Developing Water Trails In Iowa: Chapter 6 - Signage
Iowa Department of Natural Resources / Iowa State University, 2010
Low head dams pose a significant risk to public safety. Water flowing over these structures often creates a submerged hydraulic jump—commonly referred to as a hydraulic roller—that can trap and drown unsuspecting victims. Each year, numerous fatalities and accidents occur at low head dams, often because people are unaware of the extreme danger and unknowingly enter these hazardous conditions.
Whenever feasible, low head dams should be removed or modified to eliminate the hydraulic roller. When removal is not possible, effective signage is essential to warn the public and reduce risk.
Iowa’s water trail signage guidelines offer specific and detailed recommendations for installing signage around low head dams, including the appropriate types of signs, specific messaging, sizing, placement, and the number of signs needed to adequately alert users.
.....THIS PAGE IS STILL A WORK IN PROGRESS.....
Revision ID: 8254
Revision Date: 10/10/2025