Chapter 4: Floodplain Ordinance Administration
So far, this guidebook has provided information on the National Flood Insurance Program and the Oklahoma Floodplain Management Act, included floodplain information provided by FEMA, and detailed the regulatory standards communities must meet to maintain participation in the program. But how do the floodplain management aspects of the NFIP actually work? What steps must a community take to ensure development in the floodplain is not flood-prone?
Chapter 4 describes the development permit system essential to communities to guide and manage floodplain development and discusses the permit record keeping system, the local administrator, enforcement, and variances.
The regulations of the NFIP, 44 C.F.R., 60.3, outlining floodplain management criteria for flood-prone areas, state that the community shall "require permits for all proposed construction and other developments including the placement of manufactured homes" within Special Flood Hazard Areas. More importantly, when a community joins the NFIP, then that community's flood ordinance requires the same thing. At this point it is not the NIFP, OWRB, FEMA requirement, it is your requirement. In other words, no construction or development is allowed in a "flood-prone" or an identified "flood hazard" area without a permit from the community. The community may issue a permit after ensuring the proposed development meets its flood damage prevention ordinance as outlined in .
The concept of "development" goes beyond the traditional building permit. Whereas the building permit is concerned with buildings, the development permit's broad scope includes buildings and alterations to landscape (such as excavation or the use of fill) that would affect drainage patterns or the flood-carrying capacity of the watercourse.
GETTING THE WORD OUT
In Oklahoma most counties do not require building permits for construction and development. If this is the case, citizens in these communities should complete a notice of intent (NOI) form (see ) if they plan to develop or construct anything in the community. The NOI is submitted to the floodplain administrator so he/she can determine if the proposed development will fall in or outside the regulatory floodplain. If the proposed development will fall in the floodplain, the floodplain administrator requires the developer to complete the remainder of the permit application. If the proposed development is outside the floodplain, no further action is required. The floodplain administrator should keep a record of all NOIs. This is a very important part of the local floodplain management program.
A permit is required when building or enlarging a structure, placing a manufactured home, mining, dredging, filling, grading, drilling, excavating, landscaping, building, storing supplies and/or equipment, or repairing roads and bridges within flood hazard areas. In other words, any development, structural or nonstructural, that may affect flooding characteristics or flood damages is required to be permitted.
Specifically, all structural projects (buildings, manufactured homes, storage facilities, dams, dikes, etc.) need a permit. Removal, as well as placement activities, needs a permit depending on their type, magnitude, and location. For example, a street paving project at grade still may alter flood flows or increase flood heights and will require a permit. In addition, a fence may affect flooding and would also require a permit. The storage of large, round hay bales (bridge plugs) should be stored away from the main water channels. Installing a fiber optic cable across a floodplain or directional boring under a creek will require a permit. In summary, any development in the regulatory floodplain requires a floodplain development permit.
Anyone wishing to develop in the floodplain must obtain a permit application from the floodplain administrator, fill it out, pay appropriate fees, and submit it for approval before beginning any development activities. Instructions and a development permit application form are provided in . This sample building permit could be adopted by the community as a floodplain development permit. Communities may instead adapt their existing permit systems to comply with their flood damage prevention ordinance. Regardless of the form used, the following information must be supplied on a permit application for floodplain development:
Reviewing a permit application is the most important responsibility of the floodplain administrator. A permit review checklist is provided in . Floodplain administrators may use the checklist to help them determine if the proposed project meets the criteria of the floodplain ordinance. Several factors that apply to all situations must be taken into consideration when reviewing permit applications. In addition, depending on the type or location of a project, special consideration must be included in the review procedure. The items a local administrator must consider for all approved development and for special considerations are outlined below.
LOCATE THE DEVELOPMENT
An example is shown in . The proposed structure is 200 feet north of where the railroad intersects Lake Avenue and 25 feet east of Second Street. Therefore, it will be located in the Special Flood Hazard Area and must meet the requirements of the floodplain ordinance.
DETERMINE IF THE APPLICATION IS COMPLETE
In summary, when an individual proposes any type of development in a Special Flood Hazard Area (SFHA), a variety of permits may be required. As an example, a sewage lagoon is proposed to be built in a SFHA by Community A. Community A would then need to obtain a permit from the State Health Department, satisfy the requirements of the local flood ordinance and possibly the USACE. For any development in the floodplain, an individual should check with local, state, and federal officials for any permits that may be required.
DETERMINE THE BASE FLOOD ELEVATION (BFE)
Once the floodplain administrator has the flood hazard data available, by reviewing the description of the proposed project in relation to the flood hazard, measures to make it safe from flooding can be determined. For example, if a FIRM or FBFM shows a BFE of 930 ft NGVD, the proposed structure must have its lowest floor built to an elevation of at least 930 ft NGVD. The floodplain administrator would then recommend that the floodplain board issue a development permit for the development on the condition it is elevated to or above the BFE. In the case of a nonresidential structure in an unstudied community where the lowest floor is proposed below known flood heights, floodproofing measures must be identified in order for the development to proceed. These measures must be certified to or above the estimated BFE by a registered architect or professional engineer.
Structures existing in a floodway prior to the floodway identification and designation are grandfathered in and can remain as long as they serve a useful purpose. Minimum requirements for substantial improvement (50 percent of the market value or more) to such structures, however, must be elevated to comply with the floodplain ordinance.
When reviewing applications for development in the floodway, the floodplain administrator's first assumption must be that it will cause some rise in the BFE. The developer is required to prove that the proposed development, along with similar future development assumed by the equal degree of encroachment rule, will not cause any increase in BFEs. The developer provides this proof by hiring a registered professional engineer to analyze the development plans and ascertain if the BFEs will be affected. The developer should use an engineering firm experienced in analyzing and modeling hydrologic and hydraulic data.
Unless the analysis establishes that no rise in the BFE would result, the permit must be denied. Deviation from the no-rise analysis is in violation of the local ordinance and NFIP regulations. The community must retain on file certifications that establish the development in the floodway will not increase the BFE. A copy of the engineer's supporting documentation must be kept with that particular permit record. Any development allowed in the floodway must satisfy the remaining program regulations. For example, structures must be protected to the BFE. Information required of proposed floodway development is listed in . An example of permissible floodway development would be a second story addition on a house where the external dimensions of the original house are not altered and the addition's cost is less than 50 percent of pre-construction market value. A floodway development checklist for use by the local floodplain administrator is located in .
In order to do so, the floodplain administrator must require the permit applicant to provide an engineering analysis of the proposed project's impact (along with all existing and any reasonably anticipated development) on flood heights. The analysis must certify that the cumulative effects of the project's impacts are within the acceptable limit. If it does not, the permit must be denied.
The floodplain administrator must maintain certifying documentation of the project's impact on file. By doing so, the administrator will begin a cumulative collection of hydraulic data for the community's flood-prone area that can be used to review future permit applications.
The floodplain administrator should also be concerned with how the depth and velocity of floodwaters will affect proposed development. It is recommended that flood velocities not exceed two or three feet per second in residential areas. Another standard frequently used is that the safety index achieved by multiplying the depth of water by the velocity (feet x feet/second) not exceed a factor of seven. In nonresidential areas, higher velocities may be acceptable.
Generally, an applicant should provide a topographic map of the area in question, a comparison of the existing and proposed channel capacities, a description of the proposed alteration, land use of adjacent properties, identification of the project's features and an assessment of the changes it will cause.
An administrator who does not have the technical background to review such descriptions must rely on the community's engineering staff or seek outside professional assistance.
Local floodplain regulations require the floodplain administrator to notify adjacent affected communities and the OWRB of any proposed watercourse alterations. Neighboring local governments and the OWRB have an interest in water resources and activities that affect them. A sample watercourse notification letter is provided in .
If the watercourse alteration could change the BFE and footprint of the floodplain a Conditional Letter of Map Change is required (CLOMA). Map changes are addressed later in this chapter.
INTERPRETATION OF MAP BOUNDARIES
Dry floodproofing consists of the actual design of a structure providing protection from the Base Flood. The structure must be designed to prevent seepage, collapse or cracking of basement walls, buckling of basement floors, and back-up of water from sewer lines. Walls and floors must be capable of withstanding hydrostatic pressure, and all openings must be located one foot above the BFE. Walls and floors must be made watertight with waterproof seals and coverings used on exterior surfaces. The building must have sufficient weight to resist flotation. Features of dry floodproofing must operate automatically without human intervention. Floodproofing measures on nonresidential structures must be certified by a qualified engineer or architect. The FEMA floodproofing certificate for this purpose is found in .
Another method of floodproofing nonresidential structures under the NFIP is reliant on human intervention. This involves the use of door and window shields as temporary protection from the Base Flood. This method should be used only where adequate flood warning time or devices are present. Extreme caution must be used in designing this floodproofing measure. Generally, door and window shields are not effective for flood depths in excess of three feet and may cause more damage to older structures than they prevent. For instance, boards placed over window openings may prevent rising floodwaters from entering the windows, but rainwater can get behind the shields if the space between it and the wall is not closed or sealed.
Wet floodproofing allows floodwaters to enter the structure by design and to equalize the water pressure on the inside to the water pressure on the outside. The concept here is to have utilities raised above flood levels so that after a flood, only minimal cleanup and repair are necessary.
Any time a nonresidential structure is floodproofed, the design of the structure must be certified by a registered professional engineer or architect, stating that it will provide protection against the Base Flood. A floodproofing certificate must be submitted before the permit application process can be completed (see ).
Dry floodproofing measures are recognized by the NFIP for flood insurance purposes (lower premium rates), but other types of floodproofing, such as wet floodproofing, are not recognized. lists minimum floodproofing standards.
Because Oklahoma is located in an area that experiences severe storms (tornadoes, strong winds, hail, etc.), a community may pursue an exception to the "No Basement Rule" from FEMA. Such exceptions are granted from the FEMA National Office upon application and fulfillment of strict requirements. A community receiving an exception to the "no basement" rule must supply sufficient technical data and adopt a floodproofing code before FEMA will consider the exception. The preferred procedure for constructing a storm shelter in the 1% chance floodplain is to require the structure to be floodproofed and obtain a floodproofing certificate. The air vent and entrance must be elevated 1 to 2 feet above the BFE, and the structure must be anchored in the ground so it will not bouy up during the 1% chance flood.
NFIP regulations require a community to obtain and maintain a record of the elevation of the lowest floor of all new or substantially improved structures in the flood hazard area. To comply with this regulation, communities must require the owner or developer of such structures to provide an "Elevation Certification" assuring the structure has been built above the BFE (see ).
For some Oklahoma communities, floodplains make up a significant portion of the land available for subdivision development. Floodplains are attractive for subdivision development because of their location; however, if these subdivisions are improperly developed, they can become a costly burden to the community.
Local governments that approve subdivisions in the floodplain must be careful that flood levels are not increased when these subdivisions are developed. Local governments may be liable where attempts to control flooding are ineffective or aggravate an existing situation.
Manufactured homes, for floodplain management purposes, include park and travel trailers and similar vehicles that are placed on a site for a period of more than 180 days. Past provisions that allowed replacement, new placement or substantial improvements of manufactured homes in existing manufactured home parks or subdivisions without elevation are now eliminated. New or replacement manufactured homes on lots in the floodplain must be elevated above the BFE and anchored to permanent foundations. For further information regarding placement and anchoring, see .
Manufactured homes that have been continually located in the same floodplain location are affected by this rule change only if they are moved or replaced. This NFIP change will enable community officials to work closer with manufactured home parks and subdivisions located within their community's floodplain.
Only licensed installers can install manufactured homes in Oklahoma.
AO- AND AH-ZONES
The highest adjacent grade means the highest natural elevation of the ground surface prior to construction next to the proposed walls of a structure. illustrates how a structure would need to be elevated in a Zone AO, Depth 2.
AH-Zones are those areas having shallow and/or unpredictable flow paths between one and three feet. These are usually areas subject to ponding. When AH- and AO-Zones are designated, adequate drainage paths around structures are required to guide floodwaters away from these structures. Only a small number of communities in Oklahoma have AO- or AH-Zones mapped.
BOARD ACTION ON THE PERMIT APPLICATION
If a permit application is incomplete, it should not be approved. Additional information should be requested from the applicant. It is recommended that no permit application go before the floodplain board for approval until the floodplain administrator has thoroughly reviewed it and is absolutely certain it complies with the flood damage prevention ordinance.
Some floodplain administrators may choose to review and approve the permit application without any floodplain board intervention. Caution should be exercised if this is the case. It is highly recommended that some form of check and balance system be implemented in the application review and approval process. The floodplain board is an essential part of a community's floodplain management program.
If the applicant chooses to blatantly violate the floodplain ordinance and not work with the floodplain administrator, the floodplain board may have to deny the permit and explain to the applicant why it was denied. A sample denial letter is found in .
APPLICANT'S OPTIONS UPON DENIAL OF PERMIT
If a developer has already commenced construction and chooses not to work with the floodplain administrator, the administrator may then issue a cease and desist letter and post a notice of violation at the development site. provides an example of a violation notice poster.
A variance, as defined by the Federal Emergency Management Agency, is a granting of relief from the requirements of a community's floodplain ordinance, permitting construction in a manner that would otherwise be prohibited by the ordinance. Section 60.6(a) of National Flood Insurance Program regulations contains provisions for variance" allowed as a part of community floodplain management. If a floodplain management study has been completed for a community, its floodplain ordinance may contain a section allowing variances. The Variance Guide found in explains in detail what type of development constitutes a legal variance. A legal variance is dependent on the physical site characteristics of the development property.
Important points to remember about variances:
It appears the only time variances could be safely used is prior to an impending map change. The map change would remove the development area from the floodplain. The variance, in this instance, would buy time for the structure, which under the new map, would be allowable development.
It should be noted that the granting of a variance in the floodplain is a floodplain board decision. The best advice concerning variances is DON'T USE THEM! While the impact of a single variance on flood hazards may not be significant, the cumulative impact of several variances may be severe.
If a developer, however, requests a variance, the floodplain board should have a consistent and fair policy to deal with such requests. Variances can be handled through a board of adjustment or the governing body of the county or municipality where no board of adjustment exists.
First, the granting of a variance does not lessen or waive any insurance premium rates. Consequently, when a variance is granted, the floodplain administrator must provide written notification to the applicant that a project granted a variance is not exempt from insurance requirements. In some instances, a variance may result in increased insurance premium rates that could go as high as $25 per $100 of coverage. A sample "Variance" notification letter is found in .
Secondly, any floodplain board granting a variance must maintain a record of all variance actions. This would include the justification for granting the variance, a record of the appeals proceedings and copy of the written notification referred to above. These records are reviewed during CAC and CAV visits.
Record keeping is an extremely important part of a floodplain board's and floodplain administrator's responsibility when participating in the NFIP. The following records must be kept on file and open for public inspections:
A complete and up-to-date copy of the floodplain ordinance, the flood map (FBFM or FIRM) and the Flood Insurance Study should be on hand. If a study has not been completed, the community should obtain and maintain the best flood hazard data available for the area and use it in guiding floodplain development.
NFIP regulations specifically require that communities obtain and maintain the elevation of the lowest floor (including the basement) of all new or substantially improved structures in the Special Flood Hazard Area. For floodproofed structures, the elevation to which they have been floodproofed must be obtained and recorded. Floodplain administrators must require developers to provide elevation and flood proofing certifications to meet this NFIP requirement.
A project file containing the following items should be kept for each development permit application:
A file should be kept for the Biennial Reports that are submitted to FEMA. The floodplain administrator may want to keep the following information in this file:
The Biennial Report will be easy to complete if this information is readily available.
Although FEMA uses the most accurate flood hazard information available, limitations of scale or topographic definition of the source maps used to prepare the FIRM, as well as changes in flood conditions and dynamics in general, may cause small areas that are at or above the flood elevation to be inadvertently shown within the SFHA boundaries. Also, the placement of fill may elevate small areas within the SFHA boundaries to an elevation at or above the flood elevation. When this happens, structures or parcels of land may be inadvertently included in the SFHA on the FIRM. When fill is added to Zone A or AE, a certificate of fill is required (see ).
For such situations, the property owner and/or community may apply for a Letter of Map Amendment (LOMA) or a Letter of Map Revision based on fill (LOMR-f). LOMAs and LOMR-Fs are documents issued by FEMA that officially remove a property and/or structure from the SFHA. Such amendments or revisons cannot adversely impact the existing floodway or floodway delineations of the 100-year flood.
Letter of Map Revision (LOMR): A LOMR (see ) is normally based on revised hydraulic modeling and usually will not involve specific lots, properties or structures. Because it will revise official regulatory elevations or floodways, a request for a LOMR must have the approval of the community.
NFIP maps are not changed based on proposed projects. However, an applicant may request a Conditional Letter of Map Revision (CLOMR) or a Conditional Letter of Map Revision based on Fill (CLOMR-F) based on proposed plans. A Conditional Letter of Map Amendment (CLOMA) can be requested for a vacant lot. Property owners are cautioned that these conditional letters merely provide comment on the proposed plan and do not amend the map. A LOMR, LOMR-F, or LOMA will still be required to officially change the NFIP map.
It should be noted that the FIRM will not be reprinted when a LOMA, LOMR or LORM-F is granted. Because such letters of change officially amend or revise the effective NFIP map, it is a public record that the community must maintain. Any letters of map changes should be noted on the community's master flood maps and filed by panel number in an accessible location. This will help ensure that changes are not forgotten or overlooked.
The following packages containing forms and instructions for requesting the
respectively listed letters of change and information on associated fees can
be found on FEMA's website:
The MT-EZ is the shortest and simplest of the forms to complete, but a land surveyor, professional engineer, or landscape architect is still needed to certify elevation data. The MT-EZ form is available on the FEMA Web site. The MT-EZ contains detailed information regarding how to get a LOMA and how to determine the status of a map change request, as well as other map change issues.
©1998-2017, Oklahoma Water Resources Board
Page last updated: February 18, 2015