• Clearing & Grading CSWPPP Requirements

    All new development and redevelopment projects are responsible for preventing erosion and discharge of sediment and other pollutants into receiving waters. Erosion control performance standards must be maintained on site even if the project does not require a clearing & grading permit. Exemption from a clearing & grading permit is not an exemption from meeting all applicable city codes, including BCC 24.06, which requires that sediment and other pollutants be kept from the drainage system.

    A Construction Stormwater Pollution Prevention Plan (CSWPPP) is required for all projects that meet the thresholds for permitting in section 23.76.035 of the clearing & grading code. The CSWPPP must be implemented beginning with initial soil disturbance and until final stabilization. Erosion and sediment control Best Management Practices (BMPs) shall be consistent with the BMPs contained in the Clearing & Grading Development Standards.

    Plan Requirements

    The CSWPPP must include a narrative, drawings and a turbidity and pH monitoring plan. The required elements of a CSWPPP are described in Section CG7 of the Clearing & Grading Development Standards. All BMPs must be clearly referenced in the narrative and marked on the drawings, and a copy of the referenced BMPs must be included in the CSWPPP. The CSWPPP narrative must include documentation to explain and justify the pollution prevention strategies made for the project. Permitted clearing and grading areas and any other areas required to preserve critical or sensitive areas, buffers, native growth protection easements, or tree retention areas as may be required by the city, must be delineated on the site plans.

    Appendix A1 of the Clearing & Grading Development Standards details the required contents of a CSWPPP. A worksheet for completing a CSWPPP is provided in Appendix A3 of the Clearing & Grading Development Standards. Turbidity and pH monitoring requirements are provided in Appendix A3 also.

    For projects that involve clearing less than 7,000 square feet and grading less than 100 cubic yards, the CSWPPP may consist of a completed CSWPPP Short Form for Small Construction Projects and a site plan that includes erosion and sediment control (ESC).

    The requirement for a turbidity and pH monitoring plan may be waived by the Director, depending on site characteristics, such as topography, soil type, proximity to receiving waters, retention of vegetation, extent of land disturbing activities, or location of critical areas and critical area buffers.

    Use the Site Plan or Plat Plan identified for the permit as the underlying base map for the clearing & grading plan. State whether the topography is based on the City of Bellevue NAVD 88 or NGVD 29 datum.

    1. Provide plans that have been stamped and signed by a Washington State-licensed civil engineer (Exception: plans prepared for a single-family lot).
    2. Show existing and proposed finished grades (elevations) at a 2-foot contour interval, clearly labeled, for proposed structural, infrastructure and site improvements. Note: Slope indicator symbols are not acceptable.
    3. Indicate quantity of excavation and quantity of fill (in cubic yards) on the plan.
    4. Delineate the boundary of all clearing and grading and label as "Limits of Clearing & Grading."
    5. Show the surveyed location of all Significant Trees (as defined in the Land Use Code [LUC 20.20.520]) to be retained within and adjacent to the clearing limits, and give the accurate dimensions of their associated drip lines.
    6. Show details for tree protection techniques for these Significant Trees to be retained.
    7. Show the location of all proposed structures and impervious surfaces (improvements). If these are adjacent to a critical area (per LUC 20.25H.070) - such as a stream, floodplain, steep slope, landslide hazard area and wetland - show the distance from the improvement to the critical area boundary or setback.
    8. Provide finished grade spot elevations for the following locations:
      • Around the base of the structure(s) measured at 20 feet on center and at all corners.
      • Within proposed paved areas at all corners and high and low points.
      • At the top and bottom of all existing and proposed walls (rockery, retaining, etc.); at the ends, highest elevation and the midpoint.
      • At the top and bottom of all steps.
      • At the top and bottom of all ramps.
    9. Provide details of the erosion and sedimentation control measures to be implemented, based on the Bellevue Clearing & Grading Development Standards.
    10. Show the cross-section detail for TESC ponds and swales; include the pond and swale sizing calculations on this plan. (Not required on plans prepared for a single-family lot).
    11. Attach the Standard Notes for Erosion Control Plans (included in this information sheet) to the plan or copy them onto the face of the plan.

    Preliminary Clearing & Grading Plan

    1. Provide plans that have been stamped and signed by a Washington State-licensed civil engineer (Exception: plans prepared for a single-family lot).
    2. Show existing and proposed finished grades (elevations) at a 2-foot contour interval, clearly labeled, for proposed structural, infrastructure and site improvements. Note: Slope indicator symbols are not acceptable.
    3. Show the surveyed location of all Significant Trees (as defined in the Land Use Code [LUC 20.20.520]) to be retained within and adjacent to the clearing limits, and give the accurate dimensions of their associated drip lines.
    4. Show the location of all proposed structures and impervious surfaces (improvements). If these are adjacent to a critical area (per LUC 20.25H.070) - such as a stream, floodplain, steep slope, landslide hazard area and wetland - show the distance from the improvement to the critical area boundary or setback.

    Standard Notes for Erosion Control Plans

    • All clearing & grading construction must be in accordance with City of Bellevue (COB) Clearing & Grading Code, Clearing & Grading Development Standards, Land Use Code, Uniform Building Code, permit conditions and all other applicable codes, ordinances and standards. The design elements within these plans have been reviewed according to these requirements. Any variance from adopted erosion control standards is not allowed unless specifically approved by the City of Bellevue Development Services Department prior to construction. It shall be the sole responsibility of the applicant and the professional civil engineer to correct any error, omission or variation from the above requirements found in these plans. All corrections shall be at no additional cost or liability to the City of Bellevue.
       
    • Approval of this erosion/sedimentation control (ESC) plan does not constitute an approval of permanent road or drainage design (e.g. size and location of roads, pipes, restricters, channels, retention facilities, utilities, etc.).
       
    • A copy of the approved plans and drawings must be on site during construction. The applicant is responsible for obtaining any other required or related permits prior to beginning construction.
       
    • The implementation of these ESC plans and the construction, maintenance, replacement and upgrading of these ESC facilities is the responsibility of the applicant/contractor until all construction is completed and approved and vegetation/landscaping is established.
       
    • The ESC facilities shown on this plan must be constructed in conjunction with all clearing and grading activities, and in such a manner as to insure that sediment and sediment laden water do not enter the drainage system or roadways, or violate applicable water standards.
       
    • The ESC facilities shown on this plan are the minimum requirements for anticipated site conditions. During the construction period, these ESC facilities shall be upgraded as needed for unexpected storm events and to ensure that sediment and sediment-laden water do not leave the site.
       
    • All locations of existing utilities have been established by field survey or obtained from available records and should, therefore, be considered only approximate and not necessarily complete. It is the sole responsibility of the contractor to independently verify the accuracy of all utility locations and to discover and avoid any other utilities not shown which may be affected by the implementation of this plan.
       
    • The boundaries of the clearing limits shown on this plan shall be clearly flagged in the field prior to construction. During the construction period, no disturbance beyond the flagged clearing limits shall be permitted. The flagging shall be maintained by the applicant/contractor for the duration of construction.
       
    • Clearing shall be limited to the areas within the approved disturbance limits. Exposed soils must be covered at the end of each working day when working from October 1 through April 30. From May 1 through September 30, exposed soils must be covered at the end of each construction week and also at the threat of rain.
       
    • At no time shall more than one foot of sediment be allowed to accumulate within a trapped catch basin. All catch basins and conveyance lines shall be cleaned prior to paving. The cleaning operation shall not flush sediment laden water into the downstream system.
       
    • Stabilized construction entrances shall be installed at the beginning of construction and maintained for the duration of the project.
       
    • The contractor must maintain a sweeper on site during earthwork and immediately remove soil that has been tracked onto paved areas as result of construction.
       
    • The ESC facilities shall be inspected daily by the applicant/contractor and maintained as necessary to ensure their continued functioning.
       
    • Any excavated material removed from the construction site and deposited on property within the city limits must be done in compliance with a valid clearing & grading permit. Locations for the mobilization area and stockpiled material must be approved by the clearing & grading inspector at least 24 hours in advance of any stockpiling.
       
    • The ESC facilities on inactive sites shall be inspected and maintained a minimum of once a month or within the 48 hours following a major storm event.
       
    • Final site grading must direct drainage away from all building structures at a minimum five percent slope, per the International Residential Code (IRC) R401.3.