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HomeMy WebLinkAboutDrainage Reports - 12/02/1983DRAINAGE DESIGN FOR OLD TOWN SQUARE, FORT COLLINS x 1 u DRAINAGE DESIGN FOR OLD TOWN SQUARE, FORT COLLINS Prepared for SLP, A Professional Corporation 1100 Stout Street, Suite 300 Denver, Colorado 80204 By Simons, Li & Associates, Inc. 3555 Stanford Road PO Box 1816 Fort Collins, Colorado 80522 Project CO-OTA-03 September 9, 1983 t F 1 I. INTRODUCTION ,t 1.1 Project Description ' This report presents the pertinent data, methods, assumptions, and calcu- lations used in the analysis and preparation of the drainage plan for the pro- posed re -development of the Old Town Square in Fort Collins. The proposed re -development site is situated on a 2.49-acre portion of } Blocks 18 and 19 located at the intersection of College and Mountain Avenues in north Fort Collins. The area, originally platted in 1867, is part of an official Historic District. .Because of this designation, the re -development seeks to restore the existing buildings which have historical significance and to construct additional office and retail space which is in character with the existing construction. The project includes plans for closing a one -block portion of Linden Street to traffic and constructing a pedestrian mall. A proposed site plan for development is shown in Figure 1.1. 1.2 Study Methodology Because of the nature of the proposed re -development project, several potential drainage problems were addressed. Construction of the pedestrian 1 mall, featuring both a raised plaza and a sunken theater, will reduce the overland capacity of Linden Street and could create areas where water can pond. The existing building first -floor elevations are low enough to receive significant flood damage during a major storm if not protected. The amount of flow which can be captured by storm sewers in Linden Street is limited by a low gradient through the area and existing storm sewer mains downstream of the site•which are undersized. Finally, the existing ground elevations at the intersection of Mountain Avenue and Linden Street allow a large portion of the off -site flow to enter the project area which would result in -substantial flooding of existing buildings on the site during major flows. Considering these factors, the drainage study for the Old Town project tincluded the following items: 1. Determination of the peak off -site flows which reach the perimeter of the project area through the use of the Colorado Urban Hydrograph Procedure. 2. Determination of the percentage of the above flows that will pass down Linden Street for various configurations of the intersection at Mountain Avenue and Linden Street. 3. Determination of on -site runoff for the design storms. 2 a ro k O 'o O N fD R. N r• rt m 10 r a 60"Eui AVE14UE .. 3 4. Determination of the flow depths at critical points on the site for the peak flows. 5. Evaluation of several alternative drainage schemes and selection of the best alternative. 6. Detailed design of the recommended alternative. The analyses and design of the drainage system, as described above, are based on the City of Fort Collins Storm Drainage Design Criteria, the Larimer County Storm -water Management Manual, and other data and reports as listed in Appendix A. The drainage study found that complete protection of all areas within the project limits for the major (100-year return period) storm is not economi- cally feasible. The proposed design will provide limited protection for the 25-year storm and represents significantly greater protection than is currently being provided for existing buildings. 9 I 4 II. DEVELOPMENT OF OFF -SITE FLOW The design flows at the perimeter of the project site were determined through an analysis of tributary off -site areas. As shown in Figure 2.1, contributing areas were divided into subbasins based on the topography of the watershed. The areas of the sub -basins are presented in Table 2.1. Flows from each sub -basin were derived using the Colorado Urban Hydro - graph Procedure (CUHP) in accordance with the guidelines found in the City of Fort Collins Storm Drainage Design Criteria. The rainfall input for the CUHP were taken from the Larimer County Stormwater Management Manual (May 1979). Since the east -west streets acted as collectors for the main north -south channel on College Avenue, flows from each of the sub -basins were directed to intersections in College Avenue. By analyzing the configuration of the inter- sections, the percentage of the flows entering the intersections and con- tinuing down College Avenue was estimated. The hydrographs of the remaining run-off were routed down College Avenue, assuming minimal storage, to arrive at the design flows at the perimeter of the Old Town site. The peak flows as determined by this procedure are shown in Table 2.2. Supporting calculations are summarized in Appendix B. 0 �4 40 ob w 4b .w 11 Table 2.1. Sub -basin Areas. Sub -basin 1 2 3 4 5 Area(acres) 71.0 59.1 64.6 194.7 93.0 Table 2.2. Design Flows. Flow East on Flow Southeast on Mountain from College Walnut from College Storm Frequency Peak Time to Peak Peak Time to Peak (Years) _(cfs) (min) (cfs) (min) 10 408 55 34 55 25 506 55 42 55 50 609 55 49 55 100 709 55 59 55 u III. ALTERNATIVES FOR HANDLING OFF -SITE FLOWS Several alternatives for the drainage of flows at the project site were considered. Drainage options were limited due to the magnitude of the design flows, the relatively flat gradient across the site, and the inadequate capa- city of existing storm drains. Three alternatives, which were capable of meeting the drainage require- ments of the site, were investigated: 1. Total blockage of 100-year flow down Linden Street through the use of a berm or headwall at the entrance to Linden from Mountain Avenue. 2. Partial blockage of 100-year flow down Linden Street with construction of a new storm sewer to the Poudre River capable of draining all flows from the project site. 3. Partial blockage of 100-year flow down Linden Street with discharge of ' excess flow from the storm drain through a "bubbler" outlet in Walnut Street. The first alternative was eliminated due to the difficulty of incorporating a ' berm or headwall into an aesthetically -pleasing architectural design. The second alternative was judged to be excessively expensive. ' Since it is possible to reduce flows, both at the entrance to the site and at critical areas on the site, through a well -designed grading plan, and ' since the streets surrounding the project area have a large overland capacity, the third alternative was chosen as the most feasible. This design will pro- vide a system that will be compatible with future upgrade of the storm sewer main in Mountain Avenue. 0 IV. ON -SITE DRAINAGE 4.1 General Concept The storm drain system was designed to handle a 25-year storm, which is greater than the 10-year design storm recommended by the City of Fort Collins Storm Drainage Design Criteria. It was found that flow depths from the larger storms would be sufficient to cause significant flooding of existing buildings, and higher finished floor elevations in proposed buildings would be required if the system was designed for only a 10-year storm. A grading plan was devised which will limit the flow in Linden Street and reduce the impact of the flows on existing and proposed development. The storm drain system, as designed, will collect as much of the off -site flow as possible at the up -stream end of the project. The flow in excess of the capa- city of the existing storm sewer main will be discharged into Walnut Street, downstream of the project. Flow which is not collected by the storm drains on the project site will be allowed to flow overland and will be directed to the center of the proposed pedestrian mall in order to avoid excessive impact on the buildings. 4.2 Design Consideration Considerations used in the analysis and design of the storm drainage system of the Old Town site are in compliance with standards set forth by the City of Fort Collins Storm Drainage Design Criteria. A summary of the design parameters used in the analysis follows: 1. Initial storm: 25-year storm, frequency factor - 1.1. 2. Major storm: 100-year storm, frequency factor - 1.25. 3. Minimum allowable storm drain pipe diameter: 15". - 4. Minimum flow velocity: 2 fps. ' S. Rational method runoff coefficient for developed area - 0.95. 6. Percentage impervious area for Old Town site - 95 percent. ' 7. Roughness coefficients: n value ' Concrete pipe 0.013 Asphalt paving 0.016 G 8. Zoning: Commercial and General Business District. 9. Detention: Not required. 4.3 Analysis and Design of Drainage Plan This section summarizes the results of the drainage analyses for the Old Town site and the surrounding area and presents the principal features of the site drainage plan. Figure 4.1 shows the project site and proposed storm sewer system. The Old Town site is relatively flat and generally slopes to the northeast. Sub -basins are indicated on Figure 4.1 and flow arrows show the general direction of the overland flow within each sub -basin. The discharges at various points due to on -site runoff for the 25-year storm were calculated using the Rational Method. These values, combined with ); off -site flows, were used for the preliminary storm sewer design. Inlet capa- cities were checked using the Fort Collins Storm Drainage Criteria and pipe capacities were calculated based on Manning's equation. For all of the sub -basins which do not drain to the alleys, the peak flows caused by the influx of off -site flows occurring about 55 minutes after the beginning of rainfall are greater than the on -site peak flows, which occur much earlier in the storm. The proposed grading plan, as shown in Figure 4.1, will prevent any substantial flow from entering the alley of Block 18 and will significantly reduce the flow into the alley of Block 19. The storm drain calculations for the alleys are presented in Table 4.1. Because of the low gradient across the site, minimum pipe cover require- ments, and the necessity of using a "bubbler" outlet, significant changes to the preliminary design were required to account for the hydraulic charac- teristics of the storm drain system. Since the hydraulic grade line is above the pipe crown during peak flows, the capacity of the pipes is considerably reduced. A summary of the storm drain design calculations is presented in Table 4.2. Supporting calculations are summarized in Appendix C. Drainage improvements required for the site, in addition to existing i facilities, are: 1. One pedestrian -suitable inlet (0.5 ft.2 open area minimum). 2. Twelve light -duty grated trench -type inlets (30.1 ft.2 open area minimum). A fn 0 0 O Aj� O 0 v Z rn r� M M m r_ R Z A v m CA 5 Z v D ,r r r O p r a - D p. 8 I kICvk-I 'rim vi I IO I lit 0 UI OI Inlet Time Street P min. 04 O °� pip* N N N min. -� { LI Ih , 1 pp Time o1 N N L"k w Concentration min, r, I i 9IU mL ffuant C"H V1 .�I L I� � (A UA Intensity D 00 0I� I.. in,nr. z 0 "{ ) I o Nf — Area D N l'\ e N O I o ..o.oa• M `O,, I IUk I� I .� O _ 1Orill _ I J = Direct Runoff :n P` C IO I.� NN Oth CAI H unafIt �-i*1 Summation Runoff cis Islope m u Capacity CIS clSlope % L1 I Utl I NI k U\I I S. m mIc}faaty W � b Design Z V CIS Vl vl velocity D o tpe D I I N I rn Deeipn \I � I ,l,}, mo °a) ef■ � 0 I WI I Gl Nlfpectty C 1 tDG DD <-�-N2 �D fAm IN 1 �• �- (` -� 3 - r rTI E DU~ C ^ n c r XD 2r Z 12 Table 4.2. Summary of Hydraulic Analysis for Storm Drain at Peak of Off -Site Flows. Pipe Size Pipe Slope Maximum Flow (cfs) Design Point (in.) (8) (As Limited by Head) Main Line* MH-5 36 --- 34.6 MH-6 36 0.4 34.6 MH-4 36 0.5 34.6 MH-7 36 0.6 37.6 MH-8 36 0.6 41.2 MH-9 36 0.6 43.1 MH-12 36 0.6 47.5 MH-13 36 0.6 47.5 Laterals A 21 0.7 0.0 B 15 1.39 3.0 C 18 0.77 3.6 D (existing) ---- 1.9 E 15 0.6 4.4 *See Figure 4.1 for location of manholes and laterals It k13 3. Six heavy-duty grated trench -type inlets (7.0 ft.2 open area minimum) 4. One grated manhole inlet (1.0 ft.2 open area minimum). -' S. One Type R curb inlet (5 ft.). 6. One Type R curb inlet (24 ft.). 7. Nine (9) standard manholes. 8. Three (3) shallow manholes. F3 9. 437.5 LF 15" reinforced concrete pipe (RCP). A=' 10. 350 LF 18" RCP. (? 11. 70 LF 21" RCP. 12. 23 LF 24" RCP. 13. 588 LF 36" RCP. Because of the extent of the constraints on the storm drainage design, the proposed design cannot provide complete protection for the 25-year storm, although it gives significantly greater protection than is currently being provided for existing buildings. Table 4.3 shows the peak discharges entering Linden Street from Mountain Avenue for each of the design flows for the pro- posed grading plan. Since the storm sewers cannot be designed to entirely capture the peak flows, the water surface elevations for the portion of the flow which is carried overland were determined using Manning's equation to (.., determine the amount of flooding that may occur. These elevations, at criti- cal points on the project site as shown in Figure 4.2, and the quantity of Loverland flow are presented in Table 4.4. 4.4 Design of Outlet on Walnut Street As previously discussed, the existing 24" x 36" storm sewer main in Mountain Avenue does not have sufficient capacity to handle the runoff from the contributing area for more than approximately the two-year storm. Because of the need.to lower the flood depths in Linden Street, the storm drain system for the site was designed to collect as much water as possible at the upstream end of Linden Street, carry it off the site through the storm drain and i j discharge it back into Walnut Street through an outlet downstream of the site (see Figure 4.2 for location). If the storm sewer main is eventually u 14 Table 4.3. Peak Discharges in Linden Street from Mountain Avenue. Return Period Discharge (years) (cfs) 10 53 25 65 50 91 100 105 qy. W COLLEGE AVENUE a`' m v ST 16 w 0 -- 0 r 4 C O k. O O •'I Oi ro 41 a N ro a 0 C W A •.+ ro w U- ro C o w O o 0 4J IT 0 IT w i4 ai > v r-I O 4J W A 3 ro N c .14 O a m O * * o Ep N N O v - f11 m O 10 O ET Q1 ET r rn m ao co rn co 9 ao 1� Eo 1 � r n r r r r r r n n r r En to N N N d Ln En CD ^ O O CD Eb OD m r m N En En m m r I I I O En v 00 00 %D n p C; C; ao C; rn n n n n r n n r n r r r En rn rn r m N r n N .- O 0 m N N N N r- to En N N E✓ : C C C 'a v v v I w v 14 rw w W a a ro m Q 0 a •� r•1 a a c rn c o a a c rn v c RI C C C C 0 C •.I C U •�I �+ m -1 r+ •.I .I 4J u it H c ro >, ro ro ro ro ro r-I ro v >, v 41 ro ro aJ i4 'd . q r-I .•I N •.i r- X v X C r 4 14 C v •14 ro > s4 �q �4 0 •H +-) 0 Q w 0 0 w a w X a x x vr m x N m v . Ln tD r co rn o N 11 ro N v .c a rn N A ro 1) •'1 N w v v 4J v 0 In z 17 upgraded, the proposed design can be tied into the new main, eliminating the need for the outlet. The proposed outlet is a modified version of the Colorado Department of Highways Type R curb inlet. The required opening length of 24.0 feet was determined based upon the design discharge of approximately 48 cfs. Flow velocity from the outlet at this discharge will be approximately 4.7 feet per second. 18 V. IMPACT OF PROPOSED DESIGN ON OFF -SITE FLOWS Since the proposed design calls for diversion of a portion of the flows away from Linden Street for the return period storms, the impact of the selected design alternative on certain off -site areas was evaluated. The pro- posed design provides for raising the ground elevations at the intersection of a Mountain Avenue and Linden Street above the existing elevations, reducing the quantity of'water flowing down Linden Street. Table 5.1 shows a comparison of the estimated discharges for the existing and proposed conditions for the various storm events in Mountain Avenue and Linden Street. This table indi- cates that the proposed design will increase the discharges in Mountain Avenue by approximately 123 cfs for the 25-year storm and 158 cfs for the 100-year t storm. i To evaluate the significance of this increase in discharge, the change in flow depth at various points along Mountain Avenue was estimated. Table 5.2 compares the elevation of the sidewalk and the estimated water surface eleva- tions at the southwest corner of Building K and the southwest corner of the building at the corner of Walnut Street and Mountain Avenue for the existing and proposed conditions. This table shows that the increase in flow depth is 0.3 feet or less for each case at both locations. Considering that the flow depth above the sidewalk would be 0.6 feet or more for the existing condi- tions, indicating that significant flooding will occur, it is felt that the proposed design does not have a significant negative impact on flow conditions ' in Mountain Avenue. The other area of concern involves the impact of the discharge from the ' "bubbler" outlet on the flows in Walnut Street. The purpose of the proposed underground storm drainage system within the project site is to capture as much flow as possible and pass it from the site below ground to reduce the ' water depths in the Plaza area. Since a portion of the flow that would now pass down Linden Street will be directed down Mountain Avenue as discussed ' above, the discharge from Linden Street into Walnut Street is significantly reduced. Table 5.3 shows a comparison of the discharges in Walnut Street up. and downstream of the bubbler for the existing and proposed conditions showing the reduced discharges for the proposed conditions. 19 Table 5.1. Comparison of Peak Discharges in Mountain Avenue and Linden Street for Existing and Proposed Conditions. Total Discharge at Discharge Discharge Mountain (Existing Condition) (Proposed Design) Return Period & College Linden Mountain Linden Mountain (Years) (cfs) (cfs) (cfs) (cfs) (cfs) 10 408 134 274 53 355 25 506 188 318 65 441 50 609 229 380 91 518 100 709 263 446 105 604 20 Table 5.2. Comparison of Water Surface Elevations on Mountain Avenue Water Surface Elevation (ft.) Existing Condition Proposed Condition Return Period SW Corner SW Corner Bldg. SW Corner SW Corner Bldg. (Years) Bldg. K* @Mt. & Walnut** Bldg. K @ Mt. & Walnut 10 76.7 74.8 76.8 75.0 25 76.7 74.9 76.9 75.2 50 76.8 75.0 77.1 75.3 100 76.9 75.2 77.2 75.5 *Sidewalk Elevation = 76.0 Existing 76.4 Proposed **Sidewalk Elevation = 74.2 Existing and Proposed 21 Table 5.3. Comparison of Discharges in Walnut Street for Existing and Proposed Conditions Bubbler Discharge in Walnut Street Return Period Discharge Existing Proposed (Years) (cfs) U/S Bubbler D/S Bubbler 10 48 106 47 95 25 48 145 70 118 50 48 176 108 156 100 48 203 132 180 9 22 VI. SUMMARY AND CONCLUSIONS This study was conducted to estimate the design flows at the Old Town site, and to develop a drainage design that will minimize the potential for flooding of existing and proposed buildings within the site. The proposed design; 1. Prevents off -site flows from entering Linden Street and provides adequate internal drainage for the 10-year storm. 2. Collects a large percentage of the off -site flow entering Linden Street for the 25-year storm. 3. Provides a significant reduction in the amount of flooding that will occur for the 100-year storms compared to the existing condition. n ® Appendix A Data Summary The data, reports, maps, and other pertinent information used in the analysis, design, and general preparation of this drainage report are listed below. - Topographic Survey, Old Town - Fort Collins, scale 1" = 30', Simons, Li & Associates, Fort Collins, CO, March 1983. - City of Fort Collins topographic mapping, scale 1" = 100', CI = 2', M & I Consulting Engineers, Fort Collins, CO, July 1978. - Topographic Survey, Fort Collins Downtown Redevelopment, scale 1" = 30', James H. Stewart and Associates, Fort Collins, CO, 1976. - City of Fort Collins Storm Drainage Map, Department of Public Works and Water Utilities, Fort Collins, CO, scale 1" = 600', 1973. - City of Fort Collins Utility Plan, Department of Public Works and Water Utilities, Engineering Division, Fort Collins, CO, 1976. - Major Drainageway Plan for the West Vine Drainage Basin, Engineering Professionals, Inc., Fort Collins, CO, December 1980. - City of Fort Collins Storm Drainage Design Criteria, Department of Public Works and Water Utilities, Engineering Division, Fort Collins, CO, January 1980. - Report on Storm Water Drainage Facilities for Fort Collins, Colorado, Black and Veatch Consulting Engineers, June 1971. - Larimer County Storm -Water Management Manual, Resource Consultants, Inc., Fort Collins, CO, 1979. 0 I APPENDIX B OFF -SITE DRAINAGE CALCULATIONS COLORADO URBAN HYDROGRAPH PROCEDURE SIMONS L' &ASSOCIATES CLIENT JOB No. PAGE ENGINEERING CONSULTANTS PROJECT DATE CHECKED- DATE FORT COLLINS COLORADO DETAIL CHECKED BY COMPUTED BY -52� 4;0 zv '7 �A- 1,'7 4 ww .: SIMONS LI S ASSOCIATES CLIENT JOB NO. PAGE L — z 'I � ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE d FORT COLLINS COLORADO DETAIL CHECKED BY COMPUTED BY Qa c MWE �mml I I zo �•� GO "mod '�''J ,�U r G J i iI W 11 V > \ e` Lk It W 1 n _ •\ `1 c E L C L' 11� J !a t� x '1 o � t e l e 0 W Oo Oppc,C,oO — 'm S c 0- T v N O O O e c ` C o < v�� ooa�oNht`coo�cco Q N ,c'o c _ m >::� �COC�GGG W O O \ 6 _ a_ a E a cW�-Qlc - C. c E c II mom IN I.... co 2 C v L r, D II � . m ^ o � x � N I N I: � Wo 0 mi:, i OI° NIJ � i wCL N AID � � Q)IN � ��Iv � SIMONS LI A ASSOCIATES CLIENT Jos No. PAGE -;,:> ENGINE EKING CONSULT AN IS PROJECT DATE CHECKED- DATE FORT COLLINS COLORADO DETAIL CHECKED BY COMPUTED BY 61, 7,e 7 /'0 Z 7-t4 A7C 7 7-- 7v e 77, 4, VT.1 TC7 ,V7, -2 -Z A/ T 77 I'V7 /3-3 LF zw-o 113� 2 A�z 11-7 /00 ---- ------- 77", -7 l 0 ,le 7 .7 27 2 r E: ty Hi L SWONS. LI A ASSOCIATES CLIENT JOB NO. PAGE - ENGINEERING CONSUL TAN tS PROJECT DATE CHECKED DATE FORT COLLINS, COLORADO DETAIL CHECKED BY COMPUTED BY - --f icy // _ c '-�'/c� �(,v T � �a •/ i,y_�/ /c y7ai"7%G ✓ -_ . _ f /? �%/G / �%C,_.=C:y1.V..Z/ _1'1C.:_i?L i.✓7 �/ C� APPENDIX C SUPPORTING CALCULATIONS ON -SITE DRAINAGE SIYONS LI 6 ASSOCIATES ENGINEERING CONSULTANTS FORT COLLINS COLORADO JOB NO. PAGE DATE CHECKED DATE CHECKED BY COMPUTED BY :) .-I N - 1 I Chl H-IA ^ : - Z Z" H -`] Mli•;,^. ,i ��P•. sf.n 5 .Ii 7< .'�C .: P _�/'I i>%C%i iJ - �/ ri !� �, C� / /l / C _ -- .. C� --.-''-% � /c .-�,' � /�'/f� - / z = %, J'. i = ->•r; � � to i• 9 � i � G FS. 7 z iV� . fr./,^•i y rf,J ...eft— � ' ..G i• ��7.'�C,CG��( .:; % j =�,^�•�� i� _ —17 n 71 a SMONS. U! wS50WwLE5 CLIENT JOB NO. PAGE n- z -i; ENGINEERING CONSUL TAWS PROJECT DATE CHECKED DATE �a EORT COLLINS COLORADO DETAIL CHECKED BY COMPUTED BY r: //y- L71� .9 // 11Ci / --'---- f-ii fps / %..-! ( "G>✓%C�/ �� l/i?/./L'I'/ ��% J .. _. i I SIMONS LI A ASSOCIATES ENGINEERING CONSULTANTS FORT COLLINS. COLORADO CLIENT_ PROJECT DETAIL_ JOB No. PAGE �- DATE CHECKED DATE CHECKED BY COMPUTED BY Cn/- ITE ZI�i11NAC�F 1i/VAL — t"—tOA/f?L M>_'Tt—+r-- Z�LOCt< 1`d — --? -5/ N r1 Q��tOXI—e-d..P _irr.Lv-}, /%j i-I - 3 ^ 1 r"IY) TC GLT M H h ee.rviFle, e ci ave.fla� i-Im� a icy v U F, C 1 N -j { oLJ -Pro 1, 0,I1rrC�l YI gY 1Cic? 1 j //f�rP4 " cI A, Y6 VIP 0.N`r _.._ __ . .. '1 �O W T t n'l 2 J - 1_._.. +C /t'� t-I' .�. G vQ ✓ �Q /� Gl �^ G�. V m � V1 Ity 1► C. tYN �.`7nf5 tUr +f = Z. J rr1n. _ �• r Ilhr 5ury f mac'. SIMONS LT a ASSOCIATES CLIENT JOB NO. PAGE ENGINEERING CONSULTANTS PROJECT DATE CHECKED DATE FORT COLLINS, COLORADO DETAIL CHECKED BY COMPUTED BY SIMONS Li A ASSOCIATES ENGINEERING CONSULT AN IS FORT COLLINS. COLORAp CLIENT_ PROJECT DETAIL_ JOB No. PAGE �- DATE CHECKED DATE CHECKED BY COMPUTED BY SIUONS u A ASSOCI-TES CLIENT JOB NO. PAGE ENGINEERING CONSUL TANTS PROJECT DATE CHECKED DATE EOAT COLLINS. COLOAAOO�/ DETAIL CHECKED BY COMPUTED BY LJ 7- / V141 31 ' �!/ a . 7. •J , -. Z-ice✓oi 7` r'YTZ = 7� •%� �. Cam': /(/�Zi =7/� -- SIMONS. LI A ASSOCIATES JOB NO. PAGE DATE CHECKED DATE CHECKED BY COMPUTED BY CLIENT ENGINEERING CONSULTANTS PROJECT FORT COLLINS. COLORADO DETAIL i,Lcc_r u-k�l- L:.I -f S = p,zc7o +( C(-r y, Cl Q 0 j 0 41' 1-7 - 2 G,T r 'L- Lft lr✓ I� - mQ,rh�(?�IQ I T -C) 5 -- 41.0w z n7" � r"IV1 �'r0y", rr S�MONS. Li 6 ASSOCIATES CLIENT ENGINEERING CONSULTANTS PROJECT FORT COLLINS, COLORADO DETAIL - JOB NO. PAGE �- - DATE CHECKED DATE - CHECKED BY COMPUTED BY / J � ri Ifw 7 -- /'Gi/'U��J,Y� //7v?/f� -far" ;'7'.',r c-i' �• �:i'�' //. .-----_I -1 SIMONS, Ll A ASSOCIATES CLIENT JOB No. PAGE ENGINEERING CONSULTANTS PROJECT DATE CHECKED- DATE FORT COLLINS, COLORADO DETAIL CHECKED BY COMPUTED BY Z/� i 71 -7 6- 716- VC7 'e" te7Z 7. Lipir;c-tJ A{ L L F PAX C-D, t-um k FIJ t.lj L C-1 S I-L I GC? A P -L A -1AL 11 L)T- I H -7 -7. Cl F'A k-k A L L E-ke' 4c �a I kead' V2 H, - ----- — ------ ----- .1P H P/--/4 A 4,L L .44-,L -2 L 144,L H L HI- rl-;L- F L Z. �7 Hj� U koL 61 1�lee�,7101 Z s 'le /0 e--) SIMONS LI a ASSOCIATES CLIENT ,JOB NO. PAGE ENGINEERING CONSULTANTS PROJECT DATE CHECKED - FORT COLLINS. COLORADO DETAIL CHECKED BY COMPUTED BY J 7 i. v .� �: 7. 7 _ i / �:�t!-%=�/" ��i /�r+ �. ..-ems �J PQi� :� /6ri+•i 1 .. T . 1