Chapter 5.28   FLOOD CONTROL

Sections:


5.28.010   Findings of fact.

(a)

The flood hazard areas of the city are subject to periodic inundation which results in loss of life, 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 are caused by the cumulative effect of obstructions in floodplains causing increases in flood heights and velocities, upstream construction that alters the rate of natural runoffs and the occupancy in flood hazard areas by uses vulnerable to floods or hazardous to other properties which are inadequately elevated, floodproofed or otherwise protected from flood damages.

(Ord. O-04-97 § 4(1), 1997)

5.28.020   Purpose of chapter.

It is the purpose of this chapter to promote the public health, safety and general welfare and to minimize public and private health, safety and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:

(1)

Restrict or prohibit uses which are dangerous to the health, safety and property due to water or erosion in flood heights or velocities;

(2)

Require that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;

(3)

Control the alteration of natural floodplains, stream channels and natural protective barriers, which are involved in the accommodation of floodwaters;

(4)

Control filling, grading, dredging and other development which may increase erosion or flood damage; and

(5)

Prevent or regulate the construction of flood barriers which will unnaturally divert floodwaters or which may increase flood hazards to other lands.

(Ord. O-04-97 § 4(2), 1997)

5.28.030   Objectives of chapter.

The objectives of this chapter are:

(1)

To protect human life and health;

(2)

To minimize expenditure of public money for costly flood control projects;

(3)

To minimize the need for rescue and relief efforts associated with flooding and generally undertaken at the expense of the general public;

(4)

To minimize prolonged business interruptions;

(5)

To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines and streets and bridges located in floodplains;

(6)

To help maintain a stable tax base by providing the sound use and development of floodprone areas in such a manner as to minimize future flood height areas; and

(7)

To ensure that potential home buyers are notified that property is in a flood area.

(Ord. O-04-97 § 4(3), 1997)

5.28.040   Definitions.

For the purpose of this chapter, the following words and phrases shall have the meanings respectively ascribed to them by this section; provided, that unless specifically defined below, words or phrases used in this chapter shall be interpreted so as to give them the meaning they have in common usage and to give this chapter its most reasonable application:

"Area of special flood hazard" means land in the floodplain within a community subject to a one percent or greater chance of flooding in any given year.

"Base flood" means the flood having a one percent chance of being equaled or exceeded in any given year.

"Development" means any man-made change to improved or unimproved real estate, including but not limited to, buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations.

"Flood" or "flooding" means a general and temporary condition of partial or complete inundation of normally dry land areas from:

(1)

The overflow of inland or tidal waters; and

(2)

The unusual and rapid accumulation of runoff of surface waters from any source.

"Flood hazard boundary map (FHBM)" means the official map issued by the Federal Insurance Administration where the boundaries of the areas of special flood hazard have been designated as Zone A.

"Floodway" means 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 one foot.

"Lowest floor" means 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 areas, 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 nonelevation design requirements of this chapter.

"Manufactured home" means a structure, transportable in one or more sections, which is built on a permanent chassis and designed to be used with or without a permanent foundation when connected to the required utilities. The term also includes park trailers, travel trailers and other similar vehicles.

"Structure" means a walled and roofed building that is principally above ground, as well as a manufactured home.

"Substantial damage" means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would be equal to or exceeded fifty percent of the market value of the structure before the damage occurred.

"Substantial improvements" means any repair, reconstruction or improvement of a structure the cost of which equals or exceeds fifty percent of the market value of the structure either (1) before the improvement or repair is started; or (2) if the structure has been previously damaged and is being restored, before the flood damage occurred.

For the purpose of this definition, "substantial improvement" is considered to occur when the first alteration on any wall, ceiling, floor or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure. The term does not, however, include either (1) 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, or (2) any alteration of structure listed on the National Register of Historic Places or a state inventory of historic places.

(Ord. O-14-97 § 1, 1997; Ord. O-04-97 § 4(4), 1997)

5.28.050   Applicability of chapter.

(a)

The community shall select and adopt a regulatory floodway based on the principle that the area chosen for the regulatory floodway must be designed to carry the waters of the base flood, without increasing the water surface elevation of that flood more than one foot at any point,

(b)

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

(Ord. O-04-97 § 4(5), 1997)

5.28.060   Basis for establishing the areas of special flood hazard.

The areas of special flood hazard identified by the Federal Insurance Administration in its most recent floodway boundary map and most recent Flood Insurance Rate Map 450089.

(Ord. O-04-97 § 4(6), 1997)

5.28.070   Compliance with chapter and other regulations.

No building permit shall be issued for the development of any structure being located or extended, converted or structurally altered without full compliance with the terms of this chapter and other applicable regulations.

(Ord. O-04-97 § 4(7), 1997)

5.28.080   Abrogation and greater restrictions.

This chapter is not intended to repeal, abrogate or impair any existing easements, covenants or deed restrictions. However, where this chapter and another conflict or overlap, whichever imposes the more stringent restrictions shall prevail.

(Ord. O-04-97 § 4(8), 1997)

5.28.090   Interpretation of chapter.

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

(1)

Considered as minimum requirements;

(2)

Liberally construed in favor of the governing body;

(3)

Deemed neither to limit nor repeal any other powers granted under state statutes.

(Ord. O-04-97 § 4(9), 1997)

5.28.100   Warning and disclaimer of liability.

The degree of flood protection required by this chapter 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 chapter does not imply that land outside the areas of special flood hazard or uses permitted within such areas will be free from flooding or flood damages. This chapter shall not create liability on the part of the county or any officer or employee thereof for any flood damages that result from reliance on this chapter or any administrative decision lawfully made thereunder.

(Ord. O-04-97 § 4(10), 1997)

5.28.110   Building permit.

(a)

A building permit shall be required in conformance with the provisions of this chapter.

(b)

Applications for building permits in areas designed on the flood hazard boundary map as specific flood hazards shall include the following information:

(1)

Elevation in relation to mean sea level (MSL) of the lowest floor, including basement, of all proposed structures.

(2)

Elevation in relation to mean sea level to which any nonresidential structure will be floodproofed.

(3)

Certification by a registered professional engineer or architect that the nonresidential floodproofed structure meets the floodproofing criteria.

(4)

Description of the extent to which any watercourse will be altered or relocated as a result of proposed development.

(Ord. O-04-97 § 4(11), 1997)

5.28.120   Use of other base flood data.

In special flood hazard areas where the city has not been able to determine base flood elevations, no encroachments, including fill material or structures, shall be located within a distance of the streambank equal to two times the width of the stream at the top of the bank, unless certification by a registered professional engineer is provided demonstrating that the encroachment shall not result in any increase in flood levels during the occurrence of the flood base discharge.

Whenever the city is unable to determine a base flood elevation from other sources in order to administer all new construction and substantial improvements of existing structures, including manufactured homes, shall be elevated so that the lowest floor of the lowest enclosed area is no less than five feet above the highest adjacent natural grade at the building site.

(Ord. O-04-97 § 4(12), 1997)

5.28.130   Alteration of watercourses.

(a)

The city shall notify adjacent communities and the state water resources commission prior to any alteration or such relocation of a watercourse and shall submit evidence of such notification of the federal insurance administration.

(b)

The city shall require that maintenance is provided within the altered or relocated portion of such watercourse so that the flood-carrying capacity is not diminished.

(Ord. O-04-97 § 4(13), 1997)

5.28.140   Interpretation of boundaries of areas of special flood hazard.

Where interpretation is needed as to the exact location of the boundaries of the area of special flood hazard (for example, where there appears to be a conflict between a mapped boundary and actual physical conditions), the city shall make the necessary interpretation.

(Ord. O-04-97 § 4(14), 1997)

5.28.150   General standards for all areas of special flood hazard.

Encroachments, including fill, new construction, substantial improvements, and other development within the adopted regulatory floodway shall be prohibited unless it is demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment will not result in any increase in flood levels within the community during the occurrence of the base flood discharge. In all areas of special flood hazard, the following provisions are required:

(1)

Anchoring.

(A)

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

(B)

All manufactured or modular homes to be placed or substantially improved within A1-30 or AH shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is two feet above the base flood elevation and be securely anchored to an adequately anchored foundation system. Specific requirements shall be that:

(i)

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

(ii)

Frame ties be provided at each corner of the manufactured home with five additional ties per side at intermediate points and manufactured homes less than fifty feet long requiring four additional ties per side;

(iii)

Components of the anchoring system be capable of carrying a force of four thousand eight hundred pounds; and

(iv)

Any additions to the manufactured home be similarly anchored.

(2)

Construction Materials and Methods.

(A)

All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage. Electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities must be designed or located so as to prevent water from entering or accumulating within the components during conditions of flooding.

(B)

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

(3)

Utilities.

(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 discharges 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.

(4)

Subdivision Proposals.

(A)

All subdivision proposals shall be consistent with the need to minimize flood damage.

(B)

All subdivision proposals shall have public utilities and facilities such as sewer, gas, electric and water systems located and constructed to minimize flood damage.

(C)

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

(D)

Base flood elevation data shall be provided for subdivision proposals and other proposed development which are greater than the lesser of fifty lots or five acres.

(E)

All subdivision proposals shall be designed so as not to increase the level of flooding existing at the time of development.

(5)

Encroachments. The cumulative effect of any proposed development shall not adversely affect the area of special flood hazard.

(Ord. O-09-97 § 1, 1997; Ord. O-04-97 § 4(15), 1997)

5.28.160   Specific standards for areas of special flood hazard where base flood elevation data provided.

In all areas of special flood hazard where base flood elevation data has been provided as required, the following provisions are required:

(1)

Residential Construction. New construction or substantial improvement of any residential structure or any residential structure, including manufactured homes, shall have the lowest floor, including basement, elevated two feet above base flood elevation. The placement of manufactured or modular homes within the adopted regulatory floodway is prohibited including existing manufactured home parks or manufactured home subdivisions presently existing within the regulatory floodway.

(2)

Nonresidential Construction. New construction or substantial improvement of any commercial, industrial or other nonresidential structure, including manufactured homes, shall either have the lowest floor, including basement, elevated two feet above the base flood elevation or, together with attendant utility and sanitary facilities, be floodproofed so that below the base flood level 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 and effects of buoyancy. A registered professional engineer or architect shall certify that the standards of this subsection are satisfied.

(3)

Use of Openings in Enclosures Below a Structure's Lowest Floor. For all new construction, substantial improvements including manufactured homes and modular homes, fully enclosed areas below the lowest floor that are subject to flooding shall be designed to automatically equalize hydrostatic floor 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 must meet or exceed the following minimum criteria: 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. The bottom of all openings shall be no higher than one 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.

(Ord. O-04-97 § 4(16), 1997)

5.28.170   Violation—Penalty.

Violation of the provisions of this chapter or failure to comply with any of its requirements, including violation of conditions and safeguards established in connection with grants of variances or special exceptions, shall constitute a misdemeanor. Any person who violates this chapter or fails to comply with any of its requirements shall, upon conviction thereof, be fined not more than two hundred dollars or imprisoned for not more than thirty days and in addition shall pay all costs and expenses involved in the case. Each day such violation continues shall be considered a separate offense. Nothing herein contained shall prevent the city from taking other lawful action as is necessary to prevent or remedy any violation.

(Ord. O-04-97 § 4(17), 1997)