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Hyatt House Arborist Report 10-15.pdf 10380 Perimeter Road Cupertino, California Michael L. Bench Consulting Arborist (831) 594-5151 7327 Langley Canyon Road Prunedale, California 93907 A Review of the Existing Trees And A Review of the Project Plans Hyatt House Hotel Project 10380 Perimeter Road Cupertino, California Assignment I was asked by Erick Serrano, Assistant Planner, City of Cupertino, to provide preliminary observations and recommendations concerning the Hyatt House Hotel Project. Observations I inspected the trees at the site on October 7, 2015 using the Arborist Report prepared by David Babby, October 15, 2014. I was surprised to find most of the trees in approximately the same condition as Mr. Babby found in October 2014, considering the fact that the drought is in its fourth year and the fact that drought conditions tend to have a accumulative effect in sequential years. However, I noted a few changes. The most obvious was the fact that Trees # 1, 5, 6, and 7 have died. Tree # 5 was listed to be preserved. Also, the Shamel ash (Fraxinus uhdei) Tree # 3 has declined sharpely. In my opinion, Tree # 3 is no longer in good condition worthy of preservation. Bear in mind that the Shamel ash (Fraxinus uhdei) species is a relatively high water consuming tree and typically declines dramatically when drought stressed. I expected to find more of the Coast redwood trees (Sequoia sempervirens) in severe decline, but in fact found them in about the same condition as described by David Babby. The existing row of Coast Redwood Trees along the north side are planned to be preserved as a screening buffer between the hotel and the 280 Freeway. However, the coast redwood Trees # 27, 37, 38, 40, 43, and 53 are slated to be removed. The reasons for these removals were not readily apparent when I reviewed the plans. The report by specimens are in no greater crowded conditions than essentially all of the redwood trees in this row. Also, their health is fair, but again the health of most of the coast redwood trees in the row is fair. Prepared by Michael L. Bench, Site Observations: 1 Consulting Arborist October 7, 2015 10380 Perimeter Road Cupertino, California Their removal would leave a sizable gap in the screen, especially in the case of Trees # 37 and 38 together. I could not find a specific construction feature that would necessitate the removal of any of the Trees # 27, 37, 38, 40, 43, and 53. For the reasons stated, I recommend that these individuals be preserved, if for no other reason than a hedge against any specimens that may die during the course of the project. I have served as the project arborist for many projects of this size. It has been my experience that one or two trees unexpectedly die during the course of construction. The cause is usually plugged irrigation emitters or a sticky irrigation value the kind of thing that no one notices until it is too late. For this reason, I suggest that Trees # 27, 37, 38, 40, 43, and 53 be considered for preservation during the course of construction. I am confident these trees would improve if irrigated. In fact, it would be essential that a permanent irrigation line be installed, if these redwood trees would be expected to survive for very long. Except in unique locations where an underground water source is available, coast redwood trees simply will not live for long in this valley. The reasons for removing Trees # 9, 11, 12, 13, 17, 18, and 19 are not entirely clear, after reviewing the plans. There are construction features nearby (i.e. demolition of existing cell equipment, the existing large sign), which may result in sufficient root damage to individual trees to warrant removal. The current condition of these trees individually is not significantly worse that most of the other redwood trees. In all likelihood, these 7 redwood trees will improve if adequately irrigated. I do not judge them to be automatic candidates for removal. I suggest that the fate of these 7 trees be decided on an individual tree basis during the course of construction, depending on possible root damage during construction. I disagrees with the assessment of one tree by David Babby. This is Tree # 143, a cork oak (Quercus subers preservation potential at Moderate, apparently because of its branching structure. This trees health was excellent, as shown in the photo by Mr. Babby, and its health is still excellent. The structural defect, to which Mr. Babby alludes, can be easily corrected by pruning. None of the other trees in the interior of this site were suggested to be transplanted, and, it appears that none of the other trees were in good enough condition to be suggested for transplant. The lone exception is Tree # 143. It is in excellent health, which is the primary factor for consideration for transplant. Another factor is that this tree is a Cork oak, which when healthy has a high success rate for transplant. Lastly Tree # 143 is currently growing in an island planter. It is likely that the majority of its root mass has been confined to this planter area, which should greatly reduce the root damage during transplant. I suggest that Tree # 143 be considered for transplant, possibly in exchange for a few of the replacement trees, which will be required. If this were to be considered, it would be essential that the transplanting be done by an experienced professional tree mover. I could provide referrals if requested. Prepared by Michael L. Bench, Site Observations: 2 Consulting Arborist October 7, 2015 10380 Perimeter Road Cupertino, California I did not observe any significant heaving of the paving on the edge of the existing parking lot near the row of Coast redwood trees. This may be because there is a wide are of open soil space on the opposite side facing the 280 Freeway. I expect that the majority of the root mass of each redwood tree stops at the edge of the existing curb, as roots do not tend to grow into severely compacted soil (the base rock under the paving) where there are other places in the soil to expand (in this case, the north side facing the freeway). The removal of the curb and paving along the north side adjacent to the row of redwood trees must be done by pulling and dragging the curb and paving toward the south away from the trees, as opposed to taking bites with the jaws of an excavator, taking curb, paving, sub-soil, and possible roots (at the edge of the curb). I suggest that at least 6 feet of the paving and curb, nearest the trees along the north edge of the parking lot, be done carefully with bucket of an excavator or backhoe, catching the back of the curb and pulling i dripline. At that point the material may be scooped up and loaded for removal. This procedure is expected to minimize the root damage to the redwood trees during demolition. It would be essential that the demolition contractor agree to removing the edge of this paving and curbing in this manner prior to initiation. Otherwise, I suggest that this work be supervised by the Project Arborist on site during this phase of demolition. This implies that the Project Arborist would have authority to supervise the contractor. Immediately following the demolition of the curb and paving, as described, chain link tree protective fencing must be installed along the new exposed edge. The tree protective fencing must: Consist of chain link fencing and having a minimum height of 6 feet. Be mounted on steel posts driven approximately 2 feet into the soil. Fencing posts must be located a maximum of 10 feet on center. Protective fencing must be installed prior to the arrival of materials, vehicles, or equipment. Protective fencing must not be moved, even temporarily, and must remain in place until all construction is completed, unless approved by the Project Arborist. Depending on the volume of roots encountered along the edge after demolition of this paving, it may be essential to spread 6-8 inches of wood chips along the edge to prevent further root die-back. Immediately after spreading the chips, the area (and especially the edge covered by new wood chips) must be irrigated thoroughly every day for 2 weeks. At the initiation of Demolition, a temporary irrigation system must be installed to irrigate the redwood trees. There must be no trenching across the root zones. The irrigation service must be on top of the existing grade. It will be essential that these trees must be irrigated throughout the entire construction period during the dry months (any month receiving less than 1 inch of rainfall ). Irrigate one time per week, and the moisture must penetrate to a depth of 15-20 inches with each irrigation. Prepared by Michael L. Bench, Site Observations: 3 Consulting Arborist October 7, 2015 10380 Perimeter Road Cupertino, California A soaker hose or a drip line is preferred for this purpose, but the soaker hose(s) must be located near the dripline (not near the trunk) to be effective. Often this requires turning the system on when work begins for the day and turning it off when the work day ends. Assuming it is expected that these redwood trees would live at this location for several years, it would be essential to install a permanent irrigation system. This would also require that there must be no trenching across the root zones. The irrigation service must be on top of the existing grade. It may be covered with mulch. I asked Mr. Erick Serrano to inquire about the storage of the soil, which will be excavated for the underground parking structure. He sent me the Plan A-1.1 showing the locations where the soil is planned to be stored. It appears that the two locations shown on this map would not pose a risk to trees. However, items tend to get moved during construction. It would be essential that at no point may the soil be piled against the tree protective fencing. Respectfully submitted, Michael L. Bench, Consulting Arborist International Society of Arboriculture Certification # WE 1897A American Society of Consulting Arborists Member Prepared by Michael L. Bench, Site Observations: 4 Consulting Arborist October 7, 2015