Beach Recharge

Is this policy destroying our beaches and wasting our money?

For the past twelve years (1994 to 2006) the Environment Agency has been purchasing sand and shingle taken by the dredging companies from the offshore seabed along the East coast (and similarly elsewhere in the UK) in order to place this material back onto our worst depleted beaches in an attempt to maintain them and to prevent serious inland flooding. With insufficient funding for permanent long-term defences, and due to the continuity of offshore aggregate dredging combined with rising sea levels and worsening storms, this particular sea defence policy forms a temporary stop gap measure.

Waves breaking over breakwater

This practice of beach recharging is not entirely an aesthetic decorative exercise. In most cases it is a dire necessity because many vulnerable areas have been so stripped of their sand depth cover that this allows the sea to erode the toe foundations of the sea walls themselves. Once these walls were set back in the dune system, but now they face the sea on almost every high tide.

This incursion of the sea has been mainly brought about by dredging aggregate offshore, which deepens the sea bed by up to five metres, so creating closer, greater and more erosive waves. Furthermore the steepened beach enhances the gravitational run-off of its covering sand which then returns offshore to the dredged areas, so requiring constant replacement by recharge.

Thus we are reminded of the story of the unwise monkey who, wishing to grow a longer tail, ate his own tail in order to obtain the protein necessary with which to grow a longer tail. But we also see the story of a ‘recharge’ in another sense, that of paying the exploiters of the sand a regular never-ending and very considerable sum of money to replace the beach that they were mainly responsible for the loss of in the first place.

Precisely the same recharging of beaches occurs in the United States. Jerry Berne of Sustainable Coastlines wrote in Raleigh (North Carolina) Metro Magazine in July 2004 ‘Beach Nourishment: A Starvation Diet’ of a self-same situation. He described how the $45 million Broward County beach nourishment project, completed the previous year, had already gone, and that no more offshore sand remained.

In late September the previous year, the mayor of Folly Beach had told how 85% of the $12 million of sand pumped onto shore at the end of last year had disappeared. This occurred during the summer months when beaches supposedly build. Further, Folly had an extensive groyne field which was supposed to hold this fill.

In 2005 Florida spent $180 million to “nourish” its beaches with most of the fill sand mined from the seabed. Earlier that year, Barry Drucker, the Minerals Management Service scientist responsible for studying the offshore sand mining process used for nourishment, wrote “Some of this shift is definitely due to the realization that exploiting too much of deposit in close proximity to the beach can actually have a devastating effect on the shoreline and subsequent increases in erosion.” He advocated dredging far further out to sea.

Jerry Berne has pointed out that what he did not say is that the erosion caused by doing so is ongoing because those once protective shoalsshoal A sandbank or sandbar that makes the water shallow are now obliterated by the earlier mining, and that this means more expense, a spreading destruction of the seabed habitat and further harm to onshore and nearshore ecosystems. It also means that our nearshores are deepening and steepening allowing more destructive storm energy to reach the shoreline.

He wrote “The term beach ‘nourishment’, carefully chosen to sound healthy, is really a starvation diet. The research and empirical data continues to demonstrate its environmental damage to coastal ecosystems as well as it leading to increased erosion. The dredging of inlets and offshore shoals for sand fill increases onshore erosion according to the EU’s 2004 ‘Guide to Coastal Erosion Management’. This 2005 EU study further states that this causes sediment starvation and hydraulic changes inducing even more erosion.

He quoted a research abstract for the Minerals Management Service, which in 2000 stated: “When a shoalshoal A sandbank or sandbar that makes the water shallow is flattened (by dredging), the degree of wave energy concentration is likely to be reduced, resulting in greater wave energies hitting the coastal area. This may result in increased coastal erosion or unwanted, detrimental changes in longshore or nearshore current patterns. Significant coastal impacts could also be expected during storm events in that increased wave energies which might have been somewhat dissipated by the presence of the shoal would now impact the coastal area with greater forces.”

Research performed by the North Carolina Geological Society and the University of Arkansas off Pea Island in 2000 directly related offshore shoal topography to erosion hot spots. Up to three miles offshore (the farthest area studied), the shoal topography still effected onshore erosion.

There are also health risks in dumping dredged sediments onto beaches. In 2001, the US Office of Naval Research warned of dredging tainted sediments because, “In harbours, waterfronts and shorelines around the world, sediments that have been contaminated by even small amounts of oil, chemicals or other pollutants may pose a risk to humans and to natural ecosystems.”

A further characteristic often found on recently renourished beaches are rip currents. These potentially deadly currents form as the steep profile of the unnatural beach is moved into troughs along the nearshore. Several people drowned near Pensacola, Florida following beach recharge. One lifeguard in Savannah said they know after each nourishment to expect this.

Jerry Berne concluded “We are losing our shorelines and the coastal resources these protect. Almost all of this lost is directly attributable to man. We can help mitigate this damage with methods proven to be sustainable and environmentally sound. Unfortunately for our coastlines and our taxpayers, beach nourishment is not one of these.”

Top world Coastal Geomorphologist Professor John Pethick, who is independent of the aggregate companies and environmental organisations such as MARINET, recognising that sources of sand which supply the shoreline come from offshore banks, expresses similar concerns to those of MARINET, stating “We must not dredge and place that dredged material upon the shoreline, otherwise it will increase the erosion, the very reverse of what is required!”

In hard economic terms the cost of this replenishment exercise is considerable, but with the lack of funding for a long term comprehensive protection strategy ( i.e. permanent and effective sea defences) and with money only granted by government on a year to year allocation, only stop gap measures are possible, with allocation given only to those most urgent cases as a means of temporary repair.

Only 8% of the sand taken from offshore goes to the repair of our coastline, compared with 57% going to London for building projects and 35% exported to Europe, but this 8% is still a considerable burden on our resources, and comes at no little cost, as constant replacement is required.

Mablethorpe to Skegness, Lincolnshire

According to the minutes of the East Coast Dredging Liaison Committee beach recharge has been taking place between Mablethorpe and Skegness for the past 12 years (1994 to 2006). During these twelve years 11,000,000 cubic metres (which is the equivalent of 18.7 million tonnes of sand) have been dredged from offshore and deposited on these beaches in order to counter the effects of erosion/loss of beaches, nearly all of which would appear to have been washed away again.

This means that an average of 1.6 million tonnes of sand has been artificially placed on these particular beaches each year, only to subsequently disappear again within twelve months and thus be artificially replaced by another 1.6 million tonnes (average annual figure).

The cost of this whole exercise, paid for by the Environment Agency, over the twelve year period has been £79 million. This translates into an annual average cost of £6.6 million. The question must be, is this sound expenditure of money or would an alternative strategy be more cost effective?

Three years ago a review of the beach recharging between Mablethorpe and Skegness indicated that 200,000 cubic metres (equivalent to 340,000 tonnes) wasn’t keeping pace with erosion because most of the recharge material was being lost. A new programme was developed which entailed 3 years of intensive recharge, bringing the beach up to the level it needs to be, then to revert to a lower maintenance recharge regime. About 350,000 cubic metres (595,000 tonnes) a year was indicated as a necessary level for maintenance. This will be reviewed every 5 years.

Happisburgh to Winterton (Norfolk)

We have the figures of the beach recharge which has been taking place here for 8 years (1996 to 2004).

  • 1996: 300,000 cubic metres (510,000 tonnes) beach recharge south of Sea Palling Gap
  • 1996-7: 1,000,000 cubic metres (1,700,000 tonnes) beach recharge behind reefs 5 to 13 and at Waxham
  • 2000: 480,000 cubic metres (816,000 tonnes) beach recharge at Eccles and 450,000 cubic metres (765,000 tonnes) at Waxham
  • 2002-3:450,000 cubic metres (765,000 tonnes) beach recharge at Waxham
  • 2004: 350,000 cubic metres (595,000 tonnes) beach recharge at Waxham and Bramble Hill

During these eight years 3,030,000 cubic metres (5,151,000 tonnes) have been dredged from offshore and deposited on the beaches from Happisburgh to Winterton in order to counter the effects of erosion/loss of beaches.

This means that an average of 640,000 tonnes of sand has been artificially placed on these particular beaches each year. It still continues today, but we have no figures for the past three years.

The cost of this whole exercise, paid for by the Environment Agency from the public purse, over the eight year period has been an estimated £21.4 million (calculated by extrapolation from the Lincolnshire coast costs where 1 tonne = £4.20p), which translates into an estimated annual average cost of £2.7 million.

The question has to be, is this sound expenditure of money or would an alternative strategy be more cost effective?

Further works at Happisburgh to Winterton area for 2007 are under consideration, based upon the results of the existing monitoring programme and the availability of funds.

No funds are yet available for Felixstowe and Suffolk District Council works, so this scheme has now slipped to next year, although last month the seawall began to be badly undermined. The construction of a small offshore breakwater at Jaywick next year is now under consideration, but it is felt that funding is most unlikely.

The future – if any

With the government’s myopic ‘Managed Retreat’ policy still in vogue, along with the recent cut of £5m from the East Anglian Coastal Defence Budget and the continuing licensing for offshore aggregate dredging, the loss of our beaches and coastal villages now appears inevitable. But possibly even worse is the failure by government to contemplate employing some of the more modern low cost methodologies that have been found to be so effective and sound value-for-money in the United States.

The huge amount of money provided to assist the income of the dredging companies by governments aiding and abetting short term non-sustainable and repetitive stop gap measures surely tells us that commercial interests are being placed over and above alternative strategies that could prove to be both permanent and more effective. It is time to think hard about the sea defence policies for our ailing coastline and the threatened public.

The question is: will the government listen and be persuaded to do so?

Pat Gowen, 24th January 2007

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