Dredging

Exo Environmental team of experts provide advice on all aspects of the dredging process. These services are always delivered with economic and environmental benefits as one of the primary targets. By working in close cooperation with the client and stakeholders solutions are achieved that have benefits across the pillars of sustainability. Exo offers the development of new ‘capital’ projects and ‘maintenance’ projects, through design, engineering, execution, supervision and monitoring.

Dredging Processes

Generally a dredging process involves much more than just the dredging activity alone, therefore the range of services is equally extensive. With our international experience, Exo provides an insight into a multitude of solutions.

Dredging is an excavation activity that is at least partly carried out under the water level. To generalise the dredging sector, there are two main dredging activities. Maintenance dredging (de-silting); where accumulated sediment is removed from an existing bed profile and capital dredging; where sediment or rock is removed to create a new bed profile. Subsequent to dredging, sediment often needs treatment or dewatering before it can be reused or stored (also referred to as disposal)

Most dredging activities are carried out for the benefit of navigation, the environment, water management (drainage), land reclamation or to obtain resources such as aggregates or minerals. It is generally accepted that there are three main dredging methods

  • Mechanical dredging; sediment is moved from the bed by mechanical means, with a backhoe, grab or clamshell.
  • Hydraulic dredging; sediment is moved from the bed by hydraulic means, with a suction cutter dredger or trailing suction hopper dredger.
  • Other dredging techniques; an agglomeration of all different types of dredging, such as water injection dredging (hydrodynamic dredging), bed-levelling (ploughing), freeze dredging, etc.
Dredging, plough, bed levelling

Expertise

Exo Environmental provides a wide range of services. The summary below provides a non-exhaustive overview:

  • Surveying and sediment sampling
  • Sediment analysis and characterisation
  • Appraisal of sediment applications (disposal and reuse)
  • Feasibility studies and option appraisal
  • Pre-tender calculations and budgeting
  • Tender evaluations
  • Sediment engineering (stabilisation and solidification)
  • Application for consents, exemptions and permits
  • Waste management applications
  • Planning applications
  • Stakeholder and landowner consultation
  • Community engagement
  • Environmental impact assessments
  • Habitat Regulations Assessment
  • Baseline documents
  • Risk assessments
  • Cost benefit analysis
  • Project development and design
  • Site supervision

For further reading also visit membership websites of CEDA and PIANC

For further information and advice please don’t hesitate to contact us.