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HomeMy WebLinkAboutEIR 91-01; Rancho Santa Fe Rd Realignment and Mass Grading; EIR; 1989-09-01RANCHO SANTA FE ROAD REALIGNMENT AND EXPANSION TO A SIX-LANE PRIME ARTERIAL ENVIRONMENTAL IMPACT ASSESSMENT FORM PREPARED FOR: CITY OF CARLSBAD 2 07 5 Las Palmas Drive carlsbad, CA 92009 PREPARED BY: FAY ROUND AND ASSOCIATES 2630 Cazadero Drive Carlsbad, CA 92009 (619) 438-2407 September 1989 CASE NO. DATE: ENVIRnriMFNTAL IMPACI ASSF.SSflENT FORM - PART I (To be Completed by APrilCANT) Applicant: City of Carlsbad Address of Applicant: 2075 Las Palmas Drive Carlsbad, CA 92009-4859 Phone Number: ( 619 ) Name, address and phone number of person to be contacted (if other than Applicant): Mark Rowson, Project Design Consultants, 1010 Second Ave, Ste. 2109 San Diego, Ca 92101 619-235-6472 GENERAL INFORMATION: (Please be specific) Project Description: Realignment and expansion of Rancho Santa Fe Road to a six-land prime arterial fron La Costa Avenue on the south to Melrose Avenue on the north and associated grading to accotmiodate the road construction and and timing. See accompanying Rancho Santa Fe Road Adoption Report for detailed descriptions. Project Location/Address: Eastem area of La Costa in the Citv of Carlsbad. between La Costa Avenue and Melrose Avenue. Assessor Parcel Number: Varies General Plan/Zone of Subject Property: Six-lane prme arteyial as shown on Circulation Elements of the General PlanTor Qii City of Carlsbad. Local Facilities Management Zone: Zone 11 Is the site within Carlsbad's Coastal Zonp? No Please describe the area surrounding the sU." to the North: Existing residential & vacant East: Open space South: Existing residential & vacant West: Existing residential & vacant List all other applicable permits & ^pprov-ils related to this project: Grading and improvement plan from tJie City of Carlsbad. Also U.S. Anny Corps of Engineers Section 404 permit, and State Fish & Game Section 1603 permit related to the crossing of San Marcos Creek. 2 fPlease be Specific. Attach Additional Pages or Exhibits, if necassarv) 1. Please describe the project site, including distinguishing natural and manmade characteristics. Also provide precise slope analysis when a slope of 15' or higher and 15% grade or greater is present on the site. Project site is approximately two miles in length and enccirpasses the Rancho Santa Fe Road right-of-way proposed by the City's Rancho Santa Fe Road Alignment Coitmittee from La Costa Avenue on the South to Melrose Avenue on the north. Vacant open land cuinrently exists along both sides of the of the.proposed alignment. (See next page) ^ , . 2. Please describe energy conservation measures incorporated into the design and/or operation of the project. None 3. PLEASE AHACH A PROJECT SUMMARY SHEET WHICH SHOWS THE FOLLOWING: a. If a residential project identify the number of units, type of units, schedule- of unit sizes, range of sale prices or rents, and type of household size expected, average daily traffic generation (latest SANDAG rates). b. If a commercial project, indicate the exact type, activity(ies), square footage of sales area, average daily traffic generation (latest SANDAG rates), parking provided, and loading facilities. c If an industrial project, indicate the exact type or industry(les), average daily traffic generation (latest SANDAG rates), estimated employment peV shift, time of shift:;, and loading facilities. If an institutional project, indicate the major project/site function, estimated employment per shift, estimated occupancy, loading facilities, and community benefits to be derived from the project. Major project function is to provide a 6-lane P^^^^^j;^^^ .^f for in^e Circulation Element of the City of ^^^f^* .?^S^d benefits will include reduced congestion, unproved traffic flow and increased safety. 1. (Continued from page 3) Ihe nearest urbanized uses include the La Costa Vale residential subdivision roughly one-quarter mile to the west of the proposed alignment, the Stanley Mahr Water Reservoir just east of the alignment, and the Rancho Santa Fe Industrial Park southeast of its intersection with Melrose Avenue. The proposed alignment crosses San Marcos Creek just south of its intersection with Melrose Avenue. ENVIRONMENTAL IMPACT ANALYSIS Please Answer each of the following questions by placing a check in the appropriate space. Then, fully discuss and explain why each item was checked yes or no. Provide supporting data if applicable. Attach additional sheets as necessary. 1) Could the project significantly impact or change present or future land uses in the vicinity of the activi ty? EXPLANATION: The project is in full conformance with the Circulation Element of the City of Carlsbad. as well as with other elements of the General Plan. 2) Could the activity affect the use of a recreational area, or area of aesthetic value? EXPLAflATION: 3) Could the activity affect the functioning of nn established community or neighborhood? EXFLANAnON: The project will improve traffic flow fron existing and planned neighborhoods. 4) Could the activity result in the displacement of community residents? EXPLANATION: YES NO X YES NO 5) Could the activity increase the number of low and moderate cost housing units in the city? EXPLANATION: . 6) Could the activity significantly affect existing housing or create a demand for additional housing? EXPLANATION: 7) Are any of the natural or man-made features in the activity area unique, that is, not found in other parts of the county, state or nation? EXPLANATION: 8) Could the activity significantly aff^^ct an historical or archaeological site or its settings? EXPLANATION: As described in Attachment A^_no important cultural resources were located within the proposed alignment, and no direct or indirect impacts will result from its development. 9) Could the activity significantly affect the potential use, extraction, or conservation of a scarce natural resource? EXPLANATION: . YES NO 10) Could the activity significantly affect fi-^h wildlife or plant resources? ' x EXPLANATION: As described in AttachTngnt_R^4-ho proposed alignment will impact existing riparian habitat along San Marcos Creek, as well as Coastal Sage Scrub (Gnatcatcher Habitat). 11) Are there any rare or endangered plant or animal species in the activity area? x EXPLANATION:The riparian habitat along .S;:.n Marcos Creek is potential habitat for the state RW^ endangered Least's RPILS vSeoT M^±O^^^ .j^^^^^^y eight breeaing pairs of Gnatcatchers (which is'under review for potential listing as either threatened^^?'' endangered) may be present onsite (See Attachment B) 12) Could the activity change existing features of any or beach'esf ''''' '^"^^^^"^^ X EXPLANATION: The project will involve impacts to San Marcos Creek near the northem end of the proposed alignment. 13) Could the activity result in the ern.ion or elimin- ation of agricultural lands? EXPLANATION: 14) Could the activity serve to encourage development of presently undeveloped areas or intensify develop- ment of already developed areas? EXPLANATION: While the project is in full conformance with the General Plan of the Citv of Carlsbad, it could encourage the development of currently vacant along both sides of the proposed alignment. 15) Will the activity require a variance from estab- lished environmental standards (air, water, noise etc.)? ' US HQ EXPLANATION: 16) Is the activity carried out as part of a larger project or series of projects? x EXPLANATION: This project will serve to implement a portion of the overall roadway systan as called for in the Circulation Element of the Citv of Carlsbad. 17) Will the activity require certification, authoriza- tion or issuance of a permit by any local, state or federal environmental control agency? x EXPLAfJATION: The project will most likely require a U.S. Army Corps permit (Section 404), and a Streaitibed Alteration Permit (Section 1603) from the State Department of Fish and Game. ~ ~ 18) Will the activity t-equire issuance of .T variance or conditional use permit by the City? EXPLANATION: 19) Will the activity involve the application, use, or disposal of potentially hazardous materials? EXPLANATION: 21) Will the activi 1 22) 23) nthrir^r^H^ - ^-imi EXPLANATION: es on or near an active fault. Could the activity resuU in fk., significant amounts of dusi? 9^"^^^tion of ^^^^^^^^^OU: ill?_^ojec^^4ii_^^ ^-^^^^^^^^^struc^^ significant as defjner2_>vr^,^ EXPLANATION: EXPLANATION: §arL^fercos^ee]w^^^ ~ ^^^^^^-^2Eosed_ali3n^^ ^ ^^ood NO 24) Could the activity resuU in , o' r- in the qualitv nf.n!n\ ^ significant change or wate? ?e oirces? °f ^^^ion's air water, offshore ) " ^''^'"^ EXPLANATION: YES 25) Will the project substantially increase fuel consumption (electricity, oil, natural gas, etc.)? EXPLANATION: NO X 26) Will the activity involve construction of facilities on a slope of 25 percent or greater? EXPLANATION: Approximately 15-20 percent of the graded area involves slopes 25% or greater. 27) Will there be a significant change to existing land form? (a) Indicate estimated grading to be done in cubic yards: 5,000,000 CY excavate & compact (b) Percentage of alteration to the present land form: 80 percent Maximum height of cut or fill slopes- 80-100 feet (c) EXPLANATION: |23) Will the activity result in substantial increases in the use of utilities, sewers, drains or streets? EXPLANATION: Although the project will require the relocation of certain of these facilities,' it will not result in increased tjsage. 29) Will the project significantly increase wind or water erosion of soils? EXPUVrWTION: YES NO X 30) Could the project significantly affect existing fish or wildlife habitat? EXPLANATION: As described in Attachment B, the project will resxilt in significant impacts to existing riparian habitat as well as to the Coastal Sage Scrub habitat. 31) Will the project significantly produce new light or glare? EXPLANATION: The proiect will include street lights typical of a prime arterial roadway. 10 II. HAIEMENT OF NON-SinMlFrr/^NT ENVIRONMPNTU EFFECT.S Unless some form of acceptable mitigation can be develooed for the -i™^ ans^gn^fxcant levels or not .«^c™siaeL.'^S^iScS?"^S=ras Buastion 16), in idd^-Uo'lVrhe'et/'',\"„J|.;r''' '"'""'"^ ^"""""s, attach Signature Date Signed (Pers Fay 0. Round, Jr. Fay Round and Associates eting Report) September 11, 1989 Instruct.eia LBS;lh II ATTACmffiNT A CULTURAL RESOURCE SURVEY Cultural Resource Survey of the Rancho Santa Fe Road Alignment, Carlsbad. California Prepared for: Fay Round and Associates 2630 Cazadero Drive Carlsbad, California 92008 Prepared by: ERG Environmental and Energy Services Company 5510 Morehouse Drive San Diego, California 92121-1709 Project No. 39147.001 Dennis Gallegos Project Manager Andrew Pigniolo Associate Archaeologist August 1989 TABLE OF CONTENTS SF.CTTON 1 1.1 1.2 TITLE ABSTRACT INTRODUCTION Project Description Environmental Setting PAGE 1-1 1-1 1-1 2 2.1 2.2 3 3.1 3.2 4 4.1 BACKGROUND DATA Cultural Prehistory Previous Research FIELD METHODS AND RESULTS Survey Methods Survey Results IMPACTS AND MITIGATION RECOMMENDATIONS Impacts and Recommendations REFERENCES CITED 2-1 2-1 2- 1 3- 1 3-1 3- 1 4- 1 4- 1 5- 1 N^^MBER 1-1 1-2 3-1 LIST OF FIGURES TTTLE Regional Location of Project Site Project Location Map Project Location Showing Areas of Cultural Material PAGE 1-2 1-3 3-2 ABSTRACT An archaeological Uteratuie review, site record check, historic map check, and survey was conducted for road improvements along a portion of Rancho Santa Fe Road between La Costa Avenue and Mekose Drive. Record search information indicated that no culuiral resources had been previously identified directiy within tiie project alignment. Site SDi-4498 (W-659) was located just west of tiie project area. Historic maps of the area indicated tiiat no historic structures were located witiun of tiie proposed aUgnment altiiough a historic cemetery, structure and anotiier structure (H-1) were located just outside tiie eastem end of tiie alignment. The entire route had been included in previous surveys and only a field check was conducted during diis study. Altiiough several clusters of trees were located during tiie survey tiiese trees could not be linked witii any structures on historic maps and no historic remains were associated. Site SDi-4498 (W-659) did not extend witiun tiie project boundary. Under tiie Califomia Environmental (Quality Act (CEQA), it is only necessary to mitigate impacts to important cultural resources. Since no important cultural resources are located witiun tiie project right-of-way no direct impacts wUl occur. Indirect impacts to SDi-4498 (W-659) and tiie historic cemetery and two stmctures should be avoided. II SECTION 1 INTRODUCTION 1.1 PROJECT DESCRIPTION The foUowing report presents tiie results of an archaeological Uterature review, site records check, historic map check, and field survey of tiie Rancho Santa Fe Road alignment. This program was conducted by ERC Environmental and Energy Services Company for Fay Round and Associates. Literature information and site records on recorded cultural resources witiun a one mile radius of tiie project area was obtained from data provided by tiie South Coastal Information Center at San Diego State University and tiie San Diego Museum of Man. Microfilm copies of historic USGS maps of the area, located at the University of Califomia, San Diego were checked for historic structures. In addition to tiie record search and historic map check, an in-field survey was conducted to identify cultural resources within tiie project boundary. The Rancho Santa Fe Road project consists of a realignment and widening of tiie existing road between La Costa Avenue and Melrose Drive in Carlsbad, Califomia. The project is located on tiie USGS Rancho Santa Fe 7.5' quadrangle in tiie northern portion of San Diego County (Figure 1). The new alignment includes portions of both sides of the existing road alignment and follows, a portion of an existing truck route. The project is located witiiin portions of Sections 29, 30, and 31 in Township 12 S, Range 3 W (Figure 2). 1.2 ENVIRONMENTAL SETTING The project alignment crosses several ridges and ridge slopes as well as Encinitas and San Marcos Creek which provide seasonal water. The majority of the alignment crosses undisturbed areas with dense vegetation. Plant communities include coastal sage scmb and riparian vegetation. The area is underlain by the Santiago Peak Volcanic Formation which includes rock outcrops of fine-grained volcanic material which was an important lithic resource for prehistoric inh abitants of tiie area. Elevations witiiin the project range from approximately 3(X) to 600 feet above mean sea level (MSL). 1-1 FALLBROOK I WARNER VSPRINGS iUkt VISTA PROJECT LOCATION 1 ^ Vohllori ESCONDIDO LEUCAOIM JULIAN^ RAMONA OEL MAP LAJOLLi^ 'TOWAY SANTEEf ELlCAJON ALPINE Rntnotr POINT LOMA^ fSAN. '^DIEQO ^ JAMUL ^NATIONAL , CITY .OULZURA HULAVVISTA^ IMPERIAL^ BEACHI FIGURE Regional Location of Project Site U ERC Environmental and Energy Services Co. Project Location as Shown on the 7.5" USGS Rancho Santa Fe Quadrangle FIGURE Mr. Fay O. Round September 6,1989 Page 3 The adverse impacts to these sensitive plant species is considered to be not significant since tiiese species occur in small numbers and are better represented elsewhere in tiie La Costa area (WESTEC 1986). If you have any questions, please call me at 458-9044. Sincerely, Patrick J. Mock Senior Biologist PJM/dp References Califomia Department of Fish and Game. 1987. Designated endangered, threatened or rare plants. January. 4 p. Califonua Department of Fish and Game. 1988. Natural Diversity Data Base, "Special Animals" December. 18 p. Pacific Soutiiwest Biological Services. 1982. A biological si^ey of Rancho La Costa properties (Battiquitos Lagoon). Prepared for Scott Engelhom, Cardiff, California. Smith, J.P. and K. Berg. 1988. Inventory of rare and eridangered vascular plants of Califomia. Califomia Native Plant Society. Special Publication No. 1 (4tii edition). 168 p. US Fish and WUdlife Service. 1986. Endangered and tiireatened wildlife and plants. Federal Register 50 CFR 17.11 and 17.12. January. 30 p. WESTEC Services. 1986. Biological resources analysis of tiie La Costa plaining sub- areas. Prepared for Fay O. Round and Associates, Calsbad, Califomia. September. 50 p., plus appendices. SECTION 2 BACKGROUND DATA 2.1 CULTURAL PREHISTORY For tiie past 10,000 years, tiie area now comprising San Diego County was occupied by Native Americans. This 10,000-year span is divided into two major archaeologically distinct periods (Early and Late). The Early Period includes two cultural complexes, tiie San Dieguito and tiie La Jolla/Pauma. The earliest occupants are known as tiie San Dieguito, who moved to inland and coastal San Diego County areas from the east. These people have been characterized by tiie use of Santiago Peak Volcanics in die manufacture of large leaf-shaped bifaces and scraper planes. La Jolla sites, also within tiie Early Period tend to be located near tiie coast. The people who occupied tiiese sites depended primarily upon marine resources, as well as seed and vegetable foods. In general, tiie stone tool technology associated witii tiiese people is primarily cobble-based at coastal La Jolla sites. This refers to tiie use of locally available coarse-grained Eocene cobbles for stone tool manufacture. Termed Pauma by Tme (1959), inland La Jolla sites more closely resemble San Dieguito sites, witii finelyrmade stone tools, predominance of grinding implements (manos and metates, in particular), and a lack of shellfish remains. The use of tiie terms La Jolla and Pauma reflects availability of food, . location of sites, and stone tool material for people occupying different regions of San Diego County, within the same general time period. For the past 2000 years, material goods and traits associated with speakers of Yuman languages firom tiie east (Colorado River region) were brought into Imperial and San Diego Counties. This period is identified as the Late Period or Late Prehistoric. These Late Period material goods and traits include ceramic artifacts, small projectile points, obsidian from Obsidian Butte, and the practice of cremation. 2.2 PREVIOUS RESEARCH ERC Environmental and Energy Services Company completed a thorough review of pertinent record data from tiie South Coastal Information Center at San Diego State University and the San Diego Museum of Man which indicated tiiat no cultural resources 2-1 had been previously recorded witiiin tiie project boundary, however prehistoric site SDi-4498 (W-659) was recorded adjacent to tiie project boundary. SDi-4498 (W-659) was originally recorded by RusseU Kaldenberg as a Late Period site witii stone enclosures located on a knoU overlooking San Marcos Creek. Artifacts noted at tiiat time included 40+ flakes/angular waste, 2 scrapers, 2 metate fragments, 10+ mano fragments, 1 pestie, 10 thennally fractured rocks, 2 potsherds, 7 bedrock miUing slicks, and 1 bedrock mortar. Randy Franklin filed a site update on tins resource in 1981 noting an additional bedrock milling outcrop to tiie west. Disturbance at the site in tenns of potiiunting was noted by both recorders. A total of 28 otiier cultural resources were located witiiin a one mile radius of the project area. These sites include a variety of types such as; a historic mine, a historic adobe, large prehistoric lithic quarry sites, bedrock nulling stations, Utiiic scatters, and prehistoric temporary camps. The entire project area has been previously surveyed by Kaldenberg (1976a and 1976b) using 25 foot transect intervals (Kaldenberg 1976b). Complete coverage, but no transect interval, was described in Kaldenberg (1976a) which covers tiie soutiiem portion of the project alignment. Other studies which include portions of tiie project area include Eckhardt (1977), LSA (1982), and Cheever and Gallegos (1986). Historic maps of tiie area were checked for historic stmctures. A single stmcture (H-1) was located on tiie 1901 edition of tiie San Luis Rey 15' quadrangle just northeast and outside tiie project area on tiie east side of tiie present alignment of Rancho Santa Fe Road near tiie intersection of Melrose Drive. A stmcnire was also located further north on the same map, near tiie same location as a historic cemetery identified on tiie 1968 edition of tiie Rancho Santa Fe 7.5' USGS quadrangle. The historic cemetery was field located. No stmcmres are located along tiie project alignment on the 1948 edition of tiie Rancho Santa Fe 7.5' USGS quadrangle. 2-2 SECTION 3 FIELD METHODS AND RESULTS 3.1 METHODS Because d,. project area had been previously surveyed a spo. check was conduced ocu u,g on ^ ^^^^^^ - Check was conduced was co™luc»d on ;uiy 25,1989 by Andrew Pigniolo and S^ef H Bnggs^ ttg^ po«n.u, areas for culh^ resources such as bedrock oulps and ridZps w«e Checked as weU as concen^tos of non-nadve nees which ar. of Jassoc,"^ 3.2 RESULTS Results of tiie records and field check were neaariv*. M«^„I*, i , were negative. No ciutural resource"! w#»ri» JH»r.*;«-j directiy witiun tiie project area. Site SDi-4498 rw fiso^ , T .=e.wes.of.heproi..a.e.Ahis.oH::Zl^^^^^^ e.an.eddur.gr:re:r:Li:i:~^^^^^ s.^ large rectangular Pi. (app.^.,, we„ Is:^:":: LtuLT^'-""""" "'"^ ™- - ™ ~ 3-1 SECTION 4 IMPACTS AND MITIGATION RECOMMENDATIONS 4.1 IMPACTS AND RECOMMENDATIONS Un^ "Tr.T- ^ "^'^ -*i" *e P^jec. area Under CEQA nnp«an. cutanal resources need » be addressed as io i„,a«s I ZZ, of .mpac«. No drrea in^ac« wiU occur .o culn^ resources as a result of du^pr^^Tt ^w^er .drrect unpacts to site SDi.4498 (W-659,. the approxitnate locadon o^Hrrd me hrstonc cen^tery and sm^uue should avoided by linndng aU cons«cdon equipn^t and activity to the project alignment as shown in Figure 2. equipment 4-1 SECTION 5 REFERENCES CITED Cheever, Dayle and Dennis Gallegos 1986 Cultural Resource Survey of Industrial Parcel #096, San Marcos, Califomia. Ms on file at ERC Environmental and Energy Services Company, San Diego, California. Eckhardt, William T. 1977 Archaeological Survey of the Assessment Districts Number 76-1 and 76-3, San Marcos County Water District. Ms on file at ERC Environmental and Energy Services Company, San Diego, Califomia. Kaldenberg, Russell L. 1976a An Intensive Archaeological Reconnaissance of the La Costa Land Company Property Carlsbad, Califomia. Ms on file at ERC Environmental and Energy Services Company, San Diego, Califomia. 1976b An Archaeological Impact Report on La Costa Far South (Easterly Area) Including Santa Fe Knolls. Ms on file at ERC Environmental and Energy Services Company, San Diego, Califomia. 5-1 ATTACHMENT B BIOLOGICAL RESOURCE SURVEY 5510 Morehouse Drive San Diego, California 92121 Telephone: 619-458-9044 Fax: 619-458-0943 ERC Environmental 89-1223-E and Energy September 6,1989 Services Co. Mr. Fay O. Round Fay O. Round and Associates 2630 Cazadero Drive Carlsbad, Califomia 92008 Re: Rancho Santa Fe Road Dear Fay: The biological resources along Ranch Santa Fe Road, between La Costa Avenue and La Costa Meadows Drive were surveyed by ERCE biologists on June 16, July 7 and 14, and August 11 and 18, 1989. This field effort supplements tiie extensive data base for tiie La Costa Soutiieast subarea of tiie La Costa Planning Area. This information was summarized by WESTEC Services (1986). Areas tiiat support namral vegetation occur along tiie entire length of tiie proposed road ahgnment (Figure 1). Vegetative cover types include oak woodland, riparian woodland, elderberry woodland, chaparral, grassland, and coastal sage scmb tiiat is dominated by either Califomia sagebmsh (Artemisia californica) or black sage {Salvia mellifera). Of tiiese habitats, oak woodland, riparian woodland, native grassland, and coastal sage scmb are habitats tiiat are considered to be of regional importance due to tiieir lunited distribution, declining stams, support of sensitive species, or high value to wildlife. The willow-dominated riparian habitat found along San Marcos Creek is potential habitat for tiie state and federally endangered least Bell's vireo {Vireo bellii pusillus). This vu-eo species has not been detected along tius drainage, however a single least Bell's vireo was detected in tiie Green Valley riparian corridor in 1982 (PSBS 1982). No otiier reported sightings of tius species are known for tiie area, despite a number of attempts in locating this species in tiie area. The proposed road alignment will cross San Marcos Creek. An estimated 1.5 to 2.0 acres of riparian habitat would be directiy impacted by the constmction of tiie bridge over San Marcos Creek. Due to tiie rarity of tiiis habitat and its importance to least bell's vireo and otiier wildlife, this impact would be considered significant Impacts to riparian habitat could be mitigated elsewhere in tiie project vicinity. The coastal sage scmb in tiie project area represents habitat for tiie declining San Diego coast homed lizard {Phrynosoma coronatum blainvillei) and orange-tiiroated whiptail {Cnemidophorus hyperythrus beldingi). Botii of tiiese reptiles are candidate 2 species for hsting by tiie U.S. Fish and Wildlife Service. The major drainages in tiie area provide potential habitat for tiie declining two-striped garter snake (Thamnophis couchi hammondi). The Califomia gnatcatcher {Polioptila californica) is an obligate resident of coastal sage scmb habitat. The concem for tiiis species' status has intensified recentiy and tiie U.S. Fish and Wildlife Service is currentiy evaluating the potential listing of this candidate Mr. Fay O. Round September 6, 1989 Page 2 species as eitiier tiireatened or endangered. The major cause for tiiis species decline is the loss of suitable sage scmb habitat. Sightings of gnatcatchers witiiin tiie project area indicate tiiat at least 8 breeding pairs of gnatcatcher may be present onsite (Figure 1). The distribution of tiie gnatcatcher sightings suggest tiiat gnatcatchers prefer sage scmb that is dominated by Artemisia californica. Sage scmb composed of near pure stands of Salvia mellifera is not extensively used by gnatcatchers and is generally of low value to otiier wildlife species. About 284 acres of Arremwza-dominated sage scmb exists in the project area. The road alignment and associated grading plan is expected to directiy impact about 71 percent (194 acres) of Artemisia-doTninated sage scmb. Most of the presumptive gnatcatcher territories would be eitiier lost or significantiy reduced in size to tiie extent tiiat tiie capacity of tiie remaining sage scmb habitat to support breeding gnatcatchers in tiie long-term may be impaired. A maximum estimate of tiie number of gnatcatcher pairs tiiat could potentially be supported onsite after implementation of the proposed project would be about 4 pairs. However, tiie remaining areas of suitable sage scmb habitat would be fragmented witiiout dispersal corridors between tiie patches of habitat. Isolation of small areas of habitat would likely reduce tiie long-term potential of tiiese areas to support gnatcatchers. Since tiie regional status of tiie Califomia gnatcatcher is currentiy under review, tiie loss of 194 acres of coastal sage scmb habitat tiiat supports at least 8 pairs of Califomia gnatcatcher would be considered significant Several sensitive plant species have been recorded within tiie project area (see Figure 1). None of tiiese plant species is listed as endangered by eitiier tiie U.S. Fish and Wildlife Service (USFWS 1986) or tiie Califomia Department of Fish and Game (CDFG 1987; 1988), but tiiey are identified by tiie CaUfomia Native Plant Society (Smitii and Berg 1988) as sensitive species. These plant species are listed below:. Scientific Name Adolphia californica Brodiaea orcuttii Iva hayesiana Midlla clevelandii Common Name Califomia adolphia Orcutt's brodiaea < 50 indiv. <50 indiv. San Diego marsh elder common in drainages onsite San Diego goldenstar <50 indiv. spiny msh Selaginella cinerascens ashy spike-moss Juncus acutus var sphaerocarpus common in San Marcos Creek common in sage scmb onsite Stams CNPS List 2, 1-2-1 FWS Candidate 2 CNPS List IB, 1-3-2 CNPS List 2, 2-2-1 FWS Candidate 2 CNPS List IB, 2-2-2 CNPS List 4, 1-2-2 CNPS List 4, 1-2-1 Mr. Fay O. Round September 6,1989 Page 3 The adverse impacts to these sensitive plant species is considered to be not significant since tiiese species occur in small numbers and are better represented elsewhere in tiie La Costa area (WESTEC 1986). If you have any questions, please call me at 458-9044. Sincerely, Patrick J. Mock Semor Biologist PJM/dp References Califomia Department of Fish and Game. 1987. Designated endangered, tiireatened or rare plants. January. 4 p. Califomia Department of Fish and Game. 1988. Natural Diversity Data Base, "Special Animals" December. 18 p. Pacific Soutiiwest Biological Services. 1982. A biological survey of Rancho La Costa properties (Battiquitos Lagoon). Prepared for Scott Engelhom, Cardiff, Califomia. Snuth, J.P. and K. Berg. 1988. Inventory of rare and endangered vascular plants of Califomia. Califomia Native Plant Society. Special Publication No. 1 (4tii edition). 168 p. U.S. Fish and Wildlife Service. 1986. Endangered and threatened wildlife and plants. Federal Register 50 CFR 17.11 and 17.12. January. 30 p. WESTEC Services. 1986. Biological resources analysis of the La Costa planning sub- areas. Prepared for Fay O. Round and Associates, Calsbad, Califomia. September. 50 p., plus appendices. Existing RSF Road || CHP = Chapafral EW = Elderberry Woodland OW = Oak Woodland DGL Disturbed Grassland ACSS - Artemisia - dominated Coastal Sage Scrub SCSS « Salvia - dominated Coastal Sage Scrub RW = Riparian Woodland Brodiaea orcuttii Selaginella cinerascens Adolphia californica Muilla clevelandii California Gnatcatcher Sighting ERC Environmental and Energy Services Co. Rancho Santa Fe Road Mass Grading Plan and Biological Resources FIGURE