Construction of Great Yarmouth Outer Harbour (GYOH) was permitted under powers granted by the Great Yarmouth Outer Harbour Act 1986 and subsequent HROs. The Harbour Revision Orders (HRO) were made by the Department for Transport (DfT) in 2005. A licence under the Food and Environment Protection Act 1985 (FEPA) was issued by the marine and Fisheries Agency (MFA) for the marine works in 2007. Construction of GYOH was completed in 2012. In 2011, FEPA licence became a deemed marine licence.
In 2010, Marine Management Organisation (MMO) became aware of local press reports attributing an increase in erosion to the construction of GYOH and began a review of the monitoring, in 2011 the MMO commissioned Cefas to undertake a desk-based study entitled “Shoreline variability in the vicinity of the Great Yarmouth Outer Harbour”(issued 9 march 2012). The 2011 report concluded that:
- there is a build-up of sediment to the north of GYOH that could be due to the presence of the Outer Harbour
- the change in accretion rate at Gorleston is coincident with port construction and requires further investigation to determine cause and effect
- the erosion in the Hopton area is persistent over the last 20 years, shows no change following GYOH construction and is therefore not an impact of the GYOH.
The report recommended further investigation work to be undertaken. In 2014 the MMO commissioned Cefas to undertake a further, more detailed study entitled “The Impacts of the Construction of Great Yarmouth Outer Harbour on Coastal Evolution”. This study involved use of a numerical model to establish potential changes to sediment transport pathways and any resultant potential impacts on the section of coastline between Winterton-on-Sea and Lowestoft, driven by the introduction of GYOH.
In summary, this report has concluded that the construction of GYOH has had a direct impact upon waves and tidal currents, and hence coastal processes, in the local area, however such impacts are limited to a distance of approximately 1.5 km north and south of GYOH. These findings are in line with the conclusions reached in the 2011 Cefas report, and are also broadly in line with predictions made in the document “Great Yarmouth Outer Harbour Development: Environmental Statement” published in May 1997.
In conclusion the 2014 report has provided no evidence of a plausible mechanism for impacts upon coastal processes as a result of the presence of the GYOH to occur in areas outwith 1.5km from the GYOH.