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Home My WebLink AboutEIA 966; CITY OF CARLSBAD BIKE PATH; Environmental Impact Report (EIR)PRELU M NARY 66-02 CITY OF CARLSBAD JEFFERSON STREET BIKE PATH SCOPE: The purpose of this report is to determine the feasibility of the construction of the proposed Jefferson Street Bike Path. The project is located south of the Buena Vista Lagoon and East of Interstate 5. At the present time, no bike path exists on Jefferson Street. Bike riders using Jefferson Street are forced to drive on the edge of the traffic lanes, which is extremely dangerous considering this roadway averages only 25 feet wide. To correct this situation a bike path was proposed. Bike paths already exist on Jefferson Street west of' the Interstate 5 overpass and to the east on Marron Road. The proposed path would connect the two forenamed paths, except on the overpass where the amount of right-of-way is limited. ALIGNMENT: The suggested alignment is to parallel Jefferson Street with a five-foot off-set from the northern berm (See Figures 1 and 2). This alignment provides a minimum amount of encroachment into the lagoon environment without changing the existing street alignment. Encroachment into the lagoon area is a concern for two reasons. One being the nature of the soil found in this area (see Appendix for soils information), the other being the delicate balance of the riparian surroundings themselves. Minimum standards given in the Caltrans Bikeway Design Standards, such as on 81 path width and a 51 offset from roadway, were used as a basis for this study. The City may want to consider a wider path with less of an offet from the roadway and a barrier between roadway and bike pat h. A wider path would allow for easier two-way bike traffic. '] he enclosed cost estimate reflects the minimum design standard with no barrier other than the existing berm between roadway and bike path. SOILS: Two consolidation tests, performed on near-surface soils, support the fact that some' settlement should be expected. This settlement should be very similar to the settlement occurring on the Jefferson Street pavement, which, at this time, has produced only minor pavement distresses. Further soil tests (borings) are necessary prior to final design to determine the consistency of _A01 the soil under Jefferson Street. Another concern pertaining to the soils in the area is that of an ancient landslide deposit. An ancient landslide deposit traverses the existing alignment. Movement by this slide would affect not only the roadway and this project, but surounding residential property as well. However, no evidence of recent activity is noted or is anticipated as a result of this project (see Appendix for slide location). CONSTRUCTION TECHNIQUE: To minimize the disturbance to the surrounding lagoon area, different construction methods should be employed. One such method would be to assemble the crib walls entirely by hand, keeping heavy equipment out of the lagoon area. The contractor should make every effort to minimize construction equipment from entering the lagoon area. The proposed alignment calls for over 2,900 feet of pathway. Approximately 600 feet of'the path requires a low retaining wall to stay within the Jefferson Street right-of-way. To construct a retaining wall, it is suggested that criblock, a retaining wall that is assembled by hand and will allow foliage to grow in the open-grid wall face. Other materials needed for construction of this bike path are asphalt concrete and standard agregate base. Figures 1 and 2 show the locations of the cross sections taken at every 300 feet. Cross sections 1, 2, 4, 5, 8, 9, and 10 show that no crib wall is necessary in those areas. Cross sections 3 and 7 show areas that will need crib wall in order to keep the path entirely in the Jefferson Street right-of- way. Cross section 6 is a boarderline situation, which may or may not require crib wall. Cross section 6 is shown using no crib wall. SUMMARY The proposed Jefferson Street Bike Path will run parallel and at the same elevation as Jefferson Street. This path should be constructed during the dry summer months to ease cons.t,e-t±Ofl near the lagoon. The estimated construction cost using a 8-foot wide asphalt path (see Cost Estimate)A 1Te consideration is the duck feeding area, although not an engineering matter it is an aesthetic concern. 'S -35- I: - J_` J~__ CROSS SECTION NO. 1 SCALE HORIZ 1'L 5' VERT. 1' 5' -J. LUKE -DUDEK Sheet / of // Sheets Date _____________ By -25 CROSS SECTION NO.2 SCALE HORIZ 1'5'VERT.i'5' w1i LUKE -DTJDEK Sheet 2 of Sheets Date _____________ By qw 30' / /8/iiTH / V . CROSS SECTION NO.3 SCALE: HORIZ. 1'5' VERT. LUKE -DUDEK Sheet -3 of—Z1—Sheets Date _____________ By- --20 -/5 2'I FIL LOPE CROSS SECTION NO.4 SCALE: HORIZ. 1'-'5' VERT. 1'-'5' LUKE DUDEK' Sheet_ 4 of /1 Sheets Date_ By VAI -w -/5 CROSS SECTION NO.5 SCALE: HORIZ. i'5' VERT. 1 1 . LUKE -DUDEK Sheet of /1 Sheets Date_ By :/ FiLL SLOPE--. -/5 CROSS SECTION NO-6 SCALE: HORIZ. 1' 5' VERT.1' 5' LUKE -DUDEK Sheet 6 o /1 Sheets Date By 30' P,f'OR2SED 8' 8/XE PAM XIAZL CROSS SECTION NO.7 SCALE. HORIZ. 1' 5' VERT. LUKE -DIJDEK Sheet 7 of _Sheets Date_ ________ FILL - ruzur'll -/5 - -/0 CROSS SECTION NO.8 SCALE: HORIZ. 1' 5' VERT.1 LUKE DUDEK Sheet 8 of-IL-Sheets Date_____________By I 2:/FILL SLOPE- V CROSS SECTION NO.9 SCALE: HORIZ.1' 5' VERT. 1' 5'L LUKE -DUDEK Sheet 9 of Sheets Date By 1e'w 4 30' PROPOSED 8 / ,-BIKE e4rN -20 -./5 CROSS SECTION NO. 1O SCALE: HORIZ. 1' 5' VERT.1'5 LUKE DUDEK Sheet /0 of // Sheets Date By JEFFERSON STREET BIKE PATH CONTRACT NO. OF lIñTi'l CHECKED BY ,7II September 16, 1985 - 1111,11 111 3" Asphalt Concrete / 6n Agregate Base NOW i Site Clearing I and Preparation - .411 I0 TOTAL CONSTRUCTION :• ----- LUKE-DUDEK APPENDIX 106 consulting engineers and geologists September 20, 1985 Dennis Davies Luke-Dudek Civil Engineers 575 Second Street Encinitas, California 92024 Gentlemen: Submitted herewith are the results of a preliminary geotechnical review, provided in order to determine the feasibility of the proposed bicycle path on Jefferson Street. The site is located on the south side of Buena Vista Lagoon between Highway 78 and Interstate 5. This proposed alignment of the bicycle path is shown on the attached plan. GEOTECHNICAL CONDITIONS Geotechiiical conditions underlying the project area were chiefly determined from geological mapping of surface exposures along Jefferson Street. The following earth materials were recognized: Formational Rocks underlie the road alignment at depth and crop-out in isolated road cuts above the southside of Jefferson Street. The rocks consist chiefly of pale gray colored sandstone units which have been designated Santiago Formation. Noted exposures are massive and moderately well-cemented. However, elements of Santiago Formation have been associated with massive hillside instability in the nearby areas of Carlsbad and :• Oceanside. - An ancient landslide deposit has been mapped beneath the project area as -.shown on Plate 1 This slide extends from off-site residential area above, through Jefferson Street and the project. area and into Buena Vista Lagoon below. Recent activity withini the slide is not indicated in available surface exposures. 77720 Rosa//a 5traai Suith F' San Lgo e4 92727'579-455-7750 SF-276 Page 2 Alluvial Soil underlie much of the project area as shown on Plate 1. The alluvium consist of soft silty-clay soil and the perimeter areas of the lagoon which grade upward into sandier soils south of Jefferson Street. Fill Soils directly support much of the existing road-bed. These are locally derived sandy soils, which were placed in order to achieve a level road surface above Buena Vista Lagoon. Grading records for the fill were unavailable to us. Local areas of street cracking (see Plate 1) may reflect settlement and consolidation within the underlying fill section. Faults or unfavorable geologic structure was not i'n evidence along the alignment. CONCLUSIONS Construction of the planned alignment is feasible from a geotechnical viewpoint. Conditions which may adversely impact the project include: 1. Reactivation of a possible landslide feature which traverses the alignment. . 2. Instability within loose fill alluvial soils beneath the project. The landslide is an ancient feature, which is postulated chiefly upon topographic evidence and surface exposures. Confirming data for the slide includ'ing the subsurface information is unavailable.. Renewed movement within the slide would adversely impact off-site residential property d Jefferson Street as well as the plan project alignment..,:---However,-no evidence of recent activity within the slide is noted or is anticipated as a result of the plan project NT - . - consulting engineers and geologists SF-276 Page 3 Fill-alluvial soils beneath the existing roadway are locally loose as evidenced by areas of street cracking, and supported by results of consolidation tests performed on near-surface soils. Similar conditions will prevail beneath the bike path alignment. Unreinforced paved surfaces may be expected to experience similar distress in the same affected areas. This opportunity to be of service is sincerely appreciated. If there are any questions, please do not hesitate to contact this office.1. Sincerely, Dennis Middleton, CEG 980 DM/rd Enclosures 1NT1 AWAW ffL'nw. - consulting engineers and geologists ----------) I- 000 '1 , Tl \ /N \\ \\ ' \ SEE PLATE 2 9 SEE PLATE I cn /1 . .1) - N ( . I. 'N N? N / N 1/ '°O • SEE PLATE 3 2 Co 1 \ \ \ç 1' Al Lu -J IL Lu Lu Lfl ON OF / Arm / OAL 70 / 1.5 00 I . / 0 00 "S 4110 ,3;-, rwW WHITE 1-DON'T SAY IT INTER-DEPARTMENT MEMORANDUM TO DATE 72 19 P. M. O-tQ- W f III REPLY ON THIS SHEET FROM \ WILMER SERRICE(LNE STANDARD INTER DEPT. MEMO FORM 11-24-PD 8U5NA V/irA LAGOON IN Yl." I / I . NOeMAL Ji'541 PROM/DE 4I 7R4, VS/ TO BIKE TH -/000 - uJ / IT / I / AAA - INDICATES CR/BWALL EASTERN &7/0N PROPO5&9 il(FFEI?80N3'T SCAL E.- i' ioo' 5/KE PATH 00 &1A 44k I "lY I S •2' RI7DED 191eE1Q M/U. P1Q7IIMQY - FElICE 2:1 'EX/ô 1/W TR2/L/Zfl /36f/y- ?- REt10 yE IT CW3' 7?/W 5' TC ,997711,1QY 70 P€'&EA17 H1qzizeIj 70 131C YCd67! REi91QC6 A/1711 7Pg/7/ &9e1e/e1e F/L TYPICAL CROSS SECTION JEFFERSON STREET PATH MARSH CONDITION '.4 Q 0 -----------.-----.LUKE -DUDEK J K -2' ',eqDeD QE1? jWAJ. /7 \ \\\ / ( 2 7o FILL R6MOV6 IF CL2E 7/!/7A1 5' TO PQTHNicY 7-0 PREVéL17 N //,qZ,Qx'D 70 13/CYC/JT. — J'?EFLJ?CE NIThI 7'QFF/C CR/i3 J47LL vgJ?/E, I! ZWOXV TYPICAL CROSS SECTION JEFFERSON STREET PATH NARROW SHOULDER CONSTRUCTION '4 ,q6b 'cl to Al LUKE -DUDEK J CASE NO. 47 /4 DA &/? Zi 5- APPLICANT:________________________________ REQUEST: /[ J*S)IV Posted: Prior Compliance: Published:________ Filed: Filed: NEGATIVE DECLARATION:__________________________ Posted: Published: Notice of Determination: ENVIRONMENTAL IMPACT REPORT:___________________ Notióe of Notice of Preparation: Canpletion: PLANNING COMMISSION 1. Date of Hearing: 2. Publication: 3. Notice to Property Owners: 4. Resolution No. Date: (Continued to:__________________________ 5. Appeal: Notice of Determination:__________ CITY COUNCIL 1. Date of Hearing: 2. Notices to City Clerk:___________________ 3. Agenda Bill:___________________________ 4. Resolution No. Date: ACTION: 5. Ordinance No. Date:_____________ CORRESPONDENCE Staff Report to Appiicant____________________ Resolution to Applicant:_____________________ I