The purpose of this chapter is to: (1) minimize hazards associated with grading; (2) minimize the erosion of land during clearing, excavation, grading, construction, and post-construction activities; (3) prevent the transport of sediment into water courses, wetlands, riparian areas, thus protecting water quality and fish and wildlife habitat; and (4) prevent the transport of sediment onto adjacent property.
(Ord. 24-05, 6/5/2024)
A. 
Development Permit Required.
1. 
Persons proposing to clear, grade, excavate or fill land (regulated activities) shall obtain a development permit as prescribed by this chapter unless exempted by Section 17.92.030. A development permit is required where:
a. 
The proposed clearing, grading, filling, or excavation is located within 100 feet of a stream, watercourse, or wetland; or
b. 
The proposed clearing, grading, filling, or excavation is located more than 100 feet from a stream or watercourse or wetland and the affected area exceeds 250 square feet; or
c. 
The proposed volume of excavation, fill or any combination of excavation and fill exceeds 10 cubic yards in a calendar year.
2. 
A development permit for regulated activities in conjunction with a structure requiring a building permit shall be reviewed pursuant to Chapter 17.12, Development Permit.
3. 
A development permit for regulated activities in conjunction with a subdivision or partition shall be reviewed in conjunction with construction drawings as required by Section 17.124.020.
4. 
A development permit for regulated activities not in conjunction with building permit, subdivision, or partition shall be reviewed pursuant to Chapter 17.12. However, notice to adjacent property owners is not required.
B. 
Exceptions. The following are exempt from the requirements of subsection A of this section;
1. 
Residential landscaping and gardening activities up to 2,000 square feet in area;
2. 
Forest management undertaken pursuant to Section 17.86.150; or
3. 
Construction which disturbs five acres or more. Such activities are regulated by the Oregon Department of Environmental Quality through its stormwater program.
C. 
Information Required for a Development Permit.
1. 
An application for a development permit for regulated activities subject to the requirements of this chapter shall include the following:
a. 
A site plan, drawn to an appropriate scale with sufficient dimensions, showing the property line locations, roads, areas where clearing, grading, excavation or filling is to occur, the area where existing vegetative cover will be retained, the location of any streams or wetland areas on or immediately adjacent to the property, the general direction of slopes, the location of the proposed development, and the location of soil stock piles, if any;
b. 
The type and location of proposed erosion and sedimentation control measures.
2. 
The city may require a grading plan prepared by a registered civil engineer where the disturbed area has an average slope of 20 percent or greater, the disturbed area is located in a geologic hazard area or is part of a subdivision or partition. Such a grading plan shall include the following additional information:
a. 
Existing and proposed contours of the property, at two-foot contour intervals;
b. 
Location of existing structures and buildings, including those within 25 feet of the development site on adjacent property;
c. 
Design details for proposed retaining walls; and
d. 
The direction of drainage flow and detailed plans and locations of all surface and subsurface drainage devices to be constructed.
3. 
The city may require that the sedimentation and erosion control plan be prepared by a registered civil engineer where the disturbed area is greater than one acre in size, or the disturbed area has an average slope of 20 percent or greater.
(Ord. 24-05, 6/5/2024)
A. 
The review and approval of development permits involving grading shall be based on the conformance of the proposed development plans with the following standards. Conditions of approval may be imposed to assure that the development plan meets the appropriate standards.
1. 
Cuts.
a. 
Designs shall minimize the need for cuts;
b. 
The slope of cut surfaces shall not be steeper than is safe for the intended use and shall not be steeper than two horizontal to one vertical unless an engineering report finds that a cut at a steeper slope will be stable and not create a hazard to public or private property;
c. 
Cuts shall not remove the toe of any slope where a potential land slide exists;
d. 
Cuts shall be set back from property lines so as not to endanger or disturb adjoining property; and
e. 
Retaining walls shall be constructed in accordance with Section 2308(b) of the Oregon State Structural Specialty Code.
2. 
Fills.
a. 
Designs shall minimize the need for fills;
b. 
The slope of fill surfaces shall not be steeper than is safe for the intended use and shall not be steeper than two horizontal to one vertical unless an engineering report finds that a steeper slope will be stable and not create a hazard to public or private property. Fill slopes shall not be constructed on natural slopes steeper than two horizontal to one vertical;
c. 
Fills shall be set back from property lines so as not to endanger or disturb adjoining property;
d. 
The ground surface shall be prepared to receive fill by removing vegetation, noncomplying fill, topsoil and other unsuitable materials, and scarifying to provide a bond with the new fill; and
e. 
Any structural fill shall be designed by a registered engineer, in accordance with standard engineering practices.
3. 
Drainage.
a. 
Proposed grading shall not alter drainage patterns so that additional stormwater is directed onto adjoining property; and
b. 
All cut and fill slopes shall be provided with subsurface drainage as necessary for stability.
(Ord. 24-05, 6/5/2024)
A. 
The review and approval of development permits for regulated activities subject to this chapter shall be based on the conformance of the development plans with the standards of this section. Conditions of approval may be imposed to assure that the development plan meets the appropriate standards. The city manager may require modifications to the erosion and sedimentation control plan at any time if the plan is ineffective in preventing the discharge of significant amounts of sediment onto surface waters, wetlands, or adjacent property.
B. 
The design standards and specifications contained in "Soil Erosion Guidance" prepared by the Columbia River Estuary Study Taskforce (CREST), are incorporated into this chapter and are made a part hereof by reference for the purpose of delineating procedures and methods of operation for erosion and sedimentation control measures.
C. 
Standards.
1. 
Natural vegetation should be retained and protected wherever possible.
2. 
Stream and wetland areas shall only be disturbed in conformance with the requirements of Chapter 17.102 Wetland Overlay Zone and Chapter 17.116 Stream Corridor Protection.
3. 
In dune areas, erosion and sedimentation control measures shall also meet the requirements of Section 17.110.020, Wind erosion prevention plan.
4. 
Sedimentation barriers, such as filter fences and straw bales, shall be placed to control sedimentation from entering streams, wetlands, or adjoining property. The sedimentation barriers shall be installed prior to site clearance or grading activities.
5. 
Critical areas, as determined by the city manager, cleared of vegetation may be required to be temporarily stabilized with mulch, sod, mat or blanket in combination with seeding, or equivalent nonvegetative materials such as mat or blanket if in the opinion of the manager such an area represents an erosion hazard. Prior to the completion of construction, such slopes shall be permanently stabilized by seeding.
6. 
Stormwater inlets and culverts shall be protected by sediment traps or filter barriers.
7. 
Soil storage piles or fill shall be located so as to minimize the potential for sedimentation of streams, wetlands or adjacent property. Where, in the opinion of the manager, a soil storage area or fill has the potential for causing sedimentation of streams, wetlands or adjoining property, the manager may require temporary stabilization measures.
8. 
Temporary sedimentation control, not in conjunction with a structure, may be required.
9. 
Erosion and sedimentation control measures shall be maintained during the period of land disturbance and site development in a manner that ensures adequate performance.
10. 
The city manager may require a graveled entrance road, or equivalent, of sufficient length, depth, and width to prevent sedimentation from being tracked onto streets.
11. 
Trapped sediment and other disturbed soils resulting from sediment control measures shall be removed or permanently stabilized to prevent further erosion and sedimentation.
12. 
Measurable amounts of sediment that leave the site shall be cleaned up and placed back on the site or properly disposed of.
13. 
All temporary erosion and sedimentation control measures shall remain in place until the disturbed area is stabilized with permanent vegetation.
14. 
Under no conditions shall sediment from the construction site be washed into storm sewers, drainage ways or streams.
15. 
A ground cover will be established on exposed soils as soon as possible after finish grading or construction is complete.
16. 
No more than 10 cubic yards of fill shall be placed on an undeveloped site within a calendar year.
17. 
The city may make periodic inspections to ascertain that erosion and sediment control measures as proposed have been implemented and are being effectively maintained.
(Ord. 24-05, 6/5/2024)