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HomeMy WebLinkAboutCDP 96-10; North Batiquitos Sewage Force Main; Coastal Development Permit (CDP) (12)BIOLOGICAL TECHNICAL REPORT FOR THE NORTH BATIQUITOS SEWAGE FORCE MAIN Prepared for CARLSBAD MUNICIPAL WATER DISTRICT 5950 EL CAMINO REAL CARLSBAD, CA 92008 4241 Jutland Drive, Suite 201 San Diego, CA 92117-3653 619/270-5066 fax 270-5414 Prepared by GERALD BIOLOGIST RECON NUMBER 283 IB OCTOBER 14, 1996 o H ©JLULJ OCT » 5 CARLSBAD 1 J This dot ument1 TABLE OF CONTENTS Introduction 1 Methods 1 Results 5 A. Alternative Route 1 5 B. Alternative Route 2 7 C. Alternative Route 3 7 D. Proposed Water Line 7 Sensitive Biological Resources 8 Impact Analysis 8 Recommendations 10 References Cited 10 FIGURES 1: Project location in San Diego County 2 2: Location of project on U.S.G.S. topographic map 3 3: Location of habitats and alternative sewer alignments 4 PHOTOGRAPHS 1: View looking west showing existing utility easement 6 2: View looking north along Caltrans right-of-way fence 6 TABLE 1: Impact Analysis for the Proposed Alternative Routes 9 ATTACHMENT 1: Plant Species Observed Introduction The Carlsbad Municipal Water District is planning to construct a pipeline to replace the existing North Batiquitos Sewage Force Main on the north side of Batiquitos Lagoon near Interstate 5 (Figures 1 and 2). This existing pipeline has been repaired numerous times in the past and is deteriorating. In addition, a development project now under construction is being built over this pipeline, placing it within an easement behind houses which makes it difficult to access for possible future repairs. The new pipeline would be constructed mostly within public rights-of-way. A water pipeline is also proposed to be replaced within the new development and be extended up the slope to an existing water connection. Three alternative alignments of the new sewage force main are evaluated in this study (Figure 3). All alignments begin at the existing sewage lift station on the southeast portion of the area. The pipelines would then travel either under existing access roads to and under the streets of the new development project (Alternative Routes 1 and 2) or within or adjacent to a proposed pedestrian trail (Alternative Route 3) and then up a steep slope to an existing manhole at the top of a hill to the west of the development project. The proposed water line is currently designed within the streets of the new development but will leave the project area and travel up the slope parallel to the sewer line to the top of the western hill. There it will connect to an existing water main just north of the sewer manhole. This report presents the results of a biological resource survey conducted along the three alternative sewer alignments and proposed water line. An impact analysis was conducted that compares the impacts to biological resources from each of the proposed alternative sewer lines and the water line. Mitigation measures are recommended for unavoidable impacts to sensitive biological resources. Methods The biological resources present within the proposed alternative sewer alignments and water line were documented during a field visit to the site. Each alternative pipeline alignment was walked on foot and biological resources present were documented. In addition, information on the biological resources in this area was collected through secondary sources (i.e., environmental reports) (RECON 1989). The vegetation types were mapped and a list of plant species was prepared for each alignment. A complete list of plant species observed is included as Attachment 1. Locations of any sensitive biological resources present were noted and mapped. L--J 'MARINE CORPS BASE CAMP JOSEPH H. PENDLETON • MISSION—^£D A— J rLLBRo°K PROJECT LOCATION 4 MILES 0 FIGURE 1 Regional Location of the Project IRECON PROJECT LOCATION Map Source: U.S.G.S. 7. minute Encinitas quadrangl 4000 2000 FEET 0 FIGURE 2 Project Vicinity mi^^HHBHH RECDN Results Biological resources are described for each alternative sewer pipeline alignment below. The proposed water line is discussed separately. A. Alternative Route 1 Biological resources along this route have largely been removed by the grading operations for the development occurring in the area. All habitat from the pump station to where the line goes through the future Gabbiano Lane and turns west is disturbed (see Figure 3). The last segment of this pipeline alignment goes up a steep hill through an existing 40-foot utility easement previously disturbed during the installation of a pipeline (Photograph 1). The scar left on the hillside from the previous pipeline installation at this location is slowly recovering from the disturbance. Young seedlings of California ^ sagebrush (Artemisia californica), black sage (Salvia mellifera), California buckwheat ^ (Eriogonum fasciculatum), and common encelia (Encelia californica) have begun to- appear in the disturbed area. However, the most prominent species in the scarred area are " • non-native plant species such as smooth brome (Brotnus hordaceus), Russian thistle C- (Salsola tragus), black mustard (Brassica nigra), ripgut grass (Bromus diandrus), and foxtail chess (Bromus madritensis ssp. rubens). The disturbed area going up the hillside is approximately 10 to 15 feet wide. The lower half of the scar is disturbed by the project development on the south side and has undisturbed coastal sage scrub habitat on the north side. The upper half of the scar has undisturbed coastal sage scrub habitat on both sides. A flat area at the top of the hill supports an open stand of coastal sage scrub species to the manhole. The undisturbed areas of coastal sage scrub support a dense stand of brush comprised of California sagebrush, California buckwheat, common encelia, black sage, lemonadeberry (Rhus integrifolia), purple needlegrass (Nassella pulchra), and sawtoothed goldenbush (Hazardia squarrosa). Wildlife species expected to occur in the undisturbed coastal sage scrub habitat are similar to those reported previously (RECON 1989). Birds species expected to use the coastal sage scrub habitat include bushtit', Bewick's wren, northern mockingbird, wrentit, house finch, rufous-sided towhee, brown towhee, and white-crowned sparrow. Mammals expected in the area include coyote, cottontail rabbit, woodrat, and ground squirrel. Reptiles that have the potential for occurrence on the slope include orange-throated whiptail, San Diego horned lizard, fence lizard, side-blotched lizard, and red-diamond rattlesnake. PHOTOGRAPH 1 View Looking West Showing the Existing Utility Easement through Coastal Sage Scrub Habitat 1 PHOTOGRAPH 2 View North along Caltrans Right-of-Way Fence Showing Coastal Sage Scrub Habitat 1REC&N B. Alternative Route 2 The first two-thirds of this route (pump station to Gabbiano Lane up to Piovana Court) is identical with Alternative Route 1, traversing area already disturbed by the ongoing development project. At Piovana Court, Alternative Route 2 turns west and travels up the hill in one of two subalternative alignments. Subalternative alignment 2A travels to the end of Piovana Court and turns northwesterly to the edge of the development area and then west up the hill in the pipeline easement described under Alternative Route 1. Subalternative alignment 2B goes to the end of Piovana Court but continues up the hill in a southwesterly direction to the Caltrans right-of-way fence and then northward up the hill to the existing manhole. After leaving the development area southwest of the end of Piovana Court, subalternative alignment 2B travels up the slope in an existing 20-foot utility easement to the Caltrans right-of-way fence and then north through a proposed 15- foot-wide easement (Photograph 2). Both areas are vegetated with undisturbed coastal sage scrub habitat similar to that described under Alternative Route 1. Wildlife use of the undisturbed habitat areas would be similar to that described for coastal sage scrub under Alternative Route 1. C. Alternative Route 3 This proposed pipeline route begins at the sewage lift station, travels northwesterly to the south end of Gabbiano Lane, proceeds in a northerly direction within or adjacent to a proposed pedestrian trail, through an existing eucalyptus grove to the west end of Piovana Court. The vegetation in the area of the pedestrian trail, where not disturbed by current construction activities, is a disturbed, open stand of goldenbush scrub. Plant species in the goldenbush scrub area include coast goldenbush (Isocoma menziesii), Russian thistle, black mustard, sea-fig (Carpobrotus edulis), telegraph weed (Heterotheca grandiflord), and giant reed (Arundo donax). At Piovana Court, one of two subalternative alignments can be chosen at this point to route the pipeline up the hill to the manhole connection location. Subalternative 3A continues in a northerly direction through the west end of Piovana Court to the edge of the development area and turns west up the hill in the existing 40-foot utility easement described under Alternative 1. Subalternative alignment 3B goes in a westerly direction from the end of Piovana Court and up the hill in the same route described under subalternative alignment 2B. Vegetation and wildlife in these areas are the same as previously described. D. Proposed Water Line The proposed water line would be installed within Gabbiano Lane and other streets in the current development area. It would leave Gabbiano Lane and travel up the hill to the west parallel to the proposed sewer line discussed under Alternative Routes 1, 2A, and 3A within the existing 40-foot utility easement described under the above sewer routes. At the top of the hill, the water line would turn north and connect to an existing water line behind the existing housing development. The flat area at the top of the hill is essentially disturbed with widely scattered individuals of brittlebush (Encelia farinosd), coyote bush (Baccharis pilularis), and telegraph weed. Sensitive Biological Resources One sensitive plant species was observed on the site, ashy spike-moss (Selaginella cinerascens). This plant species is considered a California Native Plant Society List 4 species. List 4 species are species that are being monitored because current trends suggest that populations of these species are in decline. No other sensitive plant species are expected to occur in the undisturbed coastal sage scrub portions of the three alternative pipeline routes. One sensitive wildlife species is known to use the area based on past observations, coastal California gnatcatcher (RECON 1989). The coastal California gnatcatcher is a federally listed threatened species. This species was observed using the undisturbed coastal sage scrub habitat on the slope in the study area in 1989. Although no subsequent surveys have been conducted, it is assumed that this species uses or has a high potential to use the coastal sage scrub habitat on this slope. There is a low to moderate potential for the orange-throated whiptail or San Diego horned lizard to occur in the coastal sage scrub habitat within the study area. Coastal sage scrub habitat is considered a sensitive habitat type by federal, state, and local resource agencies due to large-scale losses of this habitat type in the past and present. It is currently the focal habitat for the statewide Natural Community Conservation Plan (NCCP) and the local Multiple Species Conservation Program and Multiple Habitat Conservation Plan. One of the key species found in coastal sage scrub habitat is the coastal California gnatcatcher, but other sensitive plant and animal species occur in this habitat type also. Impact Analysis Direct impacts to biological resources from the proposed installation of the sewer force main and water line were calculated for a number of optional construction corridor widths. Final selection of the construction corridor width is to be made during the final design and engineering of the pipelines. Impacts from each of the three alternative routes and subalternatives are presented in Table 1 for easy comparison. TABLE 1 IMPACT ANALYSIS FOR THE PROPOSED ALTERNATIVE ROUTES FOR THE BATIQUITOS NORTH SEWER FORCE MAIN AND WATER LINE (acres) Construction Corridor Route/Habitat 10-ft Alternative 1 Disturbed Coastal sage scrub Ruderal Alternative 2A Disturbed Coastal sage scrub Ruderal Alternative 2B Disturbed Coastal sage scrub (easement) Coastal sage scrub Alternative 3A Disturbed Eucalytpus Baccharis scrub Coastal sage scrub_ Ruderal Alternative 3B Disturbed Eucalyptus Baccharis scrub Coastal sage scrub (easement) Coastal sage scrub 0.3 0.02. 0.06 0.3 0 0.06 0.3 0.02 0.08 0.23 0.02 0.03 0 0.06 0.21 0.02 0.03 0.02 0.08 Construction Corridor 20-ft 0.6 0.03>i. 0.14 < 0.59 0 0.11 0.59 0.04 0.16 0.47 0.05 0.06 0 0.11 0.42 0.05 0.06 0.04 0.16 Construction Corridor 40-ft 1.3 0.24 0.14 1.18 0.11 0.11 1.18 0.09 0.32 0.95 0.1 0.12 0.11 0.11 0.63 0.1 0.12 0.09 0.32 Construction Corridor 60-ft 1.9 0.4 0.14 1.77 0.23 0.11 1.77 0.13 0.48 1.45 0.15 0.18 0.23 0.11 0.84 0.15 0.18 0.13 0.48 The majority of the impacts from each of the alternatives occurs in disturbed or ruderal areas. The only native habitat that would be impacted is coastal sage scrub on the east- facing slope leading up to the manhole connection. Alternatives 2B and 3B impact the most coastal sage scrub habitat followed by Alternative 1. The least impact to coastal sage scrub habitat would occur under Alternatives 2A and 3A. Since coastal sage scrub is considered a rare plant community and the habitat on the site supported coastal California gnatcatchers in the past, impacts to coastal sage scrub habitat on the site would be considered significant. Consultation with the City of Carlsbad, U.S. Fish and Wildlife Service (USFWS), and California Department of Fish and Game (CDFG) must take place to address the incidental take of habitat for a threatened species. Recommendations The impacts to coastal sage scrub on the site need to be mitigated in conformance with all resource protection requirements of the jurisdictions, an enrolled jurisdiction's 4(d) guidelines, or the guidelines provided by the resource agencies and the California Environmental Quality Act as outlined in a joint CDFG/USFWS letter dated Decem- ber 30, 1993. A set of findings of consistency with the NCCP is required to be submitted for review and approval by the City of Carlsbad, CDFG, and USFWS to conform with the 4(d) Rule process. Mitigation options range from the purchase of coastal sage scrub for conservation purposes to coastal sage scrub restoration to providing funding for programs aimed at the conservation of coastal sage scrub habitat in the subregion or county. Final mitigation measures are reviewed and approved during the 4(d) Rule process. References Cited RECON 1989 Biological Technical Report for the Broccato at Batiquitos Shores Development. Prepared for Odmark and Thelan and Davidson Communities, San Diego, California. 10 ATTACHMENT 1 ATTACHMENT 1 PLANT SPECIES OBSERVED Scientific Name Common Name Origin Apium graveolens L. Artemisia californica Less. Arundo donax L. Baccharis pilularis DC. Baccharis sarothroides A. Gray Brassica nigra (L.) Koch. Bromus diandrus Roth. Brotnus hordaceus L. Bromus madritensis L. ssp. rubens (L.) Husnot Carpobrotus edulis (L.) Bolus. Chenopodium ambrosioides L. Cirsium vulgare (Savi) Ten. Conyza canadensis (L.) Cronq. Cortaderia selloana (Schultes) Asch. & Graebner Datura wrightii Regel Distichlis spicata (L.) E. Greene Encelia califomica Nutt. Encelia farinosa Torrey & A. Gray Eriogonum fasciculatum Benth. \3T.fasciculatum Eriophyllum confertiflorum (DC.) A. Gray var. confertiftorum Eucalyptus spp. Foeniculum vulgare Mill. Hazardia squarrosa (Hook. & Arn.) E. Greene Heliotropium curassavicum L. Hemizonia fasciculata (DC.) Torrey & A. Gray Heterotheca grandiflora Nutt. Isocoma menziesii (Hook. & Arn.) G. Nesom Isomeris arborea Nutt. Malosma laurina (Nutt.) Abrams Nassella pulchra (A. Hitchc.) Barkworth Nicotiana glauca Grah. Opuntia littoralis (Engelm.) Cockerel!. Opuntia prolifera Engelm. Pluchea odorata (L.) Cass. Rhus integrifolia (Nutt.) Brewer & Watson Salsola tragus L. Salvia mellifera E. Greene Sambucus mexicana C. Presl Selaginella cinerascens Maxon Urtica dioica L. ssp. holosericea (Nutt.) Thorne Yucca schidigera K.E. Ortgies Celery^ I California sagebrush N Giant reed I Coyote bush N Broom baccharis N Black mustard I Jlipgut grass I Smooth brome I Foxtail chess I Hottentptfig I Mexican tea I Bull thistle I Horseweed N Selloa pampas grass I Jimson weed N Saltgrass N Common encelia N Brittlebush, incienso N California buckwheat N Golden-yarrow N Eucalyptus I Fennel I Sawtoothed goldenbush N Chinese pusley N Golden tarplant N Telegraph weed N Coast goldenbush N B ladderpod N Laurel sumac N Purple needlegrass N Tree tobacco I Shore cactus N Cholla N Salt marsh fleabane N Lemonadeberry N Russian thistle, tumbleweed I Black sage N Blue elderberry N Ashy spike-moss N Hoary nettle N Mohave yucca N N = native to locality; I = introduced species from outside locality.