Chapter 15.08
FLOOD DAMAGE PREVENTION
Sections:
15.08.030 Flood plain administrator and duties.
15.08.050 Application of provisions.
15.08.060 Establishment of development permit.
15.08.090 Below-grade crawlspaces.
15.08.100 Before regulatory floodway.
15.08.110 Habitat restoration in floodway.
15.08.010 Short title.
The county court of Crook County, Oregon, declares this chapter to be known as the “Crook County flood damage prevention ordinance.” (Ord. 38 Amd. 2 § 1, 2000)
15.08.020 Purpose.
The purpose of this chapter is 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:
(1) To protect human life and health;
(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 assume responsibility for their actions. (Ord. 38 Amd. 2 § 2, 2000)
15.08.030 Flood plain administrator and duties.
The planning director is hereby appointed to administer and implement this chapter by granting or denying development permit applications in accordance with its provisions.
The duties of the planning director 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 Other Base Flood Data. When base flood elevation data has not been provided in accordance with CCC 15.08.050, the planning director shall obtain BFE information from the applicant for review and reasonably utilize any base flood elevation and floodway data available from a federal, state or other source, in order to administer specific standards and floodways.
(3) Information to Be Obtained and Maintained.
(a) Where base flood elevation data is provided through the Flood Insurance Study or as otherwise required, obtain and record the actual elevation (in relation to mean sea level) of the lowest floor (as determined by FEMA elevation certificates and instructions) 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 for permit review.
(c) Maintain for public inspection all records pertaining to the provisions of this chapter.
(4) Alteration of Watercourses.
(a) Notify adjacent communities and the department of land conservation and development prior to any alteration or relocation of a watercourse, and submit evidence of such notification to the Federal Insurance Administration.
(b) Require that maintenance be provided within the altered or relocated portion of said watercourse so that the flood-carrying capacity is not diminished. (Ord. 253 § 3 (Exh. C), 2012; Ord. 38 Amd. 2 § 3, 2000)
15.08.040 Definitions.
Unless specifically defined below, words or phases 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.
“Appeal” means a request for a review of the planning director’s interpretation of any provision of this chapter 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 path of flooding is unpredictable and indeterminate; and velocity flow may be evident. AO is characterized as sheet flow and AH indicates ponding.
“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 in any given year. Designation on maps always includes the letters A or V.
“Base flood” means the flood having a one percent chance of being equaled or exceeded in any given year. Also referred to as the “100-year flood.” Designation on maps always includes the letter A.
“Basement” means any area of the building having its floor subgrade below ground level on all sides; a floor that is below ground level (grade) on all sides, even if the floor is used for living purposes, or as an office, garage workshop, etc.
“Below-grade crawlspace” means an enclosed area below the base flood elevation in which the interior grade does not exceed two feet below the lowest adjacent exterior grade and the height, measured from the interior grade of the crawlspace to the bottom of the lowest horizontal structural member of the lowest floor, does not exceed four feet at any point.
“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 or storage of equipment or materials located within the area of special flood hazard. [44 CFR Part 59.1]
“Essential facility” or “critical facility” means:
(a) Hospitals and other medical facilities having surgery and emergency treatment areas;
(b) Fire and police stations;
(c) Tanks or other structures containing, housing or supporting water or fire-suppression materials or equipment required for the protection of essential or hazardous facilities or special occupancy structures;
(d) Emergency vehicle shelters and garages;
(e) Structures and equipment in emergency-preparedness centers;
(f) Standby power generating equipment for essential facilities; and
(g) Structures and equipment in government communication centers and other facilities required for emergency response. [ORS 455.447 and Table 1-1 of ASCE 24]
“Flood” or “flooding” means a general and temporary condition of partial or complete inundation of normally dry land areas from:
(a) The overflow of inland or tidal waters; and/or
(b) The unusual and rapid accumulation of runoff of surface waters from any source.
“Flood Insurance Rate Map (FIRM)” means the official map 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 Map, and the water surface elevation of the base flood.
“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 area, 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 is designed for the 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 park or subdivision” means a parcel (or contiguous parcels) of land divided into two or more manufactured home lots for rent or sale.
“New construction” means structures for which the “start of construction” commenced on or after the effective date of the ordinance codified in this chapter.
“Recreational vehicle” means a vehicle that is:
(a) Built on a single chassis;
(b) Four hundred square feet or less when measured at the largest horizontal projection;
(c) Designed to be self-propelled or permanently towed by a light duty truck; and
(d) Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use. [44 CFR Part 59.1]
“Start of construction” includes substantial improvements, 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 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 and roofed building; includes a gas or liquid storage tank that is principally above ground.
“Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.
“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:
(a) Before the improvement or repair is started; or
(b) 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. The term does not, however, include either:
(i) Any project for improvement of a structure to correct existing violations of state or local health, sanitary or safety code specifications which are solely necessary to assure safe living conditions, or
(ii) Any alteration of a structure listed on the National Register of Historic Places or a State Inventory of Historic Places.
“Variance” means a grant of relief from the requirements of this chapter, which permits construction in a manner that would otherwise be prohibited by this chapter. Variances shall be granted consistent with the standards of the Rules and Regulations of the National Flood Insurance Program. (Ord. 253 § 3 (Exh. C), 2012; Ord. 38 Amd. 2 § 4, 2000)
15.08.050 Application of provisions.
This chapter shall apply to the areas of special flood hazard identified by the Federal Insurance Administration in a scientific and engineering report entitled “The Flood Insurance Study for Crook County, Oregon and Incorporated Areas,” dated July 17, 1989, and February 2, 2012, with accompanying Flood Insurance Rate Maps; the engineering report and accompanying maps are hereby adopted by reference and declared to be a part of this chapter. The Flood Insurance Study and Flood Insurance Rate Maps are on file at the Planning Department, Room 11, Crook County Courthouse, Prineville, Oregon. (Ord. 253 § 3 (Exh. C), 2012; Ord. 38 Amd. 2 § 5, 2000)
15.08.060 Establishment of development permit.
(1) Development Permit Required. A development permit shall be obtained before construction or development begins within any area of special flood hazard established in CCC 15.08.050. The permit shall be for all structures including manufactured homes, as set forth in CCC 15.08.040, and for all development including fill and other activities, also as set forth in CCC 15.08.040.
(2) Application for Development Permit. Application for a development permit shall be made on forms furnished by the planning department 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; existing or proposed structures, fill, storage of materials, drainage facilities and the location of the foregoing. Specifically, the following information is required:
(a) Elevation in relation to mean sea level, of the lowest floor (including basement) of all structures;
(b) Elevation in relation to mean sea level to which any structure has been floodproofed;
(c) Certification by a registered professional engineer or architect that the floodproofing methods for any nonresidential structure meet the floodproofing criteria in CCC 15.08.080; and
(d) Description of the extent to which a watercourse will be altered or relocated as a result of proposed development. (Ord. 38 Amd. 2 § 6, 2000)
15.08.070 General standards.
In all areas of special flood hazards, 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 in conformance with adopted building codes;
(b) 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 in conformance with adopted building codes. 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).
(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 and conform to adopted building codes;
(c) Electrical, heating, ventilation, plumbing fixtures and air-conditioning equipment and other service facilities shall be designed and/or otherwise elevated a minimum of one inch above base flood elevation 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 conforming to adopted plumbing code requirements;
(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 systems into flood waters; and
(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, 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) 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 five acres (whichever is less).
(5) Review of Building Permits. Where elevation data is not available either through the Flood Insurance Study or from another authoritative source, 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 available. Failure to elevate at least two feet above grade in these zones may result in higher insurance rates. (Ord. 38 Amd. 2 § 7, 2000)
15.08.080 Specific standards.
In all areas of special flood hazards where base flood elevation data has been provided as set forth in CCC 15.08.040, the following provisions are required:
(1) Residential Construction.
(a) New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to one foot above base flood elevation.
(b) 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 or architect or must meet or exceed the following minimum criteria:
(i) A minimum of two openings having a total area of not less than one square inch for every square foot of enclosed area subject to 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.
(2) Nonresidential Construction. New construction and substantial improvement of any commercial, industrial or other nonresidential structure shall either have the lowest floor, including basement, elevated to a minimum of one foot above the level of the base flood elevation or, together with attendant utility and sanitary facilities, shall:
(a) Be floodproofed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water.
(b) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
(c) 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 CCC 15.08.030.
(d) Nonresidential structures that are elevated, not floodproofed, must meet the same standards for space below the lowest flood as described in this section.
(e) Applicants floodproofing 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 constructed to the base flood level will be rated as one foot below that level).
(3) Manufactured Homes. All manufactured homes to be placed or substantially improved within zones A1-30, AH, and AE shall be elevated on a permanent foundation such that the bottom of the chassis on the manufactured home is at or above the base flood elevation and be securely anchored to an adequately anchored foundation system in accordance with the provisions of CCC 15.08.070. [Manufactured Dwelling Installation Specialty Code]
(4) Floodways. Located within areas of special flood hazard established in CCC 15.08.050 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters 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) If subsection (4)(a) of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of CCC 15.08.070 and this section.
(5) Recreational vehicles placed on sites within the flood plain shall meet the placement requirements of subsection (5)(a) or (b) of this section, or the requirements of subsections (5)(c) and (d) of this section.
(a) Be on the site for fewer than 90 consecutive days; or
(b) Be fully licensed and ready for highway use. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions; or
(c) Recreational vehicles in a space or on a lot, for more than 90 consecutive days, shall be elevated on compacted fill so that the lowest floor of the recreational vehicle will be a minimum of 18 inches above the base flood elevation; and
(d) Adequate surface drainage and access for a hauler shall be provided. (Ord. 253 § 3 (Exh. C), 2012; Ord. 38 Amd. 2 § 8, 2000)
15.08.090 Below-grade crawlspaces.
(1) The building must be designed and adequately anchored to resist flotation, collapse, and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy. Hydrostatic loads and the effects of buoyancy can usually be addressed through the required openings stated in subsection (2) of this section. Because of hydrodynamic loads, crawlspace construction is not recommended in areas with flood velocities greater than five feet per second unless the design is reviewed by a qualified design professional, such as a registered architect or professional engineer.
(2) The crawlspace is an enclosed area below the base flood elevation and, as such, must have openings that equalize hydrostatic pressures by allowing the automatic entry and exit of floodwaters. The bottom of each flood vent opening can be no more than one foot above the lowest adjacent exterior grade.
(3) Portions of the building below the BFE must be constructed with materials resistant to flood damage. This includes not only the foundation walls of the crawlspace used to elevate the building, but also any joists, insulation, or other materials that extend below the BFE. The recommended construction practice is to elevate the bottom of joists and all insulation above BFE.
(4) Any building utility systems within the crawlspace must be elevated above BFE or designed so that floodwaters cannot enter or accumulate within the system components during flood conditions. Ductwork, in particular, must either be placed above the BFE or sealed from floodwaters.
(5) The interior grade of a crawlspace below the BFE must not be more than two feet below the lowest adjacent exterior grade.
(6) The height of the below-grade crawlspace, measured from the interior grade of the crawlspace to the bottom of the structural support of the next higher floor, must not exceed four feet at any point.
(7) There must be an adequate drainage system that removes floodwaters from the interior area of the crawlspace. The enclosed area should be drained within a reasonable time after a flood event. The type of drainage system will vary because of the site gradient and other drainage characteristics, such as soil types. Possible options include natural drainage through porous, well-drained soils and drainage systems such as perforated pipes, drainage tiles or gravel or crushed stone drainage by gravity or mechanical means. (Ord. 253 § 3 (Exh. C), 2012)
15.08.100 Before regulatory floodway.
(1) In areas within zones A1-30 and AE on the community’s FIRM with a base flood elevation but where no regulatory floodway has been designated, new construction, substantial improvements, or other development (including fill) shall be prohibited, unless it is demonstrated that the cumulative effect of the proposed development, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood more than one foot at any point within the community. [44 CFR Part 60.3(c)(10) and ORSC R324.1.3.2]
(2) Applicants of proposed projects that increase the base flood elevation more than one foot shall obtain from FEMA a conditional letter of map revision (CLOMR) before the project may be permitted. As soon as possible, but no later than six months after project completion, an application for a letter of map revision (LOMR) shall be submitted by the applicant to FEMA. The applicant is responsible for paying any costs associated with the CLOMR and LOMR process. [44 CFR Parts 60.3(c)(13), 65.3, and 65.12)] (Ord. 253 § 3 (Exh. C), 2012)
15.08.110 Habitat restoration in floodway.
Projects for stream habitat restoration may be allowed without certification by a registered professional civil engineer provided:
(1) A development permit is obtained prior to initiating development activities; and
(2) The project qualifies for a Department of the Army, Portland District Regional General Permit for Stream Habitat Restoration (NWP-2007-1023); and
(3) A qualified professional (a registered professional engineer; or staff of NRCS; the county; or fisheries, natural resources, or water resources agencies) has provided a feasibility analysis and certification that the project was designed to keep any rise in 100-year flood levels as close to zero as practically possible given the goals of the project; and
(4) No structures would be impacted by a potential rise in flood elevation; and
(5) An agreement to monitor the project, correct problems, and ensure that flood carrying capacity remains unchanged is included as part of the local approval. [Oregon Solutions Regulatory Streamlining Project 2009] (Ord. 253 § 3 (Exh. C), 2012)