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BEACH NOURISHMENT

Beach nourishment is the addition of sand to increase the width or sand volume of a beach. It is commonly used to rehabilitate or prevent coastal erosion. To undertake beach nourishment, sand is obtained from a source and distributed onshore and/or in dunes.The source of sand can be divided into two categories: Image removed.

  • Inland sources: Sand is excavated close to a shore and transported by truck. This technique is suited for small scale nourishment.
  • Offshore sources: Sand is dredged from the seafloor. Sand can either be pumped through pipelines to the nourishment site or suction-dredged then transported and dumped by ship. This technique requires careful planning to avoid disturbance of the marine environment.

Pacific Island countries have diverse beach types, such as sand, gravel or a mix of both. Appropriate methods must therefore be selected based on the beach type, erosion processes and beach use.

  • Relatively environmentally friendly response to coastal erosion if well planned and implemented.
  • Provides increased protection from coastal hazards while maintaining natural values and aesthetics of a beach and coastline.
  • Extended beach areas created by beach nourishment can provide opportunities for recreational and tourism activities.
  • Sand dredged for other uses (e.g. enabling ship navigation) can be used for nourishment, avoiding the need to dump the sand elsewhere.
  • Beach nourishment is not a permanent solution and requires periodic renourishment every few years.
  • Uptake of this approach is dependent upon sufficient quality and quantity of sand being available (and the extraction of the sand not causing other environmental issues).
Indicative cost

Beach nourishment can be low (e.g. inland source nearby to the beach) to medium (e.g. offshore sources requiring dredging and transport) cost. Whilst providing cost estimates is difficult given the broad range of influencing factors across the Pacific, the below table outlines the key components that should be taken into account when estimating an beach nourishment project budget for a specific location.

Components

Unit
(A)

Number of units (B)

Unit Cost
(C)

Budget
(B x C)

Establishment Cost

        
  • Planning and design including community outreach

e.g. hours

      
  • Materials e.g. sand procurement

e.g. cubic yards

      
  • Sand transportation

e.g. truckload or container vessel

      
  • Labour

e.g. hours

      
  • Reporting to donor (if required)

e.g. hours

      

Ongoing Cost

        
  • Maintenance Cost (materials and labour)

e.g. cubic yards and hours

      
  • Reporting and Monitoring

e.g. hours

      

 

Beach nourishment is compared against construction of dikes and seawalls as well as other hard coastal protection infrastructure.

Comparison of the two approaches is presented below:

Hard Coastal Infrastructure (Seawalls, dikes etc.)

Beach nourishment

Construction of dikes and seawalls can further degrade natural habitats by exacerbating erosion and disturbing the coastline and seabed.

A routine beach nourishment program can often be a more cost-effective adaptation option.

Hard infrastructure can be effective in stabilizing the shoreline but can destabilise the beach and other environmental services provided by the coast.

Beach nourishment provides recreational and aesthetic benefits
  • -

    1. Northern Peninsula Area Regional Council: Coastal Hazard Adaptation Strategy (CHAS) Phase 3-8, Phase 6 Report

On-ground impacts that the EbA option addresses
Coastal erosion
Saltwater intrusion
Loss or damage of coastal assets

Case study

Gravel Beach Nourishment

Fongafale Island, Tuvalu

The beaches of Tuvalu are comprised of coral gravel and sand. The beaches are vulnerable to sea level rise and storm waves which leads to extensive erosion. Given these erosion-prone conditions, the Japan International Corporation Agency (JICA) conducted one of the Pacific’s first beach nourishment trials on the Tuvaluan Island of Fongafale. To examine the applicability of beach nourishment for the Pacific, continuous monitoring was undertaken for a year to check the shoreline change and beach profile. The results show that the gravel beach nourishment maintained stability under seasonal and extreme condition of wave actions.

Reference: Future Development of Beach Nourishment Project, https://openjicareport.jica.go.jp/pdf/12357216_03.pdf