • a4.- � - Qi ^ Mh r v- o O � 1 "1 V` M •'� ` C A CI a' 1 -'COMPUTATION* STEWARTIL' Sr )CIATES Consultin3Engineersanu Surveyors . - 214 N. Howes St. Ft. Collins, CO 80521 . (303) 482-9331 By: EJ R Date Z Client:' 30) Ti f e y Sheet No. of Chkd By: Date Project: L0 CJ a I d 13vs (n of 5 Vo rk- Subject f_o rrT7 17 rcrin itv — GO Her C? C- Ir7ijiQ I Lo p I. crass s��I `e.=i_:- �'— ..L j _..I- �... X I Z. i !? :r QZj � I; �cal �v�.l,�. ,.I. I I_ Q.4.Z; I I I! iz Jr-7 Q.k z ro GZ Olt l 0 y le el%i (4f pk I 0 $L 0 9 0! sI 5- 7 0 7ZS�: &.17 to. IJI ....... 0 it 0_3 0. 0 1 0J 71 z Golre.c._ - - -._ it aI✓I j I j A/ ;J1 41. V 1'ef W el r C-4 I e r *J C_ 1-C r --- 'e R; i L e 7.. 0� f i�- (_VJ r 0 A 'Z_­ ­ 'COMPUTATIONS STEWART""t Sf CIATES t Corisultingb-xgineersano Surveyors 214 N. Howes St. Ft. Collins, CO 80521 (303) 482-9331 By: Date.. Z 17),rr7 Client: LC 13M TiIeZ Sheet No. I Of Chkd By: —Date— Project: COffi f) Jcz le. T3 . us n '05 - Jr PO 4 / Subject Storms VrOl in Q�e ir ee-L Cct�cxcit:g L (�C L 1. _ U IL on ri at- C. _ at I j Jz_ 2 LLL � � �,_�--.-d,o �: ,..+ Leo. (� S � I _ � � zS I � � j i I � i JI. F 3 _T� Aaw�d'�' 4- 0 1.6 C7. 7 I el 3. Al 'CIATES COMPUTATIONE STEWART� S. CorisultiMEnSineersanu Surveyors 214 N. Howes St. Ft. Collins, CO 80521 (303) 482-9331 By: Date 2 z a Client: d I IIP.y Sheet No. I I of A— Chkd By: Date— Project: '('—`olb'o-,ccn-le Cusfe)e-ri -PC, Subject n lej,S ol el <4 z2i12e5 L 'V r 93 -57-� II 5r R) S j ! i i )gel F-7 T S L/ ":;P 511 .. .. ...... jT' I �� li ► i � i�I�Il COMPUTATION'.. STEWART \.Ir OCIATES C"isulting ErvZineers and Surveyors 214 N. Howes St. Ft. Collins, C080521 (303)482-9331 By: PIK Date Client: Lr- 13 ill 71) e� e-. Sheet No. l3 of Chkd By: Date Project: 13v5illesf Pork Subject -O-Orwn 2rcalnc(�e- efe) c r—I ow I n --57oun-s tArov�6 Sw'gle-s f a" I, ic f 4-11 z 0' 67 ic/ /V el z ur .0 ire A4 Oiz- - Pa -77 a oi�AA