All work must be designed to a standard as required by the city and will follow standards of good engineering practices and principles. The applicant will be responsible for providing a design that is acceptable and, when constructed, a facility that can be easily maintained by the property owner. If circumstances create a hazard to life, endanger or adversely affect the use or stability of a public or private way or drainage courses, the city may impose additional or greater requirements to fulfill the intent of this chapter.
A. Excavation Standards – Cut Slopes. Slopes shall be no steeper than is safe for the intended use and shall not be steeper than two horizontal to one vertical, or as recommended by a soils engineer.
The catch point of the top of the slope shall be set back from the site boundary line in accordance with the following table unless a retaining wall is designed by the engineer and constructed for the project:
Cut Depth | Setback Distance |
|---|
Under 5 feet | 2 feet |
5 – 20 feet | Height x 2 |
Over 20 feet* | Per approval |
* For cut depths over 20 feet, a geotechnical report shall be submitted to the city for review and approval prior to excavation. |
B. Fill Standards.
1. General. Fill which is intended for building sites shall be constructed in conformance with the requirements of the latest edition of the IBC, as adopted by the city.
2. Fill Location. Slopes shall be no steeper than is safe for the intended use and shall not be steeper than one and one-half horizontal to one vertical, or as recommended by a soils engineer. Fill sites must be approved by the engineer as suitable locations for the proposed fill.
3. Preparation of Ground. The ground surface for fills over five feet in height shall be prepared by removing vegetation, noncomplying fill, topsoil and other unsuitable materials, scarifying to provide a bond with the new fill, and, where existing slopes are steeper than five horizontal to one vertical, by benching into competent material as determined by the engineer. The bench under the toe of a fill on a slope steeper than five horizontal to one vertical shall be at least 10 feet wide, or as recommended by a soils engineer.
4. Fill Material. Except as permitted by the city, no material other than earth material shall be buried or placed in fills. Placement of other than earth material is regulated by state statutes or federal laws and additional permits may be required.
5. Slope Stability. Fills shall be constructed using earth materials, compaction methods and construction techniques, so that stable fills are created.
6. Setback from Property Lines. The toe or catch point of fill slopes shall be set back from the site boundary line in accordance with the following table, unless a retaining wall is designed by the engineer and constructed for the project:
Fill Depth | Setback Distance |
|---|
Under 5 feet | 2 feet |
5 – 40 feet | Height x 2 |
Over 40 feet | 20 feet |
7. Notice of Grading or Filling. The city may cause a notice to be recorded as a public record containing provision which will include the nature and extent of the filling which has occurred on the parcel.
C. Drainage Requirements. All drainage facilities, improvements, drainage design and maintenance of drainage facilities shall be in accordance with the provisions of this title and the most recent version of Ecology's Stormwater Management Manual for Eastern Washington.
D. Erosion Control. Erosion control requirements shall be implemented by the applicant prior to site grading or clearing.
1. Slopes. Slopes shall be prepared and maintained to control erosion. Slope protection shall be installed immediately upon achieving final grade or as soon as weather permits. Where cut slopes are not subject to erosion, due to the nature of the materials, such protection may be omitted.
2. Other Devices. Where necessary, check dams, silt fences, cribbing, riprap, natural buffer areas or other devices or methods shall be employed to control erosion. Where natural buffer areas are required, no building, clearing, filling, grading, or ditching is permitted within that area except for minor watercourse maintenance when applicable. The natural buffer area as delineated or described shall be preserved and maintained in its natural undisturbed state for erosion and drainage control.
3. Erosion control measures shall be in accordance with the most recent version of Ecology's Stormwater Management Manual for Eastern Washington.
E. Wetland Areas. Grading, filling or clearing within 25 feet of a wetland or stream or any grading, filling or clearing that could affect a wetland or stream shall comply with the critical area requirements of Chapter
18.90 RMC.
F. Archaeological Sites. Grading, filling or clearing of archaeological sites shall be done in accordance with the provisions of this title and Chapter
25-48 WAC, as now adopted or as may be amended, or other applicable state or federal law.
(Ord. 1059 § 2 (Exh. A (12.100.030)), 2010; Ord. 1060 §§ 5, 6, 2010; Ord. 1192 § 1 (Exh. A), 2022)