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Home My WebLink AboutCDP 03-07; THOMPSON RESIDENCE; BIOLOGICAL LETTER REPORT; 2003-09-300 !F r ~ t 19 8100 Lijkra Bid, Suite 150 LnMea, CA 919-11-&776 e-maikadmin@helLvepi.com fax 619)462-0552 phone (619) 462-1515 . . September 30, 2003 Mr. David Thompson D.K.&T., ac do Thompson Rose Company 949 Cassou Road San Marcos, California 92069 DKS-03 hilandEmpfre Office Subject: Biological Letter Report for the 1.7-acre Rose Drive Site phone (909)423-0701 Dear Mr. Thompson: This letter presents the results of a biological survey conducted by HELIX Environmental Planning Inc. (HELIX) on the 1.7-acre Rose Drive site in the City of Carlsbad (City) and identifies existing biological conditions of and potential impacts to on-site resources from the proposed project. This letter report includes an assessment of potential biological impacts and mitigation associated with grading on the parcel as well as the project's consistency with the Habitat Management Plan (HMP) for Natural Communities in the City. This report provides the City, the California Department of Fish and Game (CDFG), the U.S. Fish and Wildlife Service, and the public with information necessary to assess project impacts to biological resources under each agency's jurisdiction. Regulatory act(s)/plan(s) that may apply to project development include the federal and state Endangered Species Acts (ESAs), the California Environmental Quality Act (CEQA), and the iaIP. INTRODUCTION I The site is located within the City southeast of Poinsettia Lane, southwest of Aviara Parkway, and northeast of Batiquitos Drive (Figures 1 and 2). The project site contains an existing home surrounded by disturbed habitat that was previously l used as a plant nursery. The abandoned nursery has an approved subdivision and will be developed as a residential community. Most of the area beyond the fields has already been developed (Figure 3). The proposed project includes the filling of a hollow in the southeastern portion of the site to provide additional space for the I expansion of the homeowner's usable yard. From a regional perspective, the project site is within the Carlsbad HMP, which is I a Subarea of the Multiple Habitat Conservation Plan (MHCP). The MHCP proposes to preserve open space in a viable network of large blocks and connecting U linkages in the northwestern San Diego County incorporated cities. The northeast corner of the project is adjacent to coastal sage scrub habitat that is a Hardline Conservation Area (HCA) of the liMP. Indirect impacts to the HCA must be minimized through project design and will be addressed in this report. I I RIVERSIDE COUNTY ORANGE I SAN DIEGO L I COUNTY .3 COUNTY / i OIIOFRE SAN FAUBROO1( I 75 WARIER SPRINGS • lake R Ha,Mw 15 56 i 0CENE VISTA / I CARlSBAD PROJECT SITE EScONDIDO • lake 75 Hes ENcIIITAS JUUAN • $6 RAMM - — 67 Lake I P0WAY DEL MAR sa * 1 flCapbca 15 - S I LA CAJOII ØMSA 54 Resenw SAN I Rczcn'uu I LOMA 54 H VISTA a. I I '?2. . MEXICO IN TIJUANA C _ I fl It I NOT TO SCALE ROSARITO I Regional Location Map ROSE DRIVE PROPERTY HELIX Figure 1 I . . I Ce Cr I I I ylaqu 4,, HOUDAY ISO, IAW I I PAW 5 EM L I ME I I_________ I 99 Ct S, N., I CT I )p BWUA I Project Vicinity Map I ROSE DRIVE PROPERTY IELIX Figure £\ ç -- • 1/ m)1 ) % PARA I - \CCaRLsMD 1 — 0 •0 -fl t4 S_- --- - - iva&cr — U : Laxr4 '°DR' 22 93L 11\\ r- %% Soi aaMYW 5, —,. gs \\ 54)4 rr fl,% fl t u1)4ec t' — jsii.. t.D C. t r frfl) souTh' ".Dt1\ c WISiUaL '-- — 3W50CC1 I 0 — C4?,cPAfl 14 :t ts\t\t k f8 QtctTh EflTlA ': / ,. AVIAR4 PROJEcT1 CCURSE a% rSpy - — SITE j BtWIA tCf[ RffORT s AVIMA o \$; 1& W E € r 3tfra —o .125 - .375 . r irtos 34 1 mlles 1 in. – 1900 ft. Ease map ,eprodiced with pesnussian granted b moMAs BROS. MA PS ' This map is co1 sighted by I7IOMAS EROS. M4PS /t &wdapd taco orzvpmdsce all or any pan th ereof n#.etherforpersor4 use or resale. wsthoiapnmzssm I I AA I IP I I ?Aj I : - g ; I , !7 4 I • -, •'1.Ifwk't \ .t p, '& _I :• ' I' —4 m b•ta ______I, .;;%i • U I Ip S • j -t I - 4ProjectSite fi4 dep I I I r / AN I - ''':.- ••• Aerial Photograph of Project Vicinity I ROSE DRIVE PROPERTY HELIX Figure I I 0 Letter Report to Mr. David Thompson . Page 2 of 7 September 30, 2003 METHODS The site was visited on May 29, 2002 by HELIX biologist Derek H. Langsford, Ph.D. for vegetation mapping, and rate plant and general wildlife surveys. Vegetation was mapped on an aerial photograph of 111=150 scale. A project map (1"40' scale) was used to assist in mapping the project boundaries. The general vegetation survey included mapping vegetation types for the entire property and searching all habitats within the project area for potentially occurring protected plant and animal species. Potentially occurring rare species were determined by a habitat-based analysis and by consulting the known distribution of sensitive species in the vicinity of the project. Nomenclature for this report is from Hickman ed. (1993) for plants; Holland (1986) for vegetation communities; Crother (2001) for amphibians and reptiles; the American Ornithologists' Union (1983, as updated) for birds; and Jones et al. (1997) for mammals. Sensitive species status is taken from CDFG (2002a and 2002b). RESULTS Vegetation Communities Three vegetation communities, none of which is native, occur within the project boundaries: eucalyptus woodland, disturbed habitat, and urban/developed (Table 1; Figure 4). Table 1 VEGETATION COMMUNITIES/IMPACTS VEGETATION HMP COMMUNITY HABITAT ACRE(S) IMPACTS GROUP _______ Eucalyptus woodland F* 0.22 0.20 Disturbed habitat F' 0.16 0.04 Developed areas F* 1.32 0.09 TOTAL 1.70 0.33 *Qff..site mitigation for habitat in this group not conserved or mitigated on site shall be subject to a per-acre fee in lieu of mitigation in an amount to be determined by City Council not to exceed $500.00 per acre (City of Carlsbad 1999). Eucalyptus Woodland Eucalyptus woodland is dominated by eucalyptus (Eucal;prnc sp.), an introduced tree species that produces a large amount of leaf and bark litter. The chemical and physical characteristics of this litter limit the ability of other plant species to grow I ill II II 1-i Ii II II II I I U I I I I I I_EGEI1D 1/7 • Vegetation I Diegan Coastal Sage Scrub (32500) III I/ Non-native Grassland (42200) Jr j I I Eucalyptus Woodland (11100) 1 1 I Disturbed Habitat (11300) L ' Developed (12000) Note Numbers in parentheses represent the Holland code for the vegetation type Ir Diegan Coastal Sage Scrub Within the HCA Project Site / H 1 1 I 1 I / I / \ Pr 1 H I ( I H r I i N H HI S Nbser I This rna i basedon site conditions as observed at the time of our field I -100 - 0 - -- -100 Feet j jnveststitirIs. The infom,ation presented herein was developed by visual - - -- mtpeoson and/or aerial photograph mterpsesaeon Note that both site - j$i $-O3 Date: 6/21/02 Vegetation Map I ROSE DRIVE PROPERTY II [[IX Figure 4 I II , fluIyTm *L I a- t.., Letter Report to Mr. David Thompson • Page 3 of 7 September 30, 2003 in the undersrory, resulting in low plant diversity. Eucalyptus trees have been planted extensively in San Diego County as wind blocks, as ornamentals, and for hardwood production. Eucalyptus trees are often able to establish and naturalize in riparian habitats and other areas with sufficient moisture. Eucalyptus woodland is not considered sensitive, but may support nesting raptors, many of which are state or federally protected. A 0.22-acre patch of eucalyptus trees occur in the southeastern corner of the property. These trees cover much of the slope leading down to the southeast from the existing house. The understory contains iceplant and species typical of disturbed areas described below. No raptors were observed using the eucalyptus trees at the time of the survey. Disturbed Habitat Disturbed habitat includes land that has been cleared of vegetation (e.g., dirt roads, abandoned yards), contains a preponderance of non-native plant species (such as ornamentals or ruderal exotic species that take advantage of disturbance), or shows signs of past or present cultivation that has removed any capability of providing viable habitat or foraging for sensitive species. The 0.16 acre of disturbed habitat consists of three different areas at the project site. The northern, western, and southern edges of the project are all abandoned nursery fields that have been disced regularly to control weeds. The southeast corner of the property contains a depression that appears to have been previously graded and has been used as a play area by children. On the northeast edge of the current residence is a disturbed area that has been used for access to the existing home. The disturbed areas were mostly bare dirt with sparse weeds such as bristly ox-tongue (Pint ethioides), tumbleweed (Salvo/a trapic), and white goosefoot (Chenop odium album). A few non-native grasses were also present but not prevalent and included rip-gut (Bromus diandrus), foxtail chess (Bromus madritensis), and wild oats (Avenafa:ua). Urban/Developed Urban/developed lands are dearly altered, tended, and maintained. Developed land include areas containing permanent structures, where land is kept cleared of vegetation, is landscaped, or where septic systems are present. The bulk of the project site consists of developed land (Table 1),which inlcudes the existing house, driveway, swimming pool, outbuildings, and associated landscaping. Plants observed on the project site included pines (Pinses sp.), sago palms (Cycas revobne), and hibiscus (H;'biscus sp.). Three types of iceplant, including .Mesernb;yanthemum sp. and Carpobroms sp., were observed growing on embankments around the house. Sensitive Resources The project area supports no native plant communities, and is dominated by developed or disturbed areas vegetated with ornamental or weedy species. The only I II [1 I L] [1 I I I . . Letter Report to Mr. David Thompson Page 4 of 7 September 30, 2003 remnant of native habitat was a single lemonadeberry (Rhus integrifolia) shrub on the eastern edge of the property. Given the disturbed nature of the project site, sensitive species have a low potential to occur on site. However, there is low to moderate potential for raptors to nest in the eucalyptus trees in the southeastern portion of the site. Nesting raptors are protected under the Migratory Bird Treaty Act, which prohibits impacts to active raptor nests. Indirect impacts to nesting raptors caused by construction activities within 300 to 500 feet of active raptor nests (depending on the raptor species) are typically considered significant. Raptor nests are generally active between February and July. IMPACTS Direct Impacts Proposed project development and landscaping would directly impact a total of 0.33 acre in the southeastern corner of the property, including 0.20 acre of eucalyptus woodland, 0.4 acre of disturbed habitat, and 0.09 acre if urban/developed land (Table 1; Figure 5). No sensitive plant species would be directly impacted by the project. No sensitive animal species were observed on the property, but there is moderate potential for raptors to nest in the eucalyptus trees. No direct impacts (or significant indirect impacts) to nesting raptors are permitted. If construction occurs during the breeding season, a qualified biologist would conduct a pre-construction survey, and no construction could occur within 300 to 500 feet of any active nest until the young fledge. Indirect Impacts The project occurs within the boundary of the Carlsbad I-IMP (City of Carlsbad, 1999). The proposed project is not included in the HCA, which delineates core biological resource areas and corridors targeted for conservation. However, the northeast corner of the project is adjacent to the HCA (Figure 5). Therefore, there is a slight potential for indirect impacts to the HCA. An indirect impact consists of secondary effects of a project, including habitat isolation, edge effects, exotic species invasion, increased lighting, vehicular noise and increased human intrusion. An indirect impact typically takes longer to become apparent but may be of the same magnitude as a direct impact. Indirect impacts are important due to the location of the project in relation to the HOt and include drainage, lighting, noise, barriers, invasive plant species, and brush management. A small ridge separates the project site from the HCA, which approaches the property from the northeast. This topography decreases the potential for indirect effects associated with drainage and invasive plants, and will buffer the HCA from the indirect impacts of light and noise. In addition, the impact area is in the southeastern corner of the site and is largely separated from the HCA by disturbed habitat and urban/developed areas. Compliance with the following recommendations will minimize any indirect impacts and ensure compliance with the HMP. I I I I I LEGEND I Vegetation / 1 Diegan Coastal Sage Scrub (32500) Non-native Grassland (42200) I Eucalyptus Woodland (11100) Disturbed Habitat (11300) Developed (12000) ---- : I Note: Numbers in parentheses represent the Holland code for the vegetation type EII Project Impacts Diegan Coastal Sage Scrub Are Within the HCA 'II1 I _ Project Site \ I II I I I N I w S - --- - This map is based on site conditiom as observed at the time of our field 100 0 100 Feet investigations. The infomsatton presented heroin was developed by visual I - - - - inspection and/or aerial photograph interpretation. Note that hothsite Job No: DKS-03 Date: 09/29/03 conditions and applicable regulatory reclairernents tnay change. Vegetation/Impacts I ROSE DRIVE PROPERTY HELIX Figure I I Letteport to Mr. David Thompson Page 5 of 7 September 30, 2003 Drainage and Toxins Erosion during construction could impact the RCA. Drainage into the RCA will be minimal due to the topography of the site. Use of appropriate Best Management Practices such as silt fencing and dust control during grading will minimize erosion. Following project completion, stormwater runoff from developed areas into the RCA may cause erosion or introduce fertilizer, exotic plant materials, and/or other harmftul elements. Most stormwater will likely not flow toward the RCA. Alternatively, appropriately planting of the fill slope can eliminate most of these effects if stormwater were to be directed towards the RCA. Lighting Lighting, if used in the landscaping of any developed areas adjacent to the HCA, should be directed away from the RCA, or development should provide adequate shielding with non-invasive (preferably native) plant materials, berms, or other measures. The use of side-mounted inclined light fixtures, limited mounting height, and shields, combined with the topography of the site, should minimize light pollution in the RCA. Barriers A fence currently exists between the RCA and the project site. Maintenance of this fence combined with signage should be sufficient to protect the RCA from dumping of garbage or landscaping refuse, trail creation by people, and hunting or harassment of native species by pets. Invasive Plant Species Invasive exotic plants are a serious indirect threat to natural communities in southern California. Invasive plants should not be introduced to areas adjacent to sensitive habitats such as occur in the RCA because their seeds can be spread into the natural habitats by wind, run-off, or animals. Landscaping with native species is preferred, but non-invasive ornamentals are acceptable. Potentially invasive species, particularly pampas grass (ConeakS jubata) and fountain grasses (Pennisetum sp.) should be avoided in the landscaping of the graded area. Two invasive plant species, iceplant and eucalyptus, are established on site adjacent to the RCA. These species should be removed during grading to the extent possible. MITIGATION Mitigation may be required for direct and indirect impacts. The only potential direct impact of the project would be to nesting raptors protected by the Migratory Bird Treaty Act. The proposed project would remove 0.20 acre of eucalyptus woodland. While this is not a sensitive habitat, raptors could nest in Ii' II II ii II I I [1 I I Li I I I I IT:i±t Letter Report to Mr. David Thompson Page 6 of 7 September 30, 2003 I these trees. To avoid impacts to nesting raptors, these trees will either be removed outside of the breeding season (generally February to July) or a pre-construction survey would be conducted to determine the presence or absence of nesting I raptors. If nesting raptors are present, then construction within 300 to 500 feet of the trees will be delayed until the young leave the nest if a qualified biologist determines an impact would occur. I Following the guidelines for drainage, lighting, noise, barriers, and invasive plant species, outlined above, would minimize potential indirect impacts to the HCA. I I The proposed project is confined to previously developed or planted areas but is adjacent to the Carlsbad HCA. Direct impacts would be occur to 0.20 acre of eucalyptus woodland, 0.04 acre of disturbed habitat, and 0.09 acre of developed habitat. Impacts to nesting raptors must be avoided per the federal Migratory I Bird Treaty Act. A pre-construction survey could be performed to determine the presence or absence of nesting raptors. If no raptors are detected, clearing could I commence. However, if nesting raptors are present tree clearing must be postponed until after the nesting season. No other sensitive resources would be directly impacted by the proposed project. No direct or indirect impacts would occur to habitats or other resources within the HCA. Please call me if you have questions. I Sincerely, I Derek H. Langsford, Ph.D. I Biologist REFERENCES I American Ornithologists' Union. 1983. Checklist of North American Birds (6th Edition). American Ornithologists' Union, 877 pp. Updated every two I years. California Department of Fish and Game (CDFG). 2002a. Special Animals List. I http://www.dfg.ca.gov/whdab/spaminals.pdf. Updated January. 2002b. Special Plants List. http:f/www.dfg.ca.gov/whdab/spplant.pdf I Updated January. 1993. Natural Community Conservation Planning Process Guidelines. I Unpublished. I I LeReport to Mr. David Thompson Page 7 of 7 September 30, 2003 City of Carlsbad. 1999. Habitat Management Plan for Natural Communities in the City of Carlsbad. Crother, B.I. 2001. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, With Comments Regarding Confidence in Our Understanding. Society for the Study of Amphibians and Reptiles. Circular No. 29. 84 pp. Hickman, J.C. (ed.). 1993. The Jepson Manual: Higher Plants of Califonhi2. University of California Press, Berkeley, 1400 pp. Holland, R.P. 1986. Preliminary descriptions of the terrestrial natural communities of California. Nongame-Heritage Program, California Department of Fish & Game. Jones, J.K., KS. Hoffman, D.W. Rice, C. Jones, R.J. Baker, and M.D. Engstrom. 1997. Revised checklist of North American mammals north of Mexico. Occasional Papers of the Museum, Texas Tech University 146: 1-23. Ii 11 ii: II II II II II II II II II I I I El 11