COSTS – coastal restoration and other common protection options.

The many years of experience with the above coastal restoration option has allowed some detailed and robust financial appraisals to be prepared. And these costings compare very favourable when considered alongside other more common means of attempting to achieve apparently similar goals – protection of coastal margins. The real advantages of this least cost option have also been published in the 4th Assessment report of the IPCC .

COSTS FOR ASSIDUOUS DUNE RESTORATION:

The work required for success is best achieved by partnering with local communities – principally to ensure their close involvement with the ethos of this restoration effort. These informed members of the affected community can then enlighten their peers of the importance and functional nature of this work, and thus engender strong community support and further spread for this successful and low-cost restoration option. The fact that such community involvement keeps costs low is relatively unimportant; project enlightenment is essential. However this aspect does appeal to accountants…

Complete and actual costs for all the inputs required total approximately NZ$30-40/lineal metre of beach – depending on the width of the planting – usually 5m or 10 (including all costs for plants, fertiliser, initial weed control, planting spades, plant protection barriers, plus refreshments and overhead costs). This assumes that the planting is undertaken by volunteer members of the community, which is by far the best option to choose. In NZ, the Bay of Plenty dune restoration was overwhelmed with volunteer members – up to 1,500 members within over 35 groups. The subsequent plantings were publicised, along with the positive effects of their work, so these planting days became social occasions of some standing, and thoroughly enjoyed by all who voluntarily attended. This positivity was extended to include school students and the education curriculum – through the publication of an explanatory education kit called “Life’s a Beach”: http://www.boprc.govt.nz/residents/teachers/teacher-resources/lifes-a-beach-education-resource/

Experience reveals that ONLY ONE initiating planting is most often required, but the plants must remain unconfined so they can proliferate and naturally colonise sand volume being progressively returned by the restored cross-shore sediment exchange processes. To put these low costs into context, the above successful work increases beach and dune width, and also enhances coastal resilience while similarly increasing shoreline biodiversity, and costs only NZ$30,000-40,000 per kilometre of beach (or US$22,500–30,000)

COSTS FOR OTHER COMMON OPTIONS

  1. Seawalls: a local and relatively recent NZ example is the Waihi Beach seawall, which cost NZ$6,000,000 for this one kilometre long refurbished structure. This equates to NZ$6,000/lineal metre of beach – or about 200 times the expense of dune restoration. Additionally this increasingly unsupported work decreases beach and dune width, and decreases coastal resilience while also decreasing biodiversity.
  2. Beach nourishment: the best examples of this work emanate from the United States of America. The numbers below are taken from a project undertaken on Virginia Beach, Virginia USA, and published in the National Geographic Magazine, November 2013: The actual costs of the described beach nourishment project are US$3.5 million/km (or US$ 3,500/metre) in 2013, and repeated every 15 months on average (utilising the information supplied in the article “… rebuilt 49 times since 1951”) So the true costs of this beach renourishment (using current US$ values) could be as high as US$1.4billion for this five mile (8km) stretch of shoreline since commencement in 1951 (49 times & US$28million/time = US$1.4billion).

No ecological restoration or biodiversity improvement is possible with work of this type.

In contrast, work restoring locally indigenous dune plants onto this nourished beach would cost just US$22-30/metre (see DUNE RESTORATION costs above), and this would be undertaken just once (based on the NZ model). This modern action would be the supremely successful and enduring option here (Jenks et al. 2007), and this costs less than 1% of a single renourishment project. This modern 21st century option will also provide wider, naturally protective persistent buffers and better beaches for all to enjoy. The surplus funds should be utilised for other more urgent tasks.