Loading...
HomeMy WebLinkAboutDrainage Reports - 11/13/1992 (2)nd ScJ�Vtit�-rt'n� I CON i r2 ev; ewEJ Final A proved Report Date r/ FINAL DRAINAGE STUDY FOR REPLAT OF WEST ELIZABETH PLAZA P.U.D. FORT COLLINS, COLORADO ndmnrh FINAL DRAINAGE STUDY ' FOR REPLAT OF WEST ELIZABETH PLAZA P.U.D. FORT COLLINS, COLORADO Prepared For. MocGregor/Wathen Construction Company 2267 West Yale Avenue Englewood, CO 80110 Date. September, 1992 Project No. MCGWA-92047E-01-321 CONSULTING ENGINEER Landmark Engineering Ltd. 3521 West Eisenhower Boulevard Loveland, Colorado 80537 CERnF/CAflON 1 hereby certify that this Drainage Study for The Replat of West Elizabeth Plaza P. U. D. was prepared by me or under my direct supervision in accordance with the provisions of the City of Forte Qtgns Storm Drainage Criteria for the Owners thereof. //-4�,-9z Martin Reynolds Colo. P.E. 23847 yq` TABLE OF CONTENTS SECTION 1 - EXECUTIVE SUMMARY Introduction .......................................... 1-1 Findings, Conclusions and Recommendations ................ 1-3 1) Offsite Drainage and Existing Drainage Patterns 2) Proposed Onsite Storm Drainage System 3) Drainage For Future Development on Lot 1 and Lot 2 4) Erosion and Sediment Control Plan SECTION 2 - PROJECT DESCRIPTION Location and Project Description .......................... 1 - i Vicinity Map .......................................... 2-2 SECTION 3 - DRAINAGE FACILITY DESIGN General Concept ...................................... 3 - 1 SECTION 4 - EROSION AND SEDIMENT CONTROL Discussion ............................................ 4-1 General Erosion and Sediment Control Measures ............. 4-1 APPENDIX EXHIBIT A - Drainage Plan SECTION I EXECUTIVE SUMMARY This section explains the purpose of the Drainage Study and presents a summary of the major findings and recommendations. The development of the recom- mendotions is presented in the following sections of the report. Introduction The Replat of The West Elizabeth Plaza P.U.D. is a proposed 3.32 acre develop- ment in Ft. Collins, Colorado. The development consists of 2 lots and is located on the North side of West Elizabeth Street, approximately 300 feet West of Taft Hill Road in Ft. Collins. This drainage study addresses drainage for a proposed Kentucky Fried Chicken outlet to be located on the Southeast comer of the site and identifies drainage requirements for future development of the remaining portion of the site. The purpose of this Drainage Study is to provide comprehensive drainage planning for the development. This includes identifying and defining conceptual solutions to drainage problems which may occur onsite and offsite as a result of this development, and identifying drainage structures and other drainage features which should be included in the development plans to provide a complete, safe and economical drainage system design. A fundamental objective of this drainage study is to develop a visionary drainage plan that can be adopted, implemented and controlled effectively. This Drainage Study evaluates the existing drainage patterns of the site and identifies future drainage patterns for the development based on the Replat of The West Elizabeth P.U.D., the proposed grading plan, and other existing site constraints. This includes evaluating historical runoff, investigating routing for design storms through the development, determining what improvements and structures. are necessary along with required design capacity, and evaluating offsite drainage which may affect or be affected by the development. The policy and guidelines outlined in the 1984 City of Fort Collins Storm Drainage ' Design Criteria and Construction Standards Manual have been utilized for planning drainage facilities with some modifications. A major storm drainage system and a minor storm drainage system have been planned and designed as ' shown on the accompanying Drainage Exhibit. The major storm drainage system is designed to convey runoff from a 100-Year storm through the development in ' a manner which minimizes health and life hazards, damage to structures and interruption to traffic and services. The minor storm drainage system is designed ' to convey runoff from a 10-Year storm, and/or nuisance flows, through the development with a minimum disruption to the urban environment. A previous Drainage Report entitled `Drainage Investigation for West Elizabeth Plaza P.U.D., Fort Collins, Colorado', prepared by Landmark Engineering and dated February 6, 1985 has been used as a reference for this Drainage Study. 1-2 Findings, Conclusions and Recommendations The principal findings, conclusions and recommendations which arise out of this Drainage Study are presented below. These findings are supported by the detailed material presented in the body of the report. 1) Offsite Drainage and Existing Drainage Patterns The site is located in the Canal Importation Basin as defined on the City Master Drainage Plan, and runoff from the general vicinity of this site drains North to the West Plum droinogeway. The West Plum droinogeway is located about 400 feet North of the site and drains in on Easterly direction following existing downstream drainage patterns. Due to topography and boundary conditions, the only offsite drainage that currently drains to this site is approximately 600 feet of street drainage from West Elizabeth Street and about 0.45 acres located adjacent to the West boundary. The street runoff flows in a roadside ditch along the North side of West Elizabeth Street, to the Southwest comer of the site, where it discharges into on existing onsite retention area. As can be seen on the Drainage Exhibit, the existing site topography includes a depression between contours 75 and 76 which act as an onsite retention pond. Calculations, included in the Appendix, show that this retention pond has more than enough capacity for the 100-Year Storm for the tributary onsite and offsite properly. Normally_, temporary onsite detention is to be 2 times the 100-Year volume needed by the mass diagram method. However, for the purposes of this report, the triangular hydrograph method was used to approximate this volume. Because it is on existing condition and the onsite 1-3 improvements meet detention requirements, there will be no significant change for this retention area. It is believed that this onsite retention area was created partly as a result of development to the North and East of this site. Because the property to the North and East of the site has been developed with no provisions to receive drainage from this site, and because of the capacity of the onsite retention area, this property has become 'drainage locked', with no outlet for storm runoff. Currently, storm runoff drains to the existing retention area and then evaporates and/or seeps into the ground. It appears that in the event of a very large storm with a volume greater than the retention area, the flow would be toward the Northwest comer of the site and then North to the West Plum Drainage - way. Therefore, based on the above information, a downstream drainageway will have to be acquired for this property before development of the entire site can be accomplished. 2) Proposed Onsite Storm Drainage System Based on the City of Fort Collins drainage policy the allowable 100-Year release rate from this site for developed conditions is equal to the 2-Year historic peak runoff rate. As can be seen on the Drainage Exhibit, the proposed Kentucky Fried Chicken outlet will be located near the Southeast comer of Lot 1, and based on the Grading Plan, approximately 2,500 to 3,000 cubic yards of imported fill will be installed to provide surface drainage away from the building and parking areas. It is proposed that the peak release rate from this site be controlled utilizing onsite detention areas as shown on the Drainage Exhibit Storm water will be released from the 1-4 detention pond(s) at a rate equal to the capacity of the outlet structures ' for each pond. Orifice plates have been designed for each outlet structure to control the combined release rate from both ponds to less than the allowable release rate for the site. The detention ponds have been planned and designed to allow expansion for future development. The size of the detention ponds and the proposed release rate has been ` determined based on practical use of the landscape area for the Kentucky Fried Chicken site. As can be seen from calculations included in the ` Appendix, the proposed total combined release rate from the two detention ponds is 0.65 cfs, which is below the 2-Year historic peak runoff rate of 0.93 cfs. ' Because of the proposed grading plan and practical limitations relative to ' the grading of the driveway entrance and street, approximately 14,985 square feet of the site will not drain into the detention ponds. The 100-Yeor ' peak runoff rate from this area is 2.25 cfs. A variance is requested for the requirement that this drainage be detained onsite and released at the 2- Year historic rate. It is proposed that this drainage and release rate be taken into account during drainage planning for any future development on this site, by intercepting West Elizabeth Street drainage and routing it ' through future detention on this site. The onsite storm drainage system as shown on the Drainage Exhibit, utilizes surface drainage facilities to route storm water to the detention ponds. The ' East detention pond utilizes part of the parking lot for its ultimate capacity before storm water overflows into the driveway and to West Elizabeth Street. 1-5 Drainage patterns for the remaining part of Lot 1, Lot 2 and the offsite street ' drainage will not be affected by the construction of the Kentucky Fried Chicken outlet. For the interim, until any portion of the remaining area is ' developed, drainage will continue to flow to the existing retention pond. 3) Drainage for Future Development on Lot 1 and Lot 2 Drainage planning for future development will require that runoff from the ' undetained area in the street and driveway for the Kentucky Fried Chicken outlet be taken into account so that the total 100-Year release rate from the site is not more than 0.93 cfs, or that downstream drainage facilities be upgraded to handle the additional flows. The following is a discussion relative to options available for providing ' drainage from this site as future development occurs. Option 1: Construct an outfoll line to drain North from the Northwest ' comer of Lot 2 to the West Plum Droinogeway. ' This option would require the owner to obtain a drainage easement from the Northwest corner of Lot 2, North along the ' West boundary of Sunray Place P. U.D., or on adjacent proper- ty, Jo the West Plum droinageway. Onsite storm drainage Icould be collected in a storm drain system that would run adjacent to the North and East property line and discharge i into the proposed outfoll line. An inlet could be installed in West Elizabeth Street near the Southeast comer of the site to ' collect drainage from the undetained area of the Kentucky 1 1-6 tFried Chicken site and discharge from the West detention I pond. The East detention pond could discharge directly into the proposed storm drain system. This requires the future iinstallation of a drain pipe within the East detention pond and landscape area for the Kentucky Fried Chicken site. This option might reduce the amount of onsite detention required for ultimate development of this site, depending on the capacity of downstream drainage facilities. Option 2: Expand the detention ponds to limit the discharge from the site to not more than 0.93 cfs and reduce the peak flow in West Elizabeth Street by intercepting some of the street drainage and routing it through the West detention pond. This could include a trade off with upstream street drainage for the undetained drainage included within the driveway of the rKentucky Fried Chicken site. Option 3: Fill the entire site so that it can have onsite detention that discharges at Q2 into the curb and gutter along West Elizabeth Street. 1 There may be other options available depending on the type of any future development for Lot 2 and the remaining portion of Lot 1. ■ 1-7 4) Erosion and Sediment Control Plan The Erosion Control Plan for this project during construction consists of the following: A) Construct the detention ponds as an initial part of construction and utilize the ponds as a sediment trap until construction is complete and the site is landscaped. The contractor will be required to control the grading so that runoff is directed to the sediment ponds during construction. 8) Install temporary gravel filters and sediment traps within the detention ponds to filter storm water that is released from this site during construction. i-3 SEC77ON 2 ' PROJECT DESCRIP77ON 1 This project description defines the limits and general topography of the study area and provides a description of the proposed development. Location and Proiect Description 1 The study area for drainage evaluation is the area within the boundary of the replot of the West Elizabeth Plaza P.U.D. and the surrounding areas which drain to the site. It is located in Section 76, Township 7 North, Range 69 West of the 6th Principal Meridian, and is within the City limits of Ft. Collins, Colorado. The site is ' bounded on the South by West Elizabeth Street, on the North by Sunray Place P.U.D. and Les Chatelets P.U.D., on the East by a commercial development, and on the West by open pasture land. The proposed development consists of 2 lots on a site area of 3.32 acres, and the topography generally slopes from the Southwest to the Northeast at about 2%. Historical drainage is by sheet flow to the West Plum drainageway. However, adjacent development(s) have created a retention pond on the site where storm water evaporates and/or seeps into the ' ground. A Grading Plan has been developed for the proposed Kentucky Fried Chicken outlet, and has been used as a basis for drainage planning. 2-1 i a a s a I SECTION 3 DRAINAGE FACILITY DESIGN ' This section describes the drainage facilities shown on the Drainage Exhibit and explains how storm water will be routed through the development. ' General Concept The overall drainage plan for this project is to provide storm water detention for ' the Kentucky Fried Chicken outlet where practical, and maintain the existing drainage patterns for the undisturbed area of Lot 1 and Lot 2. The runoff for the undisturbed areas, along with offsite drainage, will continue to drain to the existing retention area where it will evaporate and/or seep into the ground. Several options have been outlined in the Executive Summary section of this report relative to providing drainage for any future development on the site. Drainage for the proposed Kentucky Fried Chicken outlet includes routing storm ' water to detention ponds where practical, and releasing it to _West Elizabeth Street. A variance is requested for that portion of this site which does not drain ' to the proposed detention ponds with the understanding that this runoff will be taken into account during drainage planning for any future development to limit ' the total release rate to the 2-Year historical rate, unless other arrangements are made. The remaining site area for the Kentucky Fried Chicken outlet has been broken down into two separate subbosins which drain to a detention pond releasing to West Elizabeth Street at a controlled rate. It is proposed that the release from each detention pond be controlled utilizing on orifice plate as detailed on the Drainage Exhibit. 1 3-1 ' SECRON 4 ' EROSION AND SEDIMENT CONTROL ' This section 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, and swoles, may cause high localized erosion rates with subsequent deposition and damage to offsite properties. Uncontrolled, such erosion could destroy the aesthetic and practical values of individual lots, and cause damage to downstream properly. In general, the erosion and sediment control measures may 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 during any construction activity which occurs at this site. General Erosion and Sediment Control Measures Minimizina 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 it is begun. A temporary cover crop, a permanent vegetative cover crop, or other landscaping should be established in the disturbed areas. Revegetation 4-1 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. Reseeded areas should be mulched with straw or hay to protect exposed soil until vegetation is established. Controlled Runoff Across Exposed Areas: Where practical, construction may include constructing temporaryswoles to intercept and directstorm water around exposed areas. Swoles can be constructed to control surface water which collects on exposed areas and prevent gross erosion in the form of gullies. Riprop or other temporary erosion control devices may be installed to control storm water velocities across exposed areas. Sediment Control: Temporary and/or permanent sediment control devices may be installed at the major drainage structures and flow concentration points shown on the Drainage Exhibit. Such structures can be used to intercept and trap sediment once it is produced and prevent it from getting offsite onto downstream property. 4-2 APPENDIX CSC« NO• trCcwA-O2o532U1-37-1 �L�'ZP� • �'.u• p, Fo? � e ol.t\ti,S�-otu�f��d , Z. EXISC\�!G CoNp\�\uHS RoF- otisi-VEE APC'R KC7JSL5 PtND OUT GLiIIO\HC,j = S5U:J Sr pR�V F 1.,,,1�`tS � Gr=RvCl, S�bO S F + t` C3P�S� C)"A �ISI\rAG Co>`\CL�tv.�P.�\oN \Po\t--r FAT ti! —7z (' 11CF07LI�- 17�t�1c�p1Y,L�v� I�ib12717 %AHD Cyr' bF /`?rl= S/%FJ CF = 6 v. -t u Do = 5-60 FT SLC>pe _ a.. _ --i— _ 0.25% 160 ={ uo s = �.����eo�t ��s�C�roo� = o•�z% S60 DI/z/S1/3 �i ion I/Z C- 70 "1 27 C/• I - C25�C �2Z/3 EWST\4,iV- C.-ortoXTXoNS e-oHT. f�T Tom_ �t2 miN AT Tr_ - 31min C? = C47A =ioo- 3.55 )i)/hv QZ = 3.3z�) = 0,93 cFS 4S = C•2�r�� 1."70�(3.32� = 1.35 IFS Qto = C.24�L2.1o��3.32� = 1.6,7 CFS Q i oo : (2 y� C/.25DC3 55)C 3.32. = 3.5Y' of S F./o ir,Jhr 21 �Ro �bSFD C o N o iZlo� frog O N S �E ��� Q?�Sk�, oN"CYtt R`3ovC- 1NFoRn�'4.Tn�,� "11-tF ��L {°�l\ol�.�f��lE RFLF'(�SC rah l��Tll�^,ATF �L`«ZoP�O coNo��otiS iS 0.93 cFs CQZ, F�Lorv\ GC SLt ot-� �C ��A�NP.CC Qch�ro�T, Aao�� j4`i$5 r Squ ARC- rcr-T of Tmt:- NOT DZAiN 7D 7?7F-- PR4P35Ez ��tnTtoH ����TtFb Is �t �-�yvttLC-1'�,�rT �i-trcT i�(LA�N Ptve' F-Row� "�=,.•tS S�S3-�#�S�N 17 1-S 7FR-oPcS, 7hC- M �F-E��HC Tm� of �-ohC��e.ToH Fob �itoposE'fl 1�FL S l� � _ Zito ' @ 1'b T < : l . a7 C 1.1 - ° S� C �16� _ �• 77 ` -3 _ ;Z-c_ «< by »0 oaa /46 SAY /2/J�iN -Z> tiE 6.ss,;,/h� 8.3'A Ah ' 0.71 crs e 1hr�� 7l IESE r=l 73 c 1�. CTA 0-y I1-vis 11 ' 3Cct�vs�t �FCI\E�\ri\HCr �N��Rop� F�R�� of 1i5 SlZ CvR2 ��4 "p�t��hj 7b tTlj- -,Z)RLN\\-ANCti�z rF�� �tit� lS �upoSl=� 11-1 �T �-t C- �o � 31 •N C-"� �Z�� F �-1�'�F Z}-1 �j L. 4z. q4! E'P.ST PoN� C-�•�C- "� of O.3S c� . -73•� SF RASFD ot4 Pcau 2/605 S'= G = /i`2SS� `15J C735a C . 2b� O , 67 Z! 6oS I�oo Cj�C-N, Q100 VOL IN \[OLour Vol. RED Tnin lnJhr I•z5X•69�c r36 �o •3 5_Fs� 0_Y281_ 3.16 /900 Z I D /690 15 6•0 o.yz8 Z.57 E313 315 1998 30 v.2 o-.y28 1.50 324`0 �6lp 40 3.5 O-Y28 1.50_ 3660 8S`D 2760. 50 3.0 ©.yZB DSa 2790' (60 E.6> o-yz8 399( IZ�o_ 2736 70 213 0.C/o a p.,9a -///6 I`i7o Z6V6 z-os 0. y28 o: 88 f22 f 6Go esyq W ES-r -POND . .- 131KsVtA dN N VNII- VY\NurA 7-�tC- of s 7 �lC- P�R�� of GR1�sS = 52D6 SF � = �62so� 95� t �SzoC�C -20� _ ©• 6/ _ rn�n �hl►,� Cc+A 6�i� 125�C.2b3� Qtoo cE ��� VOL ouT ec 0.30CF5 fr3 von 26Q'r fr' /O _ 7. St 0• Z0o 1 46 88a 1 2,0 70 6 /s 6.0 0,200 1.20 loan 270 8l0 30 y.2 0.000 . p g`F - 1.5 1Z 5`iD q�Z yo 3,5 d •Z00 0 .7D I (DSO 720 50. 3.0.._. 01000 O •CEO _ 1 ao0 `Z 00_ _goo . 60 2-6 O.2D0 0.52 1 B12. I OaC7 79Z 70 2-3 0. e0o O- Y6 193Z IZGo G7Z So z.os p.000 440 5Z`3 M�N�r,vv� Vot-urnr '?J�'D = 97E �T3 I G »> coo coo �LP.ti\ �l�luw�C �F �=NToti��u�CS 3i R� ot� Ff�R���Hv EL.� uta rr,� 7S.o 7530 - -- - %7-o z86o / 357 76-0 G5 12Ts so,7Nt U�:QETSZ o_C L'— c7, _. 77.25 a16:0 77.0 if- 070' 76. 3 0 Coe ova NNN ZZZ Ong00 `�2 Q 0 -C> ESI 6N C) R\ F cC- I .PAST -,;L) C7z- N-7,� (Z5 i)t-A Z� - -- s� off 7t�,e Ido Cz ��\c_n t�� �NZ- ���.� 3C Aix 772D �I�S Fo o� o � \ F 1 ,� F E'�•� f\"�? O� -- 4 = C� 4� � ZG �( LS A0.06YS f7'1-- USt 3 X 3��t PE1AkIz- - P� •0677 C-T 0 97z- TT3 PST- 77.2 . -------- JZx3z-vc 0•78� C 3' OPFNlHU� H = C-77. 2 — 76.3� }} = O.O 65J Z _. w s — l hv — OPc-.N)NG 0-0651 fi z off. p,93 I i�1WruA� OFFS\Tti-�2A�r�i�G� ONTO �'lF �t�L _ /I��h6 �Rll'jNGv\AR h'(02oC�RAP\ MCi?to0 Z„ii/ /3F vsb'D 7b APPRuwrn*TC- 77/C RFrM- 7?DN Lo lvn F . 7T /! iS P1oT PC-lz 7t7F Tr CA47 A a �T 7}�F . M lTaoo H Rs DF�ry �P`RorFD IIELN sF O F ThF eONOjTzuri PR�nr fir /.S 517z- __ �uC-- -T� C04DG�R4ft C P�tva 30u Cv1rA—z C7F=-�S\ �F Z7CuP�\Ht�c�F 1.�.>ft\�K Cv(izc��� �RY�\Ni ol-\To �115 Sim CUz C.�E�c\ sT��e� P�tiO 4��ov� o-SAS t�cEES P��TI�c�=cv� � �tF I�..�t3T GOvtioP�'C OFTS I7L- F7\-t� j3RSED oti RAN R�/ERPVF �lE�ucZ( U% T, /.87�G-l- 20J CYSD�)~ =- 3, 3----- - - -- -- 1 Ioo= 7-� ih %hr 3�o CLSPLEO oN FST \1 1..��VS1y Fov. L. Ct�T CUIPDFTn Sr/ VU�Vrr.F �z�CY.a�(bo)C1D�tUzi�Y•89�(bo)G�D) 1160 -FT3 ----- -. . . rZ = 1,31 lv\ �hr ZOO Qoo = Lzo�c�zsJ�3-q�C. ss� = o- v��fs Volvmt Zl-lRS'�n0.M = /Z�(•Y4)C6o)C34�t��z'Cy9�L6o�(86,= /SBf�� FjC/ST11�lr '� ��r�\�1E \lOLvrr,F of IOoYR S�R1'� iTtiZ"ON Sl.7 ltRC� �ON7XlI�7l�lG 77j /ZETEW770H Zc = 3�1 ,TL = /,37 in�hi I=o)e Q(1s7)NG (!?�/pi7761'1 �.LONGCST floc+ l`A7)r G/Zo/l'i ofFSi7F- A/ZE}3 WC--3r-� . zq C sFr- et) Ijuo= 3,9� /"A'' / TDT�I o�si7C /RCA of l015 I �Z Qz = �ZY) C/-37)X 3.3Z� E TbTm- VoLumcz of /oo tf� s7aR-P>i .Cn/z ais77,V& eo�vzv77oi�s is /7.60% t /58�f f-. /3968 =3/S6 �l3 oi-A 7\1�-- "?-\Laz nm„ Nr IR Vuk- F RN A \ %s /5,y D 7(, IS, DET6-kri7/1qFL A-S C0H-7Du4L )'c Z A fT'Aam 79 / 8290 �f�96S 76 7/6sO V = Lk t 4 Nar, �- 163 5�96s f73 l�f�SFo oNF f��oxF 1�1�o�'mRTtot�, 7rtC - loo YE��z- «r nnnRF e m 1 1 1 1 w&T CUzA�t Ste_ S\vN F\ R7 sa''\Tk CkQk)mFn-7 �R ON 7�-tE S77V�zli (S C • LI S C�D �1F CUSS SIoPE_.c�� .TF -STCT 15 f�dOyT. Z-.1 °lo-t--- n_ •o\6 n L,,j 1 t . (� . 'ZkFY , A F \ b La C,F _ T-c;JL R S7z> TLy \ -Lt4 '1-7� �_bz►j�z Y �3 BNsI;',D OtA T"r1F 1v\ roc i 1 L L, - .. AT- -DI C T l O L,� o f Tr(E CL 1-(3 F.TrV D G�-1�Tti Ok- 12 1 1 1 ' MAY 1984 LL WA .3 .2 a s C'szO.6 °/ F= 0.8 s:0.4% F=0.5 I' I I I BELOW MINIMUM ALLOWABLE I 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 obtain allowable gutter capacity. (From: U.S. Dept. of Commerce, Bureau of Public Roads, 1965) 4-4 DESIGN CRITERIA No Text O F WCST `L\z_f�'��=�',-\ � L i�2 F� - � _ U • U . 25'D Flow {�V�P�vL S�oYr = O•°l% 'V:5r'. S� ovC-�[o"C G� i���HG.\HC�vo� \rnpo�T�'o ro\ li 7?. 2 i 5 7 6. 7 _ Q1v J 1s rD � = i�C�'.x I�c� Cub�c'ds( FtCRI = •5o�X /Do = SD• 1 yd3 \� ���vut e-of\s7wxP-d(iFZ� F. EFFECTIVENESS CALCULATIONS PROJECT: KFc sx-�r- STANDARD FORM B COMPLETED BY: DATE: l0 Erosion Control C-Factor P-Factor Method Value Value Comment SED�n�Lrv� �RS�H \.o O-SO \,p O.BO R(D PoS 5 I�A��S o \ 1- o rox iy2ss s� PAC- \ Soy l 1 D 1 . O Foiz 7350 Sr - MAJOR PS SUB AREA BASIN BASIN (Ac) CALCULATIONS A 70.2 ,d- I 0•� b L Td r- ci )P- . o 17, i4255 t 1X7:So 2/6oS l>Td-P-FPc�R •SOX.SOx/x/ = 5/o EFF =�- C?Ci'-) 7'1 pp .'Isx.yo�X/oo.� 86 dim MARCH 1991 8-15 DESIGN CRITERIA 11 EFFECTIVENESS CALCULATIONS PROJECT: ICFC SiTC- -KT UJC--ST STA.NDAM FORM B COMPLETED BY: DATE: / n �, / 9)Z Erosion Control C-Factor P-Factor Method Value Value Comment 50 6E5D sF ���� Sa�� I•o I.o og 5206 SF MAJOR PS SUB AREA BASIN BASIN (Ac) CALCULATIONS 76--7 A-ZC- FP«'oiz - O• Y6 -So x l XI = yO ELF = �1- •4ox.y6'x�op = �I-(� �o d lam. MARCH 1991 E-15 DESIGN CRITERIA CONSTRUCTION SEQUENCE PROJECT: RERLv.T of W C--;T EL1745(-liI PLAZA Ru• p• STANDARD FORM C L lc F C— S I TL-' ,SEQUENCE FOR 19 RZ2 13ONLY COMPLETED BY: LP.HOPAgCiV DATE: Indicate by use of a bar line or symbols when erosion control measures will be installed. ajor modifications to an approved schedule may require submitting a new schedule for pproval by the City Engineer. YEAR MONTH MOV I DEC. I -SAti I FM I MAR I AFR. I MAY 17uml I IiXY IAL'C* I sEvr I ocT OVERLOT GRADING �7IND EROSION CONTROL i I I Soil Roughening Perimeter Barrier I Additional Barriers j Vegetative Methods ' Soil Sealant I other I I 2AINFALL EROSION CONTROL ( j STRUCTURAL: Sediment Trap/Basin ( } I i Inlet Filters OA I Straw Barriers I I 1 Silt Fence Barriers Sand Bags I I Bare Soil Preparation Contour Furrows Terracing I I I I Asphalt/Concrete Paving I Other ( I I aVEGETATIVE: Permanent Seed Planting Mulching/Sealant Temporary Seed Planting ! I Sod Installation I Nettings/Mats/Blankets i Other ITRUCTURES: INSTALLED BY VEGETATION/MULCHING CONTRACTOR 'ATE SUBMITTED MAINTAINED BY APPROVED BY CITY OF FORT COLLINS ON ' MARCH 1991 8.16 DESIGN CRITERIA C Ras�cN e ON7�Lol WN7Tz NNo 6Re.Y � FkkTFt- z GR zso , 500 SEco\�� �2556 SF .oz4�sP 370 cosh es �Ies you �tov�ma/ly TD7 9 ES77mfr7� _ 870 9rea.4le*'' OP -two op-A�ns D c0s{- of P,ropa5e4 vwcas0,res Z Sed • 4ra fs 'K 2sp = g ? c�rtiLia! �'l,�e✓S - — C?-) cosf- of tese4"oi sf4-e - f2556 s.r. x so.ozvy = �' 369,f5 tF / 'CYt2 0 s: GRAPHIC SCALE 4. ( IK lt6T 1 I lope - m N \I I S89'AO't YE $„40.05" 9 / 5905' z ,rl e 3�. 9 I I/ I G5E1ENiIn \ \ 9 v It EXISTING RETENTION \ , AREA I \_. 1 \ 1 I I �\ aa5 Ac. ham' j It it OFFSITE I \ 1 ` DRAINAGEI WNW.\ 02=0.12CFS ICI DIDO O.aaCFS m n \ _I JPAD 113P30 S.F LAT\\ 30 709 S F\� It \ M \ IN CE,aryl16M _EBWWWWWWW Wes VOLUME\SRFT) f r eowsr.1 Norse \ \ } ` 59.00' _will q \\n 0 F i. \eowl Iwo S 'orIoy. Castle d Snlly. smm RneFF F U. � flp� Aryngls y INMMstM1 ISQL)=4y Pqe PIPE We4ET MTN GP NUTS V = S=rpa Rat epi Ppvn I V. law are S ar;m 1 e. arop ae.peaw SEDIMENT TRAP wdlyp.+. a«lE, e.Rnw 1 .wwW Lm OF FORT COums, C 1 STORMWATER UTILITY b 1 YT e I for .. TE STREET N59_35,31)'W 41900 _�-'DIKE n( _3 VAGE 0.55 A0: —_— _ — -- ---- —_ — Dz 1.50CFS $ �° _ _ J EST ELIZABETH kSTREET "y . 4.89 CF.S -----_—_a`3 —z--___— S POH i; Montserrat stm maywI, AER lz.4' w.t,. P.,.. ,veo.A heel.e I, tmem m is ". MY e.,p„m -,..L seart or %,a of a wt laws or rawal War, ""I'm wasol wl Wilk a, feel I' .n]v. as co. try fail YM 1all w, IIt, lTMlml wlial I•+IT..•I T+r Rif lv 1, am momm;u overall m.ral still, 91,11111 silt far "Ill'a :WWw unnT.nWu n.m iq re.be i -I wm% ...e [e.. an I ,� yµ'y ma Mi'tToet+x ,i m vu[m of ln 9. ease and SOAS Stew L6ure( Bales 4 T.en= I APsSed leas N _ e ..:. PeFtx. Ee4s int S.BIXkEllerd fanpK. ure,a.ea Cull 'cw% ::-al Be* Twin( Rwmvi �10 r °, I RpnOffice BeOR ,!T 'CRDSS4FC7eWVIEW are Np nee w be STRAW BALE DI oe, a `�; a GENERAL INSTALL lit lt a CITY OF FORT COWNS, ( vn e ,e.., a each_ - - - �\ EROSION AND SEDIMENT CONTROL PLAN I \ 1. it Is we conesucia, a m,runsibsillyr g mew career we aLmmlau ymlavw As pNub \\ d n c Jwu Ipxl ntn m wlwaNe b ooam 4 a Tel ll Dan[O e,w ebnleL. �r m= p elm « Pppm \\ ] lYcu JWI IM1e Je WIW WRM Wm, W110,4ss the \ Thwhile bWConswcuwueftpees Jl ImttepLL TMCwmnor y.W and � c e lief5pwP pMew me veE,oE eo we mart : aJKw Mo uel plm AmI,M \ 8M 6 face ACC031, J MCanoeuv JUII NSILI Iemp,arysr...mr rn aave Je J f Ne nfJler sb,m wuu r' \ a fix,.rAad v JIv ISNpseE lmm Nes ¢Jmngcwppepm The 5.4n..t le.+[M1Wh 'llel unYlluda'pwE Tb tee is an41e¢ 1 Da all— —, r DETENTION PoND SDM.]ARY TABLM , Ie I ,u newsletter weal PONBAST POND W D _K Wahl /.e(Y 4C , whet AlTWITme r9 t Is 4� j list Yale Wow Level TIM+I- 7791,f- _� a IW Ym Reksa Rve 0.10 eR 0]5[fe S V A O Wis INSTALL STRAW HALE DIKE m ACROSS PDND Vessel Disease To All D WNrt level mA, 2mv c. Olti Cahn awa S]1F MID)A.• W12M n I m a_.. sma m Ta i.IT Ofmns r alla'OpnisP _assiessons iwpe.el. t INSTA L SEDIMENT - - TRAP /LGERTAV PLI-TER elR,—L IeN RY, —.>r bvuC1Owasheara�-"-�e� Walsall .T bflLLVpAY WGFE EAnT EPET6BITUPW F WD G2e 1.a4CFS 4 ai S ' Y 8 s;� .0=.2.90CFS 1 E did 10 I(FOR PROPOSEDppp o RS'a INTERIM DRION- SPILLWAY feR VAEi'yT OMEI.ItbeJ VOtID 0 U Z C 0 F a V 0 K G F N Z aJ 0 a. Z W W W Ill a IS 3 N 06 W 0 F O N ¢ w 3 U W Q F 2 F� Mal U W Ur Q Z 0 OF