ARTICLE V. - PROVISIONS FOR FLOOD HAZARD REDUCTION
Part of the Code of Ordinances of Burnet, TX.
The text
Sec. 50-51. - General standards.#
In all areas of special flood hazards the following provisions are required for all new construction and substantial improvements: (1)
All new construction or substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;
(2)
All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage;
(3)
All new construction or substantial improvements shall be constructed with materials resistant to flood damage;
(4)
All new construction or substantial improvements shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding;
(5)
All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system;
(6)
New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from the systems into flood waters; and,
(7)
Onsite waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
(Ord. No. 2012-07, § 3(exh. A, Art. 5, § A), 2-28-12)
Sec. 50-52. - Specific standards.#
In all areas of special flood hazards where base flood elevation data has been provided as set forth in (i) section 50-32 of this chapter, (ii) subsection 50-42(8) of this chapter, or (iii) subsection 50-53(3) of this chapter, the following provisions are required: (1)
Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement), elevated to or above the base flood elevation. A registered professional engineer, architect, or land surveyor shall submit a certification to the floodplain administrator that the standard of this subsection as proposed in subsection 50-43(1)a. of this chapter, is satisfied.
(2)
Nonresidential construction. New construction and substantial improvements of any commercial, industrial or other nonresidential structure shall either have the lowest floor (including basement) elevated to or above the base flood level or together with attendant utility and sanitary facilities, be designed 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 develop and/or review structural design, specifications, and plans for the construction, and shall certify that the design and methods of construction are in accordance with accepted standards of practice as outlined in this subsection. A record of such certification which includes the specific elevation (in relation to mean sea level) to which such structures are floodproofed shall be maintained by the floodplain administrator.
(3)
Enclosures. New construction and substantial improvements, with fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding 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 meet or exceed the following minimum criteria:
a.
A minimum of two openings on separate walls 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.
b.
The bottom of all openings shall be no higher than one foot above grade.
c.
Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(4)
Manufactured homes.
a.
Require that all manufactured homes to be placed within zone A on a community's FHBM or FIRM shall be installed using methods and practices which minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and anchored to resist flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.
b.
Require that manufactured homes that are placed or substantially improved within zones A1-30, AH, and AE on the community's FIRM on sites (i) outside of a manufactured home park or subdivision, (ii) in a new manufactured home park or subdivision, (iii) in an expansion to an existing manufactured home park or subdivision, or (iv) in an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage" as a result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to or above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
c.
Require that manufactured homes be placed or substantially improved on sites in an existing manufactured home park or subdivision with zones A1-30, AH and AE on the community's FIRM that are not subject to the provisions of paragraph (4) of this section be elevated so that either:
1.
The lowest floor of the manufactured home is at or above the base flood elevation; or
2.
The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
(5)
Recreational vehicles. Require that recreational vehicles placed on sites within zones A1-30, AH, and AE on the community's FIRM either (i) be on the site for fewer than 180 consecutive days, or (ii) be fully licensed and ready for highway use, or (iii) meet the permit requirements of subsection 50-43(1) of this chapter, and the elevation and anchoring requirements for "manufactured homes" in paragraph (4) of this section. 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.
(Ord. No. 2012-07, § 3(exh. A, Art. 5, § B), 2-28-12)
Sec. 50-53. - Standards for subdivision proposals.#
(1)
All subdivision proposals including the placement of manufactured home parks and subdivisions shall be consistent with sections 50-2—50-4 of this chapter.
(2)
All proposals for the development of subdivisions including the placement of manufactured home parks and subdivisions shall meet floodplain development permit requirements of section 50-33, section 50-43, and the provisions of this article.
(3)
Base flood elevation data shall be generated for subdivision proposals and other proposed development including the placement of manufactured home parks and subdivisions which is greater than 50 lots or five acres, whichever is lesser, if not otherwise provided pursuant to section 50-32 or section 50-42(8) of this chapter.
(4)
All subdivision proposals including the placement of manufactured home parks and subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.
(5)
All subdivision proposals including the placement of manufactured home parks and subdivisions shall have public utilities and facilities such as sewer, gas, electrical and water systems located and constructed to minimize or eliminate flood damage.
(Ord. No. 2012-07, § 3(exh. A, Art. 5, § C), 2-28-12)
Sec. 50-54. - Standards for areas of shallow flooding (AO/AH zones).#
Located within the areas of special flood hazard established in section 50-32, are areas designated as shallow flooding. These areas have special flood hazards associated with flood depths of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable, and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply: (1)
All new construction and substantial improvements of residential structures have the lowest floor (including basement) elevated to or above the base flood elevation or the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least two feet if no depth number is specified).
(2)
All new construction and substantial improvements of nonresidential structures;
a.
Have the lowest floor (including basement) elevated to or above the base flood elevation or the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least two feet if no depth number is specified); or
b.
Together with attendant utility and sanitary facilities be designed so that below the base specified flood depth in an AO zone, or below the base flood elevation in an AH zone, 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 of effects of buoyancy.
(3)
A registered professional engineer or architect shall submit a certification to the floodplain administrator that the standards of this section, as proposed in section 50-43 of this chapter are satisfied.
(4)
Require within zones AH or AO adequate drainage paths around structures on slopes, to guide flood waters around and away from proposed structures.
(Ord. No. 2012-07, § 3(exh. A, Art. 5, § D), 2-28-12)
Sec. 50-55. - Floodways.#
Floodways. located within areas of special flood hazard established in section 50-32 of this chapter, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles and erosion potential, the following provisions shall apply: (1)
Encroachments are prohibited, including fill, new construction, substantial improvements and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.
(2)
If subsection (1) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this article.
(3)
Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Program Regulation, a community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the community first completes all of the provisions required by Section 65.12.
(Ord. No. 2012-07, § 3(exh. A, Art. 5, § E), 2-28-12)
Sec. 50-56. - Elevation and lot grading standards for structures located in Zone X.#
(a)
All walls and foundations of structures shall be provided with protective slopes to assure immediate drainage and diversion of surface water away from these structures and off the site, said drainage and diversion to be provided as follows:
(1)
The lowest finished floor elevation (inclusive of garages, enclosed porches, etc.) of all structures shall be elevated not less than six inches above highest adjacent, finished grade including topsoil and sod. At the time of setting the foundation formwork, which may be prior to final grade including topsoil and sod, the lowest finished floor elevation shall be elevated no less than 12 inches above the highest adjacent grade.
a.
Lots, as measured from highest adjacent grade, shall provide a minimum fall of at least six inches away from structures in ten feet, except where length is restricted by side lot lines or other major considerations. The horizontal length of such slopes may be reduced as necessary at building corners and side yards; provided however, the minimum fall of six inches shall be maintained at any length less than ten feet.
b.
In cases where highest elevation adjacent to a building pad is determined to be lower than top of curb or edge of paving, whichever is higher, of any adjacent right-of-way, fall, as measured from highest adjacent grade shall be increased to a minimum of 12 inches in 20 feet. The horizontal length of such slopes may be reduced as necessary at building corners, side yards, and other major considerations; provided however, the minimum fall of 12 inches shall be maintain at any length less than 20 feet.
c.
No more than two average residential lots may drain onto another lot, unless a drainage easement is dedicated to contain stormwater runoff.
(b)
Exceptions.
(1)
Lowest finished floor is elevated at least one foot above the calculated depth of flooding based on a flood elevation study prepared by a registered professional engineer and documented by a registered professional land surveyor, and approved by the city engineer; or
(2)
Structure is being erected on a building pad prepared in accordance with an approved subdivision master drainage plan, detailed lot grading plan, and approved subdivision infrastructure plan. The detailed lot grading plan shall provide minimum finished floor elevations for each structure on each lot based on elevating the slab 12 inches above the highest adjacent grade of the foundation pad area. The lot grading plan shall also identify the typical FHA or HUD lot grading types.
(3)
If an applicant proposes to set finished floor elevation of a structure at an elevation lower than the minimum elevation shown on the approved detailed lot grading plan, matching the master drainage plan, the applicant shall submit a detailed lot specific grading plan, prepared by a registered professional engineer, to adjust the elevation as proposed. The detailed lot specific grading plan shall, at a minimum, depict structure finished floor elevation and sufficient lot grading control elevations to determine if the structure will not be properly elevated above the adjacent grade. The lot specific grading plan shall be submitted to the city, before, or at the time of building permit application and must be approved by the city before a building permit may be issued.
(Ord. No. 2016-33, § 2, 11-8-16; Ord. No. 2022-06, § 1, 2-8-22)
Editor's note— Ord. No. 2016-33, § 2, adopted November 8, 2016, repealed and replaced § 50-56, in its entirety. Former § 50-56 pertained to "Severability," and was derived from Ord. No. 2012-07, § 3(exh. A, Art. 5, § F), adopted February 28, 2012.
Sec. 50-57. - Severability.#
If any section, clause, sentence, or phrase of this chapter is held to be invalid or unconstitutional by any court of competent jurisdiction, then said holding shall in no way affect the validity of the remaining portions of this chapter.
(Ord. No. 2016-33, § 2, 11-8-16)
Editor's note— Ord. No. 2016-33, § 2, adopted November 8, 2016, repealed and replaced § 50-57, in its entirety. Former § 50-57 pertained to "Penalties for non compliance," and was derived from Ord. No. 2012-07, § 3(exh. A, Art. 5, § G), adopted February 28, 2012.
Sec. 50-58. - Penalties for non-compliance.#
No structure or land shall hereafter be constructed, located, extended, converted, or altered without full compliance with the terms of this chapter and other applicable regulations. Violation of the provisions of this chapter 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 chapter or fails to comply with any of its requirements shall upon conviction thereof be fined not more than $500.00 for each violation, and in addition shall pay all costs and expenses involved in the case. Nothing herein contained shall prevent the city council from taking such other lawful action as is necessary to prevent or remedy any violation.
(Ord. No. 2016-33, § 2, 11-8-16)