Rock River at Jefferson (Excerpt from SIR 2008-5235)
The Rock River flows south through the community of Jefferson in Jefferson County (appendix 6). The streamgage in Jefferson is on the south side of the bridge at South Main Street. The streamgage is operated by the National Weather Service and recorded a flood-peak elevation of 788.61 ft. The high-water mark near the streamgage house had an elevation of 788.6 ft, and the Jefferson County surveyor measured a flood-peak elevation of 788.57 ft on the road on the north side of the bridge. The three separate sources of data match well and, when combined with the high-resolution 3-m DEM, were used to produce a very detailed and accurate modeled inundation area. The city water treatment plant is near the streamgage and was not flooded, although floodwaters came close, according to city officials. Very little error was found in the modeled inundated area and the correction that was needed was due to recent construction at the south end of the reach.
Photo of high-water mark 41, August 10, 2008. Photo from USGS.
Appendix 6A. High-Water Mark Table (pdf) (excel) (shapefiles)
Appendix 6B. Flood-Peak Inundation Map (pdf) (shapefiles)
Appendix 6C. Flood-Depth Maps (pdf) (grids)
Appendix 6D. Flood-Peak Water-Surface Profile (pdf)
Link to real-time National Weather Service flood prediction site Rock River at Jefferson, Wis