HomeMy WebLinkAbout0247.095, •
TO:
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DATE:
SUBJECT:
REOUEST
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City of Palo Alto
City Manager's' Report
HONORABLE cm' COllNCIL
CITY MANAGER
May 11,1995
DEPA.lnME!\jT: Public W""ks
CMR:Z47:95
Oak Trees In Parking Let G, Forest Avenue and La DoDna
Street
This report provide< Council with reports from • private Arborist and the City Arborist
regaramg the conditioil of the Coast Uve Oak (oak) in Parking Lot G and two additional oaks
located on Forest A venue and on La Donna Street.
BECOMlIAENDillON
This is an infornIational report and requires 00 Council action.
POI.ICy IMl'I.ICATIQNS
There are no policy implication; reiate<i 10 this report.
BACKGROUND
AI the Council meeting of April i7. 1995 •• Palo Alto residenI. BIll Peterson, requested that
!he City Council <ftrect staff to delay rent<'val of the oak and consider a1ternatives. Mr.
Peterson explained 10 Council that be and other members of the Fannen Market bad hired
an arborist \0 irldepomdently assess the condition of the tree and propose options to the City .
III atsC1Jssiol! with staff Mr. Peterson brought two other trees to oor 2t1ention which were
schedule<! for removal.
A copy of the private arborist's report of the oak is attached.
In summary, !he prime arborist's report COIlCIlI"5 with oor own staff findings. Specific
comments from the private arborist's report:
1. "The tree is hig.'lIy susceptible to failure by breaking over at the root croWD. "
2. "Cortsidering the use of the area (Parking Lot, Farm<'.rs Market, sidewalk and street.)
and the potential for faiJure, I reel the tree should be removed."
l. Ok u my opinion thai tbls oak is bazardous and should be removed.'
The arto.-ist·s report also descn1les "e.traordinary leogths" the City could go 10 in "an
atleIDpt" 10 save !he tree.
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DJSClISSJON
The 40' diameter Coast Live Oak tree in parking lot G (on Gilman St.=t) bas been scheduled
for removal and replacemeuL The beaI<h of !he tree bas declined below an acceptable level
and bas now becc= • potential safety hazard, The two primary dysfunctions of !he tree
which have led 10 this condition are dimInished structural integrity and loss of foliage,
The "foundation" {)f stn.'Ctura! part of the tree, the roots and trunk, have decayed so much
that the tree is. hazard, The roots are infearo with ~ (oak root fungus). The
trunk and large supporting roots have been boIIvwed by other fung;, leaving !he walls of the
trunk perilOllsly thin and riddled wltli large holes. This conc:Iition will DO( suppo<I the
signiticanl weiglll of !he wood, which is up 10 40 feet overbead, This condition is common
among oak.< in urban senmgs, wbe", soil compaction and iXlIlStructioc prevent good drainage
in the root zone,
The seconc:I function ()( decline bas been the canopy 0( IOliage overhead, The top of Ibe tree
has been dyjng and thinning over the past few years, The fungus infectioru; in the roots
prevell! circulation of water up 10 the leaves. Two years ago, City creliiS Cut hack the dead
e."I> of !be Qinopy and balanced the tree in .n attempt 10 extend its life, This season the
foliage consists mostly of sprouts emerging from the main frmbs of the tree -• sign of
accelerating decline, The '" el wdltc r bas soaked the ba.'ie of Ibe tree and with summer beat
the conditions will be perfect for increased fungal growth into the tree tissue;;. This further
increases the chances of the rOiteO base snapping and additional pJ-JUing of ,'ascular tissues
carrying moisture 10 Loe leaves,
Two add"rtlonal oaks which were identified 10 staff as C2Ildidates for removal, and !bey are
located at 417 Forest A venue and ms La Donna,
The Coast Live Oak tree at 411 Forest Avenue is suffering from two CC!\ditions; (I) The
trunk and supporting roots are hollowed with decay and the loss of strong beartwood from
ground level I<> about 15 feet has significantly weakened the trunk: (2) the tree has a severe
lean Ioward the street and • fun crown of fQIi.ge. This lean, wben ooi1sidered with the
weakened trunklroot coodition. increases the probability of fallillg.
The tree is 1oc:.1ed a<f05S the street from !be California State Automobile Association offices, .ncr is in an area with high pedestrian and vebicular traffic, Vehicles are parked benealb the
tree; and the probability of damage 10 vehicles, or injury 10 pedestrians, is high.
We are investigating Ibe extent of !be internal decay (the thickness of heailby wood of the
bo!Iow trunk) and the bealth and rigor of the supporting roots, If these are strong enough.
pemaps the weight of the foliage crown tan be reduced enough 10 prevent falling,
The second (Valley Oak) at ms La Donna is scheduled for removal. The tree is severely
decayed, with many cavities ocd missing pieces of trunk wood. The tree has. poor foliage
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crown and has a hive 0( bees in one 0( the cavities. It provides link canopy and is liable 10
collapse wq>reQlCtabiy. The tree ~ be saved.
CONOllSION
There are DO ~ aV31lable !hal would cure the infections 0( fungi. Because the fungi
have grown deeply into the woody tissue and wau.r carrying vessels, fungjcidal treatmenlS
cannoc gain access and wiIl no! S!op the infe.:tions. This mak .. the decline 0( the canopy and
death 0( the tree inevitable, perhaps within the ne<l few years.
For some trees with less extensive infections, support stru<:tures are SOme'.imes ereeled 10
provide S!ability and carry some 0( the weight. Because these trees are losing !be foliage
rapidly, such efforts are DOl relevant; and, if they were, would be imp<actical based 011 !be
location 0( !be tree. The installation 0( supports ,,'ould encroach iruo !be parking and
pedestrian area and wO'J1d DO! guarantee stability if !be 11"" were subjecled 10 high winds.
The best course of action from bo!b an arboriculrural and pnctical ,tandpoint is 10 remove
this tree and replace it with a new ooe. &alI is pr<>pOSing 10 replace !be tree in lot G with a
live oak of a substantial sa.., (6" diameler) and improve the sile 10 provide a bealthier
siruation foe !be next tree. The trees on Forest and La Dv-nna will be replaced with standard
size street tree replacements,
lISCAI,IMPACf
Funds are budgeled foe tree removal and replacement in the 1994-95 Public WorkB
Operations Division budget_
AU.4CIIMENTS
Arborist's Report
PREPAllED BY: Dave Sandage, City Arborist
DEPARTMENT HEAD REVIEW: ~ f ~
7, GLENN Spj/R RTS r Directorof lWDrks
CITY MANAGER APPROVAL, \\ '-Ct---? ~ '0
JUNE FID-hNG •
City Manager
ce: Mr. Bill Peu.rson
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~. June Fleming, City Manager
City of Palo Alto
2 SO Hamil ton
Palo ~to, California 94301
Re: rhe Oak tree in Parkinq Lot G
Dear Ms. Pleminq,
228 Fulton Street
Palo A1to l Califor.!lia 943·01
April 21, 1995
H: U5-424-3269
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Thank you for your kind words after my presentation regarding the oak
tree in City Parking ~ G to City Council OQ Monday April 11. A3 I told the
~ncilr I represent the Downtown Palo Alto Farmers' Market who are
concerned that there may be alternatives to removal that the city has not
fully considered~ We hired Mayne Tree Expert Company, Inc. of San Mateo to
independently as~es the state of the tree and advise us of ~ions ~her than
removal that are available to the ~ity. A copy of this report is attached.
My remarks to the ~n-cil were based on a preliDlieary verbal report from
Mr. Meyer that I ~alne~ at the time of his examination. The attached writ
ten report is more pessimistic tham 1 expected. The report does suqqest
however, mitigation mea~ures that could prolong the life of the tree. t woold
like the opportunity t-o review this report with the approp::-iate .city officials
~~ determine if the extraordinary mea~ures outlined OQ page 2 of the report
would be appropriate.
cc: Y.arge Able 6 1601 castelleja Ave. PA.
Dave Sandage 6 Aroborist CPA
Steve ~t~ Public works Dept. CPA
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Mayne Tree Expert Company, Inc.
ESTAR1...t5HED 19!11 ~'tATf' CONTIl,ACTOR'S LKE."":5I: NO. :16"19)
LJCEWS~D FO.R..ESTERS. CEJlTlF!:ED "-.RBORlSTS. P.EST CONTROL AOVlSOiIlS.-.N~ OPEllATORS
Mr. William Petersoo
c.{o Farmers .Markel
228 Fulton Street
Palo Alto. CA 94201
Ap<~ 19. i99S
lte: O.:t fi:~. Puking lot G, (iilman Street, hIo Abo
Dear Mr. Petersoo;
n s.:::>t.rrH aArLltOAD AV:E..""lUE
1'.0. lOX SU
!.A.JoI MA "1,[0. C,,-lI440 L
TEtEPHO",",E, (41S) ).4.1..;;1160
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On Monday. April 11. 1995. I inspe<:,.d • woost li-e oak. Qu", ... ,'i/i>riD.
1oc.te4 in PartiDg Let G Od Gilman S1reet. .rato Abo, C.liiforDia. ~ pUlJ"--"'"Se
of chis inspectio!! was 10 ("h.ect !be vitaflty and s:truc rural iDtepiry of the wet+
la. addilion. I was uted' 10 provide remedial suggestiolU iD ID eff.an 10 'Aye
!be Iree.
The .. ee. measured! lS.O inches ifl 4"LlIDC1er It a beigtu of 4.5 feet. It is about SO
feet .. 0 wiIh • .w foot wide carory. There is • !OUth«1y leu 10 the nm1. The
foli::r era .... is 1hin and" displays some diebac~ mud. of whicl. eu be
attributed SO I!.D. inte-sllDOll d oak pit scate. AsUl'ofecdllfillfc mUior.
The Iree is bcalCIS m a planting islaAd -composed! of C foot widr IWJewIIb
coming LlP 10 and ea.sr: of I:he lire«:-and' .",ay from and west of t!tc .ec... CoacrC1C"
curbs aloBS me iIiSeYo'art. extend araund lhe Iree fer distances of about 6 red
in • soutbeaS1erl1 d"1te.:ti'~D and 0& fcc.t: z"'ly OD the 0IJ1h side. Aspb.a!t
eJ.t:."tS over tfle too( :zone beyoDd die: .c~
T'!!e root crow. cf Ifi_is tree !s undermined by hem 30d' root rot. The: ~1lIei!
ride kas I 2 .I. :t foot NW cavity chat n1ends into mudl of die iD1erior portio_ « the root c:ro-.vL A l x l fnof «vii}' oa Ihe QQC1hwest side ntc-.--ilif. shows
ex1enlive interior decay_Probing ... i!h II S fOO( Ions S'tu! rod suuesu the
interior portioc'o. of. the lower 1I"wll. is hollowr A smali 3 1 6 iDei Clyirt .. 3 feet
lip 00 t:be east side. is ~ono'W 10 the ground. DrilliOS.arou.n4' 1DC$t az-...lt
sugg~iU at \east S incbes of so'fid wood: u~ This is SIlff~ie'tl b 1be s~t
itrength 0( tile !ben,. except wllcre opea uvities cornprQm'be the ic1:e-cril)" of
che cy lindc:r_
Of eve.. more imporlao<:c is 1he loss of stability from 100( rot. ODe JOO( i>G It-.e
Y.7U1Ih side was found' to be: infec1e4 willi oai: :root fungui,. Amril10utl RtI1~4. and
severa! supporting roots are sc:veret-j decayelil.. The tree is kigll.l} susceptible ~
failure It)' brea\'ing over at die tOQ( CroWL
C..olUiiferiJlg ~ .:se of me uea (Parkin, l..ot. f,nn.rn Mmrt, 'Sidewalk. aDa
weel),. and dle ~Dtill foe failure. ] feel Ibe wee sat.""Sl14 be removed. ShouTd
lOG ;2eci4e k'I Co )(} cstnOl'dioa.ry le:!gdls ia &II attulpt 10 II""'C '!be tree, 1he
fcUov,"iaS iJ recommended
[. &pct!ie lJIe root: crow. a.nd! IrUI for ~t rClOC f'vpPL
2. Liab1eD &he ~ester!y anef soulberly sleks.. Utc"tudi", Rl!tOVlt of f'6'O
10", 11 inc' 'ili>m<t<r lImb. over lIIe 1>o1l) ""u. TriJo u<\ !lie ~pper
port:iou.
3. 'nsaD two .. iDeli. diameter mAst SUPf"OlU oc die westetYy side.
4. Spra)' ill file May, June, Joly ;00 ill No!;embc:r b JTU: Ka1t cooU'ot
It is my opinloll chat Ihb '6a1c is Ilaz.&rOOIl;S ,I!uf s,hoo;d be 1e!D<JVe4.. However,
\k ne. ea.a 'be mpported .so 'that the rot of !air~e is sread, re4u<:e4. It is ;!Ol
possible 10 pR-dkt lfle rae !IpU of Ibe.ee.. HowC'\Ie£, if dU: IrCc is !realed as
su&g'tSled aOO,'(. death tftrougk 1he combinations of ltuct rot,. o&t. root furi.gu.s.
and pit _ acalc doe3 AOt .!ppeat so-be lit'!:ly ..;thiB the ~! five ,ears..
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