Surveying and monitoring are two separate processes, both of which have an essential role in dredging operations.
Surveys are conducted as a part of a project to define the characteristics of soils and subsoils at the dredging site and/or borrow area. Surveys will determine characteristics of the marine surroundings, such as water depth, currents, waves, temperature, salinity, wind, turbidity, TSS and types of sediment.
Monitoring of a project is an exercise in quality and quantity control to determine if a dredging operation is meeting the performance requirements that have been stipulated. Monitoring will determine in land reclamation projects, if the quality of fill is suitable for the purpose of the project; in deepening channels, if the correct depths have been dredged; and in all cases, if a project fulfils the environmental requirements.
- Adaptive or feedback monitoring
- Compliance Monitoring
- Contractual Monitoring
- Environmental Monitoring Programmes
- Geological and Geotechnical Data
- Hydraulic Data
- Monitoring Equipment
- Morphological and Environmental data
- Navigable Depth
- Site Investigation
- Surveillance or BACI monitoring
Managing sediments, especially from dredging, is important for the management of estuaries and coastal areas. When implemented in the right way, a sediment management strategy can be qualified as a nature-based solution as it uses the physical processes of erosion and sedimentation to create added value. There is a need for an evaluation of sediment strategies and the habitats that are created for a wider range of objectives than only biodiversity and nature conservation. The concept of ecosystem services provides this broader framework.
As regular maintenance and relocation of sediment deposits are highly expensive, Port authorities seek more efficient solutions for reducing the costs and CO2 emissions of maintenance dredging. One solution, water injection dredging (WID), is carried out for maintaining the sediment deposits which predominantly consist of clay and silt. WID has been proven to be a cheaper solution by leaving the sediment in place, eliminating substantial costs for relocation of the dredged sediment.