Environmental Impacts

Dredge near Eudora; make sure you turn on the sound on your computer and click the arrows in the lower right corner for full screen mode.

The high costs of in-river sand dredging include:

  • It endangers water quality. Dredging stirs up silt that kills mussels and other aquatic life and is expensive to remove from drinking water.

  • It increases pollution. Dredging churns up old industrial pollutants - like PCBs and heavy metals - that have settled to the river bottom, adding to the river’s contamination levels.
  • It threatens key infrastructure. Dredging damages and destabilizes the river channel and thus it risks endangering expensive, valuable infrastructure such as bridges, flood control structures, intake pipes for public water supplies, power plants, manufacturing, etc.
  • It jeopardizes riparian property rights. The river automatically seeks to fill the holes that dredging creates – and one way it does so is by carving dirt away from the riverbanks, leading to loss of some of our nation’s most valuable farmland.
  • It causes hazardous conditions for recreational boaters. Dredging cables that attach the rigs to the banks are often hidden underwater, and are dangerous for recreational river users. This is especially true for motor boaters who travel at high rates of speed.
  • It endangers habitat. Dredging causes erosion that endangers the riparian ecosystem and it alters the physical habitat needed by native fishes. Nineteen threatened and endangered fish species have been collected in the Kaw, six since 2006.
Link to scientific references

A new study, Sand Dredging Effects on Fish and Fish Habitat in the Kansas River is expected to be complete in 2011, just in time for the re-permitting of commercial sand dredging operations on the Kaw. This is an important and long overdue piece of research that will help provide the information needed to make science-based decisions during the re-permitting process. The research is being conducted by Drs. Craig Paukert and Melinda Daniels and their students from the K-State Geography Department with funding from Kansas State University and the Kansas Department of Wildlife and Parks. Link to abstract of the report

The study looks at whether in-river dredging alters fish habitat in a way that harms fish populations, and whether dredging fragments the natural river, preventing fish from moving to different areas. Dredging changes the river channel, and may cause head cutting, streambed degradation, and channel widening which may alter physical habitat needed by native fishes. Dredging can also create a behavioral barrier for migrating fish by creation of deepwater, low velocity areas that may inhibit upstream migrations of native fishes. In the Kansas River, sand dredging has resulted in bank erosion, riverbed degradation, and channel widening. Currently the US Army Corps has issued nine dredging permits through 2012 from near Topeka to Kansas City. In addition, dredging on the Missouri River from Rulo, NE to St Louis will not continue after 2009 unless an Environmental Impact Statement is developed.

Very little research has been done on the ecological effects of instream mining and therefore state and federal regulatory agencies evaluating these effects have little scientific information on which to base their decisions. Of the 21 Threatened and Endangered fish species in the Aquatic Eastern Large Rivers priority area, 19 have been historically collected in the Kansas River and six (32%) have been collected in reaches below Lawrence by Kansas State University researchers since 2006. At least three species in greatest conservation need have been collected from limited sampling near dredging operations and additional sampling may collect other species in these reaches. This study will help identify the habitat needs for Threatened and Endangered fish species and Species In Need of Conservation that are collected in the Kansas River at reference reaches and sites altered by dredging. This information can be used to assure the key large river habitats are preserved. For photographs and species accounts of many of the species go to the Critter Corner.

The YouTube video below is a short explanation of why in-stream sand and gravel dredging is harmful to rivers and streams. The video includes several key sections taken from "In-Stream Gravel Mining" produced in 1994 by the Arkansas Fish and Game Commission to educate the public on this issue.

“By allowing the highest quality construction sand... to be dredged at one of the nation’s lowest prices, the State of Kansas is basically giving away one public resource, Kansas River sand, at the expense of several others including public recreation.” - William G. Layher of Kansas Department of Wildlife and Parks letter to the Kansas City District of the COE dated April 13, 1989.