The Legislature of the State of South Dakota has in SDCL 7-18-14 & 15 delegated the responsibility to local governmental units to adopt regulations designed to promote the public health, safety, and welfare of its citizenry. Therefore, the Board of County Commission of Lawrence County, South Dakota, does ordain as follows:

Lawrence County of South Dakota elects to comply with the requirements of the National Flood Insurance Act of 1968 (P.L. 90-488, as amended). The National Flood Insurance Program, established in the aforesaid act, provides that areas of the county having a special flood hazard be identified by the Federal Emergency Management Agency and that floodplain management measures be applied in such flood hazard areas. The National Flood Insurance Program was broadened and modified with the passage of the Flood Disaster Protection Act of 1973 and other legislative measures. It was further modified by the National Flood Insurance Reform Act of 1994. The National Flood Insurance Program is administered by the Federal Emergency Management Agency, a component of the U.S. Department of Homeland Security.

FEMA's Flood Map Service Center is a great resource when looking at property. 

National Flood Insurance Program (NFIP)

By participating in the NFIP the County agrees to manage all new development and improvements in the floodplain and in exchange federally backed flood insurance is available to everyone. 

Flood damage can be costly and is not covered under most homeowner's insurance policies. It is important to understand your flood risk and take steps to insure against potential financial loss. Talk to your insurance agent for more information or stop by the Planning & Zoning Office. 

Floodplain Development Permits

Floodplain development permits are required to be obtained for any work done within the Special Flood Hazard Areas (SFHAs) This includes but is not limited to placement of fill; remodeling of existing structures; and new construction of structures including sheds and fences. Even if the work is not subject to needing a building permit it is still necessary to obtain a floodplain development permit. 

Floodplain Development Permit

Substantial Improvement

When buildings undergo repair or improvement, it is an opportunity for floodplain management programs to reduce flood damage to existing structures. Local floodplain management regulations and codes contain minimum NFIP requirements that are not only for new structures, but also for existing structures with proposed “substantial improvements” or repair of “substantial damage.” Local officials in communities that participate in the NFIP must determine whether proposed work qualifies as a substantial improvement or repair of substantial damage (referred to as an “SI/SD determination”). If work on buildings constitutes SI/SD, then structures must be brought into compliance with NFIP requirements for new construction, including the requirement that lowest floors be elevated to or above the base flood elevation (BFE). Meeting this requirement can also be accomplished by demolition followed by construction of new buildings that meet the NFIP requirements on the same sites or by relocating buildings to locations outside of the SFHA. 

The NFIP defines SI/SD as follows:

Substantial improvement (SI) means any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure (or smaller percentage if established by the community) before the “start of construction” of the improvement. This term includes structures that have incurred “substantial damage,” regardless of the actual repair work performed. 

Substantial damage (SD) 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. Work on structures that are determined to be substantially damaged is considered to be substantial improvement, regardless of the actual repair work performed. 

The 50 percent threshold was chosen as a compromise between two extremes. One extreme would be to prohibit all investment in existing structures that do not meet minimum NFIP requirements. The other extreme would be to allow structures in flood hazard areas to be improved in any fashion without regard to the flood risk. In the first alternative, there is the potential for causing hardship to those who have located in flood hazard areas without knowledge of the risk because the structure was constructed prior to the designation of the area as flood-prone. These individuals would not be able to improve their structures as damage or age contributed to deterioration. The second alternative provides no mechanism to ensure that increased investment in flood hazard areas will receive needed protection from the flood risk, 1- SI/SD Desk Reference 1 INTRODUCTION thus contributing to the increased peril to life and property. Thus, the threshold of 50 percent is a compromise at a half-way point and was chosen because it conforms to similar building code and zoning standards that also use this threshold. 

NFIP Substantia Improvement Desk Reference

Substantial Improvement/Damage Questions