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HomeMy WebLinkAbout59-91 - Ord. Regulating Development in Flood Hazard Areas ORDINANCE NO. 59-91 IN THE MATTER OF: AN ORDINANCE TO PROMOTE THE PUBLIC HEALTH, SAFETY, AND GENERAL WELFARE, AND TO MINIMIZE PUBLIC AND PRIVATE LOSSES BY REGULATING DEVELOPMENT IN FLOOD HAZARD AREAS OF MASON COUNTY. WHEREAS, specific areas in the County of Mason are subject to periodic flooding from streams and rivers resulting in serious damages to properties within these areas; and WHEREAS, financial assistance is available through the National Flood Insurance Program for damages resulting from flooding; and WHEREAS, Mason County shall be reinstated into the National Flood Insurance Program upon the adoption of this ordinance; and WHEREAS, The Skokomish River Valley Flood Control Advisory Committee and residents concerns were recognized through public meetings and incorporated into this ordinance; and WHEREAS, a comprehensive planning process for the development of a Skokomish River Watershed Flood Control Comprehensive Plan ,all begin following the adoption of this ordinance; and WHEREAS, The Planning Commission of Mason County held a public hearing on May 3, 1991 continued to May 9, 1991 to consider all testimony and exhibits filed regarding flood damage prevention regulations; and WHEREAS, The Planning Commission of Mason County has reviewed all testimony and exhibits and hereby recommends adoption of the ordinance; and WHEREAS, The Board of Mason County Commissioners held a public hearing on May 23, 1991, for the purpose taking public testimony, reviewing the Planning Commission recommendation, and to deliberate on action to be taken; NOW, THEREFORE, BE IT HEREBY ORDAINED, that the Board of Mason County hereby ADOPTS the Flood Damage Prevention Ordinance of Mason County as follows: FLOOD °TI ORDINANCE Mason County SECTION 1® STATUTORY AUTHORIZATION, FINDINGS OF FACT. PURPOSE, AND OBJECTIVES 1. 1 STATUTORY AUTHORIZATION The legislature of the State of Washington has delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety, and general welfare of its citizenry® Regulations for the Skokomish River Valley set forth in section 5. 4 are interim pending on the completion of a kokomish River Watershed Flood Control Comprehensive Flan. Therefore, The Board of Mason County Commissioners, Washington does ordain as follows: 1. 2 FINDINGS OF FACT ( 1 ) The flood hazard areas of Mason County are subject to periodic inundation which results in the loss of life and 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. ( ) These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazards which increase flood heights and velocities and when inadequately anchored, damage uses in other areas. Uses that are inadequately floodroofed, elevated, or otherwise protected from flood damage also contribute to the flood loss. (C) Current methods of flood control, particularly in the kokomish Valley, have proven unsatisfactory to local residents and governmental agencies® Comprehensive flood control measures are necessary to satisfy governmental concerns but which will at the same time allow property owners to protect their property. 1. 3 STATEMENT OF PURPOSE It is the purpose of this ordinance to promote the public health, safety, and general welfare, and to minimize public and private losses due to .flood conditions in specific areas by provisions designed: Required for approval by E MA/Washington Department of Ecology 1 ( 1 ) To protect human life, health, and property, (2) To minimize expenditure of public money and 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, streets, and bridges located in areas of special flood hazard; (6) To help maintain a stable tax base by providing for the sound use and development of areas of special flood hazard so as to minimize future flood blight areas; (7) To ensure that potential buyers are notified that property is in an area of special flood hazard; and, (8) To ensure that those who occupy the areas of special flood hazard participate, along with government, in assuming responsibility for their actions, while at the same time permitting those who occupy such areas the ability to responsibly protect their property without arbitrary and recriminating governmental action. (9) To allow individuals to protect their life, health, and property when it is done in accordance with all applicable laws and regulations. 1. 4 METHODS OF REDUCING FLOOD LOSSES In order to accomplish its purposes, this ordinance includes methods and provisions for: ( 1 ) Restricting or prohibiting 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; (2) Requiring that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction; (3) Controlling the alteration of natural flood plains, stream channels, and natural protective barriers, which help accommodate or channel flood waters; (4) Controlling filling, grading, and other development which may increase flood damage; and (5) Preventing or regulating the construction of flood barriers which will unnaturally divert flood waters or may increase flood hazards in other areas. (6) Controlling excessive erosion by constructing sound erosion control structures and obtaining appropriate permits and exemptions from all applicable local, state, and federal jurisdictions. 2 SECTION 2. 0 DEFINITIONS Unless specifically defined below, words or phrases used in this ordinance shall be interpreted so as to give them the meaning they have in common usage and to give this ordinance its most reasonable application® "A-ZONES" means those areas shown on the Federal Insurance Rate Maps (FIRM) as that area of land within the flood plain which would be inundated by the 1 -year- flood. "ACCESSORY STRUCTURE" means nonresidential structures such as detached garages, sheds, garden buildings, pole buildings, and barns which are considered normal for farming and ranching activities "APPEAL" means a request for a review of the Director of General Services interpretation of any provision of this ordinance or a request for a variance. "AREA OF SHALLOW FLOODING" means a designated AO or AH Zone on the Flood Insurance Rate Map (FIRM) . The base flood depths range from one to three feet; a clearly defined channel does not exist; the Rath of flooding is unpredictable and indeterminate; and velocity flow may be evident. AO is characterized as sheet flow and AH indicates pending. "AREA OF SPECIAL FLOOD HAZARD" means the land in the flood plain within a community subject to a one percent or greater chance of flooding at any given year. Designation on maps always includes the letters A or V. "BASE FLOOD" means the flood having a ( 1 ) percent chance of being equalled or exceeded in any given year. "CRITICAL FACILITY" means a facility for which even a slight chance of flooding might be too great. Critical facilities include, but are not limited to schools, nursing homes, hospitals, police, fire and emergency response installations, installations which produce, use, or store hazardous materials or hazardous waste. "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 located within the area of special flood Hazard. "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 of surface waters from any source. 3 "FLOOD INSURANCE RATE MAP (FIRM) " means the official crap on which the Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community. "FLOOD INSURANCE STUDY" means the official report provided by the Federal Insurance Administration that includes flood profiles, the Flood Boundary-Floodway Map, and the water- surface elevation of the base Flood. "FLOOD PROTECTION ELEVATION" Means one foot above the base flood elevation. "FLaOODWAy" means the channel of a river or other watercourse and the adjacent land areas that rust 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 area, is not considered a builder's lowest floor, provided that such enclosure is not built so as to render the structure in violation of the applicable non- elevation design requirements of this ordinance found at Section a ®1 ( ) ® "MANUFACTURED HOME" means a residential structure, transportable in one or more sections, which is built on a permanent chassis and is designed for use with or without a permanent foundation when connected to the required utilities. For flood plain management purposes the term "manufactured home" also includes park trailers, travel trailers, and other similar vehicles placed on a site for greater than 180 consecutive days. For insurance purposes the term "manufactured home" does not include park trailers, travel trailers, and other similar vehicles® "MANUFACTURED HOME FADE OR SUBDIVISION" means a parcel ( or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale. "VIEW CONSTRUCTION" means structures for which the "start of construction" commenced on or after the effective date of this ordinance. "PERMIT" means a written authorization from the Mason County Department of General Services for any construction activity on all lands regulated by this ordinance. Such permits shall include but are not limited to excavation and grading permits for fills and excavations under Chapter 7 of the Uniform Building Code, shoreline permits for developments regulated by the Mason County Shoreline Master~ Program, and building permits for all structures 4 under the Uniform Building Code. ffPERSON" means any individual, partnership, corporation, association, organization, cooperative, public or municipal corporation, or any agency of the state or local government unit however designated. "SPECIAL FLOOD HAZARD AREA" means an area subject to a base or 100 year flood; areas of special flood hazard are shown on the flood insurance rate map as Zone A, AO, Al-30, AE, A99, AH, VO, V1-30, VE, or V. "SPECIAL FLOOD RISK ZONE" means that area of the Skokomish River Valley identified by the Federal Emergency Management Agency in the scientific study entitled "The Flood Insurance Study for Unincorporated Areas Mason", Community Panel Number 530115 0180, Detailed Study Area. "START OF CONSTRUCTION" includes substantial improvement, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement, or other improvement was within 180 days of the permit date® The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation® 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 foundation 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 part of the main structure. "STRUCTURE" means a walled or roofed building including a gas or liquid storage tank that is principally above ground. "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 dimension 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 5 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. "VARIANCES" means a grant of relief from the requirements of this ordinance which permits construction in a manner that would otherwise be prohibited by this ordinance. "WATER DEPENDENT" means a structure for commerce or industry which cannot exist in any other location and is dependent on the water by reason of the intrinsic nature of its operations® "WETLANDS" means those lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water. Wetlands have the following three characteristics® ( 1 ) at least periodically, the land supports predominately hydrophytes; and (2) the substrate is predominately undrained hydric soil; and (3) the substrate is nonsoil and is saturated with water or covered by shallow water for some time during the growing season of each year® SECTION 3® GENERAL PROVISIONS 3. 1 LANDS TO WHICH THIS ORDINANCE APPLIES This ordinance shall apply to all areas of special flood hazards and special flood risk zones within the jurisdiction of Mason County® *3. 2 BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD The areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitle "The Flood Insurance Study for Mason County" dated February 5, 1987, with accompanying Flood Insurance Maps is hereby adopted by reference and declared to be part of this ordinance. The Flood Insurance Study is on file at Mason County Planning Department® 3. 3 PENALTIES FOR NONCOMPLIANCE No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this ordinance and other applicable regulations. Violation of the provisions of this ordinance by failure to comply with any of its requirements ( including violations of conditions and safeguards established in connection with conditions) shall constitute a misdemeanor. Any person who violates this ordinance or fails to comply with any of its requirements shall upon conviction thereof be fined not more than $1,,000 or imprisoned for not more than C, da�s or both, for each violation, and in addition shall pay all costs and expenses involved in the case. Nothing herein contained shall prevent Mason County from taking such other lawful action as is necessary to prevent or remedy any violation. C® ABROGATION AND GREATER RESTRICTIONS This ordinance is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. However, where this ordinance and another ordinance, easement, covenant, or deed restriction conflict or overlap, whichever imposes the more stringent restrictions shall prevail. C® INTERPRETATION In the interpretation and application of this ordinance, all provisions shall be: ( 1 ) Considered as minimum requirements; (2) Deemed neither to limit nor repeal any other powers granted under State statutes. ® C WARNING AND DISCLAIMER OF LIABILITY The degree of flood protection required by this ordinance 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 ordinance does not imply that land outside the areas of special flood hazards or uses permitted within such areas will be free from flooding or flood damages. This ordinance shall not create liability on the part of Mason County, any officer or employee thereof, or the Federal Insurance Administration, for any flood damages that result from reliance on this ordinance or any administrative decision lawfully made hereunder® SECTION 4® ADMINISTRATION 4. 1 ESTABLISHMENT OF DEVELOPMENT PERMIT *4. 1-1 Development Permit Required A development permit shall be obtained before construction or development begins within any area of special flood hazard established in Section 3. 2 and special flood risk zones® The permit shall be for all structures including manufactured homes, as set forth in the "DEFINITIONS", and for all development 7 including fill and other activities, also as set forth in the "DEFINITIONS". 4. 1-2 A.2p 1 ic t ion for _Deve�lom�ent �Permj�-t g� Application for a development permit shall be made on forms furnished by the Director of General Services and may include but not be limited to plans in duplicate drawn to scale showing the nature, location, dimensions, and elevations of the area in question and existing or proposed structures, fill, storage of materials, drainage facilities, and the location of the foregoing. Specifically, the following information is required: ( 1 ) Elevation in relation to mean sea level, of the lowest floor ( including basement ) of all structures; (2) Elevation in relation to mean sea level to which any structure has been floodproofed; (3) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in Section 5. 2-2; and (4) Description of the extent to which a watercourse will be altered or relocated as a result of proposed development. 4. 2 DESIGNATION OF THE DIRECTOR OF GENERAL SERVICES The Director of General Services is hereby appointed to administer and implement this ordinance by granting or denying development permit applications in accordance with its provisions. ® DUTIES AND RESPONSIBILITIES OF THE DIRECTOR OF GENERAL SERVICES Duties of the Director of General Services shall include, but not be limited to: b3®1 Permit Review ( 1 ) Review all development permits to determine that the permit requirements of this ordinance have been satisfied. * (2) 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. (3) Review all development permits to determine if the proposed development is located in the floodway. If located in the floodway, assure that the provisions of Section 5. 3 are met. *4. 3-2 Use of Other Base Flood Data When base flood elevation data has not been provided in accordance with Section 3. 2, BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD, the Director of General Services shall obtain, review, and reasonably utilize any base flood elevation and floodway data available from a Federal, State, or other source, in order to administer Sections 5. 2, SPECIFIC STANDARDS, and 5. 3, FLOODWAYS. *4. 3-3 Information to be Obtained and Maintained ( 1 ) Where base flood elevation data is provided through the Flood Insurance Study or required as in Section 4. 3-2, obtain and record the actual (as-built ) elevation ( in relation to mean sea level) of the lowest floor, including basement, of all new or substantially improved structures, and whether or not the structure contains a basement. (2) For all new or substantially improved floodproofed structures: (1) verify and record the actual elevation ( in relation to mean sea level) , and ( ii ) maintain the floodproofing certifications required in Section 4. 1-2 (3) . (3) Maintain for public inspection all records pertaining to the provisions of this ordinance. *4. 3-4 Alteration of Watercourses ( 1 ) Notify adjacent communities and the Washington State Department of Ecology prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration. (2) Require that maintenance is provided within the altered or relocated portion of said watercourse so that the Mood carrying capacity is not diminished. 4. 3-5 2 re n Ite ptatin of FIRM Boundaries -- Make interpretations where needed, as to exact location of the boundaries of the areas of special flood hazards (for example, where there appears to be 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 as provided by Section 4. 4. 4. 4 VARIANCE PROCEDURE 4. 4-1 &paaal Board ( 1 ) The Board of County Commissioners shall act as the Board of Appeals to hear and decide appeals and requests for variances from the requirements of this ordinance. (2) The Board of Appeals shall hear and decide appeals when it is alleged there is an error in any requirement, decision, or determination made by the Director of General Services in the enforcement or administration of this ordinance. (3) Those aggrieved by the decision of the Board of Appeals or any taxpayer, may appeal such decision to the u Q ;?�gr 10 r Court as provided in RCW IC,,.�ha ter 36. 70. (4) In passing upon such applications, the Board of _Appeals shall consider all technical evaluations, all relevant factors, standards specified in other sections of this ordinance, and; i. the danger that materials may be swept onto other lands to the injury of others; iie the danger to life and property due to flooding or erosion damage; iii. the susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner; iv. the importance of the services provided by the proposed facility to the community; vm the necessity to the facility of a waterfront location, where applicable; vib the availability of alternative locations for the proposed use which are not subject to flooding or erosion damage; vii. the compatibility of the proposed use with existing and anticipated development ; viii. the relationship of the proposed use to the comprehensive plan and flood plain management program for that area; ix. the safety of access to the property in times of flood for ordinary and emergency vehicles; X. the expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site; and xib the costs of providing governmental services during and after flood conditions, including maintenance and repair of public utilities and facilities such as sewer, gas electrical, and water systems, and streets and bridges. (5) Upon consideration of the factors of Section 4. 4-1 (4) and the purposes of this ordinance, the Board of sale may attach such conditions to the granting of variances as it deems necessary to further the purposes of this ordinance. (6) The Director of General Services shall maintain the records of all appeal actions and report any variances to the Federal Insurance Administration upon request. 4. 4-2 Conditions of Variances ( 1 ) Generally, the only condition under which a variance from the elevation standard may be issued is for, new construction and substantial improvements to be erected on a lot of one-half acre or less in size contiguous to and surrounded by lots with existing structures constructed below the base flood level, providing items (i-xi ) in Section 4. 4-1 (4) have been fully considered. As the lot size increases the technical justification required for issuing the variance increases® (2) Variances may be issued for the reconstruction, rehabilitation or restoration of structures listed on the National Register of Historic Places or the State Inventory of Historic Places, without regard to the procedures set forth in this section. (3) Variances shall not be issued within a designated floodway if any increase in flood levels during the base flood discharge would result® (4) Variances shall only be issued upon a determination that the variance is the minimum necessary, considering the flood hazard, to afford relief® (5) Variances shall only be issued upon: i® a showing of good and sufficient cause-; iim a determination that failure to grant the variance would result in exceptional hardship to the applicant; iii. a determination that the granting of a variance will not result in increased flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud on or victimization of the public as identified in Section 4. 1-4(4) , or conflict with existing local laws or ordinances. (6) Variances as interpreted in the National Flood Insurance Program are based on the general zoning law principle that they pertain to a physical piece of property; they are not personal in nature and do not pertain to the structure, its inhabitants, econ OM4C L or financial circumstances. They primarily address small lots in densely populated residential neighborhoods. As such, variances from the flood elevations should be quite rare. (7) Variances may be issued for nonresidential buildings in very limited circumstances to allow a lesser degree of floodproofing than watertight or dry-floodproofing, where it can be determined that such action will have low damage potential, complies with all other variance criteria except 4. 4-2( l ) , and otherwise complies with Sections 5. 1-1 and 5. 1-2 of the GENERAL STANDARDS. (8) Any applicant to whom a variance is granted shall be given written notice that the structure will be permitted to be built with a lowest floor elevation below the base flood elevation and that the cost of flood insurance will be commensurate with the increased risk resulting from the reduced lowest floor elevation. SECTION 5. 0 PROVISTONS FOR FLOOD HAZARD REDUCTIOM *5. 1 GENERAL STANDARDS In all areas of special flood hazards as shown on the Federal Insurance Rate Maps (FIRM) and as defined in section 2. 0, the following standards are required: *5. 1-1 Anchoring ( 1 ) All new construction and substantial improvements shall be anchored to prevent flotation, collapse, or lateral movement of the structure. (2) All manufactured homes must likewise be anchored to prevent flotation, collapse, or lateral movement, and shall be installed using methods and practices that minimize flood damage. Anchoring methods may include, but are not limited to, use of over-the-top or frame ties to ground anchors. (Reference FEMA's Manufactured Home Installation in Flood Hazard Areas" guidebook for additional techniques. ) *5. 1-2 Construction Materials and Methods ( 1 ) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage. (2) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage. (3) 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. *5. 1­3 Utilities ( 1 ) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system. (2) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharge from the systems into flood waters; and (3) On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. 12 *5. 1-4 Subdivision_Pro-2osals ( 1 ) All subdivision proposals shall be consistent with the need to minimize flood damage; ( 2) All subdivision proposals shall have public utilities and facilities such as sewer, gas electrical, and water systems located and constructed to minimize flood damage; (3) All subdivision proposals shall have adequate drainage provided to reduce exposure to flood damage; and (4) Where base flood elevation data has not been provided or is not available from another authoritative source, it shall be generated for subdivision proposals and other proposed developments which contain at least 50 lots or 5 acres (whichever is less) . ® 1- Review of uildin Permits Where elevation data is not available either through the Flood Insurance Study or from another authoritative source (Section 4. 3-2) , 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 judgement and includes use of historical data, high water marks, photographs of past flooding, etc. , where available. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates. 5. 2 SPECIFIC STANDARDS In all areas of special flood hazards and special flood risk zones where base flood elevation data has been provided as set forth in Section 3. 2, BASIS FOR ESTABLISHING THE AREAS OF SPECIAL FLOOD HAZARD or Section Use of Other Base Flood Data, the following provisions are required: *5. 2-1 Residential Construction ( 1 ) New construction and substantial improvement of any® residential structure shall have the lowest floor, including basement, elevated one foot or more above base Mood elevation. (2) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or shall be designed to 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 architect or must meet or exceed the following minimum criteria: i® 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 13 flooding shall be provided® ii. The bottom of all openings shall be no higher than one foot above grade. iii. openings may be equipped with screens, louvers, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters® 5. 2-2 Nonresidential Construction New construction and substantial improvement of any commercial, industrial or other nonresidential structure, except those defined as an accessory structure, shall either have the lowest floor, including basement, elevated one foot or more above the level of the base flood elevation; or, together with attendant utility and sanitary facilities, shall; ( 1 ) Be flood roofed so that below one foot above the base Mood level, the structure is watertight with walls substantially impermeable to the passage of water. (2) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; (3) Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this subsection based on their development and/or review of the structural design, specifications and plans. Such certifications shall be provided to the official as set forth in Section 4. 3- 3(2) . (4) Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest floor as described in 5. 2-1 (2) . ( 5) Applicants flood proofing nonresidential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (e. g. a building flood roofed to one foot above the base Mood level will be rated as at the base flood level ? ® 5. 2-3 Accessory Structures Construction or substantial improvement of accessory structures, as defined in section 2. 0, shall either have the lowest floor elevated one foot or more above the level of the base flood elevation; or must meet the following criteria : ( 1 ) A minimum of two openings having a total net area of riot less than one square inch for every square foot of enclosed area subject to flooding shall be provided. (2) The bottom of all openings shall be no higher than one foot above grade. ( 3) Openings may be equipped with screens, louvers, or other 14 coverings provided they may permit the automatic entry and exit of flood waters. (4) Structures shall not be designed for human habitation. (5) Structures shall be firmly anchored to prevent flotation which may result in damage to other structures. (6) Service facilities such as electrical and heating equipment shall be elevated or floodproofed. 5. 2-4 Critical Facility Construction of new critical facilities shall be, to the extent possible, located outside the limits of the base flood plain. Construction of new critical facilities shall be permissible within the base flood plain if no feasible alternative site is available. Critical facilities constructed within the base flood plain shall have the lowest floor elevated to three feet or more above the level of the base flood elevation at the site. Flood roofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into flood waters. Access routes elevated to or above the level of the base flood plain shall be provided to all critical facilities to the extent possible. 5. 2-5 Manufactured Homes All manufactured homes to be placed or substantially improved within Zones Al-30, AH, and AE on the community"s FIRM shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is one foot or more above the Base Flood Elevation; and is securely anchored to an adequately anchored foundation system in accordance with the provisions of section 5. 1-1 (2) . *5. 3 FLOOD WAYS Located within areas of special flood hazard established in Section 3. 2 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 except to that zone of special flood risk, Skokomish River Valley as defined in section 2. 0. ( 1 ) Encroachments are prohibited 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. (2) Construction or reconstruction of residential structures is prohibited within designated floodways, except for (i ) repairs, reconstruction, or improvements to a structure 15 which do not increase the ground floor area; and ( ii) 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 repair 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 determination. (3) If Section 5. 3( l ) is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of Sections 5. 0, PROVISIONS FOR FLOOD HAZARD REDUCTION. *5. 4 SPECIAL FLOOD RISK ZONE - SKOKOMISH RIVER VALLEY INTERIM REGULATIONS This section shall apply to that area of the Skokomish River Valley identified by the Federal Emergency Management Agency in the scientific study entitled "The Flood Insurance Study for unincorporated areas Mason County, Community Panel number 530115 0180, Detailed Study Area. It sets forth INTERIM REGULATIONS that shall apply to this designated area. These interim regulations shall be replaced using a comprehensive planning process which recognizes the role of diking in flood control management efforts. Interim shall be defined as that period of time between the adoption of this ordinance and the adoption of a Skokomish River Watershed Flood Control Comprehensive Plan and subsequent amendments to these regulations. The following regulations and construction standards shall apply to the special flood risk zone: ( 1 ) New construction and substantial improvements of residential and nonresidential structures within the special flood risk zone shall have the lowest floor elevated one foot or more above the base flood elevation and shall be constructed according to the standards provided in subsections 5. 1, 1® , and 5. 2, 1® . (2) Areas where flood water releases and overflows from the main Skokomish River channel shall not be modified, meaning levied or diked, in any manner which would result in increased stream flow in the main channel until these regulations are amended in accordance with an adopted Skokomish Watershed Flood Control Comprehensive Plan. (3) Maintenance to existing levees, dikes, and other water flow modification structures shall be permitted with appropriate approvals from all affected agencies provided that the maintenance does not result in increased stream flow within the main channel. Emergency alterations to dikes and levees necessary for the protection of human life and property shall be permitted. (4) Alterations to dikes and levees, and bank stabilization efforts that would prevent legitimate potential emergency situations shall be permitted, PROVIDED; that all affected agencies have been notified and appropriate approvals have been acquired. (5) Any fill that is allowed in the special flood risk zone shall be confined to the actual building site, other means of elevating structures shall be encouraged such as posts, piles, and stem walls. (6) Solid road fills perpendicular to the flow of water are prohibited in the special flood risk zone® The graveling of driveways and other access roads is exempt. (7) To the extent feasible fills shall be compensated by cuts or extraction of like amounts of materials to alleviate the effect of the fill. (8) The highest portion of any lot shall be utilized as the building site. Lots partially in the special flood risk zone must comply with the regulations for the special flood risk zone. (9) Whenever feasible, new structures shall be located in the hydraulic shadow of the existing structures. SECTION 6® COUNTYWIDE WETLANDS MANAGEMENT FOR FLOOD DAMAGE PREVENTION To the maximum extent possible, developments shall be reviewed to avoid the short and long term adverse impacts associated with the destruction or modification of natural wetlands, especially those activities which limit or disrupt the ability of the wetland to alleviate flooding impacts. For this section the following processes shall be implemented: ( 1 ) Review proposals for development within base flood plains for their possible impacts on wetlands located within the flood plain. (2) Ensure that development activities in or around wetlands do not negatively affect public safety, health, and welfare by disrupting the wetlands' ability to reduce flood and storm drainage. (3) Ensure areas accustomed to or previously used for agriculture, silviculture, and ranching activities such as plowing, seeding, cultivating, minor drainage, or upland soil and conservation practices where proven feasible are exempted from the this section® (4) Request technical assistance from The Department of Ecology and The Army Corps of Engineers in identifying wetland areas. Existing wetland map information from the National Wetlands Inventory (KIWI ) can be used in conjunction with the community's FIRM to prepare an overlay zone indicating critical wetland areas deserving special attention. 17 ADDENDUM GOALS AND OBJECTIVES OF THE SKOKOMISH RIVER VALLEY RESIDENTS Residents and property owners of the Skokomish River Valley have meet in numerous community meetings and by majority agreement have identif ied the following goals and objectives that are to be adequately addressed in the Skokomish River Watershed Flood Control Comprehensive Plan. These goals and objectives as well as other comments and concerns have been recognized and incorporated into this ordinance® ( 1 ) To maintain the river in its present channel in a way as to alleviate flooding conditions throughout the valley resulting in reduced flood damages to all existing structures. (2) To protect stream banks with approved stabilization methods that control excessive erosion resulting in decreased sediment and gravel accumulation within the river channel. (3) To perform proper river channel maintenance including the maintenance of dikes, drainage ditches, and potential flow obstructions resulting in reduced flood damages® (4) To maintain and enhance fish and wildlife habitat. This ordinance shall be in full force and effective this date. DATED this � day o _. 1�---_r—, lia MasonBoard of County Commissioners Mason County, Washington Chai an Cieioner Commissioner ATT Ts Clerk of the Board P OVED�MOFORM: A D Prosecuting Attorney c: File General Services Public Works