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HomeMy WebLinkAboutDrainage Reports - 02/10/1995"RT MIM u9mm IrI !ni! FINAL STORM DRAINAGE AND EROSION CONTROL REPORT FOR NORTHBROOK PATIO HOMES P.U.D. PREPARED FOR NEBARADO NO 1 , 1994 STEWART & ASSOCIATES, INC. 103 SOUTH MELDRUM STREET FORT COLLINS, COLORADO 80521 303/482-9331 qp STEWART&ASSOCIATES Consulting Engineers and Surveyors August 15, 1994 Mr. Basil Hamdan Storm Water Utility City of Fort Collins P.O. Box 580 Fort Collins, Colorado 80522 Dear Basil: The following revised drainage and erosion control report is prepared for Northbrook Patio Homes, P.U.D., which is a residential development of forty— two (42) duplex dwelling units. The total gross area of the proposed subdivision is 7.12 gross acres, which will all be developed in one phase. The site is an in —fill area with existing development all around. This report complies with the City of Fort Collins Storm Drainage Design Criteria. Sincerely, 0� lazes, Phillip I. Robinson, Vice President jrr enclosures P. E. & L. S James H. Stewart and Associates, Inc. 103 S. Meldrum Street P.O. Box 429 Ft. Collins, CO 80522 303/482-9331 Fax 3031482-9382 4502 �= NORTHBROOK PATIO HOMES P.U.D. SPECIFIC SITE DRAINAGE INFORMATION 1. Northbrook Patio Homes P.U.D. is located within the Canal Importation Study Area. 2. The existing Fairbrooke Detention Pond lies immediately east of Northbrook Patio Homes. The proposed improvements to West Prospect Road by the Prospect Road S.I.D. indicates the construction of a 30—inch storm drain which must be routed through the Northbrook Patio Homes site to the Fairbrooke Detention Pond. 3. No onsite detention is proposed for Northbrook Patio Homes, and all runoff will flow directly into the Fairbrooke Detention Pond. 4. There are two drainage routes which bring storm water from upstream offsite basins to the west (upstream) side of Northbrook Patio Homes. One route is along Hampshire Road from the south, and the Q 100 is 20.9 cfs per the Fairbrooke SID Drainage Report. The other route is along Hampshire Road from the north, and this water is that which will turn the corner onto Hampshire Road off West Prospect Road. The total Q100 along the south side of Prospect at Hampshire is 189.8 cfs per the Prospect Road SID Drainage Report. We have estimated that 67.9 cfs of this flow will turn south onto Hampshire. The total offsite flow which must be carried through Northbrook will be 20.9 plus 67.9 equals 88.8 cfs. 5. There is no upstream detention; therefore, full runoff will be released, and must be passed through the Northbrook development. These offsite flows will be carried through Northbrook Patio Homes in a 25—foot wide drainage tract by an underground pipe with an overflow swale. 6. The Northbrook site will match existing grades of all surrounding properties, and the rear yards of existing lots in Fairbrooke 2nd located to the south will have positive flow into the Northbrook drainageway. 7. Construction of this Northbrook site will not change the route or type of downstream flow since runoff is directly into the Fairbrooke Detention Pond, but the quantity of water...into the pond will increase and the high water line in the pond will raise. Since the Fairbrooke Detention Pond is designed to detain flow from the Northbrook site, construction of the Northbrook site will not adversely affect downstream properties. 8. All buildings to be constructed in the Northbrook site will be raised a minimum of 18 inches above proposed 100—year high water elevations. FINAL STORM DRAINAGE AND EROSION CONTROL REPORT NORTHBROOK PATIO HOMES P.U.D. EXISTING SITE LOCATION AND CONDITIONS Northbrook Patio Homes P.U.D. is located in the Northeast I of Section 21, Township 7 North, Range 69 West of the Sixth P.M., Fort Collins, Colorado, and is a replat of Tract G and a part of Tract'H of the Fairbrooke S.I.D. The site is bounded on the north by West Prospect Road, on the west by Hampshire Road, on the south by the rear yards. of Lots 1 through 10 in Block 1 of the Fairbrooke Subdivision, Second Filing, and on the east by the Fairbrooke Detention Pond. Hampshire Road, the lots in Fairbrooke, Second Filing, and the Fairbrooke Detention Pond are existing. The curb, walk and pavement widening along West Prospect Road shall be constructed by this Northbrook development. The gross area of the site is 7.12 acres, and the net area is 6.12 acres. The site drains from Hampshire Road on the'west to the Fairbrooke Detention Pond on the east. The finished site grades will be filled 3 to 8 feet above the grade of the original ground. Hampshire Road is existing with curb, walks and pavement, and there are also two existing catch basins in the east and west curb lines. These catch basins are located about 400 feet south of Prospect Road. The catch basins are in sump conditions. The catch basin on the west side of Hampshire Road has an 8—foot opening, and the catch basin on the east has a 4—foot opening. There is also an area inlet on the west side of Hampshire Road, apparently put there to pick up rear yard flow from the west. Flow from this area inlet is piped into the west catch basin by a 15—inch RCP. Flow from the west catch basin is piped to the east catch basin by a 21—inch RCP. The outlet from the east catch basin is by a 24—inch RCP which drains onto the ground in the Northbrook site. (As the site is developed, this flow will be piped across the site.) There are approximately 27.39 acres of offsite drainage from the west, according to Parsons' Drainage Report for Fairbrooke S.I.D. (Portions of this report are included in the appendix.) In this offsite area, 7.26 acres drainsnorth on Hampshire Road to the west catch basin, and 20.13 acres of this offsite flow is draining east in the south gutter of Prospect Road. It is estimated that one—half of this flow in the Prospect Road gutter will turn south into Hampshire Road, and one—half will cross Hampshire Road and flow on to the east in the Prospect Road gutter. The quantities of offsite flow, per the Parsons' Fairbrooke S.I.D. report, are Q = 5.1 c.f.s. and Q — 20.9 c.f.s. flowing north in Hampshire Road, and Q =214.6 c.f.s. and Q 100= 56.6 c.f.s. flowing east in the south gutter of Prospect Road. All of the offsite flows which reach the catch basins in the sump area of Hampshire Road shall be piped, or in the case of major storms, be allowed to overflow through the Northbrook development to the Fairbrooke Detention Pond. 4 Northbrook Patio Homes, P.M. PROPOSED DRAINAG The main drainage concern of the Northbrook development is the offsite flow which must be carried through the site without causing property damage. The runoff from the site itself will flow directly into the Fairbrooke Detention Pond, and this can be done by piping minor flows and allowing major storms to overflow. The offsite flows which must be carried through the site are the Qlnp - 20.9 c.f.s. from the south on Hampshire Road and the flows from the west along the south gutter of Prospect Road. The Parsons' report for Fairbrooke S.I.D. indicates Q100 — 56.6 c.f.s, for the flow in the south gutter of Prospect Road, and the drainage report by T.E.C. for the Prospect Road S.I.D. indicates a much larger Q10 flow of 189.8 cfs along the south gutter of Prospect Road. The 189.8 cgs is being, used for design by this report. A cross pan shall be installed across Hampshire on the south gutter of Prospect to keep as much of this flow as possible going east on Prospect. We have calculated that 54.0 cfs will go east on Prospect before spill to the south on Hampshire begins. Since the slope of Prospect to the east is about 3 percent and the flow to the south on Hampshire is about 0.4 percent, it seems very conservative to estimate that half the remaining flow (189.8 — 54.0) divided by 2 equals 67.9 cfs will go south on Hampshire Road. There is a pipe and inlet system proposed along Prospect which will pick up about 30 cfs of the surface flow, but it may be a long time until that system is installed, so we are keeping that 30 cfs as surface flow for.this design. The total Q100 offsite flows which must be carried through Northbrook will be 20.9 plus 67.9 equals 88.8 cfs. The existing 8 fo6t'inlet on the west side of Hampshire and 4 foot inlet on the east side of Hampshire and the outflow pipe system will pick up some of this flow now, but in the future when the Prospect Road pipe system is constructed and routed through this area, the outflow pipe system will be full, and therefore there will not be pipe capacity available to allow these two inlets to pick up surface flow. In this report we assume the entire 88.8 cfs plus an added 5.1 cfs generated by the east half of Hampshire will overflow through Northbrook. The Swale along the south side of Northbrook will also receive an additional 6.9 cfs, during the 100 year storm, from the rear yards of Lots 1 through 10 of Fairbrooke, Second Filing and Lots 30 through 42 of Northbrook. The total 100 year flow in the swale will then be 88.8 plus 5.1 plus 6.9, equals 100.8 cfs. The swale, as designed, will carry 110 cfs and will have 1 foot of freeboard. When Northbrook Drive is constructed to the east of Hampshire Road, the east curb along Hampshire will be removed to construct the street intersection. This will allow some of the Hampshire Road flow to overflow to the east in Northbrook Drive. This overflow quantity is calculated to be 19.0 cfs. This 19.0 cfs plus runoff from basins 4, 5 and 6 will overflow the curb at concentration point 5 and flow between Lots 28 and 29 to the Fairbrooke detention pond. The total overflow through this swale is 19.0 plus 5.4 equals 24.4 cfs. The Swale as designed will carry the 24.4 cfs with a flow depth of 0.7 feet, leaving a freeboard of approximately 2 feet. Northbrook Patio Homes, P.U.D. The 2—year gutter flows in all streets inside the Northbrook Patio Homes site are less than 3.0 c.f.s., so there will be no curb overtopping during the minor storm. Also, the major storm flows can be carried by the streets and overflow swales without causing property damage. EROSION CONTROL Northbrook Patio Homes is located in a high rainfall erodibility zone and in a moderate wind erodibility zone. The entire site will require overlot grading, due to the fill required, the drainage swale, and the relatively small lots. At the beginning of overlot grading and utility construction, a silt fence shall be placed all along the downstream easterly side. Gravel filters shall be placed over all catch basin inlets, and straw bale barriers shall be placed in the newly graded swales. Rip rap must be installed at the outlet of all drain pipes into the Fairbrooke Detention Pond. The rip rap is to be 10—inch thick class 6 on a 6—inch thick gravel bed. The top of the rip rap will be flush with the adjoining ground. After construction of utilities and streets, houses will be started on lots located on the west half of the subdivision. The lots on the east half of the subdivision, along with the drain swale and landscaped areas, will be seeded and mulched. The lots are to be seeded with annual rye and the landscaped areas and drain swale with permanent blue grass. The 200—foot wind barrier criteria will be satisfied by the construction and installation of /rainfall erosion control. Phillip I. Robinson, P.E. & L.S. r • • r 1 VICINITY MAP SCALE. 1"= 1,000' 1 STEWART&ASSOCIATES 10 82 9 3DRF , FORT gOLLINS, CO 80521 Consulting Engineers and Surveyors By: PJ lc Date: 6 i Client: !/V fbc, (-1:71J0 Sheet No. J— of Project: _ A O rl'-' J--Oo%� tea.:; fry hiii�C f ( ( / Subject: �� l -)-0 t-" I G S I 'j � r u n 04 l To T/t L- S I T OIC-0SS a/'&C�- = 7, /Z (cc, = O, z0 _. + _ 26,G 97 = 37,3ri I �? 0Z x CC) - — 37.-s TGtoo /`'Ih 1-17) ( 7. 7.1Z .3 r4F G'1Uv c CIA. .1S)( 7.1Z- 7.4- cT57 STEWART&ALSSOCIATES 10 82-9 3DRF , FORT gOLLINS, CO 80521 PH.Consulting Engineers and Surveyors By: Date: ( id S- Client: dfbo�-o JQ Sheet No. Z of Project: 0 i i" � , fi . �( tea t ; �/. IA Subject:-�C tir)�i"/1c. C r,�'n— O'7'� ��07/1i_ SITC. ) LOM O -S 11 C G = (9.37)(0-qi) +(2.75J 0.25) _ U. 66 7•IZ TG = /OU `i c`� �Ld CZU gVi17l( j117/3.0M: rG1ou G�(oo �//l G� Gj/i - �.25) 00,60j( -7) C 7. 12-) 4 z.q GTS STEWART&ASSOCIATES 11 82 93 DRF , FORT gOLLINS, CO 80521 PH.Consulting Engineers and Surveyors II By: P) IZ Date: 6 c I- Client: Ale-6g rG. j 6 Sheet No. 3 of II Project: 0 r' Subject: GC'(SS, /-)S)N ' Nd• 1 (sovA �7c,1G o� FrOJpecl RIJ lyi�� nvr}J� o-- Wr',jioc, Dr/ A R l� /af 0. 61 A'c S = l 0 3Q ( 0. 25 O. 67 TG 50l �Ivl 9-0G/ �v7'J-Cr = C.I +a,3= 7,4 r r�lua = 7.3M1 (0. C �(2.6) 0.C, 0(L00 - C(GJIq _ (I.z��(U,u (. 7,( 0-67) 3.6 rJr ,i rea. = 0. 93 A-,, .5 - 0,5 G = /0.50)� 4.9J k d431C0.LS� _ 0. 63 ll � 0.43 I T6 _ ¢v Ylvr 3'7� 5�rrei 4-u 370 + = S•G f-3.! _ �. I Mm 7C G�Z�- c J /) _ (U.63MZ--7 73 6 , � V f.J qto 0.63 (4 ?I (0.43 Z.F3 o.63j( ?� (U. y3 5,1 C-�s STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: F/ [--� Dater Client: 1t1eJ Qir-c-J a Sheet No. of 1� II I . Project: AJOr ^ D-0Ci-r �aII%'{G Subject: SaS- h CGAICv/(71J'ohl S,y.Sln/ �t/d. 3 SovA .5-,1aie ack-xot� 494 aFl�-siir /ois 10 sof �) /-2) Z-Z4 Ac z-z4— % _ /0 0' aye r tonz --'IUS C00 SW ate 3 3¢ to0-60o F IO.S+ C-3 = l�Mr� T�-13. 9-- �Z.,- GI /4� = (0.1.7 C-5 C�fG = C-I A = (0.33,5-)(2.2¢ 3.) 6--S � l uv - C C 14 23)(0.37)( G.3) ( 2. IAA SI A/ NO 4- ,-e- G a. I A C- T� = Y� ov 1 Zko y v4 cr q-, 7 t Z. 3 = T Z rA (Tc. lov z 2- `/ 3 Z X (0 0.75 (2.`I)( Cat 10 = G1 /� _ G• 7i' ri) � 0 -3-d cJ r C�rb6 - G Cr/} (1.25)(0.77) ( U, �-1 S•3 cT 40 STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Date: Client: AJP .L (4 r c;k J (% Sheet No. 5 of Project: -A16r r4A t-) r on k lea h 0/''r Subject: r-:5�GSi /) Ga/CvICC/J 0/4S-I/\J A/0. � (0.9�) U, c0 :�-1-- 2t 3 4 6d 5 2- Z- GU 7-G ivv J"C 0.66) 2, 0 cis C14 (1.2 i)(07)C ( . GO) - 3. G At z 0,79 A� � I TC - CC), pVerjo�L� ,�I✓S Q56� rJvi- of CO �z C-1 A - (O.7f,)Z.7)C 0,79 J.G CTS C-I /} (0.76) ' �¢.7�) ( 0.7q) = z_g ro C�Ivo;- .C�-C)A 0.79) S•3 cc �r STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: 177)T — Date: 1 Z II Client: Sheet No. of Project: /L/O �-4 -b F-OclL C) /Vl r J Subject: 13 (7t S C Ct O; 11 L31-) S I Al loa 7 r e- + 3? T, -- -- oveH04 '/VJ 2zu' 5Du4cr T6 7 3� T 7. L e . C0,73(z.6)( I - 3 3 c- � I �0.73) �4--OC 1-733) Jf 6'� c 0.73)( 1) � S IA/ /NJ 0 . B) /--'4 r-c C, -- 0, -L C/, Z,)-- cr 73 Z70 a VY �o - 0.�3 4 - I? c— X) 73) -3. 0,7 f Q 10 7Z_ 043) C STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Date: 6 /Z Client: 1�-Je bOr G.�6 Sheet No. Z of Project: AJO r] f ool � PAC f Subject: ,13 a .5 in (f c, I C v1 G') / i3/�S)N No 9-�C,I,/ d; rccJ.� i� FG /?re.a = 0,67 AC 0-•G CIA = ((U.77)(3.2 (0,c7) = I7 i .� 7Ui77) ( 5.7 ( O/ 67) L Z. P r- �IUU�1.2-* 0.17) ( 7)[0,67� ¢,5- c. t 3/-a5' n Nd, /U (sov4-k haI• of- 1�rps��c;! i� lr��s eos' o�-Alor07 roo; Dr j A rc c 2, 14 A c _ 0-/ 4- TG=, /s overlo•� �;vl �zU Svcr o + Tcluv O, -7S) ( 3.3)� C1, /9) 0,3 f �la = C- 0.7i> ( S.� C 0. /I O- C cr S G'1vo : G� C)/l - � 1,zs)C0.-7,)( 7)( G. 1 = 0- ? Gib STEWART&ASSOCIATES 10 82 g3 DRUM( FORT COLLINS, CO 80521 Consulting Engineers and Surveyors By: Fi 7� Date: !v I? 4 9 Client: ta Sheet No. �' of Project: 0_t�" ro �G is t4Me Subject: Gamic e^�rG �to� ��t'�i1 WAAS ` jnlC?- 0� N'a�PS�1Ve. 1 exl.S )0) J F-I0V Fra.V. sov4"� �er .Pot r.5as Fcrfr1Jt-oc,ke S' ID rce;-oi` J I Qtvtr = Z0. 9 c�S. 7.r..0M RUi pet Parso�S FCnif rOv4e f cJ C il)S ✓/A e P/Pe in 1`�6 rr-o-S. Rct 5 I D and i J-sYPro- os eci 5t:.C' G�S 16, I dnC� YrpSaCcr �U fUrn 5ov1h 0� 1-10.M. .Sn `f C • . j(oZ g-�, os- l41\e-`o)vre Pr Os[ pc. f! 5 1 D 1S caMP%C'j,-cf c 30 in c1 <cf� s�or� dre i� !S rnsiled on a O,CCa' 30 c�S J$ (ti! 5GG r_SS V/A� �C c� 15rovnc�� f`'GV nS f7r^I� of 17LOVEu jZ c cc-yr-c(rr i'4 pf-0 ecr` i% C ><o>Luf /00/r f/vw f�- f /Ir l89.Q LFs, FROM THE Ci:U55 '3ECTIO,t/S /s=?N17 CALCVL(-�)T10/✓5- .ON .5HEET Z7 //VcLV-DEP /nt THE /AAP POCKET OF THIS l,EPO✓z7, %HE 10CI .i;Z pt/ERFLaO,l TV `Tt4F--50VT14 ON HANI"PSHf1P )�O�D w)LL 3E 67. 7 c7�S THIS wlLL C-010(3)niE wtTH THE ZO.9 c--Tf F-SUM THE SvVTN FOR n TdTAL lOO Val; FLO,Kl /9T coNcEAl-tRATwAl FoN7 0 (R c0711 Or POiti 10t.S or THE P605PE-cT );O/1-D si> J-;EP6r,, 1 S1 INcLVDF_D l�l -To /a�/�F/l/pIX. // Si,ce fine vr)c(e raVna 7�); e sys P, LA/ /1( J. �.fr: /Pjc sec(. vp1� c;% i�rUs�/�fC•� ') I' �r? 'U'iJQI SVr�!o`ce C�C-V pT 2G,� �1J fro.-` �%�e -s0 Pf✓S 6,7..E c 1 -�r cM f-\ n01"i 0veF iio.../ 4a-, SA'If c 1<� �o %^e eCAJ -- �0 Gonce��/(q— 1>C/ n i II T)11'Z Zb, p -F G%.7 = 66.0 45 TAe Z %,'i ��ows Jiii bC 1 STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 a By: �),l�/ Date: (a 2 /� 9— (Client: Le�f � oC 0 Sheet No. 9 of y Project: A0 r '? L:) i O G I 7�:� 7- ( a- r1 0 y l P f Subject: CO h mil' n f',-- 1 0,n EO in If Gvnc��'rG��-ic� �,oi�i- Eas4, inl,4 doh I40 'S� fl Q 2 = [70 0ver--Q0 ✓ �IvS /,G c' s = /, Z cTS /T4- - f-' C.T1 5 aS/ h /�lO• Z 4) 7. 7 + ThIs 93,7 c-& h ril s vrr�oce �(o ✓ pp � She. =Y SgeM �S V��oM p rsince ( I�—A St.S 1 i.� it (7k jr 7�0 93, c- ovc�d-po {nc cv/S ih /-u fear JGI� Swale. tee., d. /0% 30 f�V-(/ 4-2 anc( i�140 /J0r4%hr00, J�) (SSE 5pEF7 111 2-7 IN MA-P PoC-fr=T) C-�on can%ra-f-i on, �C)ln4 Fiow cr0-SJ ��� fr o, Uasih4- G(z G1ivv � 5.3 ��t STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: Z,J K f Date: F 12 q Client: I_/t e bar-c;cG Sheet No. U of _ Project: Z/ r/ r'1/ � D r o c, PG i a o r4 P S Subject: �O n C e.nY (-G,f �/G� PO 14 ) ►'\-i-( ;v I1 G'.I �'I Ge _. = rU _ C- ;ffr; i� i _4� y. •G9.j� �i � _ i r =_' .� .I. I}it'II ;�Jj a,. s n. hc Il���PII !I� I i�j • L5. �S'�II.� I �,ff , �• �3G!� v Fc �''�iIi C f �o+i M7f 'II! "o 3 S 1 � r. ji !' , 1r� .I � �G i�� I I 4✓{ h 3 j'IIII` G . �GflaIj�i J r �GrC °iii,;I'i F) o� � . cilI; IS . ! t Cb.aS;ticI q--cSOL/ CO,f cor„lP('� 1-_aarl1lvI3asip s3.0 'USwe) r aVMs�i cohceC, 0vP41,p ko aSIo GG wGC, /oCc4e� G. 7(/,r-5 6001If G Jr17 a a .I 29 e U G ' :. � �- . I� ( . C= I i l! � _ /' . � I P .� ./ 11 I ! II ' G I` o } z % vi �pi' e vrC � � G eE cj C r ! s/ � I � � . ; I .� G � I4;I P •G -� IIti� S 1 f =! � G� III 7�rr �S ro � �L p/Jr S�lBircr�a✓ an -fJ I7Curl. _/ it-4-.'o ovi�eL1 C-�`C! an J�tr4� �A1 -05E /eIi"!KcPI 11G Zyl_S,V .VC 'L5 aoran5 Al caw��G�1 IToe O c;4-cd) Jr1G1,/144"SI a^� Z-4-,C41 i 3;.6-Jr F i STEWART96SSOCIATES 10 S. LD1RUM,FAX FORT gOLLINS, CO 80521 PH. 48Consulting Engineers and Surveyors By: p) )R Date: Client: A/f b ? recd o Sheet No. / % of Project: o f-�IS, r-o a k P4 (d 140 o f Subject: Cd nGen i'o� Fa -r'f Gc�hGen,t-c�iU�-f-i... i (► I� rvno, oM -�basi^ 0I 7 ( Z, 5 _.0� 'l.� M._ 4b0.S��l � i /�/p' -! � __.i ./ 31 C f ...... Jr7.s� )),I_. lal �-. Inle Ico.� c%. %a5i^ a� Corn, I +� _.. t I I! G LI G l i l O J 7 I I i U/ - -�✓��� �- 9'8i c's I I [ l i Fzc PI o+,� � it slo c i �1, Z i I e - !-fy T7.1ZS C)lArzT, 1 pi I I I i >{t/�o.4 _Troves ibasn AO- 6�'=( 0.7 II �f I �IDf/_`_rVv�dl+ (-�roe_x �6asi�,/l/v .I (¢ II le:k caIcl, baSir) ! in' 'on I or) T�aj161 1 GUhd%7 IOti iaT I GonGEh+�f �i iohl Ol^�I /v0.� v n/;1r!t I� ca%�aci� IILS.r�.._. /8!�� I ol/�LE,t .. ��2 1 lca a �i �.6- G,9 _ J �, 5 I e�-i . j ClllTTIF, Grf.U�7 p!-ii _I-._LIPlp�✓ I STEWART&kSSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: �II Date: G Z tc1 Client: /y t? " Gti o cG Sheet No. 12 of /V// t Project: O 4�^ r-00( Subject: G O n C e^ J GJ-I r' h �>O CG h c-'(f a,)-) G L" QZ = 30sin 1 P(✓S 134s'r� 10 pJ✓S %�roSPccl weS� u� l�or^PsI�IrC = 1,1 +0,3+32-.5- 33,`1 cTS 0-;00 ;= 3asi^ / P/✓1 5gsl10 �;/vs ProxfCC-�,/es�o�14c nrs )rc=3.b*U.1+ J21.? = 12G.6JS T> )s 10,/ wrJl 0L/C rDc'L-, /-n' .5-0v)1, cufG Fr- o5l�cC.-J c,r, er4-eC r-OUI[e De, t (Gh� , Coh c er� rG�.l�h ,� a �0T/ SUKF eF_ �?ND Y11 rD) Flaw - f-c"�/\ iaSin r-10 , 3 �I�s ov�� �o�✓ cry c-c�n. /P rc� rtr QZ �Z �Ipe= 0-Usli� /cM ✓eS Uf baS%1 �G� Z = a��sirc- 14.S+S.I - Ii.6 -f- 1.l = ZU,% c4f Q10o .5Vr'/ocC - oue 0M cvo. P� /�z ',Ivs J�as1 AVo, 3 93, 9 r = 100,8 (�--Fs. (or/ pines .30 'Js ��c� J�lorcci- 1 ` in1Ch C. cvn, US A 30 '/4DS AI IZ PIPF 0,✓ 1 1075 SLOP r- c G1TV F�O� G l'`UTTC IiS L4-ALT = 4j s TUT/-)L. 100 SIR PLO�-J /N SwiaL>: 77 IDD, 6 �1 STEWART&46SSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: P/)Z Date: 4 ¢ Client: IkJeJa roe J 6 Sheet No. L of Project: /v d r�-� b roo k PG') I i _ /-%vr, e J Subject: (fOnr(- n') 1-eJi0V\ ppinh COhCen�� �1Illa�, �p/n� to UJ /4rCn,: d.3U j}-c.. G (o. Z;>(0.9�)-t (/.oc' 0.2,) o.Fj3 t �iUo'- G�-Cl/q = LI�C,-7)(a.t) 1 I THIS Cl1NCE01rZ4,71OM MINT w/LL r3C IN TNI_ po/ pIA/G- AREA Or -TNE OVLrKFL.OI.✓' OF T(- E Eic�-ST 51 D: j Ol= I-��MPSNITE ,r`aAD iF3N% /00 KR OVF'IZr-LOw oVEt(r-LUw F•�aM TN) S .Pd-ln/T WUL GO Ia45T UN N4i`TI415r k PF') VF T/fIrL ol/F_K FLo w . q u/-? /TI7')/ L,L 13 F' ON 5i."F_T 27 (1N Mi;TT) i FCa l,,)LFT JAI.. wE5T SIDE 0(= HAmPSHIRE r;'D TC 0. 2s�C0-¢��t7)(�•IE) 0,5� c -1 STEWART&SSOCIATES 10 82 33DiRUM, FAX FORT gOLLINS, CO 80521 Consulting Engineers and Surveyors By: Date: � I 4- Client: /Uf G+r'c-, LIC) Sheet No. -LL-of Project: Ajot--'fib -I oat-c P A4-I d NonnlI('s Subject: C O h e' P i 1- cr i Oh o I �7 r Goncen4Poi ^� IL i F-/O�/ fn t eav- 1114�r- o� Hcar - �,S �sAir,- ; �i Tf—OvP 00J-i 0,39 AcI ! ! U.'y t� 0-�)(0.Z5). I TC-, CVSF., IU MIN, �U2.> 1 i f i GU%�Cent �o� c. �Oln /3 - -- Tliis rs PiPe� Z year -Now wr}� both Pt'eJ oil SviTC�ce ,�061 /ir�1eIs C' ahc���r a.�-/o'n Po'Alf y 5- rt on s % eC �5 /0 an) ZZ r Tl, e Z Ye o/- I w < /,do t/eo% are 6,8 cT f svr-FoCC' = Z4 ,4 c' S STEWART&kSSOC[ATES 10 82 93 ME31 LDRUM, FORT FAX aa2 93 COLLINS, CO 80521 Consulting Engineers and Surveyors 82 By: F l [Z Date: � 14" R 4 Client: /l.1&-b r-GSheet No. j S of Project: A-2 0 i L� b 7o (51 L Pc '/ 10 P-01'' e l Subject: Co v1 C.(3 r) 4- a �1 OVA ?o , r I I %/� �roPvsr?� s�arr.-N pj p� ..�^ �ras�>�cf 1Z� i neu- Draireo��Ar rrII Cc' 7 l C/,/ STEWART&ASSOCIATES 11 82 9 L RF , FORT gOLLINS, CO 80521 PH.Consulting Engineers and Surveyors / L By: {� i Date: lG / 5� Client: _ N eL�a rG c� G Sheet No. f�O of Project: N 0 r4i-7 b r0 o k �g �i 0 0 M e s Subject: /00 }fE S T 01--/v1 Ot/ FRFL01,✓ OF `�- of f%Fl MPSI-llr F_ r� OPP0.51TF_ LOT ¢Z /4ND Aldb<703RQov DRIVE -' I 'vverzGl luw' 32! l2r---- ywL-� 80,S5 -4—__ G, 33 I . U. Z CA ,\ I t I �j 1 OvIS� ITPM�f Sh C Q CGI �3 y 25 13'6 13 - 1+ C,VJ Cr Tl-y 'cl 0.2- + iuG- 321 C�=(0•�6)CO.G�)� �)(3Z► �(v z}LS 9Z.3 �r NI AIx'l MvrAT�eP,TI { �✓.17/4 . vJI D T" OF 3 2 I E_1. - i i' STEWART&kSSOCIATES 10 S. E DR31 FM, FORAX T COLLINS, CO 80521 82 Consulting Engineers and Surveyors By: Date: Client: [lfba�-a-s0 Sheet No. 1-7 of Project: A/O t'•1'j-) , o oL I 0 1owi r S I Subject: -5 -o r-M -Io T4," r o o 1-C 21"! i f G C ou I- "J,-- or e05-' 5lc(e O ;cr"l �>s%r�P J�poi ✓ _ i j S ._I�I _ IE0PRG1J 7P. � S.ECTIOn/' 0N. Sr+FEj 27; 1N M IAP Po kcET . L,or- Tr41s r�F or<—, De;;1,5 . QiUv = . %3 �/ c�s 6V7 T-5 over -"`I on 4ro' Flotpeel_. I ss �. j ..I_ I _ i I S• I GTS ener'�-Cl C ear% i L crF �tvri �n1�y I I .st GigLGVI- T10N1 01\t S4 ET �7 I NI/+P P(90-CCT 0 r. 1. ;TH15. P� EPGiZT , F ' ,a y O •. e eo ........ i o r,0 !� F FU o -- > F o F� O Crossha�c�leo arec. is la0ty- /fh/L Por-)dinj �I Ele�o-kan 5080.55 dvr-1175 over -ion V•- S oT 4QrIp'sYre OFo�T \ '�• ""�': \PAN •'''.B<.-'.....-. � I*• "'Y, �\ •\� �c _ _ter. - - . �' -. , ....Q�_-'_.._-..-.. •. JOB \� �� .� � -. repo � \ y0 asoso------------- B,G vO` p sC"I�OL Y SCl�UOL y%a�� cE,V C(:x ----------------- 5082 ................... P� ---•--•----------------------- ... --•---•--------•-•............-- o 0 0 ----- ------ t---•--- -------.-.._—..-..:te.....................•-••-- .--- •off---•----•-�•-..... �� y ----- �AMr5N4)R RD. - ------0-'---- O r o F .- :.�,.,. O U �• F ----- - --- > O FF 6L Fo VO l o� A/1 CrOSSI'1c1�'c'7Oc '7�O �A 100 yr H li- PONDING p � i+-1 ar Elevalio� $o�y,85 2 x d(Jrin) ouer4/ow of g ............. �' .ems •.: j N � J y J ? yo0 0FO0 r- 4F o eo o O • eas�- cvr� oh IiarpsLrrre � J � 2 rn r EX15T/NG TO:POGfz AOF 1-JAMP5HIITF �oAo D A DTA CE N7 TOjr}:6R00 K A I X O s O O> 1Npd-,(NLS O 0 b m n 0 on, STEWART&ASSOCIATES 10 S. 9 3DRF , FORT gOLLINS, CO 80521 Consulting Engineers and Surveyors A / L r By: > Date: _�3 _ T-- .Client: /�/ e J1-7,t rG d. 0 Sheet No. of _ Project: /v O r" L 1 L ro o Subject: S � la. � e � 10 � � l hr � � e s � s � � � 0� -- -t-- ;PESjGN Qwo 77 Jr , SIDE•✓�ca� � � ! (GO' LONG) / I f 6 �o. EXIST LUR3 �{ �a. — 7e, I z -77.7 P/aN I r•l �0 t lz ' G.0/G (!�-) I 0.03;; G I In a. 22� Thidie e clesiS� C� off. 77 I STEWART&ASSOCIATES 110 82 9 3DiRF , FORT gOLLINS, CO 80521 Consulting Engineers and Surveyors By: F)t 11II Date: �� (Client: /L)e6urUdG Sheet No. 20 of Project:/�10A �) 001; pG-�lQ 116-meJ Subject: r(2ir) .Sw(7�P Irl %rccc7 .E« Tor DuC—J)0�/ jrow, /40frlpshir'-1-cf r P�; cn LE l= ZO IF `lI Lo7 4Z Lor 41 TOP FON =8Z.0 TOP FPN =8110 t 56 .'4- e 6o G �NJ N .t i ~ � 30�� COiJC �P/7tJ v✓1TFi Z4" RET. w/-ILL "I �= 0 i I ; _ �f STEWART&LSSOCIATES 103 S. 2-9MELDRUM, FO482-9RT COLLINS, CO 80521 PH. 48331 FAX 382 Consulting Engineers and Surveyors By: P/ T,' — Date: Client: /Je 0 Sheet No. of - T-7— Project: AJO t- rI7 � r 0 Subject: C -5 0 side I n Tro <-- E J;0 I —Q-0Vt .s 77 C� , E C TJ C'". L:( )U14 c,- LI/ TF 77. 7 -3 2 Ko; it' I A,) I e- 7S E3 E LiV -To 72 3 7 2,6 � 0-037 70 F- 74- ZZ SF .._ to Mr 5.0 //0 L leu 75 42,5- 5F 42.5 0 Cf 'Zo 37. 6 V:: (4-2-5)(5,C)-- 7-36cT5 o.035 G/aa�Gl�Y OF L< CZ 57 x + V 9 Z- FT 4, 12 .0. q? 0 1-7 7 75 05E 6 t- X) -<J r, ruvPi hasp c U L -�g /lAcrf-J, )Iycl— rck -bf-T&IJ. to f r l p r o d e V L/S h 41N 5 Vr'r, 0 103 S. MELUM, FORT STEWART$,(kSSOCIATES PH. 482-933D1RFAX 482-93gOLLINS, CO 80521 . Consulting Engineers and Surveyors By: p J7 II Date: i q Client: Nk L a r a 5l0 Sheet No. Z Z of _ Project: A.40 rK brook I �ID I�{oate,et Subject: OverV OL-/ 104( ZJ- o^ �- ? 9 .over-�lie e ��cr-�lo�✓ i i I fa.r;'%��rock 19.Uc�s -- - I .i_ ovCr' Ion✓=_� ¢.61 t'1 .0� = Z.,• 6 c ! � , t I � , I _I. ! ' I i IOU' m WAM SuRFACF- wr9 TF 77 7 TF=77.Z �oO,YR HwL17,Io I -74.7 w11 I ' i Ilo i ' j • � �� 70_ i /�LIK . r I 5 �% i � 1 I- • i i I f-I 1 ; III II I I � --'-- -- I rC 0 �✓ Ar _ D EPTN; _..o F U.5', _ _._ —I----1,4_n.E�(9� SFI--- I--..�P!= I11 L �i=p�P-)%ri-- p.3�'- 1 0,3I (J,) Z _ 14: ciS I l/ 3. 6 027 I —3. I 1 6/-7." ? �..a..0L�)�? I� ZB.c I I✓ -I ¢:3 J { -, S 1 I i f STEWART&ASSOCIATES 10 S. 93 DRF , FOR482 T COLLINS, CO 80521 82 Consulting Engineers and Surveyors By: pI P� Date: Y Client: Ale bol ,:5, c10 Sheet No. 7-3 of Project: r�"h � /� a ``roa PaJ/, /0 doM e i r Subject: VOIUMP aT Eeki�Lr0okP CU VOIUMe Vofl/MP 21 � ZZ G3 �3z-2 G4 Zve33e /7-774--7 2. 1 C23 C377d e �7 3 �-C 7 k 7e3 Z1 Gr=2Z.9-G Ac F� T(6�i-5 v(o'I✓r,,4e is cglcr,l�J-ed 0- CC) MTdC)-iCr rr-i/J.oc� oi sU(-Ve o� Inc /�ro.n �G�d perto�rc� in' 3-U�Ac IT79-. 3 COMPUTATIONS Stewart &Associates, Inc. 103 S. MELDRUMSL Ft. Collins, CO 80521 (303) 482-9331 rl-.By:P/ 9 Date Client: Sheet No.Z 4— of Chkd By: Date Project: Subject ALLOW,g13LF FLOW /N LOCAL STREETS — 100 YR 5701Z/V) 1 1 1ig ......... _..I ! ...I.......I ! II I_... - - - -- ff HIE -I ! : V I nlK i�Zi 11I I'I I Z I zy> ni_C ooze /. 4e3G �ilil��l���l! SLO�� I �G2I �. TiPor C, I _ �ii� I v i it �� ��• ilon F curl hLLOWI`)VE Q --°.IS 62,14i� I I �_�cY•e...I - ... I ! ¢¢.-3 c�s S i%a l i Rt. l i L O >7S. s7w ifs fJ. 6 "ol j 1i08•L� I I I I O G' � j ! i 7oi6i cfS Q.7 :Iui I� 2il •� O.t°i !%; i I I �; 1!ZS. I I! o•.I I i '1U0�3'c-�j I o. 7%I I i If33.' I i I _I_. O..BI...! 106,4 cfS I i7o 1¢G.21 i ;. U BI . I /!2! I cf !• Z�'Ty( �S3.�I ! OIB ! i I 12Z tic S (• 4'.7l ; i I I I � l,6SBi ' ' [.. U48: I I !32!, i c�J l.� %a I 177.31 v1Bl j �IJB c�J .Q l i .I i --.�..... G18. .. i i 1 SG14 z.o y I 18B.ZI I IIS .G'JS e ! �.ff. 3.v/o I Liq- e! I I z I j 171 e!� f. !� 4- o7 ! I ! I 2YG-7 !. i .! _ j I..I_.I_ U 16 I 16 �.2 c.�S /•iS j i I! Z97. 7 I .i 313.91 i I 4B, Is�4 cif �.4� S•'S c: I I I32�.� I I I I 194G c�f I 3143.3 I i i !. iQ A I j I? 7; 3 C+-5 /oo Yr_-,4�� FL.0L;). IN AJa>�TN3 v0%t c7T<`� I'�C 1 9 GS over Fja -�� o lay /�/orrpoaC Dr iS v�. caa c,1'`� is ll Z, l G�f. so h e Z4 �1- c-.SS / 1 I- "l Oo c+ n n con �e GGti'(, �'� vJ1 "r1O(/"' GG.US nC Gay s - Zs o 13 z O POlUe: of • o • a o a o0 0 oa•:,ao /00 000i 90 80 0- 90. 70 c. B, 84'. 78 • .000T ? 60 mil. 77' ems. 66. •0003 . ,' SO co 60' .0004 40 s9- S4' .0005 .0006 ?.S vB. 4B' .0007 .0008 30 v?_ 41' 3 J6' O " OcI A r' ZO v Sot 3.5 � C oD .003 .. (0 V ��. 1T O 4 p V ° o 14 • '` .004 .00S i O 006 4.5 0 .008 m .009 i0' '--' --f y I ' y 4 U o 6 v 0 03 6.s S .04 .OS 07 7.5 O IIN 0 h .08HIL .09 i �• v, 3 e. 8. 9 I bc4- o J I s. /0 6. T tL� T .3 .4 .S .. 4' .7 i / /� Fig. 15. Diagram for the solution of Kutter's formula for circular pipes flow- ing full., c7.5 Ya = 0, 67 �� _ ! •34- 1.0 12 U.�'= �•Z Gas �..� 5 .9 11 lO 4 8 10 3 6 .8 �- 2 9 � 4 .7 w Cr e 3 �z 1.5 w .6 / 2L 7 Po< b w 0 prey i ci iov� Z 1.0 5-- xample, Part a_ \ 1.8- w 9 5.5 0 - - - a .8 U -- 6 0 w w c� w w 5 x z o .7 v_ .4 z w .4 = Z 4.5 z 0o 3 co 6 w s u_ x v o 4 2 0 5 c� ( x F- z z F- 3 0 w 3.5 W w T .4 o_ 0 w 0 0 0 .08 .25 3 x x o .06 (D .3 0 0 U z ILL w w - x = a: .04 0: .25 2.5 w w .2 .03 a F 3 a .02 0 .2 a 2 a x U � (L .15 .01 0 .15 L u _. 0 0 - - -- yo a 1.5 - -- -- - < .10 a=2 In .I 1.2 Figure 5-2 NOMOGRPAH FOR CAPACITY OF CURB OPENING INLETS IN SUMPS, DEPRESSION DEPTH 2" Adapted from Bureau of Public Roads Nomograph MAY 1984 5-10 DESIGN CRITERIA zc Mtl•1ilOUA• i h iM• �✓ i IAM EFFECTIVENESS CALCULATIONS ---------------------------------------------------------------------- PROJECT: Pad-jo pom of STANDARD FORM B COMPLETED BY: DATE: 6 Erosion Control C-Factor P-Factor Method Value Value Comment -------------------------------------- 5Are}. JrUI 1.6v -------------------- �.VU PVMi' S woltf5 O. UI /.00 seed wi}� Mplcl 0.0G 1100 b 5{-ate✓ alr barrier I.00 0.90 5roael inlet- ril}r.- I-ov 0.00 slli �enc� 160 0.50 MAJOR BASIN j d h D � PS-- 77•q SUB BASIN ---------------- ------------------------------------ AREA (Ac) CALCULATIONS ------ -------------------------------------------- /Vol-1-�+i ovn Wa1 t'J (�✓0 r+.1rs �.c Dr to F_ /rne 10137) 0, 4-5—,4c see1/4- Vic S I cr,,Qne�Y hG bare s;ai) / 3„38 AC 45r)(0.o)-t�1.95�a.oG�t�l.l2)(O.OGl j j3.3p �(LUv) 6.9 P = s i )�- Tc�ce, o. S0 s 1 ra✓ bale burriCr! c� 5-u✓PI FII1Prf 0.,f-(/ E Fr - % - (0.5z v 040) v 100 z 7 9, z n ----------------------------------------------------------------------i HDI/SF-B:1989 CONSTRUCTION SEQUENCE I r PROJECT: Alar'rb?7f`oo-L, PLO /JoM S STANDARD FORM C SEQUENCE. FOR 1994-9c ONLY COMPLETED BY: DATE: C 9 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 MONTH ------- I94- s o �,v� p�-Y-IF �^A --- OVERLOT GRADING WIND EROSION CONTROL I I I Soil Roughing I Perimeter Barrier Additional Barriers Vegetative Methods — I -- Soil Sealant I Other pvM 1 waif s I RAINFALL EROSION CONTROL STRUCTURAL: I I Sediment Trap/Basin I ! Inlet Filters I Straw Barriers -- ----- - ----I Silt Fence Barriers Sand Bags Bare Soil Preparation Contour Furrows I ! Terracing Asphalt/Concrete-Paving Other VEGETATIVE: I Permanent Seed Planting Mulching/Sealant --} — Temporary Seed Planting -- Sod Installation Nettinos/Mats/Blankets Other -----------------------------I----T ---- 1-------------------- ----------------------------- STRUCTURES: INSTALLED BY VEGETATION/MULCHING CONTRACTOR DATE SUBMITTED HDI/SF-C:1989 MAINTAINED BY APPROVED BY CITY OF FORT COLLINS ON JANU.-k 'i 1991 8-20 DESIGN CRITE.'.LA 0 0 RAINFALL PERFORMANCE STANDARD EVALUATION ------------------------.--------------------------------------------- PROJECT: /Vpr�)�,6 clG Pai jo F)omc-, STAtIUARU FORI1 A ----LETEU -- DATE: _� f -cl `-` --------------------------- �" ------------------------------- DEVELOPED ERODIBILITY Asb Lsb Ssb Lb Sb I PS SUBBASIN ZONE (ac) (ft). M . (feet) ( % ) I ( ) ---------------- ------------------------- 7T T� L -------------1------- " 1 /��� 6.12 5(90 /. 0 177,7 l7 c I --- — ---------------------------------------- ---------------------------- 111)1ISF-A;19,99 STEWART&ASSOCIATES Consulting Engineers and Surveyors 103 S. MELDRUM, FORT COLLINS, CO 80521 PH. 482-9331 FAX 482-9382 By: p i T7;\� Date: Client: / kb,:�C c -J 6 Sheet No. of Project: Af 0 4; �) r 0 CI , 'T�-1 1 a' /f U /Vv-- S Subject: EF�0-5/0// CUNTEOL COS75 Gonis-rrcvcTlUn/ ° ((`�GUSTS 0 5-�-100 -5 C- 7s,00/C 37ti-60 .J 1 SI (G ✓ %aIC Gr-r(e/S a� 7S.o 'E ¢jU UG AC' �ertroror,% sCcL k HvIG' � GSUI/4C 12G7.S0 1:IZ '4-c Yerr a. c11 se�L M�IG� Ca Al 7__= I 707/- t 3 9 7 5. 5 0 1�F_ P L IU T-1A/C- f0S7" Gl�ilp SITC /9 6. ( i`%(f rPsee .°. ,�o(.l-1c)T>:tznL = S x 27.50 No Text 4 r FINAL DRAINAGE REPORT for PROSPECT ROAD S.I.D. City of Fort Collins Larimer County Colorado December 1987 Prepared by: The Engineering Co. 1630 South College Avenue Fort Collins, Colorado December 31, 1987 City of Fort Collins 300 LaPorte Avenue Fort Collins, Colorado 80521 ATTENTION: Engineering..Department RE: Prospect Road Drainage Report Gentlemen: We are pleased to submit herewith a drainage report for the Prospect Road S.I.D. Included in the report is analysis of stormwater runoff character- istics caused by improvements to Prospect Road. Methods of stormwater con- veyance are also defined .in the report. If you have any questions concerning the report, please feel free to contact US. Respectfully, J. Brian Zick, .E. THE ENGINEERING CO. ►n+mf%_ JBZ:rc THE ENGINEFRING FT C;QI.L:ri-. n H()r I Q,* : - . Final Drainage Report for Prospect Road S.I.D. General The purpose of this report is to evaluate the impacts of stormwater flows on the proposed improvements to Prospect Road. The Prospect Road S.I.D. is located from the Taft- Hill intersection approximately 4,000 feet west to Larch Drive. Improvements consist of upgrading the south half of the roadway to arterial standards. The arterial standards are reduced to a 60' roadway in this section with the exception of the intersection of Taft Hill Road where the full 70' standard will be used. In preparing this report, we utilized information found in the "Preliminary Design Report - Diversion of Stormwater Through Irrigation Canals from Mul- berry Street to Spring Creek" by Resource Consultants, July 1980, the "Final Drainage Report for Fairbrooke S.I.D." by Parsons and Associates, November 1983, and "Fairbrooke Detention Pond Outfall Drawings", City of Fort Collins Stormwater Utility. Site Description Presently, Prospect Road from Taft Hill to Larch Drive consists of a two-lane roadway. The roadway is generally constructed to rural highway standards. The roadway slopes from west to east at grades of .5% to 3.5%. From Cedarwood Drive to Hampshire Drive, a stand of large cottonwood trees are located approximately 35' south of the section line. These trees range in size from 12" to 48" in diameter and are presently experiencing declining growth due to age and reduced water supply. Land use along the south side of the road primarily includes undeveloped tracts of the Fairbrooke S.I.D. Bauder Elementary School borders a portion of the roadway. Design Criteria The design criteria for this study was based upon City of Fort Collins - Storm Drainage Design Criteria and Construction Standards. The rational method is used to determine flows contributing to the road. Street encroachment guidelines include: a 2-year storm causing a flow spread of not more than 'one half of the roadway width in each direction and a 100-year storm not inundating the street crown by more than 6" or the gutter fiowline by 18". Theoretical gutter capacities are reduced by the "Reduction Factors". Allowable street flows are found in the Appendix. Where encroachment exceeds allowable limits, continuous grade curb opening will be used to divert flow off of the roadway and into storm sewer systems. In Proposed Improvements Hydrology for the 2-year and 100-year storm events was analyzed using the rational method. Exhibit A shows the locations of the basins, which were analyzed. Nine (9) design points were selected to determine street flooding conditions. The locations of the design points can be found on Exhibit "A". The summary of flow conditions at the design points can be found in the following table. Calculations of street flows and inlet designs can be found in the Appendix. Summary of Street Flows Inlet/ Desig Roadway Allowable Actual Flow.. Outlet Carry Storm Pt. Basins Station Flow 2-yr. (2-year) Flow Over Sewer cfs cfs 1 A 12+00 7.0 36.0 31.0 5.00 31.00 6 B 12+00 7.4 3.1 -- 3.10 -- 7 B,C 20+00 3.5 6.3 3.69 2.61 3.69 2 F-2 20+00 3.5 9.1 6.80 2.30 10.50 3 F-2,F-5 26+90 10.7 12.0 4.49 7.51 15.00 8 B,C,E 31+00 10.7 5.5 3.30 2.20 18.30 4 F-2,F-5,D 36+59 13.0 10.7 8.74 2.04 27.04 5 E 50+00 7.0 3.9 3.90 --- 15.80 9 G 50+00 7.0 11.9 11.90 --- 11.90 Presently, flow from Basin A flows undetained into the Pleasant Valley and Lake Canal adjacent to the Prospect Street bridge. Due to the large flows coming from Basin A, it will be necessary to continue to convey stormwater into the canal. This will be accomplished by constructing two (2) 15' long curb inlets at Station 11+45. An emergency spillway in the canal has been constructed south of Prospect Road in the Fairbrooke subdivision. This spillway has the capacity to release 66 cfs into the drainage channel leading to the Fairbrooke Detention Pond. At Points 2, 3, 4, 5, 8, and 9 flows exceeds the allowable steet capacity. Inlets will be installed to intercept flows. Detailed analysis of hydrologay and hydraulics is found in the Appendix. Table 1 is for calculation of basin parameters. Table 2 calculates storm flows for individual basins. Table 3 is for the design of the storm sewer system. inlet capacity calcualtion, street flow capacities and riprap designs are also included in the Appendix. The 100 -year flows are calculated in tables 5. Additional improvements to handle the major storm are not required. r I gRfl;F'ECT ROAP ;lD - ^GAJ$Cf ;T!fDY 2 :7;— of C�P.,Entfaticfl It Ti T Ti = 10 !voth %5 5;qpe %33 Tt = T,iyel — ---- -------- -------- — iap.d Easir, '-eq. t h Ti 4 5W 31 1600 f "X) N-0 0, tc 7 o 4f'w I VXJ I V . K 4 C, 1.1N 0.55 15.23 ,�(B: R5-017 mg.,N I WIS , a a., n el w e -xi �Ve i . . y It kea X 20.11 50.1E 0.50 1.50 11" 1. tM) (1, IYJ 4. K. 0.50 9.50 i 50 1.20 2.20 CK !. 1(, 2. fY) M.0 !.10 1.10 2. Tj 12. i)? i (j. .) FIRIYECT KIAD =10 LFA!hrf S?JAY I�Irj� n5.�11� �� ny 199E Ir+Oc u r�Y �C1e�r,kS _ c*nuA F1cw Tice I 1 'c!et Time of Pi•ect Other S-t irs street Pipe Conc. Coeff. '1' Area Runoff Runoff Fur.off 1 I F'oint (ft.i "UP,.) )cis.? Inin.1 !ain.) 'C' Iin;hr! )ayes.) ,cfs) (cfs) Icfsi '. I1 -PV Canal A 2920 27.91 2'0.17 41.07 0.60 1.20 :4.18 ;t.l 36.1 :6-FM Cana! N. 6 1`_ : 19.92 8.7:, 27.15 0.65 1.70 2.8 3.1 1.1 17-9, Cedarwor_,d C y(Q L. 1.11 24.8] 0.65 1.66 M, ?•.10 b.I I !2-Cedar,+ocd F-2 .00 :7.6! 0.IYJ 27.61 0.0-•0 1.71 4.K. 4.1 5.00 9,1 f as :'841'r� F ; ,tit '1.61& 0.56 77.16 (L`.Q 1.27 ff,`6 9.7 2, f; 12.0 ! :8 rccua F 1c r• . _ `.56 29.26 0.K IU 2.9,. .6ii 5. Cj I I :4-Eatpshire 0 9M, 1.60 0: 74.61 0.`.q 1. 2 4.B 2 1,50 !rl ? :5-swth Taft E 14i: i.;r: 11.67 11.61 0.95 2.40 1.7 -1.7 3,9 '944orth Taft a 1�C�l 15.23 12.09 ;.0.31 . 0.65 1.42 10.5 7.7 2 2 IM i 11 7-'ALL ! 11 -------------------- - -------- - ----- - - - ----------- - - ------- .ant: �n or, I. �' Ye!ncity Mrau!ic I 2rikind IqvEft Elevatices Lenoth 'Via, e maini- jos Fl cm Full F I cm @ 0 :Ine EEL i f hc E, ev. DLA I it. . ) !in.) !;Uft) n (Lfs? cfO it. N He!.) !ftiftl I---------------- -------------------------------- 1 1'-6- O E.74 B. " 4 55 18 0. Mo 6.'2 C'. K 4.i5 B-9 H4.4! 0 5.09 -,'.b 21 C. -X17" (1,916 10. SO I I . 1) 21 C.83 4.9U 173 97.72 *4 5-8 1 Q'.61 KS.41 3,36 21 1 0. 'XnP 0.016 !MO 1(`. 64 1). K 4.81 U. v(1A8 9S. 26 1 Ph' B-7 61 E9.41 7 C, 24 U,UIq i.016 15. W HA 0.7b M5 0.v10 ?1-46 A B K '0 E6.9! IC 71 240 24 0.01"A 0,016 2.10 iMl 0.84 6.47 0, 0 F. '15 1 16 6 7Q.96 1) 240 24 0. (1177SL26 H e-4 :b. 79. 7Q.1, v y0 A I P. R, I9, ').?1 7.55 !).Al to Q-) 71. 77.97 77,77 1 11-t 24 9,01A 5.016 la."o 12 24 C'itpa 79.44 Al B-2 - 77,1,19 X) 77.4-.9 27 0.0111 21. B0 n' I-, 77 IM4 8-1 K-. N 74.% 74, O-N65 U,016 27-04- 27.14 U.K (r. 7bP4 i iLii)Lt? 7 IKI 14.0 1 (K? 1XV 0. 9! 6 27.04 '-27 3-6 .7 f, !(67 76.1b HLE T �l !14.5 11 110.15 L)LITLET 1 ! 1.4 !:Oe. 94 IOB. 54 141.5 70 0. OOP? 0.016 -1.00 0. 85 99 Ill.,.)6 �k?�SFECT iC9;u 31D - CF,�!tiAbE S�uvY dv8: � DI1 '4nCN 1rE>R TAENE - !Y HDPCLCC,'/ CALULWH iS - BASIN 1�CEN.1i! s4 ;!ii=iEnR! 1T10e J.' ::OCentrdtl CO Tc I = Ti + ?t I Ti = I.S7 1 1.1 - C i OYKI and lenoth ^.` i Sloe '.33 ' T; = Travel Length / 60 + I :hannel vel:u tvl Tital Cverlan.d Travel Channel , Charnel - ----- Basin Lenoth :e-lath 1-,gth Slxe Cae*4. ii Slwe Velu:ty Tt irea •. A :(.-0 242') I.X) 0.6 ^.91 l.ul 2.s(! 2017 :Cj.!B 1 B 1`_d10 500 10W l.'00 0.65 !9.82 I.CO 2.60 8.33 2.8 G 600(� :dU !!V 1. C) 0.c5 23.70 0.5) 1.50 1.1! 3.(4 F-2 ;F.V 5Cd 0 0.?5i 0.5 27.61 0.00 4.K. F-; !I:a) 5d�0 `uJ G.'00 0.5 31.60 0.50 1.50 5.56 15.28 F INO 50 5W 0.500 0.65 23.70 0.50 1.50 5.56 3.ii) 0 9C-0 M W) 0.5d-0 0.5 31.60 1.20 2.20 3.03 4.P0 E 14W 0 14N 1.K.) 0.95 0.00 1.10 2.00 11.67 ;.70 8 I IKA) 5W 1450 1.1X) 0.65 1B.2.3 1.10 2.00 12.(�8 10.`4) iRCgECT 1-1-AA cID - .'AIWEE FITY T�P_E - `1 JC-P: urN? .Y P !9K .-IC1EY CALCCLAT71x1 - l: A . :iS i ix) - ,Ew, 1 ---- -- --- - ---------- - --- ---- ----�-- - ----- Fl,* L * ! point :1-FV CANAL S. A L"-FV Canal Y. 8 7-k..edancccA C ��,-CMa 2Pr.ti G :24-aua F 4-+a.'M5h.ire D :5- cr lh Taft E '9-4orth Taft 6 Ir.!et T.me cf Cast 70e So I i®e `street PiPP Ccmc, Cceff.. ."I Tree Roof RuIcaf Runcjf I ftJ !ein.) (oie.l !min;) 'Ain.) T' 'in/hr) (acresl (cfs) !rs) !cfe) 1 - - ---- - --- --- -------- ------- ----- -------- ----------- --! 2i2') 20.91 2P. P 4,.07 0.75 :.45 50.18 I?9.8 129.P I !;rxr !9.82 2-1 27.I1• 0.81 4.40 2.9 5;'0 __.71) 1.!! 24.P1 ".F1 27,5! P... 4.40 4.P: I:.? !(., ?1,M `,. 5 ?'. '.5.: 1'...41 YJ) 3L5C 3.43 34.6 4.8 11.4 !7 .C(• 141:0 0.00 !1.5? !!.57 7.(v? !.? 14.! 1?9,4k) 244.5 !?`_a! --- l8.23 ------------ 12.13 _.U.31 =---------- 0.81 M6 1P,5 --- T5.5 -------- 294,.' - 249.0 - --) / 0 i/-aL J0O YET F-LON,,/ 0/�/ -TRE 500TH S 1PE OF P9OSpE-cT T 4,=)/APS14If -(>` f�D. A/ /zc(. b c�r s)l,\) 1=-Z = J3.3 G�1 S1Pl F-5 = .3s..3 ci J %T"qL _ l 0't, (5 c-;5 TAT M"no" , a J W Z U 0 O W O a N �+ Z obi z z a W m J v \l l 1 \ d N u n 0 r I rl 8 W a O cc a 0 U J Z 30 S.D. M H ,• b m !•roM1q II � 5=00.44% �Q HAMPSHIRE ' ROAD— � a, - � I - �`•;. I f U I �, a o SAW CUT� ul O 5=0,4% 61, j9I� _00q b' o ' i — HAMPSHIRE ROAD _ S= .40^. e o 6005 _. oo F n riZ. iy n u� o _ _.. EST . W E%19T. GRADE ( YP) e o ' PROPOSE) vl + GRADE ( YP) c + CENT =R L1NE PRC FILE n m � m 6q0 W W v Y n 5=0.409. _ o m n + + n t +6 O — W O ry A 4 L 1. FINAL DRAINAGE REPORT FOR L(Lk F A I ['\'(J 0 4 rC, CITY OF FORT COLLINS COUVITY OF LARIMER SI-Al-E OF COLORADO November,.1987. Prepared by - Parsons Associates Consulting, Engineers 432 Link Lane Plaza Fort Collins, Colorado 00524 Project Number 63.10 WOR FINAL STORM DRAINAGE REPORT FAIRBROOKE S.I.D. FORT COLLINS, COLORADO GENERAL This report, in combination with the Drainage Map accompanying this report, the Fairbrooke S.I.D. Design Plans, the Brown Farm Preliminary Master Drainage Plan (Sheet 18 of 18) prepared by R. V.* Lord ed_Assoc.i ate,s,., _I_n.c. ,. AUgust,._1971, and Volume I I "Preliminary.Design Report --Diversion of Storm Water Runoff Through Irri-g�t_i_on-Canals-froni Mulberry Street to Spring Creek --Fort Collins, Colorado", prepared by Resource Consultants, Inc., July, 1980, is intended to describe the procedures and results of a . drainage study of stormwater runoff generated by this project and adjacent" properties. The proposed development along with the required drainage improvements are analyzed in accordance with the guidelines established by the City of .Fort Collins' Storm Drainage Criteria Manual. INTRODUCTION The purpose of this study is to determine the quantity of stormwater unoff.generated from the development of the various tracts within the Fairbrooke site, along with adjacent upstream property, the manner by which this runoff. will be accommodated by the Fairbrooke project, and how t.hi.s relates: to previous studies as outlined above. SITE_ DE!aCR'1!`' i 101d The site is locgted in the i./'c'. OF Section 21, Township i North, Range 69 Lest, of the c,th inch. �1, MeridiLn, Stai.c r::f Colorado, Cyunty of l_�,ri.mr=: Ci{.y c:,f f=or t: Collins . Thr_ �airlarookc, project r_onsists.of 99.42 acre:_: Wrest or leers and in boLUICIErJ by Prospect Street on the north, T a-F L I-ii 1.1 I oad on the east, The Brown Farm development. and Aspen Heights P.U.D. on the south, grid I:.F:r- Foothills' West development to the. west. The sitea is:: presently Unfle_•veloped and is used agricultUral purposes. The. exi.sting -drainage north cruel east crt slopes ranging from r'r.8 to P1 easa::t: Vr:.il 1 e.y and Lake Canal f i nws through to south. PROPOSED LAND USE f or to the The the property from primarily pattern is 1.0 percent. north The project iss planned to consist of tracts on which varying roposed land usages will occur. Several of the tracts will have cownhomes and patio homes with densities ranging from 6 to 7 1/2 units per acre. Other- tracts are proposed for apartments on which the density will vary from 0 to 12 units per acre. The remaining tracts will. be used for a day care center, a church and a detention fond. HYDROLOGIC ANALYSIS The Rational M(Ahod has been uti 1 i.:_ ed to generate stormwater runoff flows for the 2•- and 100-year develupr d return period storms for the various tracts in Fairbrooke, ft,_r Drainage Map defines the basin boundaries and the design paint , ,:u-id Table 1 summarizes the r 6sults of the hydrologic_ analysis-, of ifir�ta sub -basins. In addition, offsite stormwater from the Drown Farm development contributing runoff the the open channel along the south side of Fairbrnoke west of Hampsshire Road and the runoff in Hampshire Road have been e�timatced. It should be noted at this point that the calculated flows in Fai rbr-ooke are, apprax i m,�te due to the fact. -that the interior dr-ainagu. patterns (street layout and building locations) within the individt..tal tracts have not been established. The calculated runoff quanti.ti.ets, however. ZISS.Lune fully developed conditions using a runo r f c-mef f i c i ent of 0. 5 i concurrent with the existing RL & RP zoning. The ?�i.kj..erns of flow and the basin. configurations as con alned hLrein should be maintained when actual development occurs So as .to not advearsely affect the improvements proposed with the - Fairbrook:e Special Improvement )District. DETENTION The detention pond for Fairbrooke Special Improvement District wi11 be designed by the City of Fort Collins Storm Drainage. Div:i=;ion, and is not included as part of this report. a ioil c C OSS 14,e)TC1qFp IgRr— fS- OFF5)TE. \ —"•� BASIH F-2 �-,BASIN F 5\ \ \ \ \` TRACT 4.03AL -BA-51N F-3m b BA51N F-1 AL . ,1• —,� •�� • a \•� ' !• BA51N F-9 CR0-55 CHECKED A);�EA 15 NURTHBROOKPHnO HOMES 2Sa. � / • oesiu{ romr g (Tye) TRACT •�- fra T. aCT Z 1 a a>••C .26 AL A c- C = ' • SIN F-la) 7�� •`• O • / Tp.R •„ .~• I BASIN -l6 ` NF-3BASI� Z LZ5 AC- ` \ (921 AL �.� 2.00 AG eZrtP 1• Is ao BASIN F-4 •,I.� 25LAG •.\ _ �� J '��—� —mow BASIN F-1-1 TRACT c' 3.08 1 BASIN F-7c / AL SIP GE a q � � ,1012 P tic i "ACT 9 BASIN F-B 13.41'. AG. �EAIRBROOKE S.I. D. <--4 rA DRAINAGE MAP �— P�f=50N� pLA7�l I r.....00ac s..o. a a~� .•.ry: No Text "AYVr Ad U fe TC M ]YA _ e ' _ 0 �' Lr� x+—� NEST pA�PEtrl�\ OPo9ED [er • Am/i K.. 1 �+E�i,.Y��aa SCfiLE' l"=50 24L- Eav'01 Z7� Pip n9w ]L— Eel _'Li "__- -- .. ._.. __.. 0R I -- son 1 ' so[ III 111 �_ SOo t I III III '1 _ man . ° L iA ,.L �PU. Voris,off "IT III xl A 1 li /I .n n".'vfi° I III ~T O III // �' ,,.I M t r 1 E a 0 O ,. ` O I 1- ''b Ili. y p it �. logo}11�� 8 Q - _ — A u I OU Pop is i OP 11 mE ^� °rob f14 /� sl' r~t _- JSY f fR I ® n517 so P - i IIW Y a I) las so Jp z4 �t� a, .. � O �AI 0 1 II v v I 0' _ +� h 1143 ,11 III V Id/If•, . , V � e w Ivl y nl c ati O O,I O \ JI f Tc. 4 I I'm,�1 ® Iy`r�].i.tl yl .m a. A 10.T O , 1 Is liI eL if 77 +1 etc I I c rT /� r� ` mLxD Af J T F I low �� ca.tt> jE�va I 4� w--ReilWillrl�p ,� r ! ,,,r�•• 12.. A cm cnC P? cgomae NTRo -:. o i so / I LEGEND [ `'* 1 too ---- EKISTING CONTOUR FLOW HT cOry GCnI rOATrON POINTS 1 I ]y FINISH CONTCUF- E VR FLOW /OV YR F4% / I Qsxw[F ra .i, ee.0 ci, .. ( I (711s) EXIST SPOT ELEV, Q1 I,rtD > C e+, j0 o i[ 1 1 "Co cINISN SPor ELF✓ 1 I �suamR Ia, .+' JIM Ci, 1 F == EXIST CURB ©PIPED U 99 .� I✓ lI I PROPOSED CVRO Qj 1 7 , is r S, 1 ♦/ �—sD� veomoseD s>eRn pRwla, INur, 1 ul Q , + ; , 1_ ., Y O/RECTIO nI oc FLOv ©suErnae 01 509 Og51N MS.; AReA IN ACRES ©P)PED d951N OOUNORRV y! 5.) �.c 4�- ® ORAINIPL =PNCENMAT1ON Polew As l,b • I TF aic /OP FO vnoAPO" EceL ®A 1 c zis SuxxACE I ] if IOE.e . f' DRAINAGE SUMMAR✓ p t - SITE IS W THE NNAL IMPOR TA110N SiVOY RCA 411 aIG c{, v st r[,A GROSS RF-- ZR Ac. !� NET REAG.IZ AC L1 AG. LSill, 2.36 ,n / ,< e[ o. Eo M� 0.G c(I ,. +• 94[1. ..'I D.0 CO.+r[��r 09VEL1• eC OCVELOPEO G+ O. Q♦j MAJOR ORNIf.Mi GECHANNEL JMFi<F 1, c;f [A� •59-1 i, FOR BROWN ra A .RM AND [a' ^ pNOO NO ON SITE OP TF-/�'+lG^' IS R[p'J14ED. /� PIPED FAIRSMOOKE O�' fv� f =IO DETENTION IS Ru „rlrn V .D L.7 -�9.Vf ]V., cfCPero AS 0 2 C 2 LL U J � t/ u, SMEEi xLVEA 2B a