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HomeMy WebLinkAboutAgenda Statement 1977/07/12 Item 11CITY OF CHULA VISTA COUNCIL AGENDA STATEMENT Item No. 11 For meeting of?/12i7'7 ITEM TITLE Resolution 8712: Adopting Guidelines for the Alignment and Typical Section for Telegraph Canyon Road and for the Types of Channel Between Crest/Oleander and the Easterly City Limits SUBMITTED BY Director of Public Works/City Engineer ~~~~ ITEM EXPLANATION (4/5TH'S VOTE REQUIRED YES NO x } By Resolution #7345, the City Council approved an agreement with Wilsey & Ham for the preparation of conceptual plans for Telegraph Canyon Road and Channel. A major reason for the preparation of these plans was the need for coordinated road, channel, and sewer facilities in the valley in order to permit logical development of adjacent landso Subsequent to that action, th2 Council has accepted the work of the consul- tant, certified an EIR for the project, and held a public hearing to obtain public input. The report prepared by Wilsey & Ham has been reviewed by the Engineering Planning and Environmental Review Division. As a result of that review, a report has been prepared and is forwarded to the Council which summarizes the Wilsey & Ham study and the EIR, discusses the conclusions of both docu- ments and sets forth recommendations to accomplish the implementation of the project. The primary features of the Staff recommendations include: 1. Adoption of guidelines for the alignment, grade, and sections for Telegraph Canyon Road and Channel. 2. Formalization of the alignment through preparation of a Record of Survey Map. 3. Adoption of a seed mix design to be used as a guide for landscaping the channel. (Continued on Supplemental Page 2) rvnrnrrn cnnlDli~ Agreement Resolution x Ordinance_ Plat Notification List Other x Reports ENVIRONMENTAL DOCUMENT: Attached Submitted a~~ FINANCIAL IMPACT Estimated cost to prepare record of survey and right of way maps is $35,000. Such amount is currently budgeted in Account GT-49, Telegraph Canyon Road - Preparation of Right of Way Maps. Otherwise, there is no immediate direct financial impact to be incurred through adoption of these guidelines. The City has traditionally participated in construction of major roadways. Due (Continued on Supplemental Page 2) STAFF RECOMMENDATION Approve Resolution adopting the Public Works Department Report and Recommen- dations contained therein for improvement of Telegraph Canyon Road and Channel and find that all feasible mitigation measures have been incor- porated into the project and that it is not feasible to fully mitigate the growth inducing impact of the project (see Discussion Section 4) BOARD/COMMISSION RECOMMENDATION A P P R O V E ll COUNCIL ACTION by the City Couacil o£ Chula Vista, Cnlifc~.iia Dated - - ...._~........ ~..........T....7 ..............L...... Form A-113 (Rev. 5/77) Item NO. 11 Supplemental Page 2 4. Adoption of design flood flows to be used for the design of future flood control facilities. 5. Designation that certain measures will be undertaken to mitigate noise impacts and possible damage to archaeological sites. These mitigating measures are to be included in appropriate project construction speci- fications. The attached report includes a brief description of the ultimate improvement, recommendations, background, environmental considerations, County comments and hydrology considerations for future design. FINANCIAL IMPACT (cont) to the probable piecemeal character of development along Telegraph Canyon Road it is not now possible to determine the nature or extent of City parti- cipation. Such information will be incrementally available as the develop- ment occurs. SLH:rms AY O11 ~ ~/ 112-01 v March, 1977 /~ ~ DESIGN REPORT TELEGRAPH CANYON ROAD AND CHANNEL EXECUTIVE SUMMARY INTRODUCTION The Program In order to permit the logical and orderly development of properties adjacent to Telegraph Canyon, it was the City's desire to have con- ceptual plans prepared. The plans detail the concept for the coor- dinated development of Telegraph Canyon Road, sewer, and drainage facilities. The limits of work on Telegraph Canyon Road are from Crest Drive (near I-805 freeway) on the west to approximately 3.8 miles east at the existing county box culvert crossing Otay Lakes Road just east of Rutgers Avenue. Authorization By Resolution No. 7345, the City Council of the City of Chula Vista approved an agreement between the City and Wilsey t; Ham for preparation of conceptual plans for Telegraph Canyon Road and Channel. Scope of Work Development of the concept plan was done in phases, which are described in the agreement between Wilsey E Ham and the City of Chula Vista. The various items of work are listed below: 1. Preliminary Phase a. Review base material, and requirements of City and other agencies b. Prepare 100 scale aerial photogrammetry c. Prepare alternative preliminary engineering studies d. Prepare computerized hydrology study 2. Plan Preparation and Conceptual Design Phase a. Prepare plans at scale of one inch equals 100 feet horizontally and 10 feet vertically b. Delineate centerline of sewer, utilities, highway and major drains c. Propose grades for Telegraph Canyon Road d. Propose flowline grades for drainage channel and road crossing structures e. Indicate sanitary sewer grade f. Detail typical sections of drainage channel at various locations g. Delineate design considerations for major drainage structures EXHIBIT "B" -2- h. Designate areas requiring additional erosion protection i. Delineate approximate right-of-way lines j. Indicate approximate limits of cut and fill required 3• Preliminary Cost Estimate 4. Project Report Previous Construction The existing alignment of Telegraph Canyon Road along approximately two miles of the study area east of Brandywine Ave. was established by the County of San Diego on Road Survey Number 1086-65• Construction according to County plans was completed in February 1967. Pavement width between asphalt dikes is 40 feet centered within the right-of- way. A three foot shoulder widening on the north was included for approximately 4,575 feet. The 1967 construction included a trapezoidal channel where the existing channel was adjacent to the road (2,490 feet). The bottom width of the channel was to be a minimum of 10 feet. This channel had 24 inches of rock facing on the slope adjacent to the roadway. Between 1958 and 1g62, construction in Telegraph Canyon was performed in accordance with the alignment and plans developed by the County of San Diego as Road Survey 1086. Generally this consisted of 36 foot wide section. The trapezoidal channel where adjacent to the road was constructed with a minimum of 5 foot bottom width. Plans for the intersection with Otay Lakes Road were developed in 1964 by the County and shown on Road Survey 558-64. Widening near Buena Vista Way was done in accordance with Chula Vista City Plans for E1 Rancho del Rey, Unit No. 1. Preliminary plans have been processed by the City for improvement of Telegraph Canyon Road adjacent to the proposed Canyon Townhouses near Crest Ave. Roadway construction is underway adjacent to Windsor Views. Previous Studies In 1964, a Special Study of Storm Drainage Facilities was prepared as a supplement to the Chula Vista General Plan. This study included run- off calculations for Telegraph Canyon beginning at its upstream limit and extending to the bay. CalTrans has also studied drainage of Telegraph Canyon in reference to construction of freeway crossings. Hydrology studies of Telegraph Canyon were also conducted by the Corps of Engineers in 1974• -3- A report on the collection, treatment and disposal of sewage and industrial wastes in the City of Chula Vista, including the Telegraph Canyon basin, was prepared in 1959• A trunk sewer was constructed in Telegraph Canyon Road based on plans prepared in 1961. FINDINGS Alignment The original alignment of Telegraph Canyon Road was developed by San Diego County prior to annexation of the facility to the City of Chula Vista. In general, the road follows the canyon floor to avoid the naturally rugged terrain of the East Chula Vista area. The proposed alignment re- mains subject to the same .topographic constraints, however, it is planned to increase the radius of many of the curves. The first curve near Crest Drive is designed fora speed of 45 miles per hour, the next curve easterly at 55 and the remainder for 65 miles per hour. Alignment changes are proposed from 1,200 to 2,600 feet easterly of Crest Drive (near E1 Rancho del Rey Unit 5)• The existing right-of-way traverses a sharp (750 foot radius curve) and a short section of tangent. If the new construction followed this alignment, the design speed would be compromised. To avoid this consequence, the proposed alignment follows a straight course through this section, deviating considerably from the existing right-of-way. Hydrology A hydrologic analysis of the entire basin was performed using a modified Rational Computer Program. Both present and ultimate quantities of runoff from a 50 year period of frequency storm were estimated and compared with estirnates by the Lawrence, Fogg i; Smith study in 1864 and the recent Corps of Engineers study. After considerable study, it was determined to base the flood channel design on the Lawrence, Fogg & Smith study which balanced a higher estimate by Wilsey z; Ilam and a lower estimate by the Corps of Engineers. This will also provide continuity with existing facilities downstream. The following design flows will be used for Telegraph Canyon Channel upstream of the noted streets: Crest Drive 2,850 cubic feet per second Brandywine Avenue 2,600 " " " Buena Vista Way 2,100 " " " Rutgers Avenue 1,6.00 " " " -4- Channel Design A large variety of possible shapes, sizes, linings and slopes were hydraulically analyzed to identify suitability of each for use in con- junction with the Telegraph Canyon Road project. A number of physical constraints affect the shape and configuration of the ultimate channel. For example, if the depth of the channel exceeds or approaches the depth of the existing 15'' UCP trunk sewer, future gravity -flow sewer mains are affected and lift stations or inverted siphons may be required. Con- sequently, the ultimate channel should not exceed a depth of eight feet at expected sewer crossings (six feet depth of flow plus two feet freeboard). Extremely wide channels would require excessive right-of-way requirements and generation of high cut slopes. The existing gradient (1.0 to 1.5q) results in erodible velocities for unlined or poorly lined channels, thus restricting the types of linings which can be used or requiring the use of periodic drop structures. Telegraph Canyon Road is designated as a scenic road. As such, extra care should be taken in the design of a flood channel, to avoid detracting from the scenic qualities of the area and, if feasible, to improve the views. It was the specific desires of the Chula Vista City Council that a grassy or landscaped, "natural" appearing channel be considered. Because of the restricted width of the canyon floor and the existing urban development there, it was the feeling of the City Engineering staff that the westerly 2,500 feet would have to be developed with a lined channel. Alternate Flood Channel Sections Far evaluation of their effectiveness in controlling the storm flows, meeting a majority of the other constraints and for comparing from a cost standpoint, the following storm drain sections were evaluated: 1. Trapezoidal Channel - with grassy lining 2. Trapezoidal Channel - with heavy landscaping 3. Trapezoidal Channel - with maintenance road, low flow channel and grassy lining 4. Trapezoidal Channel - with rip-rap on side adjacent to highway 5. Trapezoidal Channel - with gunite lining 6. Rectangular Concrete Channel 7. Multi Plate Super Span 8. Multi Pipe 9. Reinforced Concrete Box Evaluation of Channel Sections The channel types were compared using the same hydraulic capacity for total costs of construction, maintenance and right-of-way. A trape- zoidal channel with heavy landscaping proved to be the most cost effec- tive design and is recommended for the majority of the project. The most westerly 2,770 feet of Telegraph Canyon is quite narrow, especially considering the widening of the highway. Because of the restriction; the westerly portion is now planned as an open trapezoidal channel with gunite lining except at roadcrossing and a reach crossing the toe of a steep slope. -5- Road crossings will require a bridge or enclosed section such as a double or triple reinforced concrete box. Approximately 1,800 feet easterly of Crest, a rectangular channel or enclosed section is re- commended to avoid extensive excavation of a hill on the north. Wherever intensive land use development is planned adjacent to the road, closed conduits maybe justified to avoid narrow, inefficient building sites. Preliminary Cost Estimate The channel construction is estimated to cost $1,475,000 based on 1876 costs. This includes excavation, lining, relocation of interfering utilities and temporary buildings as well as construction of five road crossings. The highway construction is estimated to cost approximately $90.00 per lineal foot or $1,775 000 based on 1976 costs. This includes excavation, curb, gutter, sidewalk, bikeway, new pavement on one side, reconstruction and resurfacing where existing pavement is utilized in the design, planting and irrigation of the median, but excludes right of way. COIJCLUS I ONS 1. Telegraph Canyon Road easterly of Crest Drive is too narrow and the alignment is inadequate to facilitate the traffic expected with proposed development in the eastern area of Chula Vista. 2. The channel adjacent to Telegraph Canyon Road in the same area is subject to flooding and will not contain the projected storm flows without flooding the adjacent property and street. 3• Because Telegraph Canyon Road is a scenic route, the construction of the road and channel should conform to requirements for scenic routes. 4. Development of a conceptual plan indicating acceptable types of channels, road sections, alignment and grades is necessary to allow coordination of expected phased construction of these im- provements. 5. The alignment of the road must reflect the constraints of existing improvements and topography. 6. Continued use of two channel types can best meet the goals of carrying the design flow, aesthetics, and low construction and maintenance costs while still not precluding the development of adjacent properties. -6- 7. Channel crossings should normally be enclosed sections with transition sections upstream and downstream. Their design should allow for construction of all normal utility crossings. The transition structures should be designed to avoid erosive velocities in the unlined channel portions RECOMMENDATIONS 1. Formalize the highway alignment ("PJ-Line") shown on the plans through preparation of a Record of Survey and a right-of-way map. 2. Adopt the "N-line" alignment through formal action by the City Council. 3• Designate and use the design flows for Telegraph Canyon Creek as developed in the 1964 Fogg Study of Storm Drainage Facilities for future design of flood control facilities in Telegraph Canyon. 4. Designate the gunite lined, open channel trapezoidal section (Exhibit 4-2) to be used (except where property owners desire to install an enclosed section) in that segment between Crest Drive and 2,770 feet easterly. 5. Designate the open channel trapezoidal section with heavy land- scaping (Exhibit 4-1) to be generally used from 2,770 feet easterly of Crest Drive easterly to the end of the project (near Rutgers Avenue) 6. Designate the typical highway section (Exhibits 2 and 3) to be used generally throughout the length of the project as the ultimate roadway section. 8 ,~ J~ ~ _ ~_ ° . o'c ~ . oZ~~ ~ 0 uv ~ ~ Q ~~ V ~ Q Q ~ ~ a ~ 0 ~WWW ~-~ °~ 3 ~~ Q ~ °- o ~~°0 1 ~ -°n Q ^ Q ~ , ~~ h ;, ~ ,~Py ~ d~'3h9 ~~~ s ~~ O c I ~~0~ ~G ` Q m m I • op.) RAj~ (~ ~ I ~ ~AS~I ~` a. cw ~ I~ ~/ ~`r V ~ ` ` WI O ~ 1 ` ~~ ~ ~ '`1 ~ ~ o~~ ~ a Q 1 ~ I h z , ro~~~OJ ~ o Z ?) ~~ od~J ` ~V Q~ ~ • ~ W ~ ~ ~~ ' ~ yt Qb°~~'iM~{ d~9 ,' ~ a~ '~5 o~ O~ , ~ i / ~ $J o i I % ~ ~, ~ aO s ~ ~ ~ a~o~ ~o a ~ ^'ba~o Z gOe ~N/ i BP~o I / ~~ N ~'~ • o ~, i ~h ~ a a 0 ~ / \ ti~ / N\ v W O Q ~J Q~~ ~v '~ W Vy O~ ~' ~O ~n ~: N O Z O ~~~ Q1. Q~W V~V ~~~ W h c v h~ 3 Q ~~ a Q aQ W 0 OC Q Z QW ~ `~ ~ ~Q Q ~` v 41~ 0 w ~ `' ~Q~ oaW ZZ i oQo ~v,, y~W ~~ `~ ~ Q V ~ ~ O ~ N k W N~ Zj / Al TERNATE STO/?M ORA/N ~ ~~ SECTIONS 32' /5~- P5' 32 ' i D B ~ .Q / 4 4 /. T~P~tPE2O/Q4L C~/QNNEL - !~V/T~1 GRASSY L/N/N~ _, __, 2. TR~EZO/A/JG CHANNEL - W/T~! ~/EAdV LAN05G4P/NG - L~~ 3. TR~4PE70/A4L C//.rJNNEL - W/Tf,/ /y!A/NTEN•4NCE X40 LOW FLOW L'~/gNNEL AND GRgSS L/N/NG , r ^ ~XN/B/T 4.2 ALTE,QNATE STDQM ORA/N ~ ~ 2 °f 3 SECT/ONS ,3' /log 25'-52' 32' - - - - _ _ , . 2 a ~1 8' ~~~~ 4 TQgPEZO/A4L C~IANNEG -1~{/?f~ R/P-RAP 4N QIVE S/DE ~/EA V Y L,4 NOSCA P/ NG UN REMA/NDER 2 - - 2 - o •• • .a Q / (o" B' / ~" /D' •~ ~ ~ iNA/NT. ,SAD S. TRQPEZOl0,4L Ct/ANNEL - {~V/T/,/ GUN/TE l/N/NG (A,gM~ ~~ 6 • RECTA/~lGULQR CONG~PETE Cyi4NNEL K X /O = 20' 2 ~ EXN/B/T ~-$ 3 0~'3 ALTERNATE STORM DRA/N SECTIONS 2.5" .5" " ZS~ 25 ,~ 20' = 27~ .. a: 3' 3' 7• MUL T/-PLATE SUPER SPAN o~oo '- ~~ 8'- w' ' ~ ~8"TO/2"TN/CK WgLLS~ 9. REINFORCED CONCRETE BO~-! ITEM TITLE: SUBMITTED BY~ ITEM EXPLANATION= CITY OF CHULA VISTA CQUP~CIL AGF_(~i~A STA°~Et~ENT Recommendation for utilization of bicycle lanes in preference bicycle paths on Telegraph Canyon Road, east of I-805 s ~-- ,--•r Dorance L. Ochs, Chairman/Safety Commission ~,~/~%~~CC~=!'^~ '~~~~,'~ The City's "Bicycle Committee" has recommended the installation of bike lanes along Telegraph Canyon Road from I-805 to Otay Lakes Road. In a memorandum to the Safety Commission dated February 16, 1977 (attached), the Director~ of Public l~Jorks solicited the Safety Commission's endorsement of the Bicycle Committee's recommended utilization of bicyc~ie lanes in preference to a pathway en Telegraph Canyon Road, East of I-805. The Comn~~ission voted 5-0 to forward this report to the City Council (at the meeting of February 23, 1977), requesting approval of the Bicycle Committee's recommendation. Agreement Resoi:riion~._. Ordinunoe Plat._.._ C~thor x ~._ EnvironmcMol Documents Attached ~._ Submitted on-______. STAFF RECOP~~fiil4Ei~iQF`~TiO;rl: Staff supports the position of the Bicycle Committee and Safety Corr.rnission relative to tine use of bicycle lanes an Telegraph Canyon Roaci, east of I-805, rather than bicycle paths. BOARDIC:.°,f~:ifSSfCN FECOM~,iE(~~!aTiQPd: The Safet,l~ Commission recommends that sta{i be requested to install bike larks on Telegraph Canyon Roaci, east of I-805 COf.l~~r~~ /k(. i~i7~J. ~~i ~ ~ .ITEM RrO. 2 FOR MEETWG OF: 3/15/77 ~1L~ ~CCCi1t.~.i7Ct:' C)L .L"eLO+'~.;. EXHIBIT "A" y-L r~ February 16, 1977 file No. KY 03G cz1~Y ~o1~P,DS 11;~ c~?i~uxsszozls T0: Chula Vista Safety Commission via City Manag r I~l FROM: W. J. Robens, Director of Public Wor};s G SUBJECT: Bike Path Vs. Bike Lanes on Telegraph Carryon Road The current plan for development of Telegraph Canyon Road, east of I-805 calls for construction of a two-way bicycle path along the north side of the roadway. (See Alternate #1 on attached e}alibit.) Several seg- ments of the path either already exist or are proposed to be built in the near future. The Department of Public Gdorks has become aware of certain shortcomings relative to the use of bicycle paths. We con- sider these shortcomings of sufficient importance to justify a modifi- cation in plans to include bicycle lane provisions instead of the separ-ate path. (See Alternate #2 on attached exhibit.) The follo~•.ing discussion embodies the bulk of considerations used in coming up with our recom- mendation. There are three basic types of ba_cycle route facilities; the shared route mar}ced only by signs; the bike lane marked by signs, lane stripes and various markings upon the pavement; and thei~icycle path which is con- structed beyond the street travelway. Most of the current Chula Vista system consists of the shared type. However, it i.s widely recognized that the shared route offers practi_cal]_y no physical or psycllologi.cal protection to the bicycle rider. The bike path is frequently regarded by the non-tider_ as the best and safest faci]_ity-which can be provided. Thu path gets the rider out of the street (in theory) and thereby eliminates ex~~osure of the cyclist to being struc}: by moving automati.ve traffic. T't~1e path is said to offer a safe place to ride for all classes of ri~3ers including the very young. while the bike path has some virtues, it also ha.~~ many shortcomings including: A. Two-way bicycle traffic can be quite hazarclolls, particularly in regard to head-on coll.isi.ons. Closing sped:;. can easily exceed 35 m.p.h. and therefore result in serious in_ury. B. The separate pathway is more difficult to rna:intain because it is generally i.ncanvcnient for access by a motor::ized sweeper. It~is also more likc.l.y to r.ecei_vc~ dcpo~i.ts of silt and sand because of i_ts rolat:ionshi_p to slopes adj~accnt to the right of way. C. ^hc pat-h~~~41y door not rPprF,~-ont a si<;rli_f:ir,ant= s~~~,i_ng i_n con:~truction CC::t aS ]. .a CCmPiOnl~' SuppO_;ed beCatl~;C'. It rC'g11::: reS a Stl'UCtUl"a ]_ SC'Ct1Cn - 2 - sufficiently strong to•support a street sweeper. Construction of the pathway separate from the travelway involves additional expense above a simple widening of the travelway pavement. D. Pathways are commonly constructed of asphaltic concrete material. Such pavement must receive a kneading action such as provided by heavy vehicles in order to preserve its flexibility. Lacking such, surface spalling will occur, thereby compounding the problem of surface litter and subsequent hazards to the rider. E. The pathway creates unique hazards where it intersects a street. The driver operating along the intersecting street normally antici- pates•cross traffic to occur in the street intersection first from the left and subsequently from the right. The two-way bike path interjects cross traffic at an uncommon location prior to reaching the street intersection. The path also permits disruption of the normal order of encountering cross traffic. The first encounter may be from either the left or the right. F. G. These unique hazards are further compounded by .the cyclist's speed and his characteristic reluctance to lose momentum. A rapidly moving bicycle suddenly appearing at an unaccustomed location and from an unaccustomed direction poses a realistic hazard. It is improbable that the Telegraph Canyon Road bike path wou]_d be physically co~rplete in anything less than 10 years. Meanwhile it wi1.l consist of various isolated segments. Use of that segmented system ~~,ri1.l necessitate crossing of Telegraph Canyon Road twice per segment for_ each eastbound cyclist. Such a practice would obviously be impractical and dangerous. Alternatively, the east- bound riders could be allowed to stay in the travelway while regrzir- ing the westbouncz riders to utilize the pathway. Even this practice could result in tl~e sudden and unexpected appearance of a cyclist in the vision of a west=bound driver as the cyclist weaves from path to lane. Many serious bicycle riders object to the pathway concept because it could lead to an attempt to prohibit bicycles in the travelway. Current California 1_aw classifies the bicycle as a vehic]_e ~ti~ith full rights to use the street system as would any other legally recognized vehicle. Con~pl.etion of a path~~lay has, in several agencies, been follo~oed by ordinances requiring that cyclists use such facili= ties. Or.ganizer3 bikers have offered stiff opposition to construc- tion of path~eays ~eithin street rights of way. (This does not apply to recreational paths follow.i.ng an independent course.) Ii. It is difficult to police a bike path. Riders may weave or ride on the ;aronq side, or pedestrians may mix ~~,ith cyclists. All of these factors tend to increase the' hazard pot-ential. All could be ~r.or_e eas:i.ly contro]_led through the use of lanes rather than paths. The bi}ce large places tl:e i-a.der in the ~t-reet arc? t:her.eiore providos greater expr~sure to aut.onwti.ve traffic. Parent::: of young r_hildren - 3 - fi~~d this relationship of bike to auto objectionable. however, it must be realized that local ordinance does not prohibit riding bicycles on the sidewalk. Inexperienced .riders should be encouraged to do so. In the case of Telegraph Canyon Road it is likely that nearly all of the bike riders caould be bent upon riding such distance as to eliminate the very young rider. Long range plans do not envision residential developments fronting on this major roadway and so it would not be particularly convenient to the young, inexperienced rider to use that road The bike lane concept overcomes most of the shortcomings of the pathway concept. A. It provides one-way flow. B. It is convenient to sweep and maintain. C. The bike lane commonly involves only a minimal widening of pavement over that required for emergency parking. Such construction is relatively inexpensive. D. The bike lane normally receives sufficient kneading to keep the pavement in good condition. E. The bi_l:e lane puts the cyclist in thc~ street where he•can be expected to be by the motorist. Further, he will be proceeding through intersections i_n the direction anticipated by the motorist. 1{~. The b kc~ l t-~nc~ keens t-he cycl. i ct on the right side of the roadway and will not create a need to cross the road for arbitrary reasons. G. The bike lane is regarded as the most effective and practical (as compared to a path) by organized riders. H. It i.s simpler to police the activities of riders in the travelway than on a separate pathway. At it_s meeting of Febr~.zary 3, 19?7, the Chula Vista Bicycle Commi_t~tee rerommendc~d utili_zati_on of bir_ycl.e lanes in preference to a path~~~ay on Telegraph. Canyon Pond east of I-805. ti~'e solicit your endorsement of that recommendation. I~lEH : e t Attachment 1~, t2.r,' at' ?__ °~__ ,. _...~. i I I f i . t2G' a' a' t . ~' l" .>. 4I` z--~ .,~ ~~ ~. c a.5 ~' a~ ~r~1 IG~ ~ t?~ ~ t3' ~ tCo' S3' t2` ' 1 ` t G (,..~ '~~ a . l ~ ~I I f,~~t,cH I i -rr..~vEL t~.t~>?s • -l3'T1LlTILS ~ PL4NTING -TFZC.L PL.Gt~f~C 1 N ~ • ' StU WALK. .~314~E WA`l CtrtEA.t~pC2ft1G) A LT E R ~l ~T ~ 1 _ ~ IZ6~ IZ•5~ ~ ~~.y' 8 ~ i r3 ~ 42.5 17._5' t ! i 1 ~ ~ I ' 1 ~ ~ I 5~ T•5~ I5~5 i 12 I?_~ 13~ I 16~ 13~ IZ~ 12~ 5.5~ ~~5~ ~~ ``, ~ ~ ~ ;~ 1 __, ~~ lrlcnl~-`.tJ ~ / TRAVtL L.",1~1~5 /' -- •-- FI4CG UF1G `-"" UTII_!1-IES ~ PLAt~TINS S I D F' V'J ,~ l : i~C- TYPIC1lL. SEGTIQI`~ A L~~~ ~E 4~ ~ ~~.~ ~~ Z .~i/'Xy F. Channel Cost Comparisons ;" A rough cost comparison was prepared for the channel alternatives considered. Each was based on 1974 prices and a design flaw of 2600 cfs arhich is approximately the mid-point in the range of suggested design flows. Excavation beyond channel right of way was excluded since detailed study of each section for• the length of the project would be required to provide a realistic estimate. This omission slightly favors the wider right of way earthen and grass lined channels, Cost of drop structures was also excluded as the number and design of each varies with each section. The relative costs shorn below are construction cost fora 20-year maintenance and a cost allowance for right of way at 50 cents per square foot. Costs shown are approximate and will likely vary with final design, degree of maintenance. and, of course, the actual cost of acquiring the right of way or easement. Comparative Costs per Lineal Foot Design Flow=2600 cfs Type of Drain Dimensions Costs D or H Bottom Tod R/W Cosst. Maint. R/W Total 1. Trapezoidal Channel 8' 21' 85' gl' $47.91 63.2 Grassy Lining 5 $45.50 $156.65 2. Trapezoidal Channel Heavy Landscaping 8' 30' 94' 100' 36.27 15.07 50.00 101. 4 3 3•' Trapezoidal Channel with Low Flow 8' 15' 89' 95' 56.53 24.09 47.50 128.12 4. Trapezoidal Channei Rip Rap 8' 42' 90' g6' 62.93 15.71 48.00 126.64 5• Trapezoidal Channel Gunite 8' 10' 42' S7' 71.86 7.$5 28.50 108.21 6. Rectangular Conc. Channel 8' 15' 15' 30' 243.4b 9.82 15.00 268.28 7. Multi Plate Super Span 7.5' 20' 20' 26' 284.22 2.95 13.00 300.17 8. Multiple Pipe 6' (X6) 53' 480.00 8.82 26.50 515.32 9. Reinf. Concrete Box 6' 10(X3) 38' 759.38 2.94 19.00 781.32 ~-9 EXHIBIT "C "