Floodplain Maps

Maps of Floodplains

Floodplain maps provide the basis for floodplain management, regulation, and insurance requirements by identifying flood-prone areas that may threaten life and property. Floodplain maps are reviewed and approved by FEMA. Once approved, the floodplain maps guide flood management programs, including floodplain regulation, safety, preservation, preparation and mitigation.

Re-Evaluation of Flood Hazards

FEMA completed a re-evaluation of the flood hazards in our community and has provided new Flood Insurance Rate Map's (FIRM’s) and Flood Insurance Study (FIS) report which are effective April 17, 2012. The new floodplain mapping is based on updated topographic, and in some cases, revised hydrologic and hydraulic analysis.

Map Service Center

Use the FEMA Map Service Center to access a Public Flood Map or a Flood Insurance Rate Map.

To have city staff look up your floodplain information, fill out the Floodplain Information Request Form (PDF) and either fax it to 605-642-1337 or drop it off in-person at the Planning and Development Services Center at:
625 5th Street
Second Floor

Floodplain Map Changes

Floodplain maps are periodically updated and revised to reflect changing conditions, such as impacts of flooding, new topography, land development, updated mapping studies, and construction of floodplain improvements.

Map Forms

Floodplain map changes can take several forms such as:

• Conditional Letters of Map Amendment (CLOMAs)
• Conditional Letters of Map Revision (CLOMRs)
• Conditional Letters of Map Revision based on Fill (CLOMRFs)
• Flood Insurance Rate Maps (FIRMs) or Digital Flood Insurance Rate Maps (DFRIMs)
• Letter of Map Revision (LOMRs)
• Letters of Map Amendment (LOMAs)
• Letters of Map Change (LOMCs)
• Letters of Map Revision Based on Fill (LOMRFs)
• Local Map Changes