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656, Extension for grading and cons, Studies & ReportsHORTICULTURAL RESOURCE REPORT Prepared for Dr. Robert Marshall 17 Portuguese Bend Road Rolling Hills, California 90274 Prepared By Robert McMahon, Jr. Horticulturist Landscape Architect March 13, 1996 Robert J. McMahon. Horticultural services. t ib 1,2 Sixth Street. Seal Beach. California_ 90740. (310) 493.-0186 • CONTENTS Page I. Project Description H. Scope of the Horticultural Report ID. Setting IV. Impacts A. On -Site Impacts B. Off -Site, Cumulative Impacts 1. 1. 2. 2. V. Mitigation 3, VI. Remarks on Plant Regrowth, Fire Clearances 4. and Habitat Maintenance List of Figures: EXHIBIT 1 Proposed Development Plan EXHIBIT 2 Existing Conditions Plan EXHIBIT 3 Relocated Stable Plan EXHIBIT 4 Los Angeles County Fire Department Brush Clearance Requirements Appendices Containing: Plant Species List Resumes of Project Horticulturist/Landscape Architect • I. Project Description The subject property hereafter also referred to as the site; is located at 17 Portuguese Bend Road in the City of Rolling Hills, Los Angeles County, California. The site consists of 5.39 acres of residentially zoned land with one single family residence, with lawn, gardens„ ornamental trees, and shrubs, driveway, walkways, swimming pool, and patio. The some acreage in the study area is covered by native coastal sage scrub and chaparral vegetation. The owner Dr. Robert W. Marshall is applying for a permit to subdivide the site for one additional single-family residence. The proposed 2-lot subdivision of land at Lot 79-RH, and currently, 17 Portuguese Bend Road, Rolling Hills, CA, an existing lot that has one residential unit, to be implemented by Dr. Robert W. Marshall. Lot 79-RH consists of 5.39 acres gross to be divided into two parcels as follows: Parcel 1-2.896 acres gross, 2.242 acres net; and Parcel 2 - 2.520 acres gross, 2.046 acres net (Exhibit 1). H. Scope of the Horticultural Report The applicant Dr. Robert W. Marshall has contracted Robert J. McMahon a horticulturist and landscape architect to prepare a report for submission to the Rolling Hills Planning Commission that includes the following: • Identification of native plants on the site. • Identification of wildlife utilizing native habitat on the site. • Evaluation of the relationship of the site to wildlife habitat currently existing in the City of Rolling Hills (i.e. an estimation of the ecological importance of the site) • Evaluation of impacts on wildlife on the site and in the City of Rolling Hills as a result of implementation of the proposed project (i.e. an estimation of direct and cumulative impacts on wildlife). • Recommended mitigation, if necessary, emphasizing low cost and low maintenance measures, such as revegetation. • Evaluation of the County Fire Department regulations with respect to habitat maintenance and respective impacts on wildlife on the site. • Horticultural Resource Report III Setting March 13. 1996 Page 2 The subject property area, with predominantly west facing slopes, ranging in elevation from about 500 to 600 feet, is centrally located within the City of Rolling Hills (Exhibit 2). Almost the entire area within the City limits of Rolling Hills has undergone severe habitat alterations (i.e. clearing, grading, exotic landscaping) commonly associated with suburban developments in Southern California. Most of the developments are hillside and hilltop, 1 to 5-acre homesteads, such as those currently surrounding the subject property. Very little (perhaps less than 10 percent) of the original coastal sage scrub and chaparral vegetation remains within the City limits (much of it has been removed prior to 1930, as a result of farming and cattle ranching), and whatever native habitat still exists, is isolated on steep, unstable slopes bordering in intermittent streams. Exotic planting (of blue gum, pepper tree, olive, pine) trees now dominate the landscape. In this regard, the suburban setting of the subject property is rather typical for Rolling Hills. About (50) fifty percent of the site is covered by a heterogeneous assemblage of native vegetation, growing in an isolated stand, largely undisturbed, in loose, clay -sediment soils on west facing slopes, the dominant shrubs are coastal sage, Lemonade berry and elements of moist chaparral are found on the lower slopes. This relatively large proportion of native shrubs, combined with its high visibility from a adjacent neighbors seems to enhance the uniqueness of the site. IV. Impacts A: On -site impact Implementation of the proposed project will result in the destruction of no native vegetation. Only trimming (i.e. "lollipopping" and checker boarding") to comply with fire regulations Lemonade berry, purple sage, California sage, and buckwheat will be the principal native vegetational elements. Dominant plant species should remain intact and viable retaining the native vegetation on the site and only thinning 38 areas of the entire 5.39 acres will not disturb the existing wildlife habitat (Exhibit 1). The proposed Lot 2.52 acres will result in the thinning of only .38 acres of the acres of the site. The areas in which the thinning will occur is depicted on Exhibit 1. South Bay Engineering, which is familiar with grading projects in the City, regarding whether grading would occur beyond the proposed pads. They confirm that there would be no need to go beyond the boundary of the proposed pads during grading. Horticultural Resource Report • • March l3. 1996 Page 3 Depending on the size and location of the residence on the pad no brush would need to be removed. The area of brush that will not be affected by the project is depicted in (Exhibit 1). Without the proposed lot the existing stable structure would remain, resulting in the removal of .06 acres and thinning of .60 acres of brush which will adversely effect wildlife habitat. (Exhibit 2) The Proposed stable location on the existing lot will have no adverse effects on the wildlife, due to no brush within the surrounding area will be cleared or thinned (Exhibit 3). B: Off -site, cumulative impacts In view of widespread habitat destruction in Rolling Hills, loss of any coastal sage scrub and chaparral is ecologically insignificant. Natural communities in this region are highly fragmented and could scarcely be considered integrated components of a natural ecosystem. Locally, within a few hundred yards of the site, there are patches of coastal sage and riparian vegetation on the east facing slopes along with a significant patch of baren soil. This baren soil area will erode, during heavy rains causing slope failures. It is not recommended to remove the native vegetation in this measure. (refer to City of Rolling Hills Fire Department brush clearance maintenance Exhibit 4.) V Mitigation Implementation of the proposed project will result in no disturbance of native vegetation on the site (see Exhibit 1). Although presumed impacts to biotic resources, both on and off -site, are herein judged to be overall insignificant, to the extent mitigation measures are implemented, they can be accomplished in the form of revegetation of previously cleared areas. The end result of this proposal will be no net loss of native habitat. In connection with habitat restoration and maintenance, the following measures of mitigation are suggested. • No developments shall be permitted outside the footprints and fire clearances of proposed buildings, roadways and easements shown on the approved site plan, without further review by the Rolling Hills City Planning Commission. • Fire clearances shall .be limited to minimum distances allowable by City regulations. • No new trails or access roads shall be created except as designated on the approved subdivision map and site plan. • Horticultural Resource Report March 13. 1996 Page 4 • No new trails or access roads shall be created except as designated on the approved subdivision map and site plan. No chemicals (i.e. fertilizers, pesticides, herbicides, detergents, drain oil) shall be used or disposed of within the streambed or adjacent watershed where they might leach into the natural drainage system. • Revegetation shall be done predominantly with plants native to Southern California, or of the Southwestern united States, and of the drought -resistant type. We recommend widespread initial plantings, about five feet apart, from 1-2 gallon containers of low, relatively fast-growing shrubs (i.e. buckwheat, purple sage, California sage). Slower growing shrubs (i.e. lemonade berry, toyon, elderberry), from 5 or 10-gallon containers, can be interspersed with the mentioned species. • Prior to revegetation, we recommend consultation with an authority on landscaping with native plants. VI Remarks on plant regrowth, fire clearances and habitat maintenance Any number of revegetation schemes may be used on the subject property. Depending on the availability of plantings, water, and care, complete revegetation of cleared areas can occur in five to ten years. Existing native plants will recognize without assistance, going through successional stages (i.e. grasses, herbs, fast growing shrubs, slower -growing, larger shrubs) and eventually (perhaps ten years) entirely reclaim the clearings. Natural recolonization of native vegetation is relatively slow, but can be accelerate dramatically by an aggressive native plant recovery program. Fire clearances required by the City and fire department from buildings are generally required to be 130 linear feet (measured horizontally from the edge of the building) (see Exhibit 4). We have confirmed with the County of Los Angeles Fire Captain Colmerauer that the fire department requires a clear area of 30 feet from a structure. Another 100 feet from the structure may be thinned by techniques known as "checker boarding" or "lollypopping," which are depicted in (Exhibit 4). These techniques do not result in a complete loss of habitat. Captain Colmerauer confirmed that the clearance and thinning areas are measured from the structure and not from the edge of the pad. He confirmed that the method we used to measure the areas that would be affected is correct. Consequently, recommend plantings of native lemonade berry, a hearty, low fire -risk shrub, which can help maintain the integrity of the natural community on the site. E .01311 1 f$ VJCINty .too sroQ- to n� `z • (PR/MATE) r•10' •e . too- • 2.. =a 7s 7'• - 3 o f 140 BRASH EEMpV AL. AREA SG E'E TH,NNED AAEGOF eftt)S1-1HEGKE k B 010114E OttX jING B USN AREA OF NO E • E _i CLEARANCE REQUIREMENTS Thousands of homes art . serious &Niger of destruction by fire because r,. , elr proxy.. .y to brush -covered areas. (tomes with wood shake roofs, wood siding, decks, patio covers or exposed eaves are particularly vulnerable to the spread of fire. Despite efforts by firefighters, wildland fires fanned by strong winds, can destroy homes. It is your legal responsibility to take the necessary actions to clear vegetation around any given structures. A firesafc landscape creates a defensible space to help protect against approaching wildfires. I. All flammable vegetation identified as a fire hazard by the inspecting officer shall be mowed or cut to a stubble height of 3 inches, for 30 feet around any structure or 50 feet in high hazard areas. 2. Create a firebreak for the next 70 feet, for a total of 100 feet, around any structure by clearing, trimming, thinning, cutting back and removing flammable vegetation. For high hazard areas, this distance can be increased to a maximum of 200 feet. 3. Single specimens of trees, ornamental shrubbery, or ground covers are permissible. provided that they do not form a means of transmitting fire to any structure. Such specimens shall be spaced a minimum of 15 feet or 3 times their diameter from other specimens, structures or surrounding native brush. 4. All trees and shrubs shall be maintained free of dead wood and litter. Trees and shrubs shall be trimmed up from the ground 1/3 of their height. 5. Access roads shall be maintained with a minimum of 10 feet brush clearance on each side. Trees and shrubs overhanging roadways shall be trimmed to a minimum of 16 feet vertical clearance. 6. Provide a minimum 3 feet clearance around all fire hydrants. All plants will burn under extreme fire weather conditions. Fire resistant plants burn at a relatively low intensity. slow rates of spread and with short flame lengths. To best protect your home from fire, it is recommended that fire resistant plants are used when landscaping. A list of these plants can be obtained through the Los Angeles County Fire Department, Forestry Division, telephone number: (213) 881 - 2481 BRUSH CLEARANCE MAINTENANCE IS A YEAR-ROUND RESPONSIBILITY REMEMBER: EXTRA HAZARDOUS AREAS MAY REQUIRE 200 FEET OF CLEARANCE NOTE: Care should be taken when reducing the amount of fuel corer on slopes so as not to create an erosion problem. SolP • Fence\ Weeds o d Hazardous Vr Road n ve Stydb Defensible Space • CHECKBOARDING • CHECKBOARDING IS A TERM TO DESCRIBE ONE FORM OF FUEL MODIFICATION. IT SERVES TO REDUCE FUEL LOAD AND CONTINUITY WHILE PREVENTING EROSION, LOSS OF WILDLIFE HABITAT, AND RETAINS VIEWING ESTHETICS. THE DRAWINGS BELOW DEPICT AN AERIAL VIEW OF A SLOPE BEFORE AND AFTER CHECKBOARDING. DIMENSION "A' SHOULD BE THREE TIMES THE DIAMETER OF THE PLANT CROWNS. CHECKBOARDING IS USUALLY COMBINED WITH LOLLYPOPPING. BEFORE • ****** AFTER ***** 0 e'sr # A " C.) LOLLYPOPPING MOST BUSHES AND SOME TREES IF ALLOWED TO GROW UNATTENDED WILL DEVELOP THE SHAPE SHOWN IN FIGURE A. WHEN THIS HAPPENS, DEAD MATERIAL, WILL START ACCUMULATING IN AND UNDER THEM AND CREATE A FIRE HAZARD. TO INCREASE FIRE SAFETY, THESE PLANTS NEED TO BE "LOLLYPOPPED". IN OTHER WORDS, THE PLANT NEEDS TO BE THINNED AND THE LOWER BRANCHES REMOVED. THIS SERVES TWO PURPOSES IN THAT THE FUEL LOAD IS DECREASED AND THE FUTURE ABILITY TO REMOVE FUEL FROM UNDER THE PLANT IS MADE EASIER. FUEL REDUCTION IS AN IMPORTANT ASPECT OF WILDLAND FIRE SAFETY BUT IT MUST BE BALANCED WITH EROSION CONTROL BY LOLLYPOPPING SHRUBS AND TREES WE REDUCE THE FUEL LOAD BUT RETAIN THE ROOTS FOR SLOPE CONTROL THE CANOPY FOR ENERGY ABSORPTION OF RAIN AND THE PLANT ITSELF FOR ESTHETICS AND ANIMAL HABITAT. (j1 ft" Z ROOTS PL§k1 I Jrtt.ico LIJ ,tAL COMPENDIUM • LEGEND HABITAT CSS _ Coastal Sage Scrub CH : Chaparral AG : Annual Grassland (Disturbed, Weedy areas) ABUNDANCE e - ebundent • ub►qultous throughout tht noted community; occurs In high numbers or in large, pure strands c - common - e dominant species In the noted community; occurs in relatively high numbers f - frequent - occurs in moderate numbers, but not a dominant element of the noted community o - occasional - occurs sporadically in the noted community; generally not en obvious or conspicuous component 1 - Infrequent - occurs rarely, or only in a small portion of the noted community; often not apparent unless searched for 5TATU� * Non...Wive ""LAR PLANTS FILICAE ASPIDIACEAE - WOOD FERN FAMILY CSS CH A6 Dryopteris sryute coastal wood tern - t CONIFERAE PINACEAE - PINE FAMILY • PJnuS cenerien q Canary Island pine 1 1 • Pinus pinester Cluster pine ANSIOSPERMAE (DICOTYLEDONES) AMATANTHACEAE - AMARANTH FAMILY Amerenlhus D//loides prostrate amaranth 1 1 c ANACARDIACEAE - SUMAC FAMILY 11olo<me lecrine laurel sumac Rhus lnley I(111e Iemonodeberry • Sc hinus Peruvian pepper -tree • Sc/iinus terettitithifollus Brazilian pepper -tree APIACEAE - CARROT FAMILY • Conlon meculelcdn poison - hemlock Deucus pus/llus rattlesnake weed • Foewn/culum wiper, sweet fennel 0 0 - o 0 0 - ASCLEPIAOACEAE • AIL . _0 FAMILY Asclvies /escici lens narrow -leaved milkweed ASTERACEAE - SUNFLOWER FAMILY Ar'temisi celifornice . coastal sagebrush Artenmi sia drecrmn /las tarragon Bocc,1,ispiluleris coyotebush • Cir ium vulgar" bull thistle • Cony: a caned?ns/s horseweed Corethrogyne //lepini/ol/e cudweed ester &cello cello/nice Celifornle bush sunflower 6nophellum bicolor bicolored cudweed 6Mphel/um celi/arnicarn California everlasting o Cnephol/ur» cenescens s s p. miGrocepholrm, white everlasting o HeI/onthus a vus common sunflower • L oct ce serriole prickly lettuce I1o/ocbllirix wet ills cliff melecothrix • Picris echioldes bristly ox-tongue • $a t us over prickly sow -thistle Stephonomerio virpoto twiggy wreethplent • Torexocr m offic%nele common dandelion BRASSICACEAE - MUSTARD FAMILY f 0 0 0 f 0 0 0 0 • • Brorsice gook: dole short -podded mustard o o • iresslce mre DleCk mustard • RepAeAuf'Stine Wild reddish CACTACEAE - CACTUS FAMILY • °pantie f/cus-indiCe Indian fig Opuntie lillorelis coastal prickly peer CAPRIFOLIACEAE - HONEYSUCKLE FAMILY i 1 • l onicere japonica Japanese honeysuckle - f SemPucus mexicene Mexican elderberry o o CHENOPODIACEAE - GOOSEFOOT FAMILY • CAennpoe/um ellkim Lemb's-quarters CONVOLVULACEAE - MORNING-6LORY FAMILY 1 - 1 Celyslegieme crostegie Western bindweed o o • /pomoee pulp Tee common morning-glory CURCURBITACEAE - 6ORD FAMILY Curturtite foetedissime coyote -melon 1 1 / reii mecroc-erpus wild cucumber o o EUPHORBIACEAE - SPURGE FAMILY CAemeesyctelDn merpinete rattlesnake spurge Eremecerpus set/germs doveweed • RfcMei communis cestor-been 1 1 FA9ACEAE - PEA rArILY• • Acecle lone/olio Sydney golden wattle up nus.spp. lupine • I'feenc. ego polymorpAe bur -clover • nelilotus lndic�rs yellow sweet -clover • Sporllum jenc eum Spanlsh.broom • Vicie satire Spring vetch GERANIACEAE - 6ERANIUM FAMILY • frool um deuterium • red -stemmed fllaree HYDROPHYLLACEAE - WATERLEAF FAMILY fvcryple cirysenthemi/olle common eucrypte LAMIACEAE - MINT FAMILY • lienvAium vulgere horehound 0 0 0 Selvie lei/malty/le purple sage c 1 - MALVACEAE - MALLOW FAMILY • tfelve pervi/lore cheeseweed /1YOPORACEAE - MYOPORUM FAMILY 1 • Myoporum /eeturn myoporum - 1 Mlo 411) MYRTACEAE - MYRTLE FAMILY f:ice+lyptus g/o.'ulue b)ue gum • fu(ely`tus (emelct.'IPncfs red guum - ) OLEACEAE - OLIVE FAMILY • Frexinus sp esh - 1 • - Glee europeee olive - 1 ONAGRACEAE - EVENING -PRIMROSE FAMILY Io/•',um rpm" California fuchsia OXALIDACEAE - WOOD-SORREI FAMILY 1 • C�+ eiiispe lepree Be"r,UC' DLit PITTOSPORACEAE - PITTOSPORUM FAMILY Vict0rt,ri-U^, POLYGONACEAE - BUCKWHEAT FAMILY Er�ogonom c-inereum espy-leeve4 buckwheat c o • Poolygonum ereieslrum common knotweed - • k'!/me r crl cpu ROSACEAE - ROSE FAMILY H.°!orIno./ot e•nul're)%tw 1 rj•1nr. RUBIACEAE - MADDER FAMILY e/g::c!//cowl ro)-rr,..v-)etvc,� bE,1S Ire... 0 • Robert J. McMahon, Jr. Landscape Architect, Lic. 3463 116'1 6th Street Seal Beach, CA 90740 310.493.0186 Professional Experience Mr.. McMahon's project experience extends from California to Japan and Southeast Asia. Having spent nine years working with an international landscape architectural and planning firm, Mr. McMahon has had the opportunity to work on a variety of project types covering conceptual design development to construction observation — creating a strong mufti-cisaplined background. Licensed to practice landscape architecture in the state of California, Mr. McMahon's design management expertise includes a host of assignments ranging from illustrative renderings to graphic design computer system application. In his professional capacity as Project Manager with Perician, Mr. McMahon has directed design efforts on the following projects both locally and internationally. southem California Residential Bel Air Crest — Bel Air, California The Enclave — Calabasas, California Commensal Warner Gateway, Warner Center Santa Ana Auto Mall, Santa Ana Resort The Ritz Carlton Hotel Marina Del Rey — Marina Del Rey, California The Ritz Carlton Hotel Mauna Lani — Mauna Lani, Hawaii Government The Army Corps of Engineers — Santa Ana River Mainstream Recreational Land Use Channel Simi Valley Recreation and Park District — Rancho Tapo'Ranc ho Madera Community Parks International Residential Pinegate Development — Tokyo, Japan Pandan Gardens Condominium Complex Competition — Singapore Recreational Minami Nagano Sports Park — Nagano, Japan (1998 Winter Olympics Stadium Site) Tottoi Flower Park Competition — Tottori, Japan Zhaoging Gotf and Resort Community — Zhaoging, China Mixed -Use Nishi Umeda Redevelopment Project and Ritz Carlton Hotel Osaka — Osaka, Japan Education 1982-1986 Bachelor of Landscape Architecture — State University of New York at Syracuse. Off campus thesis, Spring 1985'Cafes of Venice' Venice, Italy 1980-1982 Applied Associate Science in Ornamental Horticulture at Community College of the Finger Lakes Professional Affiliations American Society of Landscape Architecture, ASLA Horticulture Society Alumni Association at Syracuse University