Below are some frequently asked questions to help you understand flood protection in Sunset Valley.

What is a Floodplain?

A floodplain is a geographic area subject to flooding; land adjacent to waterway necessary to contain a flood. Floodplains are associated with rivers, lakes, streams, channels and small creeks that are normally dry most of the year. Sunset Valley has adopted regulations designed to protect the public safety and health. All development must adhere to federal floodplain regulations (CFR 44). Floodplain regulations can be found in Chapter 5 of the Land Development Code.

What is the Floodway?

A floodway is 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 a designated height. Residential development is prohibited within an identified floodway.

How do I find out if my property is in a floodplain?

Floodplain Mapping and Flood Information Services
Sunset Valley maintains floodplain maps (FIRM), floodways, flood inundation maps, elevation certificates and flood insurance information at City Hall. You can request this information by contacting and making the request to the Floodplain Administrator at the contact information above. Walk ins are welcome, Monday-Friday 8:00 AM to 5:00 PM.

You may also use the FEMA Map Service Center and Flood Map Store. Digital versions and images of flood maps are now available for viewing and printing from the online FEMA Flood Map Store. The Flood Map Store allows users to create a FIRMette at no cost. A FIRMette is a section of the flood hazard map at 100% scale that can be printed on standard paper sizes.

Flood Protection Assistance

The City of Sunset Valley Floodplain Administrator is available to conduct on site visits to help residents protect their property from flood damage. Residents who have site specific issues concerning flooding and drainage patterns affecting their property can call and arrange for an on- site visit. City staff will evaluate the situation, consult with City engineers and provide advice and recommendations on how to make their property less prone to flooding, without impacting neighboring properties. To schedule a visit, please contact City Hall, 512-892-1383 or email cityclerk@sunsetvalley.org. 

Building in a Floodplain

Before you file a permit to develop property within the floodplain, you will need to hire a Surveyor, Architect or Engineer who will certify that the proposed construction will meet the requirements set forth by the City. An Elevation Certificate will be required to be submitted with your plans and to determine the best course of action to assure that your property will be reasonably safe from flooding.

Regulations for development in the floodplain are found Chapter 5: Land Development Code.

Additions and Remodeling

Any addition must comply with all floodplain regulations. If the value of the addition, remodel, or repairs of the home or business exceeds 50% of the value of the existing:

• Residential home, the existing structure(s) must be elevated one foot above the base flood elevation.
• Non-Residential, the existing structure(s) must be either elevated or flood-proofed one foot above the base flood elevation.

What are the penalties if I don't secure all my permits?

• You would not be able to occupy or use your building or development until you receive all required permits.
• You may be fined per day of offense (each day constitutes a separate offense).
• The City could require the removal of the improvements constructed without permits.

Mandatory Flood Insurance Requirement

The mandatory purchase requirement applies to all forms of federal or federally related financial assistance for buildings located in a Special Flood Hazard Area. This requirement affects loans and grants for the purchase, construction, repair, or improvement of any publicly or privately owned building in the Special Flood Hazard Area (SFHA). This includes machinery, equipment, fixtures, and furnishings contained in such buildings.

How are premiums calculated?

A number of factors determine the premium rates for flood insurance coverage. They include the amount of coverage purchased, location, age of the building, building occupancy, the design of the building, and, for buildings in SFHAs, the elevation. The only buildings in Zones B, C, and X which are eligible for preferred risk coverage at a pre-determined, reduced premium rate are single-family and 1-4 family dwellings. For these exceptions, there are certain loss limitations depending on the amount of insurance purchased.

What constitutes "substantial improvement" or "substantial damage?"

"Substantial improvement" means any rehabilitation, addition, or other improvement of a building when the cost of the improvement equals or exceeds 50 percent of the market value of the building before start of construction of the improvement. The term includes buildings which have incurred "substantial damage," or damage of any origin sustained by a building when the cost of restoring the building to its pre-damaged condition would equal or exceed 50 percent of the market value of the building before the damage occurred. Substantial damage is determined regardless of the actual repair work performed.

Substantial improvement or damage does not, however, include any project for improvement of a building to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions. Also excluded from the substantial improvement requirement are alterations to historic structures as defined by the National Flood Insurance Program (NFIP).

How are flood hazard areas and flood levels determined?

Flood hazard areas are determined using statistical analyses of records of river flow, storm tides, and rainfall; information obtained through consultation with the community; floodplain topographic surveys; and, hydrologic and hydraulic analysis. The detailed FIS covers those areas that are subject to flooding from rivers and streams, along coastal areas and lake shores, or in shallow flooding areas, but do not include areas of less than one square mile.

What are flood hazard zones and what do they mean?

The Flood Insurance Rate Map (FIRM) shows areas within the 100-year flood boundary, which are termed "Special Flood Hazard Areas (SFHAs)." A "100-year flood" does not refer to a flood that occurs once every 100 years, but refers to a flood level with a 1 percent or greater chance of being equaled or exceeded in any given year. The SFHAs may be further subdivided into insurance risk rate zones (see below). Areas between the 100-year and 500-year flood boundaries are termed "moderate flood hazard areas." The remaining areas are above the 500-year flood level and are termed "minimal flood hazard areas."

Historically, about one-third of claims paid by the NFIP are for flood damage in areas identified as having only "moderate" and "minimal" risk of flood. Flooding in these often is the result of inadequate local drainage systems, and such flooding sources with small drainage areas are generally not identified on FIRMS. The SFHAs are subdivided into flood hazard zones (insurance risk rate zones) according to the following criteria:

• Zone A: SFHAs subject to inundation by the 100-year flood. Because detailed hydraulic analyses have not been performed, no base flood elevation or depths are shown. Mandatory flood insurance purchase requirements apply.
• Zones AE: SFHAs subject to inundation by the 100-year flood determined in a Flood Insurance Study by detailed methods. Base flood elevations are shown within these zones. Mandatory flood insurance purchase requirements apply. (Zone AE is used on new and revised maps in place of Zones A1-30.)
• Zone AH: SFHAs subject to inundation by 100-year shallow flooding (usually areas of ponding) where average depths are between one and three feet. Base flood elevations derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance purchase requirements apply.
• Zone AO: SFHAs subject to inundation by 100-year shallow flooding (usually sheet flow on sloping terrain) where average depths are between one and three feet. Average flood depths derived from detailed hydraulic analyses are shown within this zone. Mandatory flood insurance purchase requirements apply.
• Zone X: These areas have been identified in the community flood insurance study as areas of moderate or minimal hazard from the principal source of flood in the area. However, buildings in these zones could be flooded by severe, concentrated rainfall coupled with inadequate local creates areas of high flood risk within these rate zones. Flood insurance is available in participating communities but is not required by regulation in these zones.

What is a floodway and who designates it?

The floodway includes the channel of a river and the adjacent floodplain. FEMA requires the community to designate a floodway to avoid the possibility of significantly additional rise in base flood elevations.

If a FIRM is believed to be incorrect, what can be done to change it?

Three procedures have been established for changing or correcting a flood map. They are: Letter of Map Amendment (LOMA), Letter of Map Revision (LOMR), and physical map revision.

What is a LOMA?

A LOMA is the result of an administrative procedure in which the Federal Insurance Administrator reviews scientific or technical data submitted by the owner or lessee of property who believes the property has incorrectly been included in a designated SFHA. A LOMA amends the currently effective FEMA map and establishes that a property is not located in a SFHA.

Although FEMA may issue a LOMA, it is the lending institution's prerogative to require flood insurance as a condition of its own beyond the provisions of the Flood Disaster Protection Act of 1973 before granting a loan or mortgage. Those seeking a LOMA should first confer with the affected lending institution to determine whether the institution will waive the requirement for flood insurance if a LOMA is issued. If so, the policyholder may cancel flood insurance coverage and obtain a premium refund.

What comprises technical or scientific data?

In general, the scientific or technical data needed to effect a map amendment include certified topographic data and/or hydrologic and hydraulic analyses to support the request for amendment or revision.

What is a LOMR?

A LOMR is an official revision to the currently effective FEMA map. It is used to change flood zones, floodplain and floodway delineations, flood elevations, and planimetric features. All requests for LOMRs must be made to FEMA through the chief executive officer of the community, since it is the community that must adopt any changes and revisions to the map. A LOMR is usually followed by a physical map revision.