Sec. 8.16 General standards for flood hazard reduction

Sec. 8.16. General standards for flood hazard reduction.

a. All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure and to withstand hydrodynamic loads.

b. All manufactured homes must be elevated and anchored to resist flotation, collapse or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces. Specific requirements may be:

(1) Over-the-top ties shall be provided at each of the four (4) corners of the manufactured home, with two (2) additional ties per side at intermediate locations, with manufactured homes less than fifty (50) feet long requiring one (1) additional tie per side;

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

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

(4) Any additions to the manufactured home shall be similarly anchored.

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

a. All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.

b. All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.

c. For all new construction and substantial improvements, fully enclosed areas below the lowest floor automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or exceed the following minimum criteria: A minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall be no higher than one (1) foot above grade. Openings may be equipped with screens, louvers or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.

a. All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system.

b. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharge from the systems into floodwaters.

c. On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.

d. Electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities shall be designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

a. All proposals for the development of subdivisions including the placement of manufactured home parks and subdivisions shall meet Development Permit requirements of Section 8.12 and be consistent with the need to minimize flood damage.

b. Base flood elevation data shall be generated for subdivision proposals and other proposed development including the placement of manufactured home parks and subdivisions which is greater than 50 lots or 5 acres, whichever is lesser, if not otherwise provided pursuant to this Article.

c. All subdivision proposals shall have public utilities and facilities such as electrical and water systems located and constructed to minimize flood damage.

d. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage.

a. Located within the areas of special flood hazard established in this Article, are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of 1 to 3 feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions shall apply:

(1) All new construction and substantial improvements of residential structures shall have the lowest floor (including basement) elevated above the highest adjacent grade to an elevation at least as high as one (1) foot above the depth number specified in feet on the Town’s FIRM (at least three (3) feet if no depth number is specified).

(2) All new construction and substantial improvements of nonresidential structures:

(a) Shall have the lowest floor (including basement) elevated above the highest adjacent grade to an elevation at least as high as one (1) foot above the depth number specified in feet on the Town’s FIRM (at least three (3) feet if no depth number is specified); or

(b) Together with attendant utility and sanitary facilities be designed so that in between the BFE and the lowest floor (including basement) the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads including the effects of buoyancy.

(3) A registered professional engineer or architect shall submit a certification to the Town Engineer, that the standards of this subsection 5. are satisfied.

(4) Adequate drainage paths shall be provided around structures on slopes, to guide flood waters around and away from all proposed structures.

a. Floodways – located within areas of special flood hazard established in this Article, 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 shall apply:

(1) Encroachments are prohibited, including fill, new construction, substantial improvements and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.

(2) If subsection 6.a.(1) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this Section 8.16 and Section 8.17, as applicable.

(3) Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Regulations, the Town may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the Town Engineer for purposes of this Article, first applies for a conditional FIRM and floodway revision through FEMA. (Ord. 1148 §8, 2013)