EnviCom Guidance Document 124: Dredging and Port Construction: Interactions with Features of Archaeological or Heritage Interest (2014)

This guidance document is intended to promote the development of good practice for dredging and port construction in relation to underwater cultural heritage, comprising the physical remains of past cultures including:

• Submerged prehistory – evidence of the occupation of prehistoric landscapes at times of lowered sea level
• Coastal occupation – evidence of activities from the historic coastline that have been subsumed by the sea, due to erosion or flooding for example
• Maritime – evidence dating from the prehistoric period to the modern era relating to human exploitation of the sea
• Aviation – evidence dating from the advent of fixed wing-aviation in the early 1900s to c. the mid-20th century

 Marine heritage is a valuable, fragile, finite and non-renewable resource and physical impacts arising from dredging and port construction can result in permanent adverse effects. However, statutory protection for underwater cultural heritage is variable
internationally and the need to consider these physical impacts is often poorly understood.

PIANC (The World Association for Waterborne Transport Infrastructure) is a professional body dedicated to the promotion of good practice inter alia for those working in the field of dredging and port construction. PIANC has a number of permanent Commissions dealing with marine, inland and recreational navigation issues. There is also an Environment Commission, PIANC EnviCom. The need for technical guidance based on international good practice in areas of archaeological and heritage sensitivity was identified by EnviCom and in November 2013 an international workshop was held in Brussels, Belgium, to share examples of good practice. This guidance document is informed by the outcomes of the workshop, including case studies presented by leading experts in the field, so as to highlight lessons learned with regard to five vital steps in the assessment of potential impacts on features of archaeological and heritage interest:

• Context: understanding the strategic and local context within which a scheme or project is planned
• Scoping: understanding which type of impacts might be expected
• Assessing: collecting data; understanding how archaeology and heritage interests might be impacted and the effects of such impacts
• Mitigating: applying the mitigation hierarchy to avoid or minimise adverse effects
• Measures: implementing measures, for example to protect the features of interest