i. Over-the-top ties be provided at each end of the manufactured home, with two (2) additional ties per side at intermediate locations and manufactured homes less than fifty (50) feet long requiring one (1) additional tie per side.

ii. Frame ties be provided at each corner of the home with five (5) additional ties per side at intermediate points and manufactured homes less than fifty (50) feet long requiring four (4) additional ties per side.

iii. All components of the anchoring system be capable of carrying a force of four thousand eight hundred (4,800) pounds; and

iv. Additions to the manufactured home shall be similarly anchored.

i. The lowest floor of the manufactured home is elevated at least one (1) foot above the base flood elevation; or

ii. The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than thirty-six (36) inches in height above grade and be securely anchored to an adequately designed foundation system to resist flotation, collapse, and lateral movement.

i. Pads or lots are elevated on compacted fill to or above the base flood level (insurance can be waived).

ii. Stands or lots are elevated on compacted fill or on pilings so that the lowest floor of the mobile home will be at or above the base level (insurance required).

iii. Adequate surface drainage and access for hauler are provided; and

iv. In the instance of elevation on piers or pilings where:

i. The floor area of all floors of the accessory structure totals one thousand (1,000) square feet or less.

ii. The accessory structure shall not be used for human habitation.

iii. The accessory structure shall be designed to have low flood damage potential.

iv. The accessory structure shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters.

v. The accessory structure shall be firmly anchored to prevent flotation that may result in damage to other structures.

vi. All service facilities, such as electrical and heating equipment associated with the accessory structure, shall be elevated or flood-proofed.

i. Repairs, reconstruction, or improvements to a structure which do not increase the ground floor area.

ii. Repairs, reconstruction or improvements to a structure, the cost of which does not exceed fifty (50) percent of the fair market value of the structure either before the repair, or reconstruction is started, or if the structure has been damaged, and is being restored, before the damage occurred.

iii. Any project for improvement of a structure to comply with existing state or local health, sanitary, or safety code specifications, which are solely necessary to assure safe living conditions.

iv. Any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places that does not increase the building’s dimensions.

v. Repairs, replacement, reconstruction or improvement to existing farmhouses located in designated floodways and on designated agricultural lands that do not increase the building’s total square footage of encroachment and are consistent with all requirements of WAC 173-158-075.

vi. Repairs, replacement, reconstruction or improvements to substantially damaged residential dwellings other than farmhouses that do not increase the building’s total square footage of encroachment and are consistent with all requirements of WAC 173-158-075.

vii. Prior to the repair or replacement of a substantially damaged residential structure located within a floodway, a recommendation shall be obtained from the Washington Department of Ecology in accordance with WAC 173-158-076.

viii. The applicant shall provide a certification by a registered professional engineer demonstrating through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed development would not result in any increase in flood levels during the occurrence of the base flood discharge.

i. Have the lowest floor, including basement, elevated one (1) foot above the highest adjacent grade of the building site or above the depth number specified on the FIRM, at least two (2) feet if no depth number is specified; or

ii. Together with attendant utility and sanitary facilities, be completely flood proofed to or above that level 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 effects of buoyancy. If this method is used, compliance shall be certified by a registered professional engineer or architect.

i. If a lot has a buildable site out of the Regulatory Floodplain, all new structures shall be located in that area.

ii. If a lot does not have a buildable site out of the Regulatory Floodplain, all new structures, pavement and other development must be sited in the location that has the least impact on habitat by locating the structures as far from the water body as possible or placing the structures on the highest land and lot.

iii. A minimum setback of fifteen (15) feet from the protected area shall be required for all structures.

i. Storm water and drainage features shall incorporate low impact development techniques that mimic predevelopment hydrologic conditions. Such methods include storm water infiltration, rain gardens, grass swales, filter strips, disconnected impervious areas, permeable pavement and vegetative roof systems.

ii. If the proposed project will create new impervious surfaces so that more than ten (10) percent of the portion of the parcel in the Regulatory Floodplain is covered by impervious surface, the applicant shall demonstrate that there will be no net increase in the rate and volume of storm water surface runoff that leaves the site or that the adverse impact is mitigated.