In all areas of special flood hazards, the following standards are required:
A. 
Anchoring.
1. 
All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure.
2. 
All manufactured homes must likewise be anchored to prevent flotation, collapse or lateral movement, and shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors (Reference Federal Emergency Management Agency’s (FEMA) Manufactured Home Installation in Flood Hazard Areas guidebook for additional techniques.)
B. 
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.
3. 
Electrical, heating, ventilation, plumbing, and air-conditioning equipment and other service facilities shall be designed and/or otherwise elevated or located so as to prevent water from entering or accumulating within the components during conditions of flooding. Locating such equipment below the base flood elevation may cause annual flood insurance premiums to be increased.
C. 
Utilities.
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 the eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters; and,
3. 
On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
4. 
Water wells shall be located on high ground that is not in the floodway.
D. 
Subdivision Proposals.
1. 
All subdivision proposals shall be consistent with the need to minimize flood damage;
2. 
All subdivision proposals shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize flood damage;
3. 
All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and,
4. 
Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed developments which contain at least fifty lots or five acres, whichever is less.
E. 
Review of building permits. Where elevation data is not available through the Flood Insurance Study or from another authoritative source (PMC 16.18.430(B)), applications for building permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test of reasonableness is a local judgment and includes use of historical data, high water marks, photographs of past flooding, etc., where available. Failure to elevate at least two feet above the highest adjacent grade in these zones may result in high insurance rates.
(683 § 5.1, 1991; Ord. 823 § 1, 2005)
In all areas of special flood hazards where base flood elevation data has been provided as set forth in PMC 16.18.320, Basis for establishing the areas of special flood hazard, or PMC 16.18.430(B), Use of other base flood data, the following provisions are required. Additional standards were clarified in FEMA Technical Bulletin 11-01 to allow crawlspace construction for buildings located in the special flood hazard areas; however, using this provision can result in a twenty percent increase in flood insurance premiums:
A. 
Residential Construction.
1. 
New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to one foot or higher above base flood elevation.
2. 
Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either by certified by a registered professional engineer or architect or must meet or exceed the following minimum criteria:
a. 
A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.
b. 
The bottom of all openings shall be no higher that one foot above grade.
c. 
Openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
B. 
Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to one foot or higher above the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall:
1. 
Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water;
2. 
Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;
3. 
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 subsection based on their development and/or review of the structural design, specifications, and plans. Such certification shall be provided to the building inspector to meet requirements set forth in PMC 16.18.430(C)(2);
4. 
Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in PMC 16.18.520(A)(2);
5. 
Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (e.g. a building constructed to the base flood level will be rated as one foot below that level).
C. 
Manufactured Home. All manufactured homes to be placed or substantially improved within Zones A1-30 shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is one foot or higher above the base flood elevation and be securely anchored to an adequately anchored foundation system in accordance with the provisions of subsection 16.18.510(A)(2).
(683 § 5.2, 1991; Ord. 823 § 1, 2005)
Recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community’s FIRM either:
A. 
Be on the site for fewer than one hundred eighty consecutive days;
B. 
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
C. 
Meet the requirements of PMC 16.18.520 and the elevation and anchoring requirements for manufactured homes.
(683 § 5.2, 1991; Ord. 789 § 2, 2002)
Located within areas of special flood hazard established in PMC 16.18.320 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and erosion potential, the following provisions apply:
A. 
Encroachments are prohibited, including fill, new construction, substantial improvements, and other development unless certification by a registered professional engineer is provided demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachments shall not result in any increase in flood levels during the occurrence of the base flood discharge.
B. 
Construction or reconstruction of residential structures is prohibited within designated floodways[1], except for (i) repairs, reconstruction, or improvements to a structure which do not increase the round floor area; and (ii) repairs, reconstruction or improvements to a structure, the cost of which does not exceed fifty percent of the market value of the structure either, (A) before the repair or reconstruction is started, or (B) if the structure has been damaged, and is being restored, before the damage occurred. Any project for improvement of the 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 to structures identified as historic places, may be excluded in the fifty percent.
[1]
FEMA endorses the more restrictive Washington State Floodway standard adopted in WAC 173-158-070.
C. 
If subsection (A) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of PMC 16.18.510, Provisions for flood hazard reduction.
(Ord. 683 § 5.3, 1991)
Construction of new critical facilities shall be, to the extent possible, located outside the limits of the Special Flood Hazard Area (SFHA) (100-year floodplain). Construction of new critical facilities shall be permissible within the SFHA if no feasible alternative site is available. Critical facilities constructed within the SFHA shall have the lowest floor elevated three feet or more above the level of the base flood elevation (100-year) at the site. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into flood waters. Access routes elevated to or above the level of the base flood elevation shall be provided to all critical facilities to the extent possible.
Annotation: The following resolution is related to the above flood control title and is included for reference purposes.
Resolution No. 92-2
A resolution to ensure enforcement of National Flood Insurance Regulations.
NOW, THEREFORE, BE IT RESOLVED, that the city council of the city of Pomeroy hereby:
1.
Assures the Federal Insurance Administration that it will enact as necessary, and maintain in force in those areas having flood, mudslide (i.e., mudflow), or flood-related erosion hazards, adequate land use and control measures with effective enforcement provisions consistent with the Criteria set forth in Section 1910 of the National Flood Insurance Program Regulations; and
2.
Vests the director of public works with the responsibility, authority, and means to:
(a)
Assist the Administrator, at his request, in his delineation of the limits of the area having special flood, mudslide (i.e., mudflow), or food-related erosion hazards.
(b)
Provide such information as the Administrator may request concerning present uses and occupancy of the flood plain, mudslide (i.e., mudflow) or flood-related erosion areas.
(c)
Cooperate with Federal, State, and local agencies and private firms which undertake to study survey, map, and identify flood plain, mudslide (i.e., mudflow), or flood-related erosion areas, and cooperate with neighboring communities with respect to management of adjoining flood plain, mudslide (i.e., mudflow) and/or flood-related erosion areas in order to prevent aggravation of existing hazards.
(d)
Submit on the anniversary date of the community’s initial eligibility an annual report to the Administrator on the progress made during the past year within the community in the development and implementation of flood plain management measures.
(e)
Upon occurrence, notify the Administrator in writing whenever the boundaries of the community have been modified by annexation or the community has otherwise assumed or no longer has authority to adopt and enforce floodplain management regulations for a particular area. In order that all Flood Hazard Boundary Maps and Flood Insurance Rate Maps accurately represent the community’s boundaries, include within such notification a copy of a map of the community suitable for reproduction, clearly delineating the new corporate limits or new area for which the community has assumed or relinquished flood plain management regulatory authority.
3.
Appoints the director of public works to maintain for public inspection and to furnish upon request, for the determination of applicable flood insurance risk premium rates within all areas having special flood hazards identified on a Flood Hazard Boundary Map or Flood Insurance Rate Map, any certificates of flood-proofing, and information on the elevation (in relation to mean sea level) of the level of the lowest habitable floor (including basement if habitable) of all new or substantially improved structures, and include whether or not such structures contain a basement, and if the structure has been floodproofed the elevation (in relation to mean sea level) to which the structure was floodproofed;
4.
Agrees to take such other official action as may be reasonably necessary to carry out the objectives of the program.
(683 § 5.2, 1991; Ord. 789 § 3, 2002)