Environmental Engineering Reference
In-Depth Information
There are costs in seeking sources of beach material suitable for renourishment,
in extracting, transporting and emplacing it on the shore, and in subsequent main-
tenance. Additionally, beach renourishment requires costs associated with design,
licensing, approvals, as well as pre- and post-construction monitoring.
On the Atlantic coast of the United States the cost of beach renourishment and
maintenance in 1995 was US$500,000 per (2014 US$700,000) mile per year. A
similar figure was reported by Trembanis et al. (
1999
), who estimated the cost
of maintaining nourished beaches for 10 years along the developed coastlines
of New Jersey, North Carolina, South Carolina, and Florida would be $5.9 mil-
lion per mile; New Jersey having the highest cost of $17.5 million per mile and
South Carolina having the lowest, $3.3 million per mile (2014 US$7.6 million
per mile, 2014 US$28 million per mile and 2014 US$4.2 million per mile respec-
tively). They also found that the average cost per cubic yard was approximately
US$5 (2014 US$6.5/cubic yard), but this also differed along the coastline. It was
suggested by Campbell and Benedet (
2006
) that by 2006 the cost of beach ren-
ourishment in the United States was about US$12 per cubic metre (2014 US$13
per cubic metre). In the United Kingdom cost estimates for three beach renourish-
ments in Wales ranged from £8 to £16 per cubic metre (Wellard and Rimington
2013
).
It is also useful to compare costs for complete projects. Mention has been made
of the ongoing beach renourishment on the Lincolnshire coast in the UK between
per year between 2009 and 2013 has cost £6 million annually. At Ettalong Beach
in Australia, renourishment was estimated to cost $AUS 500,000 per 30,000 m
3
renourishment.
The cost of beach renourishment can vary, depending on a number of varia-
bles. For example, an average beach renourishment in Florida is roughly half the
cost of that in Massachusetts (Hoagland et al.
2012
). Much depends on the avail-
able sources of material for beach renourishment and the distance across which
suitable material must be conveyed. Renourishment of the beach at Bournemouth
in 1974-1975 with sand dredged from a site several miles offshore cost over £1
million, but in 1988-1989 further renourishment with sand supplied as a product
of dredging the adjacent tidal entrance to Poole Harbour cost only £130,000. The
coincidence of a need for dredging with a nearby demand for beach renourishment
thus resulted in substantial savings for Bournemouth.
Costs can be reduced by a number of means. Wellard and Rimington (
2013
)
demonstrated that the unit cost of a beach renourishment could be reduced by 25 %
by changing the volume of the dredge vessel. Economies of scale can be realised
with greater volumes of material (Hoagland et al.
2012
). Simplified placement
methods can also reduce costs. Placing renourishment sediment to a selected height
on the subaerial beach only, and allowing natural sorting rather than labour inten-
sive re-profiling, can reduce the cost of renourishment (Clarke and Brookes
2008
).
2013, where renourishment sediment was heaped on the beach and left to be sorted
by wave action (Fig.
6.2
). In Lincolnshire cost efficiencies were made by surveying
