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Home My WebLink AboutEA 10-06; CARLSBAD BOULEVARD REALIGNMENT; BIOLOGICAL RESOURCES FINAL REPORT; 1998-12-22BIOLOGICAL RESOURCES FINAL REPORT CARLSBAD BOULEY ARD REALIGNMENT STUDY Prepared for City of Carlsbad Planning Department 2075 Las Palmas Drive Carlsbad, CA 92009-1576 Woodward-Clyde Project No. 589853003K00-00 113 December 22, 1998 1/C.ia Woodward-Clyde w, Pacific Center 11, Suite 1000 1615 Murray Canyon Road San Diego, CA 92108-4314 619-294-9400 Fax: 619-293-7920 I I I ! -' i I, TABLE OF CONTENTS Section 1 Section 2 Section 3 Section 4 Section 5 Figures Figure I Figure 2 Figure 3 Figure 4 Figure 5 Summary .......... ~ ............................................................ ~········••.•································••■-••• 1-1 Methods and Approach ..................................................... ~ ........................................... 2-1 Environmental Setting ................................................................................................... 3-1 Impacts and Constraints .......................................................................... ; .................... 4-1 Conclusion ...................................................................................................................... 5-1 Regional Location Map Project Location Biology -North Biology -South Biology -Encinas Creek Floodplain WooctwarcM:lyde GI I\SDG 1 \WPDAT A \9853003K\0113BAPT. DOC\22-Dec-98\SDG ,_j SECTI0NONE summarv The proposed project would result in ·realignment of lanes of Carlsbad Boulevard through land that is generally highly disturbed and that does· not support natural biological communities. Most of this disturbed land is dominated by iceplant, other ruderal (weedy) species and non-native grasses, or barren ground. No vernal pools were observed within the area thc!t could be directly impacted by the project. One area of natural habitat occurs near Station 35000. This area consists of marshland on the east side of the northbound lane that is associated with Encinas Creek. The present project plan would not adversely affect this area. Encinas Creek passes under the present road lanes and supports a narrow highly disturbed aquatic habitat within the creek . between the lanes. The project would result in extension of the existing culvert that covers the creek from the existing northbound lane. This culvert extension would not result in significant adverse effects on biological resources because this area is small and in a highly disturbed condition. Opportunities exist for potential expansion of habitats associated with Encinas Creek if the landform between the two existing lanes were lowered in elevation to the south of the creek. This type of habitat expansion is not considered to be necessary as no compensatory mitigation measures for adverse impacts on biological resources are .expected to be required for this project. No potential adverse direct or indirect impacts on biological resources have been identified for this project. Woodward-Clyde ti W:\9853003K\0113BRPT:DOC\22-Pec-98\SDG 1 SECTI0NTWO Methods and Approach Biological resources in the project study area were evaluated during site reconnaissance surveys on August 20, 1998 and September 26, 1998. The entire route was driven and areas potentially supporting natural biological communities were inspected on foot. Aerial photographs and topographic maps of the study area were used to support this evaluation. The study area for biological resources extended from the southbound lane of Carlsbad Boulevard eastward to areas that may be affected by the project. The area of potential effect for biological resources is generally limited to areas of potential direct disturbance by the project as no actual sensitive receptors have been identified relative to indirect effects. Habitats were mapped eastward much farther than effects are expected to occur because these areas are large, continuous areas of agricultural and fallow lands that were readily mapped out to great distances. WoodwanM:lyde C, \ISDG 1\WPDATA\9853003K\0113BRPT.DOC\22-Dec-98\SDG 2-] SECTIONTHREE EnVironmental Setting The project area is located in northern San Diego County in the City of Carlsbad (Figure 1 ). The project area is bounded generally by Manzano Drive to the north, the bridge over Batiquitos Lagoon to the south, the Pacific Ocean to the west, and the Atchison Topeka and Santa Fe railroad to the east (Figure 2). The project area is located on the coastal bluffs that form the western boundary of the City (Figures 3 and 4). Elevations in the project area range from sea level to approximately 80 feet above sea level. Topography in the project area is relatively level, except in the vicinity of Encinas Creek where the roadway traverses the floodplain of this intermittent creek (Figure 5). Here,. the roadway gently. slopes from the coastal terrace to the floodplain and is located approximately 30 feet above sea level. Undeveloped areas within the project area are dominated by non-native vegetation consisting primarily of ice plant in the median and some bluff top areas, other weedy invasive species, scattered Cypress trees, and ornamental landscaping.. No vernal pools were observed within the area that could be directly impacted by the project. Native vegetation is present in the vicinity of the Encinas Creek floodplain channel located east of the northbound lane. Riparian scrub, freshwater marsh, and other natural habitats are present in this location. Residential neighborhoods in the project area .include Terr:a Mar north • of Manzano Drive, Solamar mobile home park immediately south of the Palomar Airport Road-Carlsbad Boulevard interchange, and the Lanakai Lane mobile home park adjacent to Ponto Drive north of Poinsettia Lane. Other scattered residences are located south of Poinsettia Lane on' Ponto Road. South Carlsbad State Beach is located north and south of Poinsettia Lane, west of the southbound lanes of Carlsbad Boulevard. Woodward-ctvde " W:\9853003K\0113BRPT.DOC\22•Dec-98\SDG SECTI0NFOUR Impacts and Constraints Most of the land surrounding the existing lanes of Carlsbad Boulevard support ruderal vegetation dominated by iceplant (Mesembryanthemum crystallinum) with sparse patches of non-native grassland and weedy herbaceous plants. The large patches of agricultural and fallow lands east of Carlsbad Boulevard support either ruderal vegetation dominated by various weedy species and non-native grasses, and/or barren ground. Natural vegetation was located at a small area of marsh associated with Encinas Creek. Approximately 6.8 acres of jurisdictional wetland and potentially jurisdictional wetlands subject to regulation pursuant to Section 404 of the Clean Water Act and Section 1600 of the California Fish and Game Code occurs near Station 35000 east of the northbound lane of Carlsbad Boulevard. This area supp'orts approximately 2.8 acres of emergent marsh dominated by cattails (Typha sp.), 0.4 acres of salt pan dominated by salt grass (Distichlis spicata), 0.2 acres of brackish marsh, and 3.3 acres of southern willow scrub dominated by mulefat (Baccharis salicifolia) and willows (Salix spp.). This area is adjacent to, but outside of the area of potential impact. No threatened or endangered species are expected to occur in this area. Therefore, this area should not pose a constraint to the proposed project. Should the project be modified such that filling were to occur in this area, then a Section 404 Permit from the U.S. Army Corps of Engineers, Section 401 Certification from the Regional Water Quality Control Board, and Section 1601 Agreement from the California Department of Fish and Game would be required. Encinas Creek extends from this wetland area under both of the existing lanes of Carlsbad Boulevard near Station 35000 and flows to the Pacific Ocean. The creek is exposed within the median strip between the highway lanes. The creek is approximately 10 feet in width and has water flow from the marsh area. It is above normal ocean high tidal elevations; however, it may receive tidal inundation during very high tides and storms. A clearly identifiable ordinary high water mark (OHWM) is associated with the creek. Little or no hydrophytic vegetation is associated with the creek. A narrow strip on both sides of the creek between the base flow level and the OHWM supports sparse patches of marsh fleabane (Pluchea purpurascens), pickleweed (Salicornia virginica), and frankenia (Frankenia sp.). Each strip on both sides of the creek is an average of 3 feet in width. These narrow strips qualify as jurisdictional wetlands; however, they are areas of low biological importance. The project would result in placement of a culvert and fill over a portion of this creek in an area that is less than 0.1 acres of other waters of the United States (i.e., not a special aquatic site). The creek is a jurisdic_tional other waters of the United States (nonwetland) and the narrow wetlands adjacent to the creek are considered jurisdictional wetlands. Filling in this area of less than 0.1 acres will require a Section 404 Permit from the U.S. Army Corps of Engineers, a Section 401 Certification from the Regional Water Quali~y Control Board, and a Section 160 I Agreement from the California Department of Fish and Game. This work should be authorized by Nationwide Section 404 Permit (NWP) 14 for road crossings. This NWP should not require preconstruction notification for the Section 404 permit. The small area of creek that will be affected will not represent a significant loss of local or regional biological resources, and it is unlikely that additional mitigadon will be required other than use of best management practices during construction to minimize the disturbance area and control erosion. A small topographic depression of less than 0.1 acres occurs adjacent to the south side of Encinas Creek. This depression supports salt grass and iceplant and is approximately 2 to 3 feet above Woodward~lyde ·Q IISDG1\WPDATA\9853003K\0113BRPT.DOCl22•Dec-98ISDG 4-] SECTI0NFOUR Impacts and Constraints the OHWM of the creek. It does not appear to receive water inundation or soil saturation from normal flows within the creek. It may be inundated during extreme periods of flooding or from ,storm surges that push ocean water up intO" the creek. Its local watershed between the highway lanes is very small (approximately 5.5 acres) and this area is unlikely to provide substantial stormwater runoff to the depression that would create wetland hydrology. Therefore, it is unlikely that suitable hydrology exists for periods of sufficient duration to qualify the site as jurisdictional wetland. Soil pits were excavated by hand and the soils did not exhibit hydric indicators within 12 inches of the soil surface. Some indication of oxidized root stains were observed at depths greater than 12 inches from the surface. Therefore, the soils are also not indicative of wetland conditions in this area. It appears the presence of salt grass in this area is the result of saline soil conditions and this area is considered to be salt pan/ruderal habitat and not jurisdictional wetland. If this area were later determined to be jurisdictional wetland, NWP 14 would still apply for the additional fill of 0.2 acres of this habitat, which would then require predischarge notification for the Section 404 permit. At this time, the data indicate that this area is not jurisdictional wetland. Woodward-Clyde Cl \\SDG 1 IWPDATA\9853003K\0113BRPT.DOC\22-Dec-98\SDG 4-2 SECTIONFIVE Conclusion Overall impacts on biological resources from the proposed project are not expected to be significant or pose substantial issues during project permitting. Use of best management practices to minimize disturbance areas and control erosion from the site will ensure that areas such as the Pacific Ocean, Batiquitos Lagoon at the southern end of the project route (beyond the project route), and the wetland near Station 35000 are not adversely affected. Woodward-Clyde Q \\SDG 1 \W PDA T A\9853003KI0 1 13BRPT .DOC\22-Dec-98\SDG 5-1 ._: .. :-.... • i•':. :x. :·· ·. : .. •••••• .: ".,:-:: .. t_._._.: __ i· __ ::_··_~., .. ·.·_\· --. ·.' ~.-:,, .,.,,._:·/,r<;;-:-.-,,·sAN BERNARDIN0'"'"'11~TY RIVERSIDE COUNTY SITE LOCATION N A CARLSBAD BOULEVARD REALIGNMENT STUDY REGIONAL LOCATION MAP SAN DIEGO COUNTY 0 30 Miles IMPERIAL --.· • -COUNTY: 60 Approximate Map Scale 1 Inch = 30 Miles 1:1900800 PROJECT NO. 9853003K Woodward-Clyde " t--..;..F-',,.;IG;;..;;;U;.;_R::::;E~1-cc=~S::;E::....P.;.:.TE~M;:.:.:B~E;:...;R:.,,;1~99:::::8~ :\car1sbadl ro·ects\cartsbad01.a r LEGEND N Proposed Alignment 0 1200 2400 Feet Approximate Map Scale 1 Inch = 1,200 Feet (1: 14,400) N A CARLSBAD BOULEVARD REALIGNMENT STUDY PROJECT LOCATION PROJECT NO. 9853003K SEPTEMBER 1998 FIGURE 2 I:. Woodward-Clyde ,., :lcarlsbadl r • ectslcarlsbad01.a r x Milepost {Increment = 200 Feet) N Proposed Alignment N Proposed Alignment Centerline OJ Brackish Marsh Emergent Marsh Other Waters of the United States .,.-,,,: Ruderal Salt Pan Salt Pan/Ruderal Southern Willow Scrub Impacted by Slope Other Waters of the United States N -Ruderal A ':\\~\ ~, (\l-,'.:\t .,.. --~-~ . :;-!.~~- \ ,,\\• \' · .. l ~·-.:·'.:lj7~ '" ·~--·· ~ REALIGNMENT STUDY ~~"'<"!'-.,..--~J_y-~ i-----------------------l '( 'r . BIOLOGY -NORTH .r~_<; ,t----------~---------1 ...L \ l <_ { PROJECT NO. 9853003K •• • .. 3 l , ---------~ r~ ~ . I ~ -SEPTEMBER 1998 .. __ __:,._____;., --.... FIGURE 3 Wooclward-clyde Cl :lcarlsba ·ects\carlsbad01.a r LEGEND x Milepost (Increment = 200 Feet) N Proposed Alignment N Proposed Alignment Centerline .[L Brackish Marsh Emergent Marsh other Waters of the United States //~ Ruderal Salt Pan Salt Pan/Ruderal Southern Willow Scrub Impacted by Slope other Waters of the United States N -Ruderal A ' •• ---.· ~..:2--:1\ ~--• '\ I -• .-,-.i,.. .-,,1'.\ -• • • -~,~-. ~ ► :•.,. ---"."~-~ -·\. . • /" .... _;,,;fi ,.,, • ,- .... \'-~?~t,...:". ,: -,r-,--~,, -•:/ ,. ~,0--. ~ • / • , (;.-<IJ(·.. . _/, • . ~. . lJ ..... -,J. . • • : •• !;;;" • ;--.. ~ .. : ·, y · .•. . . -. ·• . .. .. t . • .. • . ... ,,· . - '. ·~ .. ~ ::.; , \" . -\ •• •. ' ! • - ' .... ..x • t ' \"•1:{ I ' I . • ·,~~ ·f :? ~ ~. -: ~ - ,::• =~~-;: ~=-~ ...... ~. :-.t .T:,-·. ~. • I . "" ; .. ~,. -' ·· .. ••. lf..-~-~--~~J::£ CARLSBAD BOULEVARD -t-~~ __ R_EA_L_I_G_N_M_E_N_T~S--'-T--=-U-=-D--'-Y--< ~ f -~~~ ___ s_,_o_L_O_G_Y_-~s_o_u_T~H~-~ '· ; t-P_R_o_J_E_C_T_N_o_._9_8_5_3o_o_3-K •·· ~-SEPTEMBER 1998 >-------------< FIGURE4 Woodward.Qyde fl :lcarlsba ·ec1s1cansbad01.a r 400 = '§00.Feet . . '• ,- .. -. LEGEND x Milepost (Increment = 200 Feet) N Proposed Alignment N Proposed Alignment Centerline OJ Brackish Marsh Emergent Marsh Other Waters of the United States // Ruderal Salt Pan Salt Pan/Ruderal Southern Willow Scrub Impacted by Slope Other Waters of the United States -Ruderal N A ~ . ~-.. r-":"f~ •---· • _fr l ~ • -~-----~~ ... . -~,., i.~.a.. • • - CARLSBAD BOULEVARD -·•-1 « REALIGNMENT STUDY ~~-.,......., '::-~ ----------------'---~ 'i ·"-• BIOLOGY -ENCINAS CREEK • --~ FL D IN / -. ·1 .1--------'---'=""''--"£~-L.!.!C!..l ____ _ • •. J. -rL,)\ -. l • -, \ ! ----------;-' I _ __:_J, 'I----S_E_P_T_E_M_B_E_R_19_9_8~ PROJECT NO. 9853003K FIGURE 5 Wooctwarct-c1yc1e Cl :lcarlsba ro·ectslcar1sbad01 .a r