18.3.11.050 Activities and Uses Exempt from These Regulations

A. Exempt Activities Within Water Resource Protection Zones. The following activities and uses do not require a permit or authorization under this chapter to be conducted or to continue in a Water Resource Protection Zone. Exempt activities and uses may qualify as development as defined in part 18.6 and may require a floodplain development permit.

a. Landscaping Maintenance. Continued maintenance of existing vegetation such as landscaping, lawn, gardens, and trees.

b. Lawn. Existing lawn within Water Resource Protection Zones may be maintained, but existing lawn shall not be expanded and new lawn shall not be installed.

c. Tree Pruning. Maintenance pruning of existing trees shall be kept to a minimum and shall be in accordance with the chapter 18.4.5 Tree Preservation and Protection. Under no circumstances shall the maintenance pruning be so severe that it compromises the tree’s health, longevity, or resource functions (i.e., shade, soil stability, erosion control, etc.)

d. Non-Native, Noxious, and Invasive Vegetation Removal. Removal of non-native, noxious, and invasive vegetation, and replacement with local native plant species is permitted. The act of removing non-native, noxious, and invasive vegetation shall not result in the removal of native vegetation. Local native plant species for both wetland and stream bank applications are identified on the City’s Local Native Plant Species List, and noxious and invasive vegetation approved for removal is identified on the City’s Prohibited Plant List. Removal and mowing of blackberries shall occur before May 1 or after July 31 to protect nesting birds.

e. Hazardous Tree Removal. Removal of a hazardous tree is allowed under the procedures and approval criteria described in chapter 18.4.5 Tree Preservation and Protection.

f. In-Channel Vegetation Removal. Removal of emergent in-channel vegetation that is likely to cause flooding using non-invasive methods such as mowing or weed-whacking that do not disturb the underlying substrate. Mechanized removal of emergent in-channel vegetation that would involve associated removal of soil below the ordinary high water line is not permitted and would otherwise be subject to state and federal wetland permitting requirements.

g. Routine Planting. The planting of local native plant species or the replacement of non-native, noxious and invasive plants with local native plant species is allowed. Local native plant species for both wetland and stream bank applications are identified on the City’s Local Native Plant Species List, and noxious and invasive vegetation approved for removal is identified on the City’s Prohibited Plant List.

h. Use of Equipment or Machinery. Use of hand-held equipment or machinery for vegetation maintenance, planting, and removal within Water Resource Protection Zones is allowed. Power-assisted equipment or machinery may be used for vegetation maintenance, planting, and removal within Water Resource Protection Zones when soil disturbance and erosion are minimized by all of the following measures.

i. Use of power-assisted equipment or machinery shall occur from May 1 to October 31, and shall not occur during the remaining wet months of the year.

ii. The general topography of the Water Resource Protection Zone shall be retained.

iii. Soil compaction from construction equipment shall be reduced by distributing the weight of the equipment over a large area (e.g., laying lightweight geo-grids, mulch, chipped wood, plywood, OSB, metal plates or other materials capable of weight distribution in the pathway of the equipment).

iv. Local native plant species shall not be damaged or removed.

v. Disturbed areas shall be replanted so that landscaping shall obtain 50 percent coverage after one year and 90 percent after five years.

a. Testing. Site investigative work is allowed provided it has minimal surface area disturbance and is conducted by or required by a city, county, state, or federal agency. Such work may include surveys, percolation tests, soil borings or other similar tests.

b. Unpaved Trails. The establishment of unpaved trails and related educational displays is allowed provided the trail width shall not exceed 36 inches, stair width shall not exceed 50 inches, and trail grade shall not exceed 20 percent except for the portion of the trail containing stairs. Trails in public parks may be up to 72 inches in width to accommodate high pedestrian traffic areas. Trails construction within a delineated wetland boundary shall be by permit in accordance with local, state, and federal permitting requirements and approved management plans.

c. Storm Water Treatment Facility Maintenance. Routine maintenance of storm water treatment facilities such as detention ponds or sediment traps, vegetated swales, and constructed wetlands is allowed in order to maintain flow and prevent flooding when conducted in accordance with local, state and federal permitting requirements and approved management plans. Multi-year maintenance plans for existing storm water treatment facilities without previously approved management plans require a Limited Activity and Use Permit in accordance with subsection 18.3.11.060.A.2.

3. Nonconforming Activities, Uses, and Structures. An activity, use or structure legally established prior to the adoption of this chapter, which would be prohibited by this chapter or which would be subject to the limitations and controls imposed by this chapter, shall be considered a nonconforming activity, use or structure, and may continue subject to the following provisions.

a. Nonconforming Structures. Nonconforming structures within or partially within a Water Resource Protection Zone may be maintained and used.

b. Expansion of Nonconforming Structures. Expansion of the footprint of a nonconforming structure within or partially within a Water Resource Protection Zone if the expansion of the footprint occurs outside the Water Resource Protection Zone and additional surface area in the Water Resource Protection Zone is not disturbed. Additional stories may be added to nonconforming structures if the following conditions are met.

i. The existing building footprint within the Water Resource Protection Zone is not changed in size or shape.

ii. The building, including decks, does not project beyond the building footprint over the Water Resource Protection Zone.

iii. Additional surface area in the Water Resource Protection Zone is not disturbed.

c. Replacement of Nonconforming Primary Structures in Residential Zoning Districts. Nonconforming primary structures within or partially within a Water Resource Protection Zone and located in residential zoning districts may be replaced or rebuilt if the existing building footprint within the Water Resource Protection Zone is not changed in size or shape and additional surface area in the Water Resource Protection Zone is not disturbed. Repair and reconstruction of a nonconforming structure under this section shall be in accordance with the requirements of the Flood Damage Prevention Regulations in AMC 15.10.

d. Replacement of Nonconforming Structures in Non-Residential Zoning Districts and Within Historic Districts. Nonconforming structures within or partially within a Water Resource Protection Zone, located in a non-residential zoning district and within a Historic District may be replaced or rebuilt if the existing building footprint within the Water Resource Protection Zone is not changed in size or shape and additional surface area in the Water Resource Protection Zone is not disturbed. Repair and reconstruction of a nonconforming structure under this section shall be in accordance with the requirements of AMC 15.10 Flood Damage Prevention Regulations.

e. Exemptions for Historic Public Parks and Properties. Nonconforming activities, landscaping, uses, and structures included in Lithia Park, Blue Bird Park, and Calle Guanajuato and located in the Water Resource Protection Zone may be used, maintained, and replaced, but shall not be expanded or enlarged within the Water Resource Protection Zone. Repair and reconstruction of a nonconforming structure under this section shall be in accordance with the requirements of the Flood Damage Prevention Regulations in AMC 15.10.

4. City Emergency Activities. Emergency repair authorized by the City Manager or his/her designee which must be undertaken immediately, or for which there is insufficient time for full compliance with this chapter, in order to address at least one of the following.

a. Prevent an imminent threat to public health or safety.

b. Prevent imminent danger to public or private property.

c. Prevent an imminent threat of serious environment degradation.

B. Additional Exempt Activities and Uses within Stream Bank Protection Zones. In addition to the Exempt Activities and Uses in subsection 18.3.11.050.A, the following activities and uses do not require a permit or authorization under this chapter to be conducted or to continue in a Stream Bank Protection Zone.

1. Fire Hazard Prevention. Cutting or thinning of vegetation for fire hazard prevention provided that the cutting or thinning is the minimum necessary to alleviate the potential fire hazard and is consistent with City standards for Wildfire Lands described in chapter 18.3.10 Physical and Environmental Constraints Overlay.

2. Stream Restoration and Enhancement. Stream restoration and enhancement projects when all of the following standards are met.

a. The restoration and enhancement results in a net gain in stream bank corridor functions.

b. The lot is in a residential zoning district and occupied only by a single-family dwelling and accessory structures.

c. The property has not undergone stream restoration and enhancement work in the past 12 months.

d. The restoration and enhancement project does not involve in-stream work.

e. The restoration and enhancement project may include minor earth moving activities involving excavation or placement of up to five cubic yards of soil and earth-moving activity disturbing a surface area of no more than 1,000 square feet.

3. Fences. Fences limited to open wire, electric or similar fence that will not collect debris or obstruct flood waters, but not including wire mesh or chain link fencing, may be installed in the upland half of the riparian buffer furthest away from the stream. Solid wood fencing is prohibited in Water Resource Protection Zones. Temporary tree protection fencing in accordance with the Tree Preservation and Protection standards in 18.4.5 is allowed in conjunction with a development project. Fencing in a designated floodplain shall conform to the requirements of subsection 18.3.11.070.K.

4. Outdoor Patio Areas. Outdoor patio areas consisting of porous solid surfaces up to 150 square feet in size per lot, but not including decks, may be constructed in the upland half of the riparian buffer furthest away from the stream.

5. Public Utility Maintenance and Replacement. Routine maintenance and replacement of existing public utilities and irrigation pumps if work disturbs no more total surface area than the area inside the public utility easement and up to an additional five percent surface area of the public utility easement outside of the public utility easement.

6. Private Utility Maintenance and Replacement. Routine maintenance and replacement of existing private utilities and irrigation pumps.

7. Driveway and Street Maintenance and Paving. Maintenance, paving, and reconstruction of existing public and private streets and driveways if work disturbs no more total surface area than the area inside the street right-of-way or access easement and up to an additional five percent surface area of the street right-of-way or access easement outside of the right-of-way or easement. Public streets shall be located in public right-of-way or a public easement.

C. Additional Exempt Activities and Uses within Wetland Protection Zones. In addition to the Exempt Activities and Uses in subsection 18.3.11.050.A, the following activities and uses do not require a permit or authorization under this chapter to be conducted or to continue in a Wetland Protection Zone.

1. Fire Hazard Prevention. Perimeter mowing or thinning of vegetation for fire hazard prevention consistent with a wetland mitigation plan approved by the Oregon Division of State Lands, or within the wetland buffer provided that the mowing or thinning is the minimum necessary to alleviate the potential fire hazard and is consistent with City standards for Wildfire Lands described in the chapter 18.3.10 Physical and Environmental Constraints Overlay. The Staff Advisor may approve perimeter mowing or thinning of vegetation in wetlands that do not have an approved wetland mitigation plan using the ministerial process if a plan is submitted demonstrating that native plants will not be removed.

2. Fences. Fences limited to open wire, electric or similar fence that will not collect debris or obstruct flood waters, but not including wire mesh or chain link fencing, may be installed in the wetland buffer. Solid wood fencing is prohibited in Water Resource Protection Zones. Temporary tree protection fencing required in accordance with the Tree Preservation and Protection standards in 18.4.5 is allowed in conjunction with a development project. Fencing in a designated floodplain shall conform to the requirements of subsection 18.3.10.070.K. (Ord. 3192 § 120, amended, 11/17/2020)