Chapter 15.15
FLOODPLAIN REGULATIONS

Sections:

15.15.010    Statement of purpose.

15.15.020    Definitions.

15.15.030    Applicability.

15.15.040    Administration.

15.15.050    Provisions for flood hazard protection.

15.15.060    Penalties for violation.

15.15.070    Floodways.

15.15.080    Variances.

15.15.090    Liability – Disclaimer.

15.15.100    Compliance with laws.

15.15.110    Severability.

15.15.010 Statement of purpose.

In accordance with the police powers granted to the city by the Washington Constitution and state legislature, it is the purpose of this chapter to promote the public health, safety, and general welfare, and to minimize public and private losses due to flood conditions in specific areas, by methods and provisions designed to:

A. Restrict or prohibit uses which are dangerous to health, safety, and property due to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;

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

C. Control the alteration of natural floodplains, stream channels, and natural protective barriers, which help accommodate or channel flood waters;

D. Control filling, grading, dredging, and other development which may increase flood damage; and

E. Prevent or regulate construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards in other areas. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017; Ord. 649, 1989.]

15.15.020 Definitions.

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.

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

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

C. “Base flood elevation” means the water surface elevation of the base flood.

D. “Development” means any manmade 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 located within the area of special flood hazard.

E. “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/or

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

F. “Flood insurance rate map (FIRM)” means the official map on which the Federal Insurance Administration has delineated both the areas of special flood hazard and the risk premium zones applicable to the community.

G. “Flood insurance study” or “flood elevation study” means an examination, evaluation and determination of flood hazards and, if appropriate, corresponding water surface elevations, or an examination, evaluation and determination of mudslide and/or flood-related erosion hazards.

H. “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 a designated height.

I. “Lowest floor elevation” means the lowest floor of the lowest enclosed area (including basement).

J. “Manufactured home” means a structure that is transportable in one or more sections built on a permanent chassis, and designed to be used with or without a permanent foundation when connected to the required utilities. It does not include recreational vehicles or travel trailers.

K. “Manufactured home park or subdivision” means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.

1. “Existing manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of service facilities was completed prior to May 14, 1985.

2. “New manufactured home park or subdivision” means a manufactured home park or subdivision for which the construction of service facilities was completed on or after May 14, 1985.

3. “Expansion to a manufactured home park or subdivision” means the preparation of additional sites by the construction of service facilities.

4. “Service facilities” means facilities for servicing the lots on which manufactured homes are to be affixed, including, at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads.

L. “New construction” means structures for which the start of construction commenced on or after the effective date of the ordinance codified in this chapter.

M. “Recreational vehicle” shall have the meaning ascribed in RMC 15.20.010.

N. “Start of construction” means the first placement of permanent construction of a structure (other than a manufactured home) on a site, such as the pouring of slabs or footings or any work beyond the stage of excavation. Permanent construction does not include land preparation, such as clearing, grading, and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers, or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not as part of the main structure.

O. “Structure” means a walled and roofed building or manufactured home that is principally aboveground.

P. “Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its previous condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

Q. “Substantial improvement” means any repair, reconstruction, or improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure either:

1. Before the improvement or repair is started; or

2. If the structure has been damaged and is being restored, before the damage occurred.

For the purposes of this definition, “substantial improvement” is considered to occur when the first alteration of any wall, ceiling, floor or other structural part of the building commences, whether or not that alteration affects the external dimensions of the structure.

R. “Violation” means the failure of a structure or other development to be fully compliant with this chapter. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017; Ord. 649, 1989.]

15.15.030 Applicability.

A. Lands to Which This Chapter Applies. This chapter shall apply to all areas of special flood hazard within the jurisdiction of the city of Roslyn.

B. Basis for Establishing the Areas of Special Flood Hazard. The areas of special flood hazard identified by the Federal Insurance Administration in the flood insurance rate map for the city of Roslyn, dated June 5, 1985, are hereby adopted by reference and declared to be a part of this chapter. The flood insurance rate map is on file at the office of the clerk of the city of Roslyn. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017; Ord. 649, 1989.]

15.15.040 Administration.

A. Establishment of Development Permit. A development permit shall be obtained before a construction or development begins within any area of special flood hazard established in RMC 15.15.030(B). The permit shall be for all structures, including manufactured homes, as defined in RMC 15.15.020(O), and for all other development, including fill and other activities, as defined in RMC 15.15.020(D).

B. Designation of the Local Official. The planning official of the city of Roslyn is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions, and shall hereafter be referred to as the local official.

C. Duties and Responsibilities. Duties of the local official shall include, but not be limited to:

1. Permit Review.

a. Review all development permits to determine that the permit requirements of this chapter have been satisfied.

b. Review all development permits to determine that all necessary permits have been obtained from those federal, state, or local governmental agencies from which prior approval is required.

2. Use of Base Flood Data. The local official shall obtain, review, and reasonably utilize any base flood elevation data available from a federal, state, or other source, in order to administer RMC 15.15.050(B)(1), Residential Construction, 15.15.050(B)(2), Nonresidential Construction, and 15.15.070, Floodways. Where the base flood elevation cannot be determined, applications for development permits shall be reviewed to assure that proposed construction will be reasonably safe from flooding. The test for reasonableness is a judgment of the local official and includes use of historical data, high water marks, photographs of past floods, etc. At a minimum, however, the first floor shall be elevated or floodproofed (where applicable) two feet above the highest adjacent grade.

3. Information to Be Obtained and Maintained.

a. Obtain and record the actual lowest floor elevation (in relation to mean sea level) of all new or substantially improved structures, and whether or not the structure contains a basement;

b. For all new or substantially improved floodproofed structures:

i. Verify and record the actual elevation (in relation to mean sea level); and

ii. Maintain the floodproofing certifications required in RMC 15.15.050(B)(2)(a)(iii); or

iii. Where a base flood elevation has not been determined according to RMC 15.15.050(B)(2), obtain and record the elevation of the first floor (including basement) as related to the highest adjacent grade;

c. Maintain for public inspection all records pertaining to the provisions of this chapter.

4. Alteration of Watercourses.

a. Notify adjacent communities, the Washington State Department of Ecology and the mayor and city council of the city of Roslyn prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration.

b. Require that maintenance is provided within the altered or relocated portion of said watercourse so the flood-carrying capacity is not diminished.

5. Interpretation of FIRM Boundaries. Make interpretations, where needed, as to the exact location of the boundaries of the areas of special flood hazard (for example, where there appears to be a conflict between a mapped boundary and actual field conditions). The person contesting the location of the boundary shall be given a reasonable opportunity to appeal the interpretation. Such appeals shall be granted consistent with the standards of Section 60.6 of the rules and regulations of the National Flood Insurance Program (44 CFR 59, etc.). [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017; Ord. 649, 1989.]

15.15.050 Provisions for flood hazard protection.

A. General Standards. In all areas of special flood hazard, the following standards 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 homes shall be anchored to resist flotation, collapse, or lateral movement by providing over-the-top ties and frame ties to ground anchors. 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, with manufactured homes less than 50 feet long requiring one additional tie per side;

ii. Frame ties be provided at each corner of the home with five additional ties per side at intermediate points, with manufactured homes less than 50 feet long requiring four additional ties per side;

iii. All components of the anchoring system be capable of carrying a force of 4,800 pounds; and

iv. Any additions to the manufactured home be similarly anchored.

c. An alternative method of anchoring may involve a system designed to withstand a wind force of 90 miles per hour or greater. Certification must be provided to the local official that this standard has been met.

2. Construction Materials and Methods.

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. 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.

3. Utilities.

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

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

c. Any on-site waste disposal system permitted under Chapter 13.10 RMC shall be designed to avoid impairment or contamination; and

d. Base flood elevation data shall be provided for subdivision proposals and other proposed development which contain at least 50 lots or five acres (whichever is less).

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, electrical, and water systems located and constructed to minimize flood damage;

c. All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and

d. Base flood elevation data shall be provided, or generated if not available from an authoritative source, for subdivision proposals and other proposed development which contain at least 50 lots or five acres (whichever is less).

5. Review of Building Permits. Where elevation data is not available, 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 applicable. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates.

B. Specific Standards. In all areas of special flood hazard where base flood elevation data has been determined (RMC 15.15.040(C)(2), Use of Base Flood Data), the following provisions are required:

1. Residential Construction. New construction and substantial improvement of any residential structure shall have a lowest floor elevation of one foot or more above the level of the base flood elevation.

2. Nonresidential Construction.

a. New construction and substantial improvement of any commercial, industrial, or other nonresidential structure shall either have a lowest floor elevation of one foot or more above the base flood elevation; or, together with attendant utility and sanitary facilities, shall:

i. Be floodproofed so that below the base floor level the structure is watertight with walls substantially impermeable to the passage of water;

ii. Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and

iii. Be certified by a registered professional engineer or architect that the standards of this subsection are satisfied. Such certification shall be provided to the official as set forth in RMC 15.15.040(C)(2).

b. Nonresidential structures that are elevated, not floodproofed, must meet the same lowest floor elevation standards as described in subsection (B)(1) of this section.

c. Applicants floodproofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (i.e., a building floodproofed to one foot above the base flood level will be rated as at the base flood level).

3. Manufactured Homes.

a. Manufactured homes shall be anchored in accordance with subsection (A)(1)(b) of this section.

b. New manufactured home parks and subdivisions, expansions to existing manufactured home parks and subdivisions, substantial improvements to existing manufactured home parks and subdivisions, and for manufactured homes not placed in a manufactured home park or subdivision shall comply with the following requirements:

i. Stands or lots are elevated on compact fill or on pilings so that the lowest floor elevation of the manufactured home will be one foot or more above the base flood elevation;

ii. Adequate surface drainage and access for a hauler are provided; and

iii. In the instance of elevation on pilings, that (A) lots are large enough to permit steps, (B) piling foundations are placed in stable soil no more than 10 feet apart, and (C) reinforcement is provided for pilings more than six feet above the ground level. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017; Ord. 649, 1989.]

15.15.060 Penalties for violation.

Violations of this chapter shall be enforced in accordance with Chapter 8.60 RMC. Any person convicted of violating any of the provisions of this chapter shall be punished by a fine of not more than $300.00, in addition to any other civil remedies that the city of Roslyn may undertake. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017; Ord. 649, 1989.]

15.15.070 Floodways.

Located within areas of special flood hazard established in RMC 15.15.030(B) 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. Prohibit encroachments, including fill, new construction, substantial improvements, and other development, unless certification by a registered professional engineer or architect is provided demonstrating that 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, except for (1) repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and (2) repairs, reconstruction or improvements to a structure, the cost of which does not exceed 50 percent of the market value of the structure either (a) before the repair, reconstruction, or improvement is started, or (b) if the structure has been damaged, and is being restored, before the damage occurred. Work done on structures to comply with existing health, sanitary, or safety codes or to structures identified as historic places shall not be included in the 50 percent.

C. If RMC 15.15.040(C)(2) is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of RMC 15.15.050, Provisions for flood hazard protection. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017; Ord. 649, 1989.]

15.15.080 Variances.

Variances from the standards of floodplain regulations in this chapter may be authorized by the city in accordance with the provisions of RMC 18.90.120; provided, that the variance criteria contained in this section shall control.

A. Variance Criteria. The city may approve a variance if the following criteria are met:

1. The variance would not result in any increase in flood levels during the base flood discharge; and

2. The site of the construction or substantial improvement is one-half acre or less in size; and

3. The structure or other development is protected by methods that minimize flood damages during the base flood; and

4. The variance is the minimum necessary, considering the flood hazard, to afford relief; and

5. The applicant makes a showing of good and sufficient cause that failure to grant the variance would result in exceptional hardship to the applicant; and

6. Issuance of the variance will not:

a. Result in increased flood heights, additional threats to public safety, or extraordinary public expense; or

b. Create nuisances or cause fraud on or victimization of the public; or

c. Conflict with existing laws and ordinances.

B. Insurance Notice. Any applicant for a variance under this section shall be provided with written notice that (1) the issuance of a variance to construct a structure below the base flood level will result in increased flood insurance premiums; and (2) that such construction below the base flood level increases risks to life and property. Such notice shall be signed by an authorized representative of the city and a copy shall be retained by the city in its record of variance actions.

C. Variance Records. Variances issued pursuant to this section shall include justification for such issuance, and shall prescribe such conditions and safeguards as are necessary to ensure conformity with the purposes of this chapter. A report of all variances issued pursuant to this section shall be submitted to the Federal Insurance Administration in the city’s annual or biennial report. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017.]

15.15.090 Liability – Disclaimer.

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 manmade 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 city, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this chapter or any administrative decision lawfully made under this chapter. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017.]

15.15.100 Compliance with laws.

This chapter shall not in any way impair, affect or remove the need to comply with all other applicable statutes, regulations, and local laws and ordinances. Where this chapter imposes a greater restriction than other applicable laws, the provisions of this chapter shall control. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017.]

15.15.110 Severability.

Should any section, paragraph, sentence, clause, phrase, or provision of this chapter, or its application to any person or circumstance, be declared unconstitutional or otherwise invalid for any reason, or should any provision of this chapter be preempted by state or federal law or regulation, such decision or preemption shall not affect the validity of the remaining provisions of this chapter or its application to other persons or circumstances. [Ord. 1145 § 1, 2018; Ord. 1134 § 1, 2017.]