1. The Pierce County Critical Areas Atlas-Flood Hazard Area Map provides an indication of where potential flood hazard areas are located within the County. The actual presence or location of a flood hazard area shall be determined using the procedures and criteria contained in this Chapter.

2. The Department will complete a review of the Flood Hazard Area Maps, and other source documents, for any development proposal to determine whether the proposed project area for a regulated activity falls within a potential flood hazard area. When there is a conflict between the elevations and the mapped 100- or 500-year floodplain or floodway boundaries, the elevations shall govern.

3. When the Department's maps or sources indicate that the proposed project area for a regulated activity is or may be located within a potential flood hazard area, the Department shall require a flood boundary delineation survey as outlined in subsection B below, and may require a flood study as outlined in subsection C below, a deep and/or fast flowing water analysis as outlined in subsection D below, and/or a zero-rise analysis as outlined in subsection E below, except for coastal flood hazard areas which shall not be required to submit a flood study, deep and/or fast flowing water analysis, or a zero-rise analysis.

4. Any proposed development located within a flood hazard area shall comply with the flood hazard area standards set forth in PCC 18E.70.040.

5. The Department shall utilize an expedited review and approval process in communities recovering from County, State or Federally declared disasters. This process shall be developed administratively and shall be documented in the Department's Disaster Recovery Standards (DRS). The purpose of these standards is to assist property owners recovering from declared disasters including, but not limited to, floods. The DRS shall establish processes for allowing recovery related to sediment and debris removal, expedited building permit review for repair and reconstruction of damaged structures, and other recovery procedures deemed necessary by the Department. A copy of the Department's DRS shall be available to the public upon request.

6. A FEMA Letter of Map Amendment (LOMA) or Letter of Map Revision (LOMR) shall not be submitted to FEMA until review and approval has been granted by Pierce County. Pierce County shall not recognize any LOMA or LOMR as an amendment to the Department's Flood Hazard maps unless prior approval has been granted by the County Planning and Public Works Department.

7. Unless otherwise stated in this Chapter, the critical area protective measure provisions contained in PCC 18E.10.080 shall apply.

1. If the Department's maps or sources indicate that the proposed project area for a regulated activity is located within a potential flood hazard area, then a flood boundary delineation survey that delineates the horizontal and vertical limits of the base flood elevation shall be submitted to the Department.

2. The requirement to submit a flood boundary delineation survey may be waived at the Department's discretion, when the Department can determine, using contour elevations, base flood data, orthophotos, and parcel data, that the extent of the regulated activity is clearly above the base flood elevation.

3. The flood boundary delineation survey shall be prepared, signed, and dated by a professional land surveyor.

4. The Department shall review the flood boundary delineation survey to evaluate if the proposed development is located within a flood hazard area.

5. If the proposed development lies within the flood hazard area, the limits of the floodway, as well as the base flood elevation, shall be shown on the flood boundary delineation survey.

1. A flood study shall be conducted when the Department's maps or sources indicate that the proposed project area for a regulated activity is or may be located within a potential flood hazard area where base flood elevation data is not available through the Flood Insurance Study or other authoritative sources, or when an established base flood elevation is contested. An engineering analysis to determine the base flood elevation shall be required by Pierce County. Base flood elevations shall be determined using the detailed methods established in PCC 18E.70.050 – Appendix A. Alternative methods may be approved by the County.

2. The flood study shall be prepared under the responsible charge of and signed and dated by a professional engineer.

3. Once the Department has reviewed and approved the flood study, the applicant shall be required to provide a flood boundary delineation survey, utilizing the newly established base flood elevation, as outlined in subsection C above.

4. Flood studies shall not be required for coastal flood hazard areas. New coastal flood studies may, however, be accepted by the County that show a different base flood elevation if prepared by a professional engineer and based on FEMA coastal guidance. An applicant may request the use of an approved coastal study. The County may allow use of a previously approved coastal study when the conditions on the sites are sufficiently similar and the sites lie in proximity to each other.

1. When the Department determines that a proposed project area for a regulated activity is located within a flood hazard area, a deep and/or fast flowing water analysis based on Figure 18E.70-9 in Chapter 18E.120 PCC and PCC 18E.70.050 – Appendix A shall be required to determine the floodway limits.

2. The floodway limits and flood fringe limits identified in the deep and/or fast flowing water analysis shall be depicted on the flood boundary delineation survey, as outlined in subsection B above.

3. The deep and/or fast flowing water analysis shall be prepared under the responsible charge of and signed and dated by a professional engineer.

4. Deep and/or fast flowing water analysis shall not be required for coastal flood hazard areas.

1. When the Department concludes that a proposed project area for a regulated activity is located within a flood hazard area, a zero-rise analysis shall be required to determine that no increase in base flood elevation, displacement of flood volume, or flow conveyance reduction will occur as a result of the development.

2. The zero-rise analysis shall be conducted utilizing HEC-RAS modeling methodology or other alternative methodology approved by the County (see PCC 18E.70.050 – Appendix A). The analysis shall show that no rise (0.01 feet or less) has occurred as a result of the proposed development except that development proposed to occur in a FEMA mapped floodway shall show no rise in excess of 0.00 feet. The proposed development may need to be reduced or specially engineered (such as utilizing piers or pilings) to achieve zero-rise.

3. The zero-rise analysis shall be prepared under the responsible charge of and signed and dated by a professional engineer.

4. The zero-rise analysis shall be documented on the Zero-Rise Analysis Form, as set forth in PCC 18E.70.050 – Appendix A, and shall be attached to the flood hazard area permit.

5. Zero-rise analysis shall not be required for coastal flood hazard areas.

6. The requirement to submit a zero rise analysis may be waived at the Department's discretion for the following types of projects: