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Item 4 - Exhibit 6-7D avid L. Babby, R egistered Consulting A rborist® May29, 2015 SECTION 1.0 2.0 3.0 4.0 5.0 5.1 5.2 5.3 6.0 EX HIBIT A B c TABLE OF CONTENTS INTRODUCTION ............................................................................. 1 TREE COUNT AND COMPOSITION ............................................... 2 SU ITAB ILITY FOR PRESERVATION ................................................ 4 REVIEW OF POTENTIAL IMPACTS .............................................. 5 TREE PROTECTION MEASURES •••••••••••••••••••••••••••••••••••••••••••••••• 6 Design Guidelines ........................................................................ 6 Before Demolition, Grading and Construction ........................... 9 During Demolition, Grading and Construction ........................... 9 ASSUMPTIONS AND LIMITING CONDIT I ONS ............................. 12 EXHIB ITS TITLE TREE INVENTORY TABLE (three sheets) SITE MAP (one sheet) PHOTOGRAPHS (four sheets) David L. Babby, R egistered Co ns ulting Arboris t® May 29,2015 1.0 INTRODUCTION The Town of Los Gatos Co mmunity Development Department has retained me to prepare this Arboris t Report in connection with the proposed new residence, with basement, at 18151 Overlook Road , Lo s Gatos. Specific tasks conducted are a s follows: • Visit the site, performed on 5/21/15, to identify 15 "protected trees" 1 situated either within the project site, along the street frontage , or on neighboring properties and having trunks immediately adjacent to and /or canopies overhanging the site. • Determine each tree's trunk diameter at 54 inches above grade. Diameters are rounded to the nearest inch , and trees li sted with more than one diameter are formed by multiple trunks. • Estimate average canopy spreads (rounded to the nearest fifth). • Ascertain each tree's health and structural integrity, and assign an overall condition rating (e.g. good , fair, poor or dead). • Rate each tree's suitabi lity for preservation (e .g. high, moderate or low). • Obtain photographs ; see Exhibit C . • Assign tree numbers in a sequential pattern, and plot those numbers and roughly approximate locations on the site map in Exhibit B (base map being Sheet A 1, the Site & Drainage Plan , dated 9/22114 , by Chri s Spaulding Architect). • Affix round-metal tags with corresponding, engraved numbers to the trunks or limbs of accessible tree s. For inaccessible trees on neighboring properties , tags were affixed to wood fence s adjacent to re spective tree trunks . • Review the set of project plans, prepared by C hris Spaulding Architect, s tamp dated 3/30/15 , to identify potential impacts to inventoried trees. • Provide measures to help avoid or mitigate impacts to retained or rem oved trees. • Prepare a written report containing the above information, and submit via email as a PDF document. 1 Pursuant to Se ction 29 .10 .0960 of the Town 's Municip a l Code, a "pro tected tree " has a trunk with a diameter ~4" at three feet above g rade . Fruit-or nut-bearin g trees with trunk diameters less th an 18" are exempt (Section 29 .1 0 .0970). 18 151 Overlook Road , L os Ga tos Page 1 of12 Tow n of L os Gatos Community De velopment Departm ent David L. Babby, R egistered Consulting Arborist® May 29,201 5 2.0 TREE COUNT AND COMPOSITION Fifteen (15) trees of eight various species were inventoried fo r this report. They are se quentially numbered as #1 thru 15, and the ta ble below identifies their names, assig ned numbers, counts and percentages. %OF NAME TREE NUMBER(S) COUNT TOTAL Coast Jive oak 6 ,7 ,11 ,14 4 27% Deodar cedar 1 1 7% European beech 4 1 7% Evergreen pear 5 1 7% Glossy privet 9, 10, 13 3 20% Monterey pine 2,8, 12 3 20% Pacific wax myrtle 3 1 7% Western redbud 3 1 7% Total 15 100% As illu strated in the above table , the tree la ndscape o n an d surro unding the si te 1s populated predo minantly by coast live oak , followed by privet a nd Monterey pine. Specific information regarding each tree is presented within t he table in Exhibit A. The trees' corresponding numbers and approximate locations can be viewed on the s ite map in Exhib it B, and photographs are presented in E xh ibit C. Tree #3 , a small re dbud , is situated within the public right-of-way along O verl ook Road and is regarded as a street tree. 18151 Overlook Road, Los Gatos Page 2 of12 Town of L os Gatos Community Development Departmen t David L. Babby, Registered Consulting Arborist® May29, 2015 Nine (9) trees have trunks originating on neighboring properties, and due to their prox imity to the project site , were inventoried to achieve conformance with Section 29.10.0995 of the Town Code); they include #1, 4, 6-10, 12 and 13 . Ten (10) trees are not shown on the project plans, and their locations depicted on the map in Exhibit Bare only roughly approximate and should not be construed as being surveyed; they include #1, 4, 6-10, 12, 13 and 15 (accounts for all those on neighboring properties plus #15). Other' trees located throughout the site were not inventoried due to having trunks with diameters less than four inches . 18151 Overlook Road, Los Gatos Page 3 of12 Town of Los Gatos Comm unity Developm ent Department Da vid L. Babby, Registered Consulting Arborist® May29 , 2015 3.0 SUITABILITY FOR TREE PRESERVATION Each tree has been assigned e ither a "high," "moderate" or "low" suitabili ty for preservation rating as a means to cumulatively measure its ex isting health, structura l integrity, anticipated life span, location, size, particular species, tolerance to construction impacts , growing space, and safety to property and persons within striking distance. Descriptions of these ratings are presented below; the high category is comprised of no trees, the moderate category six (o r 40%), and the low category nine (o r 60%). High: Applies to none. These trees appear relatively healthy and structurally stable ; have no apparent, significant health iss ues or structural defects; present a good potential for contributing long-term to the site; and require only periodic or regular care and monitoring to maintain their lo ngevity and structural integrity. They are typically the most suitable for retaining and incorporating into the future landscape. Moderate: Applies to trees #1, 4, 6, 8, 11 and 14 . These trees contribute to the site, but at leve ls less than those assigne d a good suitab ili ty; may have health and/or structura l issues that can potentially be reaso nably address ed a nd properly mitigated; and frequent care is ty pically required for their remaining lifespan. They might be worth retaining , if provided proper care, but not see mingly at s ignificant expense or major de sign revisions. low: Applies to trees #2, 3, 5, 7, 9, 10, 12, 13 and 15. These trees have serious or significantly weakened health and/or structural defects that are expected to worsen re gard le ss of tree care measures emp loyed (i.e . beyond like ly recovery). Removal of those located within the site is reco mmended t o improve the tree landscape and /or site safety. 18151 O verlook Road, Los Gatos Page 4 of12 Town of Los Gatos Community Development Departm ent David L. Babby, R egistered Co ns ulting Arborist® May29, 2015 4.0 REVIEW OF POTENTIAL IMPACTS Implementation of the proposed de s ign allow retention of all inventoried trees, but presents significant impacts to a few, namely #3 and 6. Tree #3 is a small redbud with a poor structure, and excavation for constructing the new driveway will extend up to its trunk; based on its condition, remo val is the appropriate di s pos ition. Tree #6 is a large coast live oak originating from the neighboring eastern property. Excavation for the proposed lightwell along the home's east s ide will result in severe root loss, and as a result, subject the tree to instability and/or premature decline. To avoid thi s, the lightwell des ign requires revi sion to achieve a minimum protection zone of nine to ten feet west of the trunk, and from this point towards north and south , up to 15 feet from the trunk; the protection zo ne mu s t remain free fr om any excavation, overexcavation, fill , compaction, trenching, or othe r soil disturbance, including for s horing (and stitch piers). I also recommend onsite trees #2, 5 and 15 are removed. Tree #2 is a declining Monterey pine with a poor structure , #5 is a small evergreen pear also with a poor stru cture, and # 15 is a short tree anticipated to be removed during excavation for the basement. Tree #4 is s ituated in close proximity t o the ne w parking space. Given a distinct grade differential between the shared fence and ho me , to include a planter, short rock wall , a nd level walk belo w planter, there unlikely are s ignificant roots within the existing walk, but will be within the planter. Based on thi s, where beneath the tre e's existing canopy, the future parking s pace/driveway s hould be entire ly beyond (east of) the outer edge of existing pl anter and rock w a ll , including f or any overexcavation; i.e. maintain exi sting grade within entire planter width and beyo nd wall (note that dimens ions and grades of existing conditions are need ed , a nd not currently shown in the s ite pla n). A summary of the prior information is as follows: • Removals (four in total): #2, 3, 5 and 15. • Retained (11 in total): #1, 4 and 6-14. • Revise the lightwell and building des ign fo r achieving a reasonable chance of s urvi va l a nd rootin g stability for tree #6 . • Achieve setback noted above for the parking space adjacent to tree #4 . 181 51 Overlook Road, Los Gatos Pa ge 5 of12 Town of Los Ga tos Co mmunity Developmen t Departm ent David L. Babby, R egistered Consulting Arborist® May29, 2015 5.0 TREE PROTECTION MEASURES This section presents recommendations for achieving the protecti o n of retained trees throughout construction. They should be carefully followed , are subject to revi s ion upo n reviewing revised or additional project plans , and I should be consulted in the event any measure cannot be feasibly implemented. Please note all referenced distances from trunks are intended to be from the closest edge (face of) of their outem1ost perimeter at soil grade. 5.1 Design Guidelines I. Designate a Tree Protection Zone (TPZ) to be the section of existing unpaved ground beneath or beyond a tree's entire canopy, and for #4 and #6, as specified in Section 4.0 of this report. A TPZ is where the following activities, but not necessarily limited to , shall be avoided: trenching, so il scraping, compaction, mass grading, finish-grading, overexcavation, subexcavation, tilling, ripping, swales, bi oswales, storm drains, dissipaters, dry equipment cleaning, stockpiling and dumping of materials, and equipment/vehicle operation. In the event an impact encroaches slightly within a setback, it can be reviewed on a case-by-case basis to determine whether measures can sufficiently mitigate the impacts to les s -than-s ignificant level s. 2 . For trees #4 and 6 , implement the design recommendations provided in Section 4.0. 3. Where beneath the canopies of trees #6 and 14, confine overexcavation, compaction and other soil disturbance to within 24 inches beyond the basement wall and first floor foundation (including the drilling of piers for shoring). 4 . To achieve the above, shoring is critical to avoid overexcavation beyond the ba se ment wall and maintain setbacks. The shoring design should not require the loss or large limbs or branches during operation of a pile driver or drill rig for shoring. (and soil nailing and shotcrete utilized should a conflict exist). 5. The permanent and temporary drainage design , including downspouts, should not require water being discharged towards a tree's trunk. 18151 Overlook Road, Los Gatos Page 6 of12 Town of Los Gatos Community De velopment D epartm ent David L . Babby , R egistered Consulting Arboris t® May 29, 2 015 6. Add the assigned numbers to a ll site-related plans . The approximate trunk locations of #1, 4, 6-10, 12, 13 and 15 should also be added , as well as additional information regarding the grade differential, planter width and wall location beneath #4's canopy. 7. On the demolition plan, specify that all below ground existing and unused pipes, vaults and lighting shall be abandoned and cut off at existing soil grade where within a TPZ (rather than being dug up and causing root damage). 8 . Swales should be established well-beyond tree canopies . Where necessary within, they shou ld be as far from the trunks as possible, require no more than a two-to three-inch deep cut or fill, avoid severing roots ~two inches in diameter, and not be compacted (foot-tamping is acceptab le). 9 . The erosion control design should consider that any straw wattle or fiber rolls require a maximum vertical soi l cut of two inches for their embedment, and are established as close to canopy edges as possible (and not against a tree trunk). 10 . Per Section 29 .10.1000(C.l) of the Ordinance, a copy ofthis report (or updated one) must be incorporated into the fina l set of project plans; titled Sheets T -1, T -2, etc. ("Tree Protection In structions"); and referenced on all site-related project plans . I I. On Sheet A 1, add protection fencing for trees #4 and 6 to be along the outside eastern edge of the existing wall for #4, and five feet from the proposed home foundation or basement wall for #6; see Exhibit B for an illustration. 12 . A root zone buffer, for foot -traffic only , should also be specified on Sheet A I for trees #6 and 14, to be between protection fencing and the basement wall or foundation. It shall comprise a six-to eight-inch layer of coarse wood chips manually spread on unpaved ground, and to create a sturdy walking surface, can be covered by plywood sheets of at least %-inch thick and secured together. For tree #6, it should be installed prior to demoliti on, and for #4, immediately fo ll owing removal of the existing rear patio . 18 151 Ove rlook Road, Los Gatos P age 7 of12 Town of Los Gatos Community D e velopment D epartment David L. Babby, R egistered Consulting Arborist® May 29, 2015 13 . The landscape design should conform to the following additi onal guidelines: a . Plant material installed beneath the canopies of the oaks sho uld be dro ug ht- tolerant, limited in amo unt , and planted at least five or more feet from their trunks. Plant ma terial in stalled beneath the canopies of all other trees should be at least 24 to 36 inches from their trunks. b . Irrigation beneath the oak canopies should not be applied within a di stance of five times their trunk diameters. Irrigation for new plant materi a l beneath their canopies should be low-vo lume, applied irregularly (s uch as on ly once o r twice per week), and temporary (such as no more than three years). c. Irrigation and lighting features (e.g. main line , lateral lin es, va lv e boxes, wiring and controllers) should be establi s hed beyond TPZs. In the event thi s is not feasible , they may require be ing installed in a radial directi o n to a tree 's trunk, and terminate a spec ific di stance from a trunk (versus crossing past it). d. Ground cover should be comprised (partially or entire ly) of a three-to four- inch depth of coarse wood chips or other high-quality mulch (gorilla ha ir, bark or rock, stone , cobble , gravel , black plastic or other synthetic gro und cover should be avoid ed). Mulch sho uld rem a in s ix inches fro m the trees' trunks . e. Tilling, ripping and compaction within TPZs s hould be avoided. f. Bender board or othe r edging materi a l proposed beneath the canop ies should be established on top of existing so il grade (such as by us ing vertical stakes). 14. Mitigation is nece ssary t o compensate for the rem ova l of protected trees, a nd Section 29 .I 0.0985 can be used as the framework for det ermining amounts and sizes . The trees shall be planted pri or to final inspection, double-staked with rubbe r tre e ties (may not be necessary for trees of 36-inch box si ze and larger), a nd a ll forms of irrigation be of a n aut omatic drip or soake r hose system placed on the so il s urface and not in a s leeve. Additi o na ll y , to achieve the gre atest assurance of proper installation, a ll new trees shall be installed, includin g necessary irrigation, by an experi ence d Cali fo rni a State-licensed landscape contractor or tree-service company. 18151 Overlook Road, Los Gatos Page 8of1 2 Town of Los Gatos Community D evelopment D epartment David L. Babby, R egist ered Consulting Arborist® May 29, 2015 5.2 Before Demolition, Grading and Construction 15. Manually restore the soil grade at the rear of the site ; the ground should be 'smoothed' and leveled out, being careful not to excavate so il and roots. 16. Spread a four-to five-inch layer of coarse wood chips ('4-to %-inch in size) from a tree-service company over the ground within the property's rear section. 17 . Establish the root zone buffer for tree #6. 18 . The root collars of trees #11 and 14 must be fully cleared of rock and soil on all sides (360°), and the work performed by a professional and state-licensed tree service either through hand-digging or the use of an Airspade. 19. Establish tree protection fencing to restrict access into TPZs, and where along future foundations , no farther than five feet from the basement wall; locations are identified on Exhibit B. This fencing shall remain throughout construction, and consist of five-to six-foot high chain link mounted on eight-foot tall , two-inch diameter galvanized steel posts that are driven into the ground. 20. Pursuant to Section 29.10.1005(a)(4) of the Town Code, 8.5-by 11 -inch warning signs shall be affixed and prominently displayed on each side of fencing opposite the trees ' trunks: "WARNING -Tree Protection Zone -this fence shall not be removed and is subject to penalty according to Town Code 29.10.1025." These s igns should be intact prior to commencing demolition. 5.3 During Demolition, Grading and Construction 21 . Supply water to the root zones of #4, 6 and 14 every three to four weeks throughout the entire construction process, at an amount of five to ten gallons per inch of trunk diameter. Various application methods include either flooding the in side of a 12-inch tall berm formed around or near a canopy's perimeter, using soaker hoses , or through deep-root injection. For #4 and 6, watering only on the project site is sufficient. 22. A void using tree trunks as winch supports for moving or lifting heavy loads. 18151 Overlook R oad, Los Gatos Page 9of12 Town of Los Gatos Community Development Department David L. Babby, Register ed Cons ulting Arborist® M ay 29, 2015 23. The staging area and route(s) of access should be established beyond TPZs. 24. Excavation for section of drive (parking space location) beneath #4's canopy should first be performed by a one-foot wide trench being manually dug along the perimeter of where soil excavation will occur closest to the tree's trunk, and down to the required subgrade depth (to avoid roots breaking and being damaged closer to the trunk than otherwise needed). Roots encountered with diameters of 2:two inches shall be cleanly severed by hand (at 90° to the direction of root growth) against the tree side of the trench. All soil beyond the trench (i.e. away from the tree) can then be mechanically excavated using heavy equipment, and remaining outside the fenced area(s). Alternatively, the use of a stump grinder could be utilized precisely where a curb/gutter and any overcut (12" max) will be established. 25. Any approved digging or trenching within a TPZ shall be manually performed without the use of heavy equipment or tractors operating on unpaved ground beneath canopies. 26 . A void damaging or cutting roots with diameters 2:two inches. Should roots of this size be encountered, within one hour of exposure , they should either be covered by burlap that remains continually moist until covered by soil. If they are approved for cutting, cleanly severe at 90° to the angle of root growth against the cut line (using toppers or a sharp hand saw), and then immediately after, the cut end either buried with soil or covered by a plastic sandwich bag (and secured using a rubber band, and removed just before backfilling). 27. Tree pruning shall only be performed in accordance with ANSI A300-2001 standards, by a California licensed tree-service contractor (D-49) that has an ISA certified arborist in a supervisory role , carries General Liability and Worker's Compensation insurance, and abides by ANSI Z133 .1-2006 (Safety Operations). 28 . Removing existing hardscape and home within and near a TPZ, such as for tree #14 , must be carefully performed to avoid excavating roots and so il during the process (and above-ground portion of a tree). 18151 Overlo ok Road, Los Gatos Page 10of12 Town of Los Gatos Community Development Departm ent David L. Babby, R egistered Consulting Arboris t® May 29, 2015 29 . The root zone buffer for tree #14 shall be installed immediately following demolition of the existing rear patio (completed prior to basement excavation). 30. Any fence posts to be established within a TPZ must be carefully designed to avoid potential significant impacts. In doing so, I recommend they are planned to be at least two to three feet from a trunk , minimized in diameter, and spaced as far apart as possible (e.g . at least five plus feet apart). The design should specify that the post holes are manually dug using a post hole digger or shovel, and roots two inches and greater in diameter retained and protected during the process (in the event a root of this size is encountered during digging, the hole should be shifted over 12 inches and the process repeated). 31. Spoils created during digging shall not be piled or spread on unpaved ground within a TPZ . If essential , spoils can be temporarily piled on plywood or a tarp. 32 . Dust accumulating on trunks and canopies during dry weather periods should be periodically washed away (e .g. every two to three months). 33. Avoid disposing harmful products (such as cement, paint, chemicals, oil and gasoline) beneath canopies or anywhere on site that allows drainage within or near TPZs. Herbicides should not be used with a TPZ; where used on site, they should be labeled for safe use near trees. Liming shall not occur within 50 feet from a trunk. 34. Great care must be taken by equipment operators to position their equipment to avoid the trunks and branches of trees, including the scorching of foliage (including along the road). 35. Fertilization may benefit the trees' health, vtgor and appearance . If applied, however, soil samples should first be obtained to identify the pH levels and nutrient levels so a proper fertilization program can be established. I further recommend any fertilization is performed under the direction and supervision of a certified arborist, and in accordance with ANSI A300 (Part 2)-2004 Fertilization standards. 18 151 O verlook Road, Los Gatos Page 11 ofl2 Town of L os Gatos Community D evelopment D epartment David L. Babby, R egis tered Consulting Arborist® May29, 2015 EXHIBIT A: TREE INVENTORY TABLE (three sheets) 18151 Overlook R oad, Los Gatos Town of Los Gatos Community Development Department ( David L. Babby, Registered Consulting Arboris t® May29, 2015 EXHIBIT B: SI TE MAP (one sheet) 18151 Overlook Road, Los Gatos Town of Los Gatos Comm unity D evelopm ent Departm ent David L . Bobby, R egistered Consulting Arborist® May29, 2015 EXHIBIT C: PH OTOG RAP HS (four sheets) Ph oto Index Page C-1: Trees #1 thru 6 Page C-3 : Trees #10 thru 13 Page C-2: Trees #6 thru 9 Page C-4: Trees #14 and 15 18151 Overlook Road, Los Gatos Town of Los Ga tos Community Development Departm ent This Page I ntentional/y Left Blank David L. Babby, R egistered Consulting Arborist® September 21 , 2015 SECTION 1.0 2.0 3.0 4.0 5.0 5.1 5.2 5.3 6.0 EXHIB IT A B c TABLE OF CONTENTS TITLE PAGE INTRODUCTION ••••••••• •••••• ••. •••••• •••••• •••••••••• ••• ••• •.. • ••. ••••.•••• •••••••••••• ••. 1 TREE COUNT AND COMPOSITION ............................................... 2 SUITABILITY FOR PRESERVATION ................................................ 4 REVI EW OF POTENTIAL IMPACTS .............................................. 5 TREE PROTECTION MEASURES ................................................ 6 Design Guidelines ........................................................................ 6 Before Demolition, Grading and Construction ........................... 9 During Demolition, Grading and Construction ........................... 10 ASSUMPTIONS AND LIMITING CONDITIONS ............................. 13 EXHIBITS TITLE TREE INVENTORY TABLE (three sheets) SITE MAP (one sheet) PHOTOGRAPHS (four sheets) David L. Babby , R egistered Consulting Arborist® September 21, 201 5 1.0 INTRODUCTION The Town of Los Gatos Community Development Department has retained me to review the current set of plans and update my prior 5/29/15 report in connection with the proposed new residence , with basement, at 18151 Overlook Road , Los Gatos. Specific tasks conducted for this and the prior report are as follows: • Review the current set of plans, stamp dated 8/5/15 by the Town. • Visit the site, performed on 5/21 /15 , to as sess potential impacts by identify 15 tree s situated either within the project site, along the street frontage , or on neighboring properties and having trunks immediately adjacent to and /or canopies overhanging the site. A subsequent visit was performed on 9116/15 to asse ss potential impacts by implementing the current set of plans . • Determine each tree's trunk diameter at 54 inches above grade. Diameters are rounded to the nearest inch, and trees listed with more than one diameter are formed by multiple trunks. • Estimate average canopy spreads (rounded to the nearest fifth). • A scertain each tree's health and structural integrity, and assign an overall condition rating (e.g. good, fair, poor or dead). • Rate each tree's s uitability for preservation (e.g. high, moderate or low). • Obtain photogra ph s; see Exhibit C. • Assign tree numbers in a sequential pattern, and plot those numbers and roug hly approximate location s on the site map in Exhibit B (base m a p being Sheet A l , the Site & Drainage Plan , d ated 9/22114 , by Chris Spaulding Architect). • Affix round-metal tags with corresponding, engraved numbers to the trunks or limbs of accessible trees. For inaccessible tree s on neighboring properties , t ags were affixed to wood fences adjacent to their respective tree trunks. • Provide measures to help avoid or mitigate impacts to retained or removed trees. • Prepare a written report containing the above information, and submit via email as a PDF document. 18151 Over look Road, Los Gatos Page 1 of13 Town of Los Gatos Community De velopment Department Da vid L. Babby, Registered Consu lting Arborist® S eptember 21 , 2015 2.0 TREE COUNT AND COMPOSITION Fifteen (15) trees of eight various species were inventoried for this report. They are sequentially numbered as #1 thru 15, and the table below identifies their names, assigned numbers, counts and percentages. %OF NAME TREE NUMBER(S) COUNT TOTAL Coast live oak 6, 7, 11 , 14 4 27 % Deodar cedar 1 1 7% European beech 4 1 7% Evergreen pear 5 1 7% Glossy privet 9, 10 , 13 3 20% Monterey pine 2,8, 12 3 20% Pacific wax myrtle 3 1 7% Western redbud 3 1 7 % Total 15 100% As illustrated in the above table, the tree landscape on and surrounding the si te is populated predominantly by coast live oak, privet and Monterey pine . Specific information regarding each tree is presented within the table in Exhibit A. The trees' corresponding numbers and approximate locations can be v iewed on the site map in Exhibit B , and photographs are presented in Exhibit C. Tree #3 , a small redbud, is situated within the public right-of-way along Overlook Road and is regarded as a street tree. 18151 Overlook Road, Lo s Gatos Page 2 of13 Town of L os Gatos Community Development Department David L. Babby, Registered Consulting Arborist® September 21, 2015 Nine (9) trees have trunks originating on neighboring properties, and were inventoried due to their proximity to the project site ; they include #1, 4, 6-10, 12 and 13. Of the I 5 inventoried trees , the following 12 are regulated and defined as protected trees: 1 #1-8, 11, 12, 14 and 15. The other three trees, #9, 10 and 13, are exempt from regulation, pursuant to Section 29.10.0970 of the Town Code, due to being privets with trunk diameters Jess than 24 inches (all are situated on neighboring properties). Ten (10) trees were not shown on the prior plans reviewed , and their locations shown on the map in Exhibit B are only roughly approximate and should not be construed as being surveyed ; they include #1, 4, 6-10, 12, 13 and 15 (accounts for all those on neighboring properties plus #15). Other trees located throughout the site were not inventoried due to having trunks with diameters less than four inches. 1 Pursuant to Section 29.10.0960 of the Town 's Municipal Code, a "protected tree" has a trunk with a diameter 2::4" at three feet above grade. Fruit-or nut-bearing trees with trunk diameters le ss than 18" are exempt (Section 29.1 0.0970). 18 15 1 Overlook Road, Los Gato s Page 3 of13 Town of Los Gatos Community Development D epartm ent Da vid L. Babby, Registered Consulting Arboris t® September 21, 2015 3.0 SUITABILITY FOR TREE PRESERVATION Each tree has been assigned either a "high," "moderate" or "low" suitability for preservation rating as a means to cumulatively measure its existing health, structural integrity, anticipated life span, location, size, particular species, tolerance to construction impacts , growing space, and safety to property and persons within striking distance. Descriptions of these ratings are presented below; the high category is comprised of no trees, the moderate category six (or 40%), and the low category nine (or 60%). High: Applies to none. These trees appear relatively healthy and structurally stable; have no apparent, significant health issues or structural defects; present a good potential for contributing long-term to the site; and require only periodic or regular care and monitoring to maintain their longevity and structural integrity. They are typically the most suitable for retaining and incorporating into the future landscape. Moderate: Applies to trees #1, 4, 6, 8, 11 and 14. These trees contribute to the site, but at levels less than those assigned a good suitability; may have health and/or structural issues that can potentially be reasonably addressed and properly mitigated; and frequent care is typically required for their remaining lifespan. They might be worth retaining , if provided proper care, but not seemingly at significant expense or major design revisions. low: Applies to trees #2, 3, 5, 7, 9, 10, 12, 13 and 15. These trees have serious or significantly weakened health and /or structural defects that are expected to worsen regardless of tree care measures employed (i.e. beyond likely recovery). Removal of those located within the site is recommended to improve the tree landscape and/or site safety. 18151 Overlook Road, Los Gatos Page 4 of13 Town of Los Gatos Community Development D epartm ent Da vid L. Babby, R egistered Consulting Arborist® September 21,2015 4.0 REVIEW OF POTENTIAL IMPACTS Based on my review of project plans, in conjunction with a specific tree's condition and tolerance to impacts, the following disposition is anticipated: • Removals (four in total): #2, 3, 5 and 15. • Retained (eleven in total): #1, 4 and 6-14 . Regarding removals , tree #2 is a Monterey pine intolerant of root loss , and its decline and ultimate demise is anticipated within one or more years following site development. Tree #3 is a small redbud with poor structure, and excavation for constructing the new driveway will extend up to its trunk and result in severe impacts . Tree #5 is a small evergreen pear also with a poor structure . Tree #15 can be considered a tall shrub, and is anticipated to be removed during excavation for the basement. To my understanding, an application has been submitted to the Town regarding removing tree #11 , the rearmost oak on the property ; specific reasons for removal are unrelated to future site construction. Tree #4 is specified for retention , but would sustain substantial root impacts during construction of the proposed future curb and parking space/driveway within the existing planter and six inches from existing fence; when considering overexcavation is needed to form and pour the curb/parking space, ground disturbance will occur up to the fence . Based on #4's size, its protection zone should be a minimum of eight feet from the trunk's base to back of rock wall (i .e . where dirt of the planter and rocks meet), where all overexcavation, compaction, trenching and other ground disturbance should be avoided. Tree #4's base of trunk is roughly four feet from the fence, and the existing planter is 18 inches wide between the fence to back of rock wall (the planter is anticipated to contain significant roots). When considering this information, design revisions are needed for adhering to the TPZ and achieving a reasonable assurance of #4's survival. 18 151 Ove rlook Road, Los Gatos Page 5 of 13 Town of L os Gatos Community D evelopment Depar tm ent David L. Babby, Registered Consulting Arborist® September 21 , 2015 5.0 TREE PROTECTION MEASURES This section presents recommendations for achieving the protection of retained trees throughout construction. They should be carefully followed, are subject to revision upon reviewing revised or additional project plans, and I should be consulted .in the event any measure cannot be feasibly implemented. Please note all referenced distances from trunks are intended to be from the closest edge (face of) of their outermost perimeter at soil grade. 5.1 Design Guidelines I. Designate a Tree Protection Zone (TPZ) to be the section of existing unpaved ground beneath or beyond a tree's entire canopy; for #4, it should be as specified in Section 4.0 of this report , and for #6, a minimum distance of nine feet west of its trunk, and from this point north and south, up to 15 feet from the trunk . A TPZ is where the following activities shall be avoided: trenching , soil scraping, compaction, mass grading , finish-grading , overexcavation , subexcavation, tilling , ripping , swales, bioswales , storm drains, dissipaters, dry equipment cleaning, stockpiling and dumping of materials, equipment/vehicle operation, and shoring piers/excavation. In the event an impact encroaches slightly within a setback, it can be reviewed on a case-by-case basi s to dete rmine whether measures can sufficiently mitigate the impacts to less-than-significant level s. 2. Where beneath the canopies of trees #6 and 14, limit overexcavation, compaction , trenching and other soil disturbance to within 12 to 24 inches beyond the first floor foundation. For tree #4 , the same limitations are needed beyond the basement and lightwell walls, as well as the first floor foundation. 3. If shoring is used for constructing the basement, the layo ut should not r equire the loss or large limb s o r branches during operation of a pile driver or drill ri g for shoring (and soil nailing and shotcrete utilized should a conflict exist). 4 . For tree #4, implement the design recommendations provided in Section 4.0. 18151 Ove rlook Road, Los Gatos Page 6 of13 Tow n of Los Gatos Community D e velopm ent Departm ent Da vid L. Babby, Registered Con sulting Arborist® September 21, 2015 5. The proposed retaining wall adjacent to tree #6 shall require no excavation, trenching or compaction within its TPZ (e.g. utilize a drystack wall with no footings). Should footings be required for the desired wood wall , the post locations shall be installed as discussed in Section 5 .3 of this report. 6. The permanent and temporary drainage design, including downspouts, should not require water being discharged towards a tree's trunk. 7. The assigned numbers should be added to Sheet 3 (excluding exempt trees #9 , I 0 and 13). Additionally, #4's location should be updated on Sheets A I and 3 to reflect what is identified in Exhibit A. 8 . Update Sheets AI , AJ.I and C3 to illustrate protection fencing as shown in red on the map in Exhibit B. Other fencing locations can be omitted from the plans. 9. On the demolition plan, specify that all below ground existing and unused pipes, vaults and lighting shall be abandoned and cut off at existing soil grade where within a TPZ (rather than being dug up and causing root damage). 10. Swales should be established well-beyond tree canopies. Where necessary within , they should be as far from the trunks as possible, require no more than a two-to three-inch deep cut or fill , avoid severing roots 2:two inches in diameter, and not be compacted (foot-tamping is acceptable). 11 . The erosion control design should consider that any straw wattle or fiber rolls require a maximum vertical soil cut of two inches for their embedment, and are established as close to canopy edges as possible (and not against a tree trunk). 12. Per Section 29.10.1000(C.l) of the Ordinance, a copy of this report (or updated one) must be incorporated into the final set of project plans ; titled Sheets T-1, T-2, etc. ("Tree Protection Instructions"); and referenced on all site-related project plans. 18 151 Overlook Road, Los Gatos Pa ge 7 of13 Town of Los Gatos Community D evelopment Department David L. Babby, R egistered Consulting Arborist® September 21 , 2015 13. The landscape design should conform to the following additional guidelines: a. Plant material installed beneath the canopies of the oaks should be drought- tolerant, limited in amount, and planted at least five or more feet from their trunks. Plant material installed beneath the canopies of all other trees should be at least 24 to 36 inches from their trunks. b. Irrigation beneath the oak canopies should not be applied within a distance of five times their trunk diameters. Irrigation for new plant material beneath their canopies should be low-vo lume, applied irregularly (such as only o nce or twice per week), and temporary (such as no more than three years). c. Irrigation and lighting features (e.g. main line, lateral lines, valve boxes, wiring and controllers) should be established beyond TPZs . In the event thi s is not feasible , they may require being installed in a radial direction to a tree's trunk, and terminate a specific distance from a trunk (versus crossing past it). d . Ground cover should be comprised (partially or entirely) of a three-to four- inch depth of coarse wood chips or other high-quality mulch (gorilla hair, bark or rock, stone, cobble, gravel , black plastic or other synthetic ground cover should be avoided). Mulch should remain six inches from the tree s ' trunks. e. Tilling, ripping and compaction within TPZs should be avoided. f. Bender board or other edging material proposed beneath the canopies should be established on top of existing so il grade (such as by us ing vertical stakes). 14 . Mitigation is necessary to compensate for the removal of protected trees, and Section 29.10.0985 can be used as the framework for determining amounts and s izes . The trees shall be planted prior to final inspection, double-staked with rubber tree ties (may not be necessary for trees of 36-inch box size and larger), and all forms of irrigation be of an automatic drip or soaker hose system placed o n the soil surface and not in a sleeve. Additionally, to achieve the greatest assurance of proper installation, all new trees shall be in stalled, including necessary irrigation , by an experienced California State-licensed landscape contractor or tree-service company. 18151 Overlook Road, Los Gatos Page 8 of 13 Town of Los Gatos Community De velopm ent Department David L. Babby, R egistered Consulting Arborist® September 2 1, 2015 5.2 Before Demolition, Grading and Construction I 5. Manually restore the soil grade at the rear of the site ; the ground should be 'smoothed' and leveled out, being careful not to excavate soi l and roots . 16 . Spread a four-to five-inch layer of coarse wood chips (Yt-to %-inch in size) from a tree-service company over the ground within the property's rear section . 17 . A root zone buffer, for foot-traffic only, should be established for tree #6 between protecti on fencing and first-floor foundation. It shall comprise a six-to eight-inch layer of coarse wood chips manually spread on unpaved ground , and to create a sturdy walking surface, can be covered by plywood sheets of at lea st %-inch thick and secured together. 18 . The root collars of trees #11 and 14 must be fully cleared of rock and soil o n all sides (360°), and the work perfo rmed by a professional and state-licensed tree service ei ther through hand-digging or the us e of an Airspade (not applicable for #II if its remova l is authorized by the Town). 19. Establish tree protection fencing to restrict access into TPZs, and where along future foundations , no farther than five feet from the basement wall and /or first-floor foundation ; locations are identified on the map in Exhibit B. This fencing shall remain throughout construction, and co nsist of five-to six-foot high chain link mounted on eight-foot tall , two-inch diameter galvanized steel posts th at are driven into the ground. 20. Pursuant to Section 29.10.1005(a)(4) of the Town Code, 8.5-by 11-inch warning signs shall be affixed and prominently displayed on each side of fencing oppos ite the trees ' trunks: "WARNING -Tree Protection Zone -this fence shall not be removed and is subject to penalty according to Town Code 29 .10 .1 025 ." The se signs should be intact pri or to commencing demolit ion. 18 151 Overlook R oad, Los Gatos Page 9ofl3 Town of Los Gatos Co mmunity Developm ent Departm en t David L. Babby, Registered Consulting Arborist® September 21 , 2015 5.3 During Demolition, Grading and Construction 21 . Supply water to the root zone s of #4, 6 a n d 14 every three to fo u r weeks throughout the entire construction process, at an a mount of five to ten gallons per inch of trunk diameter. Various application meth ods include either floodin g the in side of a 12-inch tall berm formed around or near a canopy's perimeter, using soaker ho ses, or thro ugh deep-root injection. For #4 and 6, watering only on the proj ect site is sufficient. 22. A root zone buffer, for foot-traffic only , s hould be established for #4 imm ediately following rem oval of the rear patio . It should be established between protection fe ncing and the baseme nt/li g htwe ll wall, and comprise a s ix -to e ight-inch layer of coarse wood chips manually spread o n unpaved ground; to create a sturd y wa lkin g surface , the chips can be covered by plywood sheets of at lea st %-inch thi ck and secured together. 23 . Avoid us ing tree trunks as winch supports for moving or lifting heavy loads. 24 . The staging area and route(s) of access s ho uld b e established beyond TPZs . 25. Excavation for section of driv e (parking space locatio n) beneath #4's canopy should first be perfo rmed by a one-foot wide trench being manually dug along the perimeter of where soi l excavation will occur c losest to the t re e's trunk, and down to t he required subgrade de pth (to avoid roots breaking and be in g damaged closer to the trunk than otherwise ne eded). Roo t s encountered with diameters of ~two inch es shall be clean ly severed by ha nd (at 90° to the direction of root growth) agai nst the tree side of the trench. All soil beyond the trench (i.e. away from the tre e) can then be mechanically excavated usin g heavy equipment, and remaining o utsi de t he fence d area(s). Alternatively, the use of a stu mp grinder could be uti li zed precisely where a curb/gutter and any overcut (12" max) will be established. 26. Any approved digging or trenching within a T PZ shall be manually performed without the use of heavy equipment or tractors operating o n unpaved ground beneath canoptes. 18151 Overlook R oad, Los Gatos Page 10 ofl3 Town of Los Gatos Community Development Department David L. Babby, R egis ter ed Consulting Arborist® September 21 , 2015 27. Avoi d damaging or cutting roots with diameters 2:two inches. Should roots of this size be encountered , w ithi n one hour of exposure, they should either be covered by burlap that remain s continually moi st until covered by so il. If they are approved for c uttin g, c leanl y severe at 90 ° t o the angle of root growth against the cut line (using to ppers or a sharp hand saw), and then immediately after, the cut end either buri ed with soil or covered by a plastic sandwich ba g (and secured us in g a rubber band, and re moved just before backfilling). 28. Tree pruning s hall on ly be performed in accordance with ANSI A300-200 I standards, by a California licensed tree-service contractor (D-49) that has an ISA certified arborist in a supervisory r ole, carries General Liability and Worker's Compensation in s urance, and abides by ANSI Z l 33.1-2006 (Safety Operations). 29. Re mov ing existing hardscape and home within and ne ar a TPZ, s uch as for tree #14 , mu st be carefully pe rformed to avoid excavating roots and soil during the process (and above-ground portion of a tree). The section of existing hardscape within the desig ned-fenced area for# 14 s h ou ld be manually performed. 30. The root zone buffer for tree #14 shall be installed immediately following demolition of the existing rear patio (completed prior to ba sement excavation). 3 1. Any fence posts to be established within a TPZ must be carefully designe d to avoid potential signifi cant impa cts. In doing so , I recommend they are planned to be at lea st two to three feet from a trunk , minimized in diameter, and spaced as far a part as po ss ible (e.g. at least five plus feet apart). The des ign sho uld specify that th e post ho le s are manuall y du g us in g a post ho le digger or shovel , and roots two inches and greater in diameter retained and protect ed during the process (i n the event a root of this s ize is encountered during di gging , the ho le s ho uld be shifted over 12 inches and the process repeated). 32 . Spoils created during digging shall not be piled or spre ad on unp aved gro und w ithin a TPZ. If essential , spo il s ca n be temporarily piled on plywood or a tarp. 18 151 Overlook R oad, Los Gatos Page 11 of 13 Town of Los Ga tos Community Development Department David L. Babby, Registered Consulting Arboris t® September 21 , 2015 33. Dust accumulating on trunks and canopies during dry weather periods should be periodically washed away (e.g. every two to three months). 34. Avoid disposing harmful products (such as cement, paint, chemicals, oil and gasoline) beneath canopies or anywhere on site that allows drainage within or near TPZs . Herbicides should not be used with a TPZ; where used on site, they should be labeled for safe use near trees. Liming shall not occur within 50 feet from a trunk. 35. Great care must be taken by equipment operators to position their equipment to avoid the trunks and branches of trees , including the scorching of foliage (including along the road). 36. Fertilization may benefit the trees' health , vtgor and appearance. If applied, however, soil samples should first be obtained to id e ntify the pH levels and nutrient levels so a proper fertilization program can be establis hed . I further recommend any fertili zation is performe d under the direction and supervision of a certified arborist, and in accordance with ANSI A300 (Part 2)-2004 Fertiliz ation standards. 18 151 Overlook Road, L os Gatos Page 12 of 13 Town of L os Gatos Community Development Dep artment David L. Babby, Registered Consulting Arborist® September 21 , 2015 EXHIBIT A: TREE INVENTORY TABLE (three sheets) 18151 Overlook Road, Los Gatos Town of Los Gatos Community D e velopment Department David L. Babby, R egis tered Consulting Arborist® September 21, 2015 EXHIBIT 8: SITE MAP (o ne sheet) 18 151 Overlook R oad, Los Gatos Town of Los Gatos Co mmunity D evelopment Department David L. B obby, R egistered Consulting Arborist® September 21 , 2015 EXHIBIT C: PHOTOGRAPHS (four sheets) Phot o Index Page C-1: Trees #1 thru 6 Page C-3: Trees #10 thru 13 Page C-2 : Trees #6 thru 9 Page C-4: Trees #14 and 15 18151 Overlook Road, Los Gatos Town of Los Gatos Community Development D epa rtment