Vegetation Maintenance and Management

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Trees, shrubs and other vegetation contribute significantly to the functions and values that critical areas and critical area buffers provide. The Critical Areas Ordinance allows for the maintenance of existing ornamental landscaping, removal of weeds and dangerous trees, and long-term management of vegetation.

“Routine maintenance” activities include mowing; pruning; weeding; planting annuals, perennials, fruits and vegetables; and other activities associated with an ornamental landscape. “Landscape features” to be maintained include fences, trellises, rockeries and retaining walls, pathways, arbors, patios, play areas, and other similar improvements.

Landscape Maintenance

Routine maintenance of existing, legally established landscaping and landscape features developed prior to Aug. 1, 2006, in the critical area or critical area buffer may be continued without a permit. To be considered routine maintenance, activities must have been consistently carried out so that ornamental plants predominate over native or invasive species. Maintenance is performed with hand tools or light equipment only. Tree removal is not included.

Activities That Require Clearing and Grading Permit, But Not a Critical Areas Land Use Permit

Hazard Tree Removal

The removal of a hazard tree from a critical area or critical area buffer is allowed without requiring a Critical Areas Land Use Permit or a Vegetation Management Plan, provided:

  • A certified arborist, registered landscape architect, or professional forester has determined and documented that the tree or trees pose an imminent threat to public safety or present an extreme risk to a structure or permanent improvement that cannot be relocated.
  • The hazard cannot be addressed through pruning or crown thinning. If possible, trees should be converted to wildlife snags instead of being completely removed.

A Clearing & Grading Permit is required for the removal of any hazard tree in a critical area or critical area buffer, but it can be removed by the landowner prior to acquiring the permit. In order to comply, the landowner must make a reasonable effort to notify the city before or on the day of the removal and then, within 14 days, apply for the Clearing & Grading Permit. Be prepared to replace any trees that are removed by submitting a mitigation and restoration plan.

Invasive and Noxious Weed Removal

The removal of invasive and noxious weeds with hand labor and hand-operated equipment from any critical area buffer, or from a geologic hazard critical area, is allowed without a Critical Areas Land Use Permit. If the weeds are in a stream or wetland critical area, a Critical Areas Land Use Permit is required. A Clearing & Grading Permit is required in all instances, along with restoration with native species. Some examples of invasive and noxious weeds include:

  • English Ivy (Hedera helix)
  • Himalayan blackberry (Rubus discolor)
  • Japanese Knotweed (Polygonum cuspidatum)
  • Yellow Archangel (Lamiastrum galeobdolon)

Tree and Vegetation Pruning

Tree and vegetation pruning within geologic hazard critical areas or geologic hazard critical area buffers in accordance with the city’s Tree Pruning Guidelines is allowed without a Critical Areas Land Use Permit or a Vegetation Management Plan. If the trees are in a stream or wetland critical area or critical area buffer or a Native Growth Protection Area or Easement, a Vegetation Management Plan is required. The Guidelines, available on the city’s website, include the following pruning techniques: canopy reduction, canopy cleaning, canopy thinning, canopy raising or lifting, structural pruning, and canopy restoration. In some cases, a Clearing & Grading Permit may still be required, so be sure to check with a land use planner.

If trees have been consistently managed by topping, the practice may be continued. Be sure to have clear and consistent documentation of past practices, and ensure future topping allows the continued survival of the vegetation. Better yet, consider drafting a Vegetation Management Plan that replaces the topped trees with vegetation that precludes the need for future topping.

If the tree or vegetation is an active nest site for a species of local importance, it CANNOT be pruned until the nest is empty as determined by a wildlife biologist.

When a Critical Areas Land Use Permit is Required

Vegetation Management Plan

When a landowner wants to manage vegetation in a critical area buffer or a geologic hazard critical area that does not fit into one of the categories above, the proposal can be considered through a Vegetation Management Plan reviewed under a Critical Areas Land Use Permit.

The Vegetation Management Plan must be prepared by a qualified professional and include:

  • Description of existing site conditions, including critical areas and their functions and values, soils, vegetation, and wildlife habitat
  • Discussion of the plan objectives
  • Depiction of when and where the vegetation management will occur
  • Short- and long-term management prescriptions, including trees and vegetation to be removed, and restoration with native species

In determining whether the vegetation management plan should be approved, the city will consider neighborhood covenants related to view preservation or vegetation management if requested in writing. Neighborhood restrictive covenants will not be entitled to any more or less weight than any other support materials.

The city has developed the Critical Areas Handbook to assist landowners with the development of a vegetation management plan for their property.