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Streambank Stabilization


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Delaware River Streambank Restoration Program

               
What it is: 

A phased program to stabilize eroding banks along the Delaware River. Primary goals are to alleviate streambank erosion, reduce downstream sedimentation of Perry Lake, improve water quality and protect valuable farmland.

               
What has been accomplished so far: 

More than 3 dozen individual stabilization projects will have been implemented by the end of 2014.  The majority of the projects are along a reach of the Delaware River stretching from Highway K-20 in southern Brown County to Half Mound Road in northern Jefferson County. Six additional projects are planned for Muddy and Straight Creeks, major tributaries of the Delaware River.

 
Why is the Program needed: 
Changing land use, channelization (straightening), and the removal of trees alongside streams have caused drastic changes in streams and rivers in the watershed. These disturbances have increased the volume and velocity of runoff which in turn causes stream beds to erode and become deeply incised into the surrounding floodplain.  As streams become deeper, streambanks become more and more vertical and unstable.  The weakened banks become undercut and slump under their own weight while floodwaters carry away loosened, unprotected materials and sections of the banks. This destroys valuable farmland and sends massive quantities of soil into downstream lakes.  Heavy sediment loads in streams and lakes negatively impacts aquatic species, and the deeply incised streams become disconnected from the adjoining floodplain which aggravates flooding and negatively impacts groundwater.

Eroding banks along streams in the Delaware River Watershed contribute to the sedimentation of lakes in the watershed.  Eroded soil from streambanks is carried downstream where it is deposited in lakes and ponds and reducing the water-holding capacity.  This decreases water supplies, negatively affects recreation and decreases water quality. Other pollutants (examples: some pesticides, phosphorus and others) can also be transported into lakes attached to these soil particles.


Positive outcomes of the stabilization program:
 

*Reduces streambank erosion

*Prevents loss of valuable farmland

*Reduces sedimentation of downstream lakes and maintains lake water storage capacity for future water users

*Protects recreational resources

*Reduces negative impact of sediment on aquatic species

*Reduces stream channel degradation which helps maintain groundwater levels

*Restores riparian forest resources and benefits wildlife

*Reduces pollution from other soil-attached pollutants

What practices are being used to stabilize streambanks:  
The magnitude of the problem and size of the Delaware River requires a combination of engineered practices (requiring the use of heavy earth-moving equipment) and biological components (such as planting native grass and trees and installing willow poles).  


The following practices are components of most projects:                               

  • Reshaping vertical streambanks to a gentler slope which allows for the re-establishment of vegetation on the channel bank.
  • Planting of native grasses and trees on the re-shaped channel bank.
  • Installation of protective rock at the base (or toe) of the streambank.
  • Installation of re-directive rock structures such as rock vanes or weirs within the stream channel to re-direct the force of stream currents.
  • Planting a riparian buffer on the floodplain adjacent to the stabilization project.  Buffers planted are a minimum of 66’ wide and extend the entire length of the stabilization project.

    Funding Sources: 
    The stabilization projects funded through the Delaware River Streambank Restoration Program are large, requiring funding and technical assistance from a combination of several sources. 

    Sources of funding and technical assistance to date include the following:

    *2009 American Recovery and Restoration Act (ARRA)

    *Kansas Water Pollution Control Revolving Loan Fund (KWPCRF) through the Kansas Dept. of Health & Environment

    *Kansas Water Office

    *Kansas Dept. of Agriculture, Division of Conservation

    *Kansas Forest Service

    *Individual Landowners

                *Private Engineering and Design Firms
      *Delaware River WRAPS and its sponsoring agency, Glacial Hills Resource Conservation & Development Region, Inc.