A. The flood hazard areas of City of Dallas are subject to periodic inundation which may result in loss of life and property, health and safety hazards, disruption of commerce and governmental services, extraordinary public expenditures for flood protection and relief, and impairment of the tax base, all of which adversely affect the public health, safety, and general welfare. B. These flood losses may be caused by the cumulative effect of obstructions in special flood hazard areas which increase flood heights and velocities, and when inadequately anchored, cause damage in other areas. Uses that are inadequately floodproofed, elevated, or otherwise protected from flood damage also contribute to flood loss.

It is the purpose of sections 2.7.010 to 2.7.200, herein referred to as “this code,” to promote public health, safety, and general welfare, and to minimize public and private losses due to flooding in flood hazard areas by provisions designed to:

1. Protect human life and health;
2. Minimize expenditure of public money for costly flood control projects;
3. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;
4. Minimize prolonged business interruptions;
5. Minimize damage to public facilities and utilities such as water and gas mains; electric, telephone and sewer lines; and streets and bridges located in special flood hazard areas;
6. Help maintain a stable tax base by providing for the sound use and development of flood hazard areas so as to minimize blight areas caused by flooding;
7. Notify potential buyers that the property is in a special flood hazard area
8. Notify those who occupy special flood hazard areas that they assume responsibility for their actions
9. Participate in and maintain eligibility for flood insurance and disaster relief.
   

In order to accomplish its purposes, this code includes methods and provisions for:

1. Restricting or prohibiting development which is dangerous to health, safety, and property due to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;
2. Requiring that development vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
3. Controlling the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel flood waters;
4. Controlling filling, grading, dredging, and other development which may increase flood damage;
5. Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or may increase flood hazards in other areas.

Except as otherwise specifically defined below, words or phrases used in this code shall be interpreted so as to give them the meaning they have in common usage. Appeal: A request for a review of the interpretation of any provision of this code or a request for a variance. Area of shallow flooding: A designated Zone AO, AH, AR/AO or AR/AH on a community’s Flood Insurance Rate Map (FIRM) with a one percent or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow. Area of special flood hazard: The land in the floodplain within a community subject to a 1 percent or greater chance of flooding in any given year. It is shown on the Flood Insurance Rate Map (FIRM) as Zone A, AO, AH, A1-30, AE, A99, AR (V, V1-30, VE). “Special flood hazard area” is synonymous in meaning and definition with the phrase “area of special flood hazard”. Base flood: The flood having a one percent chance of being equaled or exceeded in any given year. Base flood elevation (BFE): The elevation to which floodwater is anticipated to rise during the base flood. Basement: Any area of the building having its floor subgrade (below ground level) on all sides. Below-grade crawl space: Means an enclosed area below the base flood elevation in which the interior grade is not more than two feet below the lowest adjacent exterior grade and the height, measured from the interior grade of the crawlspace to the top of the crawlspace foundation, does not exceed 4 feet at any point. Critical facility: Means a facility, the loss of which, because of its function, could result in substantial harm to public health, safety or welfare. “Critical facility” includes, but is not limited to schools, nursing homes, hospitals, police, fire and emergency response installations, installations which produce, use, or store hazardous materials or hazardous waste. Development: Any human-made change to improved or unimproved real property, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, fencing, landscaping, excavation or drilling operations or storage of equipment or materials. Flood or Flooding: (a) A general and temporary condition of partial or complete inundation of normally dry land areas from: (1) The overflow of water. (2) The unusual and rapid accumulation or runoff of surface waters from any source. (3) Mudslides (i.e., mudflows) which are proximately caused by flooding as defined in paragraph (a)(2) of this definition and are akin to a river of liquid and flowing mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current. (b) The collapse or subsidence of land along the shore of a lake or other body of water as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels or suddenly caused by an unusually high water level in a natural body of water, accompanied by a severe storm, or by an unanticipated force of nature, such as flash flood, or by some similarly unusual and unforeseeable event which results in flooding as defined in paragraph (a)(1) of this definition. Flood elevation study: See “Flood Insurance Study”. Flood Insurance Rate Map (FIRM): The official map on which the Federal Insurance Administrator has delineated both the special hazard areas and the risk premium zones applicable to the city. Flood Insurance Study (FIS): An examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide (i.e., mudflow) and/or flood-related erosion hazards. Flood proofing: Any combination of structural and nonstructural additions, changes, or adjustments to structures which reduce or eliminate risk of flood damage to real estate or improved real property, water and sanitary facilities, structures, and their contents. Floodplain or flood prone area: Any land area susceptible to being inundated by water from any source. See "Flood or flooding." Floodway: The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height. Also referred to as "Regulatory Floodway." Hazardous material: Any of the following: (a) Hazardous waste as defined in ORS 466.005; (b) Radioactive waste as defined in ORS 469.300, radioactive material identified by the Energy Facility Siting Council under ORS 469.605 and radioactive substances defined in ORS 453.005 (c) Communicable disease agents as regulated by the Health Division under ORS Chapter 431 and 433.010 to 433.045 and 433.106 to 433.990; (d) Hazardous substances designated by the United States Environmental Protection Agency (EPA) under section 311 of the Federal Water Pollution Control Act, P.L. 92-500, as amended; (e) Substances listed by the United States EPA in section 40 of the Code of Federal Regulations, Part 302 – Table 302.4 (list of Hazardous Substances and Reportable Quantities) and amendments; (f) Material regulated as a Chemical Agent under ORS 465.550; (g) Material used as a weapon of mass destruction, or biological weapon; (h) Pesticide residue; (i) Dry cleaning solvent as defined by ORS 465.200(9); (j) Any other substances or materials designated as hazardous by the federal or state law, rule, regulation or order. Highest adjacent grade: The highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. Historic structure: Any structure that is: (a) Listed individually in the National Register of Historic Places (a listing maintained by the Department of Interior) or preliminarily determined by the Secretary of the Interior as meeting the requirements for individual listing on the National Register; (b) Certified or preliminarily determined by the Secretary of the Interior as contributing to the historical significance of a registered historic district or a district preliminarily determined by the Secretary to qualify as a registered historic district; (c) Individually listed on the state inventory of historic places; or (d) Individually listed on the local inventory of historic places. Letter of Map Change (LOMC): Means an official FEMA determination, by letter, to amend or revise effective Flood Insurance Rate Maps and Flood Insurance Studies. The following are categories of LOMCs: (a) Conditional Letter of Map Amendment (CLOMA): A CLOMA is FEMA’s comment on a proposed structure or group of structures that would, upon construction, be located on existing natural ground above the base (1-percent-cannual-chane) flood elevation on a portion of a legally defined parcel of land that is partially inundated by the base flood. (b) Conditional Letter of Map Revision (CLOMR): A CLOMR is FEMA’s comment on a proposed project that would, upon construction, affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective base flood elevations, or the special flood hazard area. (c) Conditional Letter of Map Revision based on Fill (CLOMR-F): A CLOMR-F is FEMA’s comment on a proposed project that would, upon construction, result in a modification of the special flood hazard area through the placement of fill outside the existing regulatory floodway. (d) Letter of Map Amendment (LOMA): An official amendment, by letter, to the Flood Insurance Rate Maps (FIRMs) based on technical data showing that an existing structure, parcel of land or portion of a parcel of land that is naturally high ground, (i.e., has not been elevated by fill) above the base flood, that was inadvertently included in the special flood hazard area. (e) Letter of Map Revision (LOMR): A LOMR is FEMA’s modification to an effective Flood Insurance Rate Map (FIRM), or Flood Boundary and Floodway Map (FBFM), or both. LOMRs are generally based on the implementation of physical measures that affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective base flood elevations, or the SFHA. The LMOR officially revises the FIRM or FBFM, and sometimes the Flood Insurance Study (FIS) report, and, when appropriate, includes a description of the modifications. The LOMR is generally accompanied by an annotated copy of the affected portions of the FIRM, FBFM, or FIS report. (f) Letter of Map Revision based on Fill (LOMR-F): A LOMR-F is FEMA’s modification of the special flood hazard area shown on the Flood Insurance Rate Map (FIRM) based on the placement of fill outside the existing regulatory floodway. (g) PMR: A PMR is FEMA’s physical revision and republication of an effective Flood Insurance Rate Map (FIRM) or Flood Insurance Study (FIS) report. PMRs are generally based on physical measures that affect the hydrologic or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway, the effective baes flood elevations, or the special flood hazard area. Lowest floor: The lowest floor of the lowest enclosed area (including basement). An unfinished or flood resistant enclosure, usable solely for parking of vehicles, building access or storage in an area other than a basement area is not considered a building’s lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable non-elevation design requirements of this code. Manufactured dwelling: A structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when attached to the required utilities. The term "manufactured dwelling" does not include a "recreational vehicle" and is synonymous with “manufactured home”. Manufactured dwelling park or subdivision: A parcel or contiguous parcels of land divided into two or more manufactured dwelling lots for rent or sale. Mean sea level: For purposes of the National Flood Insurance Program, the National Geodetic Vertical Datum (NGVD) of 1929 or other datum, to which Base Flood Elevations shown on the city’s Flood Insurance Rate Map are referenced. New construction: For floodplain management purposes, “new construction” means structures for which the “start of construction” commenced on or after the effective date of a floodplain management regulation adopted by the city and includes any subsequent improvements to such structures. Recreational vehicle: A vehicle which is: (a) Built on a single chassis; (b) 400 square feet or less when measured at the largest horizontal projection; (c) Designed to be self-propelled or permanently towable by a light duty truck; and (d) Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. Special flood hazard area: See “Area of special flood hazard.” Start of construction: Includes substantial improvement and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement, or other improvement was within 180 days from the date of the permit. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured dwelling on a foundation. Permanent construction does not include land preparation, such as clearing, grading, and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure. For a substantial improvement, the actual start of construction means the first alteration of any wall, ceiling, floor, or other structural part of a building, whether or not that alteration affects the external dimensions of the building. Structure: For floodplain management purposes, a walled and roofed building, including a gas or liquid storage tank, that is principally above ground, as well as a manufactured dwelling. Substantial damage: Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred. Substantial improvement: Any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the "start of construction" of the improvement. This term includes structures which have incurred "substantial damage," regardless of the actual repair work performed. The term does not, however, include either: (a) A project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions; or (b) Any alteration of a "historic structure," provided that the alteration will not preclude the structure's continued designation as a "historic structure.” Variance: A grant of relief by the City of Dallas from the terms of a flood plain management regulation. Violation: The failure of a structure or other development to be fully compliant with the community’s floodplain management regulations. A structure or other development without the elevation certificate, other certifications, or other evidence of compliance required in this code is presumed to be in violation until such time as that documentation is provided.

This code shall apply to all special flood hazard areas within the jurisdiction of the city.

The special flood hazard areas identified by the Federal Insurance Administrator in a scientific and engineering report entitled “The Flood Insurance Study (FIS) for Polk County, Oregon, and Incorporated Areas, Study number 41053CV000A, Community Number 410187 December 19, 2006, with accompanying Flood Insurance Rate Maps (FIRMs) 41053C0236F, 41053C0237F, 41053C0238F, 41053C0239F, 41053C0241F, 41053C0242F, and 41053C0250F, are hereby adopted by reference and declared to be a part of this code. The FIS and FIRM panels shall be kept on file at the Public Works Department located in Dallas City Hall.

Pursuant to the requirement established in ORS 455 that the city administers and enforces the State of Oregon Specialty Codes, the city acknowledges that the Oregon Specialty Codes contain certain provisions that apply to the design and construction of buildings and structures located in special flood hazard areas. Therefore, this code is intended to be administered and enforced in conjunction with the Oregon Specialty Codes.

1. Compliance
   All development within special flood hazard areas is subject to the terms of this code and required to comply with its provisions and all other applicable regulations.
   
2. Penalties for Noncompliance
   No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this code and other applicable regulations. Violations of the provisions of this code by failure to comply with any of its requirements (including violations of conditions and safeguards established in connection with conditions) shall constitute a civil infraction, punishable by a fine not to exceed $500, pursuant to Dallas City Code Section 1.075. Each day that a violation continues shall constitute a separate offense. Nothing contained herein shall prevent the city from taking such other lawful action as is necessary to prevent or remedy any violation.

1. Abrogation
   This code is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this code and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail.
2. Severability
   This code and the various parts thereof are hereby declared to be severable. If any section clause, sentence, or phrase of the code is held to be invalid or unconstitutional by any court of competent jurisdiction, then said holding shall in no way effect the validity of the remaining portions of this code.

In the interpretation and application of this code, all provisions shall be:

1. Considered as minimum requirements;
2. Liberally construed in favor of the city; and
3. Deemed neither to limit nor repeal any other powers granted under state statutes.
   

1. Warning The degree of flood protection required by this code is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions. Flood heights may be increased by man-made or natural causes. This code does not imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages.
2. Disclaimer of Liability This code shall not be deemed to create liability on the part of the city, any officer or employee thereof, or the Federal Insurance Administrator for any flood damages that result from reliance on this code or any administrative decision lawfully made hereunder.

The Public Works Director or designee is hereby appointed to administer, implement, and enforce this code by granting or denying development permits in accordance with its provisions. The Floodplain Administrator may delegate authority to implement these provisions.

Duties of the floodplain administrator, or their designee, shall include, but not be limited to:

1. Permit Review The Floodplain Administrator shall review all development permits to determine:
   1. That the permit requirements of this code have been satisfied.
   2. All other required local, state, and federal permits have been obtained and approved.
   3. That the proposed development is located in a floodway. If located in the floodway, assure that the floodway provisions of this code in section 2.7.200(D) are met.
   4. Whether the proposed development is located in an area where Base Flood Elevation (BFE) data is available either through the Flood Insurance Study (FIS) or from another authoritative source. If BFE data is not available then ensure compliance with the provisions of sections 2.7.190(G).
   5. That the Base Flood Elevation (BFE), and any additional elevation requirements, applicable to any building requiring a development permit has been complied with.
   6. Whether the proposed development qualifies as a substantial improvement as defined in section 2.7.040.
   7. Whether the proposed development activity is a watercourse alteration. If a watercourse alteration is proposed, compliance with the provisions in section 2.7.190(A) must be ensured.
   8. Whether the proposed development activity includes the placement of fill or excavation.
2. Information to be Obtained and Maintained
   The following information shall be obtained and maintained and shall be made available for public inspection as needed or as required by law:
   1. The actual elevation (in relation to mean sea level) of the lowest floor (including basements) and all attendant utilities of all new or substantially improved structures where Base Flood Elevation (BFE) data is provided through the Flood Insurance Study (FIS), Flood Insurance Rate Map (FIRM), or obtained in accordance with section 2.7.190(G).
   2. The elevation (in relation to mean sea level) of the natural grade of the building site for a structure prior to the start of construction. If the development requires the placement of any fill, the requirements of sections 2.7.200(D), and 2.7.150(A)(2) must be met.
   3. Upon placement of the lowest floor of a structure (including basement) but prior to further vertical construction, documentation, prepared and sealed by a professional licensed surveyor or engineer, certifying the elevation (in relation to mean sea level) of the lowest floor (including basement).
   4. Where base flood elevation data are utilized, as-built certification of the elevation (in relation to mean sea level) of the lowest floor (including basement) prepared and sealed by a professional licensed surveyor or engineer, prior to the final inspection.
   5. All Elevation Certificates (EC) submitted to the city;
   6. The elevation (in relation to mean sea level) to which the structure and all attendant utilities were floodproofed for all new or substantially improved floodproofed structures where allowed under this code and where Base Flood Elevation (BFE) data is provided through the FIS, FIRM, or obtained in accordance with section 2.7.190(G).
   7. All floodproofing certificates required under this code;
   8. All variance actions, including justification for their issuance;
   9. All hydrologic and hydraulic analyses performed as required under section 2.7.200(D).
   10. All Substantial Improvement and Substantial Damage calculations and determinations as required under section 2.7.150(D).
   11. All records pertaining to the provisions of this code.
3. Requirement to Notify Other Entities and Submit New Technical Data
   1. City Boundary Alterations
      The Floodplain Administrator shall notify the Federal Insurance Administrator in writing whenever the boundaries of the city have been modified by annexation or the city has otherwise assumed authority or no longer has authority to adopt and enforce floodplain management regulations for a particular area, to ensure that all Flood Hazard Boundary Maps (FHBM) and Flood Insurance Rate Maps (FIRM) accurately represent the city’s boundaries. Include within such notification a copy of a map suitable for reproduction, clearly delineating the new corporate limits or new area for which the city has assumed or relinquished floodplain management regulatory authority.
   2. Watercourse AlterationsThe Floodplain Administrator shall notify affected adjacent communities, the Department of Land Conservation and Development, and other appropriate state and federal agencies, prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration. This notification shall be provided by the applicant to the Federal Insurance Administration as a Letter of Map Revision (LOMR) along with either:
      1. A proposed maintenance plan to assure the flood carrying capacity within the altered or relocated portion of the watercourse is maintained; or
      2. Certification by a registered professional engineer that the project has been designed to retain its flood carrying capacity without periodic maintenance.
         The applicant shall be required to submit a Conditional Letter of Map Revision (CLOMR) when required under section 2.7.150(C)(3). Ensure compliance with all applicable requirements in sections 2.7.150(C)(3) and 2.7.190(A).
   3. Requirement to Submit New Technical DataA community’s base flood elevations may increase or decrease, as soon as practicable, but not later than six months after the date such information becomes available, the Floodplain Administrator shall notify the Federal Insurance Administrator of the changes by submitting technical or scientific data in accordance with Title 44 of the Code of Federal Regulations (CFR), Section 65.3. The city may require the applicant to submit such data and review fees required for compliance with this section through the applicable FEMA Letter of Map Change (LOMC) process. The Floodplain Administrator shall require a Conditional Letter of Map Revision prior to the issuance of a floodplain development permit for: a. Proposed floodway encroachments that increase the base flood elevation; and b. Proposed development which increases the base flood elevation by more than one foot in areas where FEMA has provided base flood elevations but no floodway. An applicant shall notify FEMA within six (6) months of project completion when an applicant has obtained a Conditional Letter of Map Revision (CLOMR) from FEMA. This notification to FEMA shall be provided as a Letter of Map Revision (LOMR). The applicant shall be responsible for preparing all technical data to support CLOMR/LOMR applications and paying any processing or application fees associated with the CLOMR/LOMR. The Floodplain Administrator shall be under no obligation to sign the Community Acknowledgement Form, which is part of the CLOMR/LOMR application, until the applicant demonstrates that the project will or has met the requirements of this code and all applicable state and federal permits.
4. Substantial Improvement and Substantial Damage Assessments and DeterminationsConduct Substantial Improvement (SI) (as defined in section 2.7.040) reviews for all structural development proposal applications and maintain a record of SI calculations within permit files in accordance with section 2.7.150(B). Conduct Substantial Damage (SD) (as defined in section 2.7.040) assessments when structures are damaged due to a natural hazard event or other causes. Make SD determinations whenever structures within the special flood hazard area (as established in section 2.7.070) are damaged to the extent that the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

1. Floodplain Development Permit Required A floodplain development permit must be obtained before construction or development begins within any area horizontally within the special flood hazard area established in section 2.7.070. The development permit shall be required for all structures, including manufactured dwellings, and for all other development, as defined in section 2.7.040, including fill and other development activities.
2. Application for Development Permit Application for a development permit may be made on forms furnished by the city and may include, but not be limited to, plans in duplicate drawn to scale showing the nature, location, dimensions, and elevations of the area in question; existing or proposed structures, fill, storage of materials, drainage facilities, and the location of the foregoing. Specifically, the following information shall be required:
   1. In riverine flood zones, the proposed elevation (in relation to mean sea level), of the lowest floor (including basement) and all attendant utilities of all new and substantially improved structures; in accordance with the requirements of section 2.7.150(B).
   2. Proposed elevation in relation to mean sea level to which any non-residential structure will be floodproofed.
   3. Certification by a registered professional engineer or architect licensed in the State of Oregon that the floodproofing methods proposed for any non-residential structure meet the floodproofing criteria for non-residential structures in section 2.7.200(C)(3).
   4. Description of the extent to which any watercourse will be altered or relocated.
   5. Base Flood Elevation data for subdivision proposals or other development when required per sections 2.7.150(A) and 2.7.190(F).
   6. Substantial improvement calculation for any improvement, addition, reconstruction, renovation, or rehabilitation of an existing structure.
   7. The amount and location of any fill or excavation activities proposed.

The issuance of a variance under this section is for floodplain management purposes only. Flood insurance premium rates are determined by federal statute according to actuarial risk and will not be modified by granting a variance.

1. Conditions for Variances
   1. Variances may be issued for new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, in conformance with the provisions of sections 2.7.170(A)(3) and (5), and 2.7.170(B). As the lot size increases beyond one-half acre, the technical justification required for issuing a variance increases.
   2. Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief.
   3. Variances shall not be issued within any floodway if any increase in flood levels during the base flood discharge would result.
   4. Variances shall only be issued upon:
      1. A showing of good and sufficient cause;
      2. A determination that failure to grant the variance would result in exceptional hardship to the applicant;
      3. A determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public, or conflict with existing laws or ordinances.
   5. Variances may be issued for new construction and substantial improvements and for other development necessary for the conduct of a functionally dependent use provided that the criteria of section 2.7.170(2)-(4) are met, and the structure or other development is protected by methods that minimize flood damages during the base flood and create no additional threats to public safety.
2. Variance Notification
   Any applicant to whom a variance is granted shall be given written notice that the issuance of a variance to construct a structure below the Base Flood Elevation will result in increased premium rates for flood insurance and that such construction below the base flood elevation increases risks to life and property. Such notification and a record of all variance actions, including justification for their issuance shall be maintained in accordance with section 2.7.150(B).

In all special flood hazard areas, the following standards shall be adhered to:

1. Alteration of Watercourses
   1. The flood carrying capacity within the altered or relocated portion of a watercourse must be maintained. Maintenance must be provided within the altered or relocated portion of a watercourse to ensure that the flood carrying capacity is not diminished. Any alteration of a watercourse shall require compliance with sections 2.7.150(C)(2) and 2.7.150(C)(3).
2. Anchoring
   1. All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.
   2. All manufactured dwellings shall be anchored per section 2.7.200(C)(4).
3. Construction Materials and Methods
   1. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
   2. All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.
4. Utilities and Equipment
   1. Water Supply, Sanitary Sewer, and On-site Waste Disposal Systems
      1. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system.
      2. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters.
      3. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding consistent with the Oregon Department of Environmental Quality.
   2. Electrical, Mechanical, Plumbing, and Other Equipment Electrical, heating, ventilating, air-conditioning, plumbing, duct systems, and other equipment and service facilities shall be elevated at or above the base flood elevation or shall be designed and installed to prevent water from entering or accumulating within the components and to resist hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during conditions of flooding. In addition, electrical, heating, ventilating, air- conditioning, plumbing, duct systems, and other equipment and service facilities shall, if replaced as part of a substantial improvement meet all the requirements of this section.
5. Tanks
   1. Underground tanks shall be anchored to prevent flotation, collapse and lateral movement under conditions of the base flood.
   2. Above-ground tanks shall be installed one foot or more above the base flood level or shall be anchored to prevent flotation, collapse, and lateral movement under conditions of the base flood.
6. Subdivision Proposals & Other Proposed Developments
   1. All new subdivision proposals and other proposed new developments (including proposals for manufactured dwelling parks and subdivisions) greater than 50 lots or 5 acres, whichever is less, shall include within such proposals, Base Flood Elevation data.
   2. All new subdivision proposals and other proposed new developments (including proposals for manufactured dwelling parks and subdivisions) shall:
      1. Be consistent with the need to minimize flood damage.
      2. Have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize or eliminate flood damage.
      3. Have adequate drainage provided to reduce exposure to flood hazards.
7. Use of Other Base Flood Elevation Data
   When Base Flood Elevation data has not been provided in accordance with section 2.7.070, the Floodplain Administrator shall obtain, review, and reasonably utilize any Base Flood Elevation data available from a federal, state, or other source, in order to administer section 2.7.180. All new subdivision proposals and other proposed new developments (including proposals for manufactured dwelling parks and subdivisions) must meet the requirements of section 2.7.190(F).
   
   Base Flood Elevations shall be determined for development proposals that are 5 acres or more in size or are 50 lots or more, whichever is lesser in any A zone that does not have an established base flood elevation. Development proposals located within a riverine unnumbered A Zone shall be reasonably safe from flooding; the test of reasonableness includes use of historical data, high water marks, FEMA provided Base Level Engineering data, and photographs of past flooding, and other relevant evidence where available. At a minimum, the elevation of residential structures and non-residential structures that are not dry floodproofed must be at least two feet above the highest adjacent grade. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates.
8. Structures Located in Multiple or Partial Flood Zones
   In coordination with the Oregon Specialty Codes:
   1. When a structure is located in multiple flood zones on the city’s Flood Insurance Rate Maps (FIRM) the provisions for the more restrictive flood zone shall apply.
   2. When a structure is partially located in a special flood hazard area, the entire structure shall meet the requirements for new construction and substantial improvements.
9. Critical FacilitiesConstruction of new critical facilities shall be, to the extent possible, located outside the limits of the special flood hazard area. Construction of new critical facilities shall be permissible within the SFHA only if no feasible alternative site is available. Critical facilities constructed within the SFHA shall have the lowest floor elevated three (3) feet above the Base Flood Elevation (BFE) or to the height of the 500-year flood, whichever is higher. Access to and from the critical facility shall also be protected to the height utilized above. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters.
10. Maintaining Flood Storage CapacityDevelopment within the special flood hazard area shall result in no net loss in flood storage capacity. No net loss may be documented by demonstrating that the volume of material the development adds to the special flood hazard area below the BFE is less than or equal to the volume of material removed. No net loss may also be documented by hydraulic analysis certified by a registered professional engineer, subject to a Type II review per section 4.1.030.

These specific standards shall apply to all new construction and substantial improvements in addition to the General Standards contained in section 2.7.190 of this code.

1. Flood Openings All new construction and substantial improvements with fully enclosed areas below the lowest floor (excluding basements) are subject to the following requirements. Enclosed areas below the Base Flood Elevation, including crawl spaces shall:
   1. Be designed to automatically equalize hydrostatic flood forces on walls by allowing for the entry and exit of floodwaters;
   2. Be used solely for parking, storage, or building access;
   3. Be certified by a registered professional engineer or architect or meet or exceed all of the following minimum criteria:
      1. A minimum of two openings,
      2. The total net area of non-engineered openings shall be not less than one (1) square inch for each square foot of enclosed area, where the enclosed area is measured on the exterior of the enclosure walls,
      3. The bottom of all openings shall be no higher than one foot above grade.
      4. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they shall allow the automatic flow of floodwater into and out of the enclosed areas and shall be accounted for in the determination of the net open area.
      5. All additional higher standards for flood openings in the Oregon Residential Specialty Codes Section R322.2.2 shall be complied with when applicable.
2. Garages
   1. Attached garages may be constructed with the garage floor slab below the Base Flood Elevation (BFE) in riverine flood zones, if the following requirements are met:
      1. If located within a floodway the proposed garage must comply with the requirements of section 2.7.200(D).
      2. The floors must be at or above grade on not less than one side;
      3. The garage must be used solely for parking, building access, and/or storage;
      4. The garage must be constructed with flood openings in compliance with section 2.7.200(A) to equalize hydrostatic flood forces on exterior walls by allowing for the automatic entry and exit of floodwater.
      5. The portions of the garage constructed below the BFE must be constructed with materials resistant to flood damage;
      6. The garage must be constructed in compliance with the standards in section 2.7.190; and
      7. The garage must be constructed with electrical, and other service facilities located and installed so as to prevent water from entering or accumulating within the components during conditions of the base flood.
   2. Detached garages must be constructed in compliance with the standards for appurtenant structures in section 2.7.200(C)(6) or non-residential structures in section 2.7.200(C)(3) depending on the square footage of the garage.
3. For Riverine Special Flood Hazard Areas with Base Flood Elevations In addition to the general standards listed in section 2.7.190 the following specific standards shall apply in Riverine special flood hazard areas with Base Flood Elevations (BFE): Zones A1-A30, AH, and AE.
   1. Before Regulatory Floodway In areas where a regulatory floodway has not been designated, no new construction, substantial improvement, or other development (including fill) shall be permitted within Zones A1-30 and AE on the city’s Flood Insurance Rate Map (FIRM), unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community.
   2. Residential Construction
      1. New construction, conversion to, and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated at or above a minimum of one foot above the Base Flood Elevation (BFE).
      2. Enclosed areas below the lowest floor shall comply with the flood opening requirements in section 2.7.200(A).
   3. Non-residential Construction
      1. New construction, conversion to, and substantial improvement of any commercial, industrial, or other non-residential structure shall:
         1. Have the lowest floor, including basement elevated to one (1) foot or more above the Base Flood Elevation (BFE). Or, together with attendant utility and sanitary facilities:
            
         2. Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;
         3. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
         4. Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this section based on their development and/or review of the structural design, specifications and plans. Such certifications shall be provided to the Floodplain Administrator as set forth section 2.7.150(B).
            1. Non-residential structures that are elevated, not floodproofed, shall comply with the standards for enclosed areas below the lowest floor in section 2.7.200 (A).
            2. Applicant’s floodproofing non-residential buildings shall be notified that flood insurance premiums will be based on rates that are one (1) foot below the floodproofed level . For this purpose, a building floodproofed to the base flood level will be rated as one (1) foot below.
   4. Manufactured Dwellings
      1. Manufactured dwellings to be placed (new or replacement) or substantially improved that are supported on solid foundation walls shall be constructed with flood openings that comply with section 2.7.200(A);
      2. The bottom of the longitudinal chassis frame beam shall be at or above Base Flood Elevation;
      3. Manufactured dwellings to be placed (new or replacement) or substantially improved shall be anchored to prevent flotation, collapse, and lateral movement during the base flood. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors (Reference FEMA’s “Manufactured Home Installation in Flood Hazard Areas” guidebook for additional techniques), and;
      4. Electrical crossover connections shall be a minimum of twelve (12) inches above Base Flood Elevation.
   5. Recreational Vehicles Recreational vehicles placed on sites are required to:
      1. Be on the site for fewer than 180 consecutive days, and
      2. Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or
      3. Meet the requirements of section 2.7.200(C)(4), including the anchoring and elevation requirements for manufactured dwellings.
   6. Appurtenant (Accessory) Structures Relief from elevation or floodproofing requirements for residential and non- residential structures in Riverine flood zones may be granted for appurtenant structures that meet the following requirements:
      1. Appurtenant structures located partially or entirely within the floodway must comply with requirements for development within a floodway found in section 2.7.200(D).
      2. Appurtenant structures must only be used for parking, access, and/or storage and shall not be used for human habitation;
      3. In compliance with Oregon Specialty Codes, appurtenant structures on properties that are zoned residential are limited to one- story structures less than 200 square feet, or 400 square feet if the property is greater than two (2) acres in area and the proposed appurtenant structure will be located a minimum of 20 feet from all property lines. Appurtenant structures on properties that are zoned as non-residential are limited in size to 120 square feet.
      4. The portions of the appurtenant structure located below the Base Flood Elevation must be built using flood resistant materials;
      5. The appurtenant structure must be adequately anchored to prevent flotation, collapse, and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy, during conditions of the base flood.
      6. The appurtenant structure must be designed and constructed to equalize hydrostatic flood forces on exterior walls and comply with the requirements for flood openings in section 2.7.200(A);
      7. Appurtenant structures shall be located and constructed to have low damage potential;
      8. Appurtenant structures shall not be used to store toxic material, oil, or gasoline, or any priority persistent pollutant identified by the Oregon Department of Environmental Quality unless confined in a tank installed incompliance with section 2.7.190(E).
      9. Appurtenant structures shall be constructed with electrical, mechanical, and other service facilities located and installed so as to prevent water from entering or accumulating within the components during conditions of the base flood.
4. Floodways
   Located within the special flood hazard areas established in section 2.7.070 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of the floodwaters which carry debris, potential projectiles, and erosion potential, the following provisions apply:
   1. Encroachments, including fill, new construction, substantial improvements, and other development within the adopted regulatory floodway are prohibited unless:
      1. Certification by a registered professional civil engineer is provided demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment shall not result in any increase in flood levels within the community during the occurrence of the base flood discharge; or
      2. A community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that a Conditional Letter of Map Revision (CLOMR) is applied for and approved by the Federal Insurance Administrator, and the requirements for such revision as established under Volume 44 of the Code of Federal Regulations, section 65.12 are fulfilled.
   2. If the requirements of section 2.7.200(D)(1) are satisfied, all new construction, substantial improvements, and other development shall comply with all other applicable flood hazard reduction provisions of section 2.7.180.
5. Standards for Shallow Flooding Areas Shallow flooding areas appear on FIRMs as AO zones with depth designations or as AH zones with Base Flood Elevations. For AO zones the base flood depths range from one (1) to three (3) feet above ground where a clearly defined channel does not exist, or where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is usually characterized as sheet flow. For both AO and AH zones, adequate drainage paths are required around structures on slopes to guide floodwaters around and away from proposed structures.
   1. Standards for AH Zones Development within AH Zones must comply with the standards in sections 2.7.190, 2.7.200, and 2.7.200(E).
   2. Standards for AO Zones In AO zones, the following provisions apply in addition to the requirements in sections 2.7.190 and 2.7.200(E):
      1. New construction, conversion to, and substantial improvement of residential structures and manufactured dwellings within AO zones shall have the lowest floor, including basement, elevated above the highest grade adjacent to the building, a minimum of two feet above the depth number specified on the Flood Insurance Rate Maps (FIRM). For manufactured dwellings the lowest floor is considered to be the bottom of the longitudinal chassis frame beam.
      2. New construction, conversion to, and substantial improvements of non- residential structures within AO zones shall either:
         1. Have the lowest floor (including basement) elevated above the highest adjacent grade of the building site, a minimum of two feet above the depth number specified on the Flood Insurance Rate Maps (FIRMS); or
         2. Together with attendant utility and sanitary facilities, be completely floodproofed to or above the depth number specified on the FIRM or a minimum of two (2) feet above the highest adjacent grade if no depth number is specified, so that any space below that level is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or architect as stated in section 2.7.200(C)(3)(a)(3).
      3. Recreational vehicles placed on sites within AO Zones on the city’s Flood Insurance Rate Maps (FIRM) shall either:
         1. Be on the site for fewer than 180 consecutive days, and
         2. Be fully licensed and ready for highway use, on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or
         3. Meet the elevation requirements of section 2.7.200(E)(2)(a), and the anchoring and other requirements for manufactured dwellings of section 2.7.200(C)(4).
      4. In AO zones, new and substantially improved appurtenant structures must comply with the standards in section 2.7.200(C)(6).
      5. In AO zones, enclosed areas beneath elevated structures shall comply with the requirements in section 2.7.200(A).