#2 Report replaces report #1 Revised plans received March 25, 2009 Report completed April 15, 2009

Transcription

1 Community Development Department City of Saratoga Fruitvale Avenue Saratoga, California ARBORIST REPORT It is the responsibility of the owner, architect and contractor to be familiar with the information in this report and implement the required conditions. Application #: ARB Prepared by Kate Bear, City Arborist Site: Quito Road Phone: (408) Owner: Dan Dang APN: Report History: #1 Date: Plans received December 10, 2008 Report completed January 29, 2009 #2 Report replaces report #1 Revised plans received March 25, 2009 Report completed April 15, 2009 #3 Report replaces report #2 Revised plans received October 17, 2012 Report completed October 25, 2012 PROJECT SCOPE The applicant has submitted plans to add on to the existing non-conforming house to create a two story residence with attached garage. The Historic Preservation Commission has recommended that all trees on site be retained and preserved. No trees are requested for removal to construct the project. There is a 15 foot tall sycamore trunk/stump (#8 in the inventory) that meets the criteria for removal as part of this project. CLEARANCE with conditions This project has clearance from the arborist to proceed, with the conditions noted below in the Requirements section. PLAN REVIEW Plans Reviewed: Revised plans for this project were prepared by Rockwood Design and dated November 23, Plans reviewed for this report include Sheet G1, Cover Sheet and Site Plan; Sheet G-2, Setback Diagram; Sheet G-4, Landscape Plan; Sheet A1, Proposed First Floor Plan; Sheet A2, Proposed Second Floor Plan; Sheets A3 A5, Exterior Elevations by. Also reviewed was a Topographic Survey and Partial Boundary Survey by Associated Terra Consultants, Inc. dated August 15, Page 1 of 6

2 TREE INFORMATION Tree Inventory: Eight trees protected by City ordinance and potentially impacted by construction were inventoried for this report. Data for each tree is included in a Tree Inventory Table at the end of this report and locations of trees are marked on the attached copy of the Site Plan. Inventoried trees include three coast live oaks (#1, 2 and 6), one black walnut (#3), one valley oak (#4), one redwood (#5), and two California sycamores (#7 and 8). Tree Protection: In order to adequately protect trees #1 4, the driveway should be constructed out of pervious materials entirely on top of grade. Construction of the driveway will require the use of biaxial geogrid under the base material. This is a material used on roads to spread the load of vehicles and prevent soil compaction. Base material can be CU Structural soil or sand. The structural soil can be obtained at TMT Enterprises on Oakland Road in San Jose. Acceptable surface materials for the driveway include gravel, decomposed granite, or pavers. A concrete curb on top of grade may be used to contain the pavers or other driveway materials. No tree roots should be cut to construct the driveway. Landscaping area under oaks #1, 2 and 4 should consist of drought tolerant plants compatible with oaks. No plants or irrigation should be placed within 10 feet these tree trunks. It is acceptable to place mulch or wood chips under the oaks. Only drip irrigation should be used for irrigation under oaks. No trenching for irrigation lines is permitted under the oaks. The book, Compatible Plants Under and Around Oaks, by the California Oak Foundation, may be helpful in selecting plants for the landscape. The design of the house has been modified so that the front entrance is midway between trees #2 and #3, and this location is acceptable. Excavation for the foundation of the entry should be no more than 12 inches deep. It should be hand dug, and any roots found should be cut cleanly with pruning tools prior to pouring the foundation. Because the area of the entry is small, impacts to these two trees will be relatively low. The walkways around the house should consist of pervious materials on top of grade. Acceptable materials include flagstone set on sand or gravel (or with drought tolerant plants between them), stepping stones, gravel, pavers on sand, or other materials that do not require excavation or cement to install. Excavation for concrete is not permitted. Once a building permit has been issued for the project, the 15 foot high stump of sycamore tree #8 may be removed. Security Deposit for the Projection of Trees: Per City Ordinance , a Tree Protection security deposit equal to 100% of the appraised value of trees impacted by the project is required. Owner shall obtain, and file with the Community Development Director, the required security deposit prior to the receipt of building permits. The security deposit may be in the form of a savings account, a certificate of deposit account or a bond. The required security deposit for this project is $114,520 and is equal to the total appraised value of trees #1 6. This deposit will be held until completion of the project and acceptance by the City. Page 2 of 6

3 Appraisals: Appraised values were calculated using the Trunk Formula Method and according to the Guide for Plant Appraisal, 9 th Edition, published by the International Society of Arboriculture (ISA), This was used in conjunction with the Species Classification and Group Assignment, published by the Western Chapter of the ISA, FINDINGS Tree Removal Tree #8 is a 15 foot tall dead sycamore stump. It meets the criteria for removal as part of the project and may be removed once Building Division permits have been received. The tree removal criteria are attached to the end of this report for reference. The table below summarizes which of the criteria are met, allowing removal of the tree stump. Summary of tree removal criteria that are met Tree # Criteria met Criteria not met 8 1, 2, 4, 5, 6, 7, 9 3, 8 New Construction Based on the information provided, and as conditioned, the project complies with the requirements for the setback of new construction from existing trees under Section of the City Code. REQUIREMENTS 1. This entire arborist report, including the attached Tree Inventory Table and map showing locations for tree protection fencing shall be included in the final job copy set of plans. 2. This designated Project Arborist for this project is Straun Edwards of Trees 360 Degrees. 3. Tree Protection Security Deposit - $114,520 a. Owner shall obtain, and file with the Community Development Director, a Tree Protection security deposit for trees #1 6 prior to obtaining Building Division permits. b. The tree protection security deposit shall remain in place for the duration of construction of the project to ensure the protection of the trees. c. Once the project has been completed, inspected and approved by the City, the bond will be released. 4. Tree Protection Fencing: a. Shall be installed as shown on the attached map. b. Shall be established prior to the arrival of construction equipment or materials on site. c. Shall be comprised of six-foot high chain link fencing mounted on eight-foot tall, 2-inch diameter galvanized posts, driven 24 inches into the ground and spaced no more than 10 feet apart. d. Shall be posted with signs saying TREE PROTECTION FENCE - DO NOT REMOVE WITHOUT APPROVAL FROM CITY ARBORIST. e. Call City Arborist, Kate Bear at (408) for an inspection of tree protection fencing once it has been installed. This is required prior to obtaining building division permits. Page 3 of 6

4 f. Tree protection fencing shall remain undisturbed throughout the construction until final inspection. If contractor feels that work must be done inside the fenced area, call City Arborist to arrange a field meeting. 5. Receipt of a Planning or Building permit does not relieve applicant of his responsibilities for protecting trees per City Code Article during all construction work. 6. No protected tree authorized for removal or encroachment pursuant to this project may be removed or encroached upon until the issuance of the applicable permit from the building division for the approved project. 7. All construction activities shall be conducted outside tree protection fencing. These activities include, but are not necessarily limited to, the following: demolition, grading, trenching, equipment cleaning, stockpiling and dumping materials (including soil fill), and equipment/vehicle operation and parking. 8. No excavation, trenching for utilities or addition of fill soil is permitted within the distances listed below. a. 13 feet from trees #1, 4 and 5 b. 10 feet from tree #2, 3 and 6 9. The following mitigating measures shall be incorporated into construction of the driveway and walkways: a. Biaxial geogrid material shall be used under the driveway. b. Driveway and walkways shall be constructed entirely on top of grade. c. No excavation or cutting of tree roots is permitted. d. Acceptable materials include gravel, flagstones, stepping stones (for walkways), pavers on sand, or other pervious materials. e. Materials may be contained with a concrete curb on top of grade. 10. The project arborist shall monitor and document installation of the driveway and walkways to ensure that the project requirements are met. Following installation, the project arborist shall provide a letter with photos to the City verifying that mitigating measures were implemented. 11. A note shall be included on the plans stating that the foundation for the entrance between trees #2 and 3 shall be hand dug and no deeper than 12 inches below existing grade. Any roots that require cutting for the foundation shall be cut using a sharp pruning tool under the supervision of an ISA Certified arborist. 12. Should any tree be damaged beyond repair, new trees shall be required to replace the tree. If there is insufficient room to plant new trees, some or all of the replacement value for trees may be paid into the City s Tree Fund. 13. Any permitted pruning or root pruning of trees on site shall be performed under the supervision of the Project Arborist and according to ISA standards. Page 4 of 6

5 14. Irrigation shall be designed as follows: a. So that it does not spray trunks of trees. b. Valve boxes, controllers and irrigation lines shall be located outside of tree canopies and away from tree trunks. c. Select plants with similar water requirements to the trees under which they will be placed. d. Do not plant lawn under the canopy of oak trees #1, 2, 4 or 6. e. Plant only drought tolerant plants compatible with oaks under oaks, and keep plants at least 10 feet from tree trunk. Mulch under the canopy is recommended. f. Design topdressings so that they remain at least one foot from the trunks of retained trees and 6 inches from the trunks of new trees. g. Do not allow tilling or stripping of the topsoil beneath the trees canopies. 15. The disposal of harmful products (such as chemicals, oil and gasoline) is prohibited under tree canopies or anywhere on site that allows drainage to areas under tree canopies. Herbicides shall not be applied under tree canopies. 16. At the end of the project, when the contractor wants to remove tree protection fencing and have the tree protection security deposit released by the City, call City Arborist for a final inspection. ATTACHMENTS: Tree Removal Criteria Tree Inventory Table dated April 15, 2009 Map showing locations of trees and protective fencing around trees Page 5 of 6

6 TREE REMOVAL CRITERIA Criteria that permit the removal of a protected tree are listed below. This information is from Article of the City Code and is applied to any tree requested for removal as part of the project. If findings are made that meet the criteria listed below, the tree(s) may be approved for removal and replacement during construction. (1) The condition of the tree with respect to disease, imminent danger of falling, proximity to existing or proposed structures and interference with utility services; (2) The necessity to remove the tree because of physical damage or threatened damage to improvements or impervious surfaces on the property; (3) The topography of the land and the effect of the tree removal upon erosion, soil retention and the diversion or increased flow of surface waters, particularly on steep slopes; (4) The number, species, size and location of existing trees in the area and the effect the removal would have upon shade, privacy impact, scenic beauty, property values, erosion control, and the general welfare of residents in the area; (5) The age and number of healthy trees the property is able to support according to good forestry practices; (6) Whether or not there are any alternatives that would allow for retaining or not encroaching on the protected tree; (7) Whether the approval of the request would be contrary to or in conflict with the general purpose and intent of this Article; (8) Any other information relevant to the public health, safety, or general welfare and the purposes of this ordinance as set forth in section ; and (9) The necessity to remove the tree for economic or other enjoyment of the property when there is no other feasible alternative to the removal. Page 6 of 6

7 TREE INVENTORY TABLE TREE NO. TREE NAME Trunk Diameter (in,) - per Guide for Plant Appraisal Estimated Canopy Spread (ft.) Health Condition (100% = best, 0% = worst) Structural Integrity (100% = best, 0% = worst) Overall Condition Suitability for Preservation (High/Moderate/Low) Intensity of Impacts (1 = Highest, 5 = Lowest) In Conflict with Proposed Design Not Shown on Plans On Adjacent Proprty Appraised Value Coast live oak 1 Quercus agrifolia Good High 2 $44,400 Coast live oak 2 Quercus agrifolia Good High 1 $20,600 Black walnut 3 Juglans hindsii Good High 2 $8,600 Valley oak 4 Quercus lobata Good High 2 $14,900 Coast redwood 5 Sequoia sempervirens 41, Good High 2 $23,000 Coast live oak 6 Quercus agrifolia Good High 2 X $3,020 California sycamore 7 Platanus racemosa Poor Moderate 3 $5,600 California sycamore 8 Platanus racemosa Poor Low 3 $0 Replacement Tree Values $114, gallon = $ inch box = $ inch box = $1, inch box = $5, inch box = 7, inch box = $15,000 Should any tree listed above become damaged owner will be required to repair the damage. Should any tree listed above be removed owner will be required to replace that tree with trees equal in value to its assessed value Quito Road April 15, 2009

8 Legend Tree Protective Fencing Quito Road Tree Canopy