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HomeMy Public PortalAboutPublic Comment #15 (Tahoe Area Sierra Club Attachment #2)RANDALL FRIZZELL & ASSOCIATES _____________________________________________________________________________ Tree & Vegetation Consultants _____________________________________________________________________________ PO Box 1949, Nevada City 95959-2507, Phone /Fax (530) 265-4469 Email: rf@randallfrizzell.com _____________________________________________________________________________ XL INC. A CALIFORNIA CORPORATION     April  5,  2013       Jenna  Endres     Associate  Planner  Town  of  Truckee  Town  Council     c/o  Truckee  Community  Development  Department     10183  Truckee  Airport  Road     Truckee,  CA  96161     RE:  Tahoe  Donner  Association  Marina  Facility  Project  12-­‐020/AM  ND-­‐DP-­‐UP     Dear  Ms.  Endres,      I  was  asked  to  review  the  tree  removal  information  and  site  plans  for  the  Tahoe  Donner  Marina   project.  As  part  of  my  assignment  I  visited  the  site  once  on  March  31,  2013.  Based  on  this  one   site  visit,  in  which  I  assessed  all  of  the  numbered  and  lettered  trees  noted  on  the  site  plans,  and   a  review  of  the  development  plans,  I  conclude  that  a  number  of  adverse  impacts  to  the  existing   trees  on  site  will  occur  if  the  plans  are  implemented  as  is.  My  concerns  and  conclusions  are   outlined  in  this  letter.     After  visiting  the  site  once  and  reviewing  the  site  plans  I  have  concluded  the  landscape  design   will  require  a  high  degree  of  alteration  to  the  existing  site  including:       1. The  removal  of  approximately  19  mature  trees  and  many  young  Jeffrey  pines  of   various  sizes  under  6”  dbh.     2.  Injurious  impacts  to  the  root  protection  zones  of  21  mature  trees  (A-­‐U)  designated  for   protection.  There  is  also  another  mature  pine  with  no  number  located  10’  north  of  “K”   that  will  also  sustain  injurious  impacts.  The  impacts  include:     a.  Grading  to  install  terraces,  walkways,  and  stairs  as  well  as  preparing  the   ground  for  widespread  planting  of  groundcovers  and  possibly  the  new  lawn     b.  Digging  footings  for  walls     c.  Trenching  for  the  installation  of  irrigation  pipes  and  electrical  conduit   __________________________________________________________________________ _____________________________________________________________________________ Randall Frizzell & Associates . Tree & Vegetation Consultants   d.  Moving  large  rocks     A  list  of  the  potential  impacts  for  each  tree  are  listed  in  Appendix  A.     A  lot  of  large  equipment  will  be  necessary  to  implement  the  design.  Tree  roots  and  root  zone   environments  will  be  negatively  impacted  to  varying  degrees  which  will  predispose  the  trees  to   pests,  diseases,  decline  and/or  death.  The  potential  for  these  trees  to  become  public  hazards   will  also  increase.     The  design  requires  the  removal  of  many  young  pines  eliminating  the  important  component  of   age  diversity  in  the  pine  stand.  The  plan  does  call  for  the  planting  of  #15  and  24”  box  pines.   Unfortunately,  large  container  specimens  of  native  pines  do  not  establish  and  grow  as  well  as   naturalized  seedlings.  I  recommend  the  retention  of  the  naturalized  pines  rather  than  removal   and  replacement  with  containerized  plant  material.     I  do  recommend  the  removal  of  7  pines  because  of  their  risk  to  public  safety  or  poor  health.  I   recommend  that  trees  numbered  1,  4,  7,  9,  and  14  be  removed  for  being  high  risk  trees  and   trees  numbered  10  and  20  be  removed  because  of  very  poor  health.     Of  the  20  trees  recommended  for  removal  by  the  Tahoe-­‐Donner  Foresters  Report:    10  trees  were  for  health  reasons,    4  trees  were  for  public  safety  hazards,   1  tree  was  because  it  was  growing  too  close  to  another  tree  (that  is  proposed  for   removal  as  well)      5  trees  were  because  of  conflict  with  design     In  conflict  with  the  Foresters  Report,  I  observed:     Trees  numbered  3,  6,  8,  11,  and  15  are  not  unhealthy  enough  to  warrant  removal   Tree  number  12  is  not  a  high  risk  tree  and  does  not  warrant  removal   Tree  number  16  is  not  too  close  to  another  tree  to  warrant  removal     For  public  safety,  however,  I  do  recommend  the  removal  of  trees  numbered  1,  4,  7,  9,  14,  and   20.       Trees  Proposed  for  Protection   The  Drip  Zones  were  under-­‐estimated  on  9  trees.  I  have  accurately  measured  them  using  a   clinometer  and  tape  measure.  The  actual  measurements  are  provided  in  the  table  below.     C 15 feet D 13 feet G 14 feet J 16 feet K 15 feet __________________________________________________________________________ _____________________________________________________________________________ Randall Frizzell & Associates . Tree & Vegetation Consultants L 16 feet R 11 feet S 21 feet U 15 feet   Drip  Zones  should  be  accurately  indicated  on  all  site  plans  to  insure  the  highest  degree  of   preservation  measures  applied  to  Protected  trees.     Conifers  are  at  a  disadvantage  with  protection  zones  that  are  defined  by  the  drip  line  or  drip   zone.  Jeffrey  pines  have  a  narrow  drip  line  radius  in  relation  to  their  trunk  diameter  and  age.  A   more  accurate  method  of  defining  the  root  protection  zone  would  be  the  “Optimal  Tree   Protection  Zone”  developed  by  Matheny  and  Clark1.  This  method  specifies  the  optimal   protection  zone  as  0.75’  distance  from  the  trunk  per  inch  of  trunk  diameter  (eg.,  a  20”  dbh  tree   would  have  a  Drip  Zone  of  15-­‐feet).     In  addition  to  the  five  Tree  Protection  recommendations  provided  in  the  Foresters  Report  I   would  add  another:  Trenching  within  the  tree  protection  zone  shall  be  done  using  pneumatic  air   excavation  techniques  to  minimize  root  damage  during  the  installation  of  underground  utilities.     Air  trenching  allows  for  installation  of  utilities  under  lateral  roots  and/or  for  root  pruning  to   facilitate  the  installation  of  underground  utilities.     I  can  provide  my  C.V.  on  request  but  briefly,  I  have  36  years  of  experience  providing  tree  and   landscape  consulting  and  contract  tree  services  in  the  Sierra  Nevada  region.  I  have  extensive   experience  in  the  field  of  consulting  arboriculture,  specializing  in  plant  diagnosis,  tree  risk   assessment,  site  assessment,  plant  appraisals,  and  tree  management  plans.  I  have  provided   services  to  National  Parks,  California  State  Parks  (much  of  it  in  the  Tahoe  area),  Pacific  Gas  &   Electric,  several  municipal  utility  districts,  and  a  wide  variety  of  counties  and  cities,  as  well  as   hundreds  of  property  owners.  I  am  an  ASCA  Registered  Consulting  Arborist,  ISA  Certified   Arborist,  and  ISA  Tree  Risk  Assessment  Qualified.       Please  contact  me  if  you  have  any  questions.     Sincerely,       Randall Frizzell   Randall  Frizzell   1 Trees and Development - A Technical Guide to Preservation of Trees During Land Development __________________________________________________________________________ _____________________________________________________________________________ Randall Frizzell & Associates . Tree & Vegetation Consultants APPENDIX    A       Potential  Impacts  to  Protected  Trees      A  Footing  for  wall  on  Southeast  side     Grading  for  groundcover     Trenching  for  irrigation      B  Grading  for  terrace  on  North  side     Grading  for  groundcover     Trenching  for  irrigation      C  Grading  for  lawn  area  on  North  side     Grading  for  ground  cover  on  South  half     Trenching  for  irrigation      D  Grading  for  groundcover  on  South  half     Grading  for  new  lawn  on  Northeast  side     Trenching  for  irrigation     Rock  movement      E  Grading  for  groundcover     Rock  movement      F  Grading  for  groundcover     Grading  for  new  lawn  on  North  side      G  Grading  for  new  lawn      H  Grading  for  new  lawn      I  Footing  for  wall  on  North  side     Grading  for  terrace  on  North  side     Grading  for  steps  on  East  side     Grading  for  groundcover      J  Grading  for  steps/walkway     Footing  for  wall     Trenching  for  irrigation      K  Grading  for  groundcover     Rock  movement       __________________________________________________________________________ _____________________________________________________________________________ Randall Frizzell & Associates . Tree & Vegetation Consultants                L  Grading  for  walkway     Grading  for  groundcover      M  Grading  for  walkway     Grading  for  groundcover      N  Grading  for  groundcover     Footing  for  wall      O  Footing  for  wall     Trenching  for  irrigation      P  Footing  for  wall     Grading  for  groundcover     Trenching  for  irrigation      Q  Footing  for  wall     Grading  for  groundcover     Trenching  for  irrigation      R  Grading  for  turf  pavers     Footing  for  wall     Trenching  for  irrigation      S  Grading  for  walkway     Trenching  for  irrigation      T  Grading  for  walkway     Rock  movement      U  Trenching  for  irrigation       No  #  Grading  for  groundcover   (10'  North  of  “K”)  Rock  movement     Trenching  for  irrigation