The United States Bureau of Reclamation is exploring new or improved techniques for reservoir sediment removal that provide cost-effective solutions that still preserves and sustains the operational objectives of reservoirs. Reclamation is interested to learn about new ideas in the dredging industry that could reduce costs of collecting and/or transporting sediment out of reservoirs. Reclamation is also interested in new or improved methods for efficiently transporting abrasive sediments over several miles that would have less downtime due to mechanical breakdowns or clogging.

Background

New technology is needed to facilitate long-term reservoir sediment management focused on maintaining the remaining reservoir storage capacity, rather than trying to recover past decades of storage loss. There are 90,580 dams listed in the National Inventory of Dams and 3,381 of those are owned by the Federal government (USACE, 2016). Sediment deposition in reservoirs limits the active life of reservoirs by reducing reservoir storage capacity for water supply or flood risk reduction. Sedimentation also impairs dam outlets, reservoir water intakes, water quality, and lake recreation increases upstream groundwater level and flood stage and causes downstream channel degradation, loss of habitat for fish and wildlife, and erosion of stream-side infrastructure. Conventional dredging equipment has been used to remove reservoir sediment, but can cost more than $20 per cubic yard. Hydraulic suction dredges typically have a difficult time reaching sediment at reservoir depths greater than 50 feet. All dredges have difficulty operating during winter conditions with ice. Once sediment is dredged, slurry pipelines are often used to transport the sediment, but the abrasive nature of sand and gravel can cause frequent pipe or pump ruptures and downtime.

Constraints

Collection improvements may include:

  • Equipment setups that reduce the energy cost
  • Improved efficiency of sediment collection
  • Reducing the number of people required to operate and maintain the equipment
  • Improved durability of equipment to operate over many months in variable environmental conditions
  • Solutions capable of removing sediment from deeper water depths (greater than 50 ft)
  • Equipment capable of dredging sediment during freezing winter conditions where ice is prevalent in the reservoir

 

Sediment Transport Technologies May Include:

  • Improved slurry pipeline technology or some other new technology

 

Technologies/Methods Excluded from Search:

  • Technologies related to pressure flushing or drawdown flushing to remove reservoir sediment are not of interest.

 

Possible Solution Areas

  • Dredging technologies
  • Mining technologies
  • Permanent or easily movable installations
  • Transportation technologies

 

Field of Use and Intended Applications

Sediment removal and transportation from reservoirs located in the western United States.