Streambed adjustment and channel widening in eastern Nebraska

Update Item Information
Title Streambed adjustment and channel widening in eastern Nebraska
Creator Rus, David L.; Dietsch, Benjamin J.; Simon, Andrew
Subject Stream channelization; Stream channelization; River channels
Spatial Coverage Nebraska; Platte River (Neb.)
Description In eastern Nebraska, stream straightening and dredging efforts since the 1890s have disturbed the natural equilibrium of stream channels and have led to streambed adjustment by degradation and subsequent channel widening. This report describes a study to evaluate the effect these disturbances have had on stream channels in eastern Nebraska. Two sets of survey data were collected approximately 2 years apart during 1996­99 at 151 primary sites. Additionally, historical streambed-elevation data (dating back to the 1890s) were compiled from several sources for the primary sites and 45 supplemental sites, and relevant disturbances were identified for each of eight basin groupings. Streambed-elevation data sets were used to estimate the amount of change to the streambed at the sites over the time period of the data. Recent channel widening was documented for 73 of the primary sites by comparing the two survey sets. The majority of observed streambed-gradation responses appear to be related to the various straightening efforts and to the effects of grade-control structures in the study area. Channel responses were complicated by the presence of multiple disturbances. However, in many cases, the reambed-elevation data sets provide a reliable representation of the past streambed gradation, with some sites showing 6 to 7 meters of degradation since they were straightened. Many sites that had been straightened showed considerable degradation following the disturbance. This indicates that eastern Nebraska stream channels can regain equilibrium mainly through the slope adjustment process of head-ward-progressing degradation. Bank failures were documented at sites in all eight of the basin groupings analyzed, and widening rates were computed at 64 of 73 sites. Observed bank widening in the Big Blue River Basin, a relatively unstraightened basin, indicates that other disturbances besides stream-channel straightening may be causing channel responses in the basin and possibly in the entire study area.
Publisher U.S. Geological Survey
Contributors Nebraska Department of Roads; Nebraska Department of Natural Resources; Lower Platte South Natural Resources District; Papio-Missouri River Natural Resources District; U.S. Army Corps of Engineers; National Sedimentation Laboratory of the U.S. Department of Agriculture
Date 2003
Type Text
Format application/pdf
Digitization Specifications pdf file copied from USGS website (http://water.usgs.gov/pubs/wri/wri034003/). Uploaded into CONTENTdm version 3.7.
Identifier http://water.usgs.gov/pubs/wri/wri034003/
Source Rus, David L.; Dietsch, Benjamin J.; Simon, Andrew, Streambed adjustment and channel widening in eastern Nebraska, Lincoln, Nebraska: U.S. Geological Survey Water-Resources Investigation 2003-4003, 63 p.
Language eng
Rights Management Public Domain, Courtesy of the USGS
Holding Institution University of Utah
ARK ark:/87278/s68c9v5s
Setname wwdl_er
ID 1145912
Reference URL https://collections.lib.utah.edu/ark:/87278/s68c9v5s