2020/06/10 Council Agenda Packet

n ii. 6 D. Provide that all new construction and substantial improvements within zones V1-30,VE,and V on the community's FIRM have the space below the lowest floor either free of obstruction or constructed with non- supporting breakaway walls,open wood lattice-work,or insect screening intended to collapse under wind and water loads without causing collapse,displacement,or other structural damage to the elevated portion of the building or supporting foundation system. For the purposes of this section,a breakaway wall shall have a design safe loading resistance of not less than 10 and no more than 20 pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of 20 pounds per square foot(either by design or when so required by local or state codes)may be permitted only if a registered professional engineer or architect certifies that the design proposed meets the following conditions: 1. Breakaway wall collapse shall result from water load less than that which would occur during the base flood;and 2. The elevated portion of the building and supporting foundation system shall not be subject to collapse, displacement,or other structural damage due to the effects of wind and water loads acting simultaneously on all building components(structural and non-structural). Maximum wind and water loading values to be used in this determination shall each have a one percent chance of being equaled or exceeded in any given year(100-year mean recurrence interval).If breakaway walls are utilized,such enclosed space shall be useable solely for parking of vehicles,building access, or storage.Such space shall not be used for human habitation. E. Prohibit the use of fill for structural support of buildings within zones V1-30,VE,and Von the community's FIRM. F. Prohibit man-made alteration of sand dunes within zones V1-30,VE,and Von the community's FIRM which would increase potential flood damage. G. All manufactured homes to be placed or substantially improved within zones V1-30,V,and VE on the community's FIRM on sites: 1. Outside of a manufactured home park or subdivision, 2. In a new manufactured home park or subdivision, 3. In an expansion to an existing manufactured home park or subdivision,or 4. In an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage"as the result of a flood;shall meet the standards of paragraphs(1)through(6)of this section and manufactured homes placed or substantially improved on other sites in an existing manufactured home park or subdivision within zones V1-30,V,and VE on the FIRM shall meet the requirements of Section 19.30.090.B.3. H. Recreational vehicles placed on sites within V or VE zones on the community's FIRM shall: 1. Be fully licensed and ready for highway use,on its wheels or jacking system,attached to the site only by quick disconnect type utilities and security devices,and have no permanently attached additions;and 2. Comply with EMC Title 17. 19.30.310 Density Fringe Area A. EMC 19.30.310 through 19.30.380 provide specific criteria to be used in regulating development in areas of high flood damage potential where conventional floodway areas cannot be established.In order to foster the continued agricultural use of prime farmlands in these flood plain areas,and maintain an acceptable level of flood hazard protection,the development criteria outlined by this chapter shall apply to all development in the density fringe area.The development criteria contained in EMC 19.30.320 and 19.30.330 shall be utilized to prevent a cumulative increase in the base flood elevation of more than one foot. B. The density fringe area shall consist of the areas designated on the Flood Insurance Study(FIS)for Snohomish County and Incorporated Areas,and the Flood Insurance Rate Maps(FIRMS)dated June 19,2020,and as amended in paper or digital format. 19.30.320 Density fringe area: maximum allowable density. 19 125