Assessment of Embedded Culvert Low Flow Hydraulics

In 2010, New Hampshire adopted new rules for the permitting of stream crossings. One aspect is that new culverts should have natural materials located at the stream bed. In culverts that are not open bottom, this means oversizing the culvert and embedding it (burying the bottom of the culvert). Often the material placed in the embedded culvert is specifically sized to match the native material in the stream as well as to be stable. This results in very coarse sediments. Being coarse, at low flows, water can completely disappear into these sediments leaving no aquatic habitat there. Thus, at the same time that culverts are recommended to be embedded, the practice is criticized for its impact on aquatic habitat. The proposed research has two thrusts: to study constructed embedded culverts in NH as well as to complete literature review and interviews with the many other states requiring embedded culverts. In addition the contracting community will be interviewed to determine if there are limitations in the supply or placement of the embedment material. For the field monitoring portion, embedded culverts at various ages will be inspected at low flows for sediment imbrication. In addition the bed sediment particle size distribution at the time of inspection will be developed and compared to that of the design. Aquatic organism passage will be assessed at low flows. The products of this research will be a diagnosis of the issue (real or perceived) and the elements of bed sediment design leading to successful embedded culverts that provide passage for aquatic organisms.

• Record URL:
  https://www.nh.gov/dot/org/projectdevelopment/materials/research/projects/26962y.htm

Language

• English

Project

• Status: Proposed
• Funding: $75,000
• Contract Numbers:

  26962Y

• 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: 20210430
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Culvert inlets; Culvert outlets; Culvert pipe; Culverts; Embedded systems
• Subject Areas: Environment; Hydraulics and Hydrology; I51: Earthworks and Soil Drainage;

Filing Info

• Accession Number: 01686177
• Record Type: Research project
• Source Agency: New Hampshire Department of Transportation
• Contract Numbers: 26962Y
• Files: RiP, STATEDOT
• Created Date: Nov 20 2018 1:15PM