DIVISION 5


PROVISIONS FOR FLOOD HAZARD REDUCTION


SEC.

7-041.00 General Standards


    In all areas of special flood hazards the following provisions are required:

    All new construction and 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;

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

    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.

    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.


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

    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,

    On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding. (Ord. No. 610, adopted 12/19/74; Ord. No. 611, adopted 01/16/75; Ord. No. 791, adopted 02/16/78; Ord. 87-770, adopted 02/19/87; Ord. No. 89-1053, adopted 03/16/89)

SEC.

7-042.00 Specific Standards


    (1)     Residential construction. New construction and substantial improvements 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 certificate of elevation, documented on the Federal Emergency Management Agency Form 81-31 or subsequent agency form, indicating that the standards of this subsection and as per Article 4, Section c.(1)a. (St. Tammany Parish Code of Ordinances Chapter 7, Division 4, Section 7-023.02(1)a.), has been satisfactorily met. (amended by Ord. No. 92-1597, adopted 05/21/92)

    (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 (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 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 (2) openings having a total net area of not less than one (1) 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 (1) 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 flood waters.


    (4)     Manufactured homes

    a.    Require that all manufactured homes to be placed within Zone A shall be installed using methods and practices which minimize flood damage. For the purpose of this requirement, manufactured homes must be elevated and anchored to resist flotation, col lapse 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 appli cable State and local anchoring requirements for resisting wind forces.

    b.    All manufactured homes shall be in compliance with Division 5, Section 7-042.00(1).

    c.    Require that all manufactured homes to be placed or substantially improved within Zones A1-30, AH and AE on the community's FIRM be elevated on a permanent foundation such that the lowest floor of 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 provision of Section 7-042.00(4) of this Division. (Ord. No. 610, adopted 12/19/74; Ord. No. 611, adopted 01/16/75; Ord. No. 791, adopted 02/16/78; Ord. No. 87-770, adopted 02/19/87; Ord. No. 89-1053, adopted 03/16/89)

    (5) Construction Sites - Storm Water Runoff

a. A permit shall be required for the clearing, grubbing, grading, displacement or removal of dirt (hereafter referred to as “dirt work”) for any properties not specifically exempted as per Paragraph (c) of this Section. This permit shall be in the form of an approval of the “Culvert Data Sheet”, the “Permit Data Review Sheet”, a general work order or land clearing permit presently required for construction activity to occur. The ordinance shall be administered by Department of Engineering or any other parish personnel that should be necessary.

b. A detailed description of dirt work, boundaries of the areas to be disturbed and the proposed sediment retention measures must accompany the building permit or development proposal and be reviewed by the Department of Engineering before approval of the Culvert Data Sheet or the Permit Data Tracking Sheet or the issuance of a general work order.

c. Exemptions

        A.     Agricultural land management practices and construction of agricultural structures as defined in the St. Tammany Parish Land Use Ordinance No. 523;

        2.     Mining, quarrying, processing of rock, sand, gravel, aggregate or clay where established and provided for by law;

        3.     Activities undertaken on forest land in the production and harvesting of timber when approved via an agricultural clearing, timber harvesting or rural clearing permit in accordance with St. Tammany Parish Land Use Ordinance No. 523;

        4.     Single family residences, and related accessory structures or uses, when the disturbed area comprises of less than 50% of the lot or parcel and is located at least 10 feet from all property lines.

d.     Requirements



    1.     The owner, builder or developer of a construction project shall cause the placement of a required sediment control measure for all side slope and down slope boundaries of a construction area, unless a sedimentation basin designed to accommodate 3600 cubic feet of water and sediment for each acre of disturbed property is provided .

    2.    The owner, builder or developer will further cause the placement of said sediment control measure around all drainage structure inlets which flow into a public drainage system, or a drainage system which is intended to be dedicated to the public.

e.    Sediment Retention Measures

    The following measures are sediment retention measures, subject to review and approval of each application based upon the characteristics of the work and site being permitted. A detailed description of the application, design criteria and limitations of each is outlined in Appendix A.

        1.     Mulching
        2.     Erosion Control Mats
        3.     Vegetation
        4.     Silt Fencing
        5.     Straw Bale Dikes
        6.     Diversion Dikes
        7.     Interceptor Swales
        8.     Inlet Protection
        9.     Any other functionally equivalent technology or method deemed appropriate by the Director of the Department of Engineering.

f. A blanket permit may be issued for large scale developments when the developer provides the required sediment control measures for the development as a whole. The appropriateness of these measures will be determined by the Director of the Department of Engineering.

g. Provision of sediment retention measures on site does not release the builder/developer from responsibilities as outlined in Section 40-071.01of Appendix B (Subdivision Regulations) of the St. Tammany Parish Code of Ordinances should the retention measures fail to prevent sediment runoff. The Director of the Department of Engineering may release the builder/developer from the provisions of this Section if it is determined that the failure of sediment control measures is not attributable to faulty installation or maintenance of the required retention measures.

h.     Enforcement

    Violations will be processed by the appropriate Code Enforcement, Department of Engineering or Permit Inspections personnel using standard code violation protocol.
(Subsection 5 per Ord. 99-3156, adopted 10/21/99)

SEC.

7-043.00 Standards For Subdivision Proposals



    (1)    All subdivision proposals, including manufactured home parks and subdivisions, shall be consistent with Division 1, Sections 7-017.00, 7-018.00, and 7-019.00 of this Ordinance.

    (2)    All proposals for the development of subdivisions, including manufactured home parks and subdivisions, shall meet development permit requirements of Division 3, Section 7-022.01, Division 4, Section 7-023.02, and the provisions of Division 5 of this Ordinance.

    (3)    Base flood elevation data shall be granted for subdivision proposals and other proposed development, including manufactured home parks and subdivisions, which is greater than fifty (50) lots or five (5) acres, whichever is lesser, if not otherwise provided pursuant to Division 3, Section 7-022.00 or Division 4, Section 7-023.01(8) of this Ordinance.

    (4)    All subdivision proposals, including manufactured home parks and subdivisions, shall have adequate drainage provided to reduce exposure to flood hazards.

    (5)    All subdivision proposals, including 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. 791, adopted 02/16/78; Ord. No 87-770, adopted 02/19/87; Ord. No. 89-1053, adopted 03/16/89)

SEC.

7-044.00 Standards For Areas Of Shallow Flooding (AO/AH Zones)


A registered professional engineer or architect shall submit a certificate of elevation, documented on the Federal Emergency Management Agency Form 81-31 or subsequent agency form, to the Floodplain Administrator that the standards of this Section and as per Article 4, Section c.(1)a. (St. Tammany Parish Code of Ordinances Chapter 7, Division 4, Section 7-023.02(1)a.), has been satisfactorily met. (amended by Ord. No. 92-1597, adopted 05/21/92)

SEC.

7-045.00 Coastal High-Hazard Areas


    Located within the areas of special flood hazard established in Division 3, Section 7- 022.00, are areas designated as Coastal High Hazard Areas (Zones V1-30, VE and/or V). These areas have special flood hazards associated with high velocity waters from tidal surges and hurricane wave wash; therefore, in addition to meeting all provisions outlined in this Ordinance, the following provisions must also apply:

        (1)    Obtain the elevation (in relation to mean sea level) of the bottom of the lowest structural member of the lowest floor (excluding pilings and columns) of all new substantially improved structures, and whether or not such structures contain a basement. The Floodplain Administrator shall maintain a record of all such information.

        (2)    All new construction shall be located landward of the reach of mean high tide.


        (3)    All new construction and substantial improvements shall be elevated on pilings and columns so that:

            (i)    the bottom of the lowest horizontal structural member of the lowest floor (excluding the pilings or columns) is elevated to or above the base flood level;

            (ii)    the pile or column foundation and structure attached thereto is anchored to resist flotation, collapse and lateral movement due to the effects of wind and water loads acting simultaneously on all building components. Wind and water loading values shall each have a one (1%) percent chance of being equaled or exceeded in any given year (100-year mean recurrence interval);

            (iii)    a registered professional engineer or architect shall develop or review the structural design, specification and plans for the construction and shall certify that the design and methods of construction to be used are in accordance with accepted standards of practice for meeting the provisions of this paragraph (3)(i), (ii) and (iii) of this Section.

        (4)    Provide that all new construction and substantial improvements have the space below the lowest floor either free of obstruction or constructed with non-supporting breakaway walls, open wood lattice work, or insect screening intended to collapse under wind and water loads without causing collapse, displacement or other structural damage to the elevated portion of the building or supporting foundation system.

    For the purpose of this Section, a breakaway wall shall have a design safe loading resistance of not less than ten (10 lbs.) and nor more than twenty (20 lbs.) pounds per square foot. Use of breakaway walls which exceed a design safe loading resistance of twenty (20 lbs.) pounds per square foot (either by design or when so required by local or State codes) may be permitted only if a registered professional engineer or architect certifies that the designs proposed meet the following conditions:

            (i)    breakaway wall collapse shall result from a water load less than that which would occur during the base flood; and

            (ii)    the elevated portion of the building and supporting foundation system shall not be subject to collapse, displacement or other structural damage due to the effects of wind and water loads acting simultaneously on all building components (structural and nonstructural). Maximum wind and water loading values to be used in this determination shall each have one (1%) percent chance of being equaled or exceeded in any given year (100-year mean recurrence interval).

        (5)    If breakaway walls are utilized, such enclosed space shall be usable solely for parking of vehicles, building access or storage. Such space shall not be used for human habitation.

        (6)    Prohibit the use of fill for structural support of buildings.


        (7)    Prohibit man-made alteration of sand dunes and mangrove stands which would increase potential flood damage.

        (8)    Any alteration, repair, reconstruction or improvements to a structure started after the enactment of this Ordinance shall not enclose the space below the lowest floor unless breakaway walls are used as provided for in Division 5.

        (9)    Prior to construction, plans for any structure that will have breakaway walls must be submitted to the Floodplain Administrator for approval. (Ord. 87-770, adopted 02/19/87; Ord. No. 89-1053, adopted 03/16/89)

SEC. 7-046.00 - 7-048.99 Reserved

SEC.

7-049.00 Penalties For Violation


    Violation of the provisions of this Ordinance or failure to comply with any of its requirements shall constitute a misdemeanor and upon conviction thereof, the violator(s) shall be fined not less than One Hundred ($100.00) Dollars not more than Three Hundred ($300.00) Dollars or imprisoned for not more than thirty (30) days, or both, and in addition thereto shall pay all costs and expenses involved in the case; however, the maximum of aggregated fines are not to exceed One Thousand ($1,000.00) Dollars. Each day such violation continues shall be considered as a separate offense all in accordance with Section 1-008.00 of the Code of Ordinances of St. Tammany Parish, Louisiana.

    Said penalties as imposed are as contained in Section 1-008.00 as presently enacted and shall conform thereto as same may hereafter be amended.

    The owner or tenant of any building, structure, premises, or part thereof, any architect, builder, contractor, agent or other person who commits, participates in, assists in or maintains such violation may each be found guilty of a separate offense and suffer the penalties herein provided.

    Nothing herein contained shall prevent the Parish from taking such other lawful actions as is necessary to prevent or remedy any violation. (Ord. No. 89-1053, adopted 03/16/89)

SECS. 7-049.02 - 7-049.99 Reserved

                 SEC.

7-050.00 Drainage and Paving Plan (Commercial, Industrial and Institutional Developments)



    The purpose and intent of this section is to require a drainage and paving plan to be stamped and certified by a Licensed Louisiana State Registered Engineer for construction of commercial, industrial and institutional developments, with the goal of improving pre- development runoff and reducing post-development runoff based on a minimum twenty-five (25) year storm event.
(Ord. 07-1490, adopted 01/04/2007)

    (1)     All commercial, industrial and institutional uses that require a building permit shall submit a drainage and paving plan with the permit application. Requirements are set

forth in below in Sec. 7-051.00. Said plan shall be forwarded to the Parish Engineer for review and approval before the issuance of a building permit.

    (2)     It shall be the responsibility of the developer and design engineer to create a site development plan that will complement the drainage and paving plan utilizing site design criteria so as to result in the reduction of runoff from post-development.

    (3)     The drainage and paving plan shall be stamped and certified by a Licensed Louisiana State Registered Engineer and shall meet the following criteria:

                     (i)     Parcels 0-2 acres in size shall be required to reduce pre-development peak runoff by at least 10% for a twenty-five (25) year storm event, with on-site detention ponds optional.
                     (ii)    
                     (iii)     Parcels 2-5 acres in size shall be required to reduce pre-development peak water runoff by at least 15% for a twenty-five (25) year storm event, with on-site detention ponds required.
                     (iv)    
                     (v)     Parcels 5 acres and larger shall meet all drainage requirements for Subdivisions established by Subdivision Regulatory Ordinance No. 499, including a reduction of pre-development peak runoff by at least 25% for a one hundred (100) year storm event with on-site detention ponds required.
(Ord. 07-1490, adopted 01/04/2007)

    (4)     A combination of detention methods may be utilized to meet the criteria as established above. Off-site detention facilities may be utilized if approved by the Parish Engineer.

    (5)     Developments located within the boundaries of Gravity Drainage District No. 5 shall also submit their drainage and paving plans to the District at the time permit application is made to the Parish. A building permit shall not be issued until the Drainage District has had an opportunity to review and make comment on the proposed plans to the Parish Engineer. All costs associated with the review of the plans by the Parish and Drainage District shall be assessed to the developer. The Parish Engineer shall have final authority on approval of the permit application.

(Amended by Ord. 04-0933, adopted 07/01/2004; amended by Ord. 07-1490, adopted 01/04/2007)

SEC.

7-051.00 Documents Required For Drainage and Paving Plan Review


    In order to expedite the drainage plan review for all commercial, industrial and institutional developments, the Department of Engineering requests the following documents be provided:

    (1)     A vicinity map indicating the location of the proposed project
    (2)     A pre-development drainage plan (existing conditions)
    (3)     Identify fill area(s) and associated fill depth(s)
    (4)     A post development drainage plan
    (5)     If building has down spouts, an architect's drawing is required


    (6)     If the outfall needs to discharge to the ditch or pond, the invert elevations of associated culvert(s) and bottom elevation of accepted ditch or pond shall be provided
    (7)     If driveway culvert needs to be installed at the state highway ditch, an approval sheet from the state shall be provided prior to the Parish approval
    (8)     A hydrological analysis of both pre-development and post-development runoff shall be provided. The hydrological analysis shall meet applicable Parish Ordinances
    (9)     If the site is located in an area where known drainage problems exist, a drainage basin study can be required to demonstrate compatibility with surrounding properties

    (10)     The Department of Engineering reserves the right to hold the Certificate of Occupancy in order to allow for a final inspection.

(All the above drawings and hydrological analysis need to be stamped and certified {signature and date} by a Professional Engineer Registered in the State of Louisiana.)
(Ord. 98-2899, adopted 06/18/98)

Cross Reference: Appendix D Parish Building Code