§ 27.10. Tree preservation and replacement plan requirements.

10.1

Tree preservation and replacement plans shall be prepared by a professional landscape architect, urban forester or ISA certified arborist, other state licensed professionals of similar design discipline may be authorized by the arborist to prepare tree preservation and replacement plans, provided they demonstrate, to the satisfaction of the arborist, competency and knowledge in the principles and practices of arboriculture as well as the demonstrated ability to prepare such plans in accordance with this ordinance. Continuous and excessive reviews and re-submittals may disqualify the designer from further acceptance by the arborist.

Tree protection and replacement plans must include the following:

10.2

Tree inventories and surveys. Compliance with the required site density factor shall be demonstrated on the tree protection and replacement plan and the grading and erosion control plan. The density of 20 units per acre is based on the acreage of the overall site. All trees that are to be counted toward meeting density requirements must be inventoried or sampled based on the acreage of the overall site. The method used to inventory the trees must be indicated on the plans.

On tree save areas greater than three acres, all tree save areas must be surveyed using an approved scientific sampling method (e.g., basal area). Timber cruising methods (50 feet by 50 feet sample areas or the prism method) of sampling is needed for large tracts. The larger the site the more sample areas should be taken. Sampling should be done in areas to remain as undisturbed tree save areas, not areas intended for development. The contents of each sample area shall be inventoried. All sampling areas shall be accurately depicted on the tree protection and replacement plan and appropriately flagged to corresponding locations on the actual site. When using sample areas, the basal area units should be averaged and an existing density factor per acre determined. Using this tree density, the appropriate amount of tree save area should be preserved to meet the site density factor requirements. These calculations must be included on the tree plan.

On tree save areas of three acres or less, all trees to be considered for density requirements must be individually inventoried. This tree inventory list and tree locations must be shown on the plan.

The existing tree line and vegetation characteristics of the site shall be shown on the plans. Existing trees or stands of trees used in the density calculations must be indicated on the plan. The tree save areas should be clearly shown on the plans with their size in acres. Areas designated as tree save areas must be wooded.

10.3

Exact location of all specimen and heritage trees. Special consideration shall be given to specimen and heritage trees on development sites. Specimen trees and heritage trees must be shown on the tree preservation and replacement plan with an indication whether they are to be retained or removed and reason for removal. Said trees must be flagged and numbered in the field with correlating numbers and exact location shown on the plan. Extra tree density credit will be given for saved specimen and heritage trees. If no design features accommodate their preservation, removed specimen trees require recompense plantings of comparable species. Refer to appendix A for specimen tree criteria and tree density unit values. Use the values in the replacement tree density chart (appendix C, Table B) to determine the quantity and sizes of the needed recompense trees.

10.4

All tree save areas must be delineated on the tree protection and replacement plan and the grading and erosion control plan.

Methods of tree protection shall be indicated for all tree save areas and specimen/heritage trees, including tree save fencing, erosion control, retaining walls, tree wells, tunneling for utilities, aeration systems, transplanting, signage, etc.

10.5

All buffers must be identified on the tree protection and replacement plan.

Any portion of a zoning buffer lacking sufficient vegetation to provide effective visual screening must be supplemented with evergreen plantings. A detailed planting plan for these areas is required. Planted trees must be a minimum six feet tall.

10.6

Indicate limits of disturbed area. During construction, tree save areas, zoning buffers, stream buffers, open space, and specimen/heritage trees must be properly protected from disturbance using high visibility orange active tree save fencing. These tree save areas and the active tree save fencing locations must appear on the clearing, grading, erosion control and tree protection plans.

10.7

Existing and proposed location of underground utilities or easements must be shown.

10.8

Indicate staging areas for parking, material storage, concrete washout, debris burn, and burial holes where these areas might negatively impact protected trees.

10.9

The locations of all trees to be planted to meet site density factor requirements. All required landscaping such as street trees, parking lot trees and landscape strips should be shown graphically on the plans. In addition, a detailed planting schedule showing the type (common and botanical names), sizes and quantity of trees to be planted, and any special planting notes.

10.10

Trees planted for specimen tree recompense, are not included in overall tree density calculations. These are additional requirements.

10.11

Tree preservation and replacement plans that consist of more than ten new trees shall incorporate at least three separate tree genera whereby no single tree genus accounts for more than 33 percent of all newly planted trees.

10.12

A narrative explaining the actual planting dates is needed for larger sites. Remote and/or large replanting areas such as zoning buffers are best planted between November and April. Indicate clearly on the tree protection and replacement plan when planting will take place.

10.13

Additional information as required by the arborist on a case by case basis. After the submission of the plan, the arborist will perform a site inspection. The tree protection and replacement plan shall provide sufficient information and detail to clearly demonstrate that all applicable requirements and standards of this ordinance are or will be fully satisfied.

(Ord. No. 2008-Z-001, § 10, 1-15-08)