Dredging the Kaw Update

 From the Friends of the Kaw:

The latest news regarding Kansas River sand dredging may not be the greatest. The most recent project studying in-river dredging on the Kaw shows that the mining operations could be causing some serious damage to our river.

Beginning in 2012, the Friends of the Kaw received a grant from the Water Protection Network to work with the Kansas State University River Systems Research Group to monitor, and study, the effects of in-river sand dredging on the Kansas River. The first year of this study is coming to a close, and the most recent report from this project may help to confirm what users of the river have been saying for years. 

After surveying the dredge hole east of Topeka on several occasions, and in different river conditions, a significant impact on the bed of the river was found to take place around dredging operations. The step by step process of damage caused by dredge holes follows K-state researchers’ hypothesis closely.

1. The initial sand removal causes a deep hole (nearly 30 feet below the normal river bed).
2. Water flowing into the hole speeds up, and causes erosion heading upstream.
3. As water slows down in the hole, some sediments being carried by the water are deposited.
4. As the water leaves the downstream portion of the hole it picks up speed and causes erosion heading downstream.

As this process continues, it may result in an overall lowering of the river bed. This lowering will cause banks to collapse and the channel to widen, swallowing up valuable riverside property and aesthetic sand bars without discretion. Friends of the Kaw has long advocated for the elimination of dredging operations from the river before they result in irreparable damage. Results from this most recent study, and others, suggest that dredges do indeed significantly contribute to the problem of bed degradation.

This fall the US Army Corps of Engineers will complete their Environmental Assessment of the impacts of dredging. After the draft assessment is posted, there will be several weeks available for the public to comment and provide input on this crucial decision-making process.

Watch the KWF blog (www.kswildlife.org) and we will keep you posted on how you can have a significant influence on the Kansas River’s future..