Harnessing Waverly’s Waters

A flood protection study provided by Stanley Consultants recommended an inflatable dam to protect the City of Waverly, Iowa, from future flooding.  Unfortunately, funding could not be secured until the catastrophic 500-year flood of 2008 devastated hundreds of homes and businesses. 

The new dam, completed in 2011, features a fully automatic gated spillway that maintains a set water level elevation and automatically adjusts as needed to changing flow rates.  The "crest" gates were installed over the entire length of the former uncontrolled spillway and are "hinged" at the bottom to allow full operation, thus controlling discharge and pool level.  

The project incorporates a novel approach to managing development in flood plains.  Rather than alter the floodplain to contain the river, the river was altered to fit the floodplain.  The project lowered the flood profile of the river, thus reducing the extent of the floodplain and removing the floodplain from properties.