§ 54-588. Best Management Practices.

(1)

Standard Best Management Practices. The following Best Management Practices shall be applicable to all Tree Permits, unless specified otherwise herein. These standard Best Management Practices shall also be applicable to all activities that affect Grand Trees, Trees located within a CRPZ, and Trees located within public Rights-of-Way, regardless of whether a Tree Permit is required for the proposed activity.

(a)

Prior to commencing work and throughout the duration of the authorized activity, the owner, developer, contractor or agent shall clearly mark (with red flagging) all Trees proposed to be removed and shall erect barricades around all Trees to be protected. The barricades must remain in place and be in good condition throughout the duration of the authorized activity. Barricades may be removed for the final grading. Removal of other vegetation within the protected zone may be accomplished only if authorized by the Administrator and only by mowing or hand clearing. Where unauthorized removal of native vegetation within the protected root zone occurs, the Administrator may require the replanting of understory vegetation. If improvements are to be located within the protected zone of Trees, clearing by machinery will be allowed, but only in the area and to the extent necessary to install the improvements. The Applicant, owner, developer, contractor or agent shall not cause or permit the movement of equipment, or the storage of equipment, material, debris, or the placement or grading of fill to be placed within the required protective barrier.

(b)

Throughout the duration of the authorized activity, the owner, developer, contractor or agent shall not cause or permit the cleaning of equipment or material or the storage or disposal of debris, fill, waste materials such as paints, oils, solvents, asphalt, concrete, mortar or any other material within the Drip Line of any Tree or clump of Trees or within any native habitat or buffer.

(c)

No damaging attachment ropes or wires (other than supportive measures for a Tree), signs, posters, handbills, Tree Permits or other things may be fastened to any Tree. No gaseous, liquid, or solid substance which may be harmful to Trees shall come into contact with any portion of the Tree except pursuant to authorization under the provisions of this article or other County regulations.

(d)

Protective barricades for Trees other than Grand Trees shall be installed no closer than the Drip Line of the Tree. Barricades may be placed three feet from the trunk of palms. Barricades shall be constructed in a post and rail configuration. The upright posts shall be a minimum of a two by two-inch (common industry standard) wooden stake, four feet long. Posts shall be implanted deep enough into the ground to be stable and extend a minimum height of three feet above the ground. A minimum of a one by four-inch (common industry standard) wooden board shall be used to connect the upright posts. Silt barriers or snow fencing may be substituted upon approval by the Administrator. The maximum distance allowed between upright posts is eight feet. More protective barricades may be substituted with the approval of the Administrator.

(e)

Silt barriers, hay bales, or similarly effective erosion control barriers will be required in any area where erosion or siltation may cause damage to Trees.

(f)

Where elevation changes are proposed within the protected zone of Trees, the Applicant will be required to justify the need for the elevation change and install retaining walls or drain tiles unless the Applicant demonstrates that such protection would be impractical. The Applicant shall have the choice of the type or design. These root protection measures shall be in place prior to the deposition of fill, or excavation of soil from the protected zone.

(g)

The Administrator shall conduct periodic inspections of the site during land clearing and construction in order to ensure compliance with this article.

(h)

The Administrator may allow certain activities to be conducted within the barricaded Drip Line of a Tree, so long as the County determines that the Tree will not be adversely affected.

(i)

No Person shall deposit, place, store, park, or maintain upon any Tree or within the Drip Line of any Tree, or other plantings, planted in a public Right-of-Way or other Public Places, any Vehicle, stone, brick, concrete, soil, or other materials that may impede the free passage of water, air, and fertilizer to the roots of any Tree growing therein, except by written authorization of the Administrator.

(j)

All Trees located within public Rights-of-Way shall be protected from all digging or trenching activity within the Drip Line of any Tree. The use of tunnels or directional bores shall be required of all Persons working in a County Right-of-Way unless the Applicant demonstrates the additional cost of the tunnel or bore will exceed the appraised value of the Tree. Tree values shall be established by the most current version the International Society of Arboriculture valuation system. The tunnel or directional bore shall start at one-half the Drip Line area or six feet (whichever is greater) from the basal flare of the Tree and end in the same dimension on the opposite side of the basal flare of the Tree.

(2)

Grand Tree Best Management Practices.

(a)

Grand Tree Protection. During Development all areas within the Drip Line of every Grand Tree shall be protected from activities that may disturb or injure the tree, (such as, but not limited to, cut and fill activities, building pad placements, Travelway construction, construction material storage, driving or parking of equipment, trenching, etc.). The Administrator shall issue written conditions for work within the Drip Line of a Grand Tree only when an arboricultural plan has been approved.

(b)

Proper Grand Tree Care: Canopy and Root Pruning. When activities affect a Grand Tree within the Drip Line or when pruning must be performed on the crown of a Grand Tree, the following arboricultural techniques are required:

1.

Roots must be severed by clean Pruning cuts. Roots can be pruned by utilizing trenching equipment that is specifically designed for this purpose or by hand digging a trench and pruning roots with a chain saw, Pruning saw or other equipment designed for Tree Pruning. Root pruning shall be to a depth of 12 inches below existing grade or to the depth of the disturbance if greater than 12 inches below the existing grade. When underground utilities are to be installed through the Drip Line, root pruning requirements will be waived if the lines are installed via tunneling or directional boring as opposed to trenching.

2.

All Pruning of Grand Trees shall conform to the latest edition of the ANSI (A300 Standards).

3.

Neither canopy and/or root pruning can declassify a Tree from Grand Tree status. If Pruning activities have been conducted prior to the Administrator's determination regarding the classification of the Tree and the Tree would have met the requirements to be classified as a Grand Tree, the Administrator may classify it as such.

(c)

Grand Tree Protection Barrier Requirements. During Development activities or any other potential disturbance that will impact the area within the Drip Line of any Grand Tree, protective barriers shall be placed around each Grand Tree to prevent the destruction or damaging of roots, stems, or crowns of such Trees. Barriers shall remain in place and intact until the work is completed. Barriers may be removed temporarily to accommodate construction needs, provided that the manner and purpose for such temporary removal will not harm the tree and is approved by the Administrator. The following are the minimum requirements for protective barriers:

1.

Protective posts shall be placed at the Drip Line of each Grand Tree, except when a plan has been approved by the Administrator to place the posts closer to the trunk.

2.

Posts shall be a minimum of two by four inches or larger wooden post and shall be connected with a minimum of at least a one by four-inch wooden board and shall be clearly flagged. Other similar methods, such as construction fencing, may be permitted if approved in writing by the Administrator in advance of installation. Posts shall be implanted deep enough into the ground to be stable and extend a minimum height of three feet above the ground. Silt barriers and snow fencing may be a substitute at the discretion of the Administrator.

3.

Where Development activity is permitted within the Drip Line of a Grand Tree, the Administrator may require additional Tree Protection provisions to be incorporated in the conditions of the Tree Permit to assure the protection of the Grand Tree.

4.

Where elevation changes are proposed within the Drip Line from the trunk of any Grand Tree the applicant will be required to install retaining walls or drain tiles unless the applicant demonstrates such protection would be impractical. The applicant shall have the choice of the type or design. These root protection measures shall be in place prior to the deposition of fill, or excavation of soil within the Drip Line from the trunk.

5.

A sign shall be installed at the edge of each Grand Tree barricade stating, "No activities are allowed within barricaded area, unless approved by the County." The text on the sign shall be written in English and Spanish. The Administrator may require a barricade sign for other types of Trees based on the site-specific conditions and when there is a higher potential for adverse impacts to a Tree.

(3)

Canopy Road Best Management Practices.

(a)

All Pruning of Trees within a CRPZ shall conform to the latest edition of the ANSI A300 Standards and does not compromise the integrity of the canopy to shade the road.

(b)

Requirements for utility pruning. Franchised utilities must conform to current ANSI A300 standards when performing line clearing work in CRPZ to balance the requirement to preserve Canopy and maintain safe, reliable electric service.

1.

Franchised utilities must notify the Administrator by e-mail or mail three business days prior to any maintenance utility line clearing work in Canopy Roads.

2.

Franchised utilities must have an ISA certified Arborist directing the pruning of Trees in a Canopy Road.

3.

Utility pruning should only provide minimum safe clearance to protect utility lines with consideration for the combined movement of the conductors near Trees in severe weather, the species of the Tree, and the voltage of the conductor where applicable.

(c)

Proper Tree Care; Canopy and Root Pruning.

1.

When activities affect the Tree so that more than 25 percent of the area within the Drip Line is impacted or when Pruning must be performed on the crown of a Tree, the following arboricultural techniques are required:

a.

When more than 25 percent of the area within the Drip Line will be impacted, the affected roots must be severed by clean pruning cuts where the activity impacts the roots. Roots can be pruned by utilizing trenching equipment that is specifically designed for this purpose or by hand digging a trench and pruning roots with a chain saw, pruning saw or other equipment designed for Tree Pruning. Roots within the Drip Line must be pruned to a depth of 12 inches below existing grade or to the depth of the disturbance if less than 12 inches from the existing grade. When underground utilities are to be installed through the Drip Line, root pruning requirements may be waived if the lines are installed via tunneling or directional boring as opposed to trenching.

b.

All Pruning of Trees shall conform to the current ANSI A300 standards and be supervised by an ISA certified arborist. There shall be no flush cuts, stub cuts, or lion's-tailing of the Tree's crown.

c.

It shall be a violation of this article to perform the techniques of Topping or other Pruning techniques that remove the vertical leader stems or other pruning that result in an unnecessary reduction of shade of Trees in the Tree Permit area.

(Ord. No. 2011-023, § 9, 5-25-2011)