Completing the Form "Record of Coordination - Floodplain Development”.
1. For “Description of Location”, use a description of the bridge location, such as “Four miles east of Adel” or “Three miles north of the Boone/Story line”.
2. Panel, Number, and Effective Date of Map are found on the front of each flood map.
3. Check all “Types of Development” that are appropriate. For example, if we are replacing the bridge, raising the roadgrade, and cleaning or straightening the channel, check Bridge Construction, Road Construction and Channel Improvement. Give a one or two sentence description of the project in Description of Development.
4. A "designated flood plain" is a stream on an FIS map that has floodplain boundaries shown. If the project is not in a designated flood plain, then this form does not have to be filled out and coordination with the community as not necessary.
The zones (A, A1, etc.) are shown on the FIS maps and have no real significance to us. They indicate various insurance zones.
5. A detailed stream in an FIS has calculated hydrology and flood profiles which are shown on the maps and the flood profiles in the FIS document. A non-detailed stream (shown on the Flood Hazard Boundary Map) will show approximate flood boundaries on a map but they are estimates only and are not based on actual survey and hydraulics information.
The Base Flood Elevation (BFE) is the 100-year elevation immediately up steam of the bridge. If using a detailed FIS, use the 100-year elevation shown on the map or the flood profiles. If using a non-detailed FIS, use the elevation from your calculations (HEC-2 WSPRO or PCVAL/plus backwater).
6. The floodway is shown on the FIS maps. If only the piers are in the floodway, check
"No". If the replacement bridge is shorter then the existing bridge, you will probably need to check "Yes". If on a relocated highway, the floodway might be wide so the bridge will either need to span the floodway or we will need to coordinate with the community concerning the excess rise in flood levels (see Item7).
7. If the bridge encroaches the floodway, the FIS may need revision.
