Log Jam Monitoring

Many roads and highways exist close to streams that exhibit lateral instability (bank erosion). Conventional practices were to armor such locations, and these solutions are expensive, do not provide ecosystem value, and result in high mitigation fees. Natural channel design structures, such as engineered log jams, offer a greener, less expensive alternative to armor solutions. Route 16 in Errol, NH is an example. Extreme bank erosion requires road relocation and streambank stabilization. An engineered log jam has been proposed at the site and is to be constructed during the summer 2019. This is the first NHDOT such installation. Identifying the benefits of natural instream structures to replace conventional armoring solutions could result in significant cost savings on all such projects. Bank and channel impact mitigation costs have been eliminated with the selection of the engineered log jam solution on the Errol project. Had conventional armoring been selected for this project, bank and channel impact mitigation costs were estimated to be $101,000. At this writing, there is no demonstrated and documented information about engineered log jam solutions in New Hampshire, and although employed in the Pacific northwest, there is very limited information nationally as well. A three-year project is proposed that includes eight months of pre-construction monitoring and two years of post-construction monitoring. The monitoring is broken into the following facets: hydraulic, structural, flora, and fauna. In addition the monitoring provides inspection to assess any need for maintenance or repairs. The research objective is to document all salient aspects of engineered log jams relative to road planning, design, permitting, construction, and maintenance. In addition, stream system changes resulting from the engineered log jam will be documented.


  • English


  • Status: Active
  • Funding: $100,000
  • Contract Numbers:

    SPR 26962W

  • Sponsor Organizations:

    New Hampshire Department of Transportation

    John O. Morton Building
    P.O. Box 483
    Concord, NH  United States  03302-0483
  • Managing Organizations:

    New Hampshire Department of Transportation

    John O. Morton Building
    P.O. Box 483
    Concord, NH  United States  03302-0483
  • Project Managers:

    Scholz, Ann

  • Performing Organizations:

    University of New Hampshire, Durham

    Department of Civil Engineering
    Durham, NH  United States  03824
  • Principal Investigators:

    Ballestero, Thomas

  • Start Date: 20190501
  • Expected Completion Date: 20220430
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01686175
  • Record Type: Research project
  • Source Agency: New Hampshire Department of Transportation
  • Contract Numbers: SPR 26962W
  • Files: RIP, STATEDOT
  • Created Date: Nov 20 2018 12:16PM