Sandbanks CS

• Where is Sandbanks?

  Dorset
• Who is responsible for managing the Sandbanks peninsula?

  1. Poole Harbour Commissioners
  2. Poole Borough Council
  3. Environment Agency
• What is the plan called to manage Sandbanks?

  Two Bays Shoreline Management Plan (based on sediment cell covering Poole Bay and Christchurch Bay)
• What options does the Environment Agency currently apply strategies from?

  1. Hold the Line (HTL) - maintain, sustain or improve existing defences
  2. Managed Realignment (MR) - existing defences moved to more sustainable positions, usually further inland
  3. No Active Intervention (NAI) - areas of low economic value and/or high environmental value are not protected
• Why does Sandbanks need managing?

  To protect high-value properties and the beach
• What is the economic impact of Sandbanks Hotel and Haven Hotel?

  They create employment and spending locally
• What is the demand for residential properties in Sandbanks?

  High demand with premium prices
• How expensive are residential properties in Sandbanks?

  4th most expensive in the world per square metre
• What is the price of large detached houses in Sandbanks?

  Over £10 million
• What is the price of luxury apartments in Sandbanks?

  Over £2 million
• Why is the beach at Sandbanks a major tourist attraction?

  It has a Blue Flag award for water quality
• What makes the beach safe for family swimming?

  It has a gently sloping shoreline
• What role does Sandbanks play for Poole Harbour?

  It provides protection from waves
• What water sports are popular in Poole Harbour?

  Wind-surfing, sailing, and water skiing
• What facilities are found in Poole Harbour?

  Numerous yacht clubs and marinas
• What is located at the end of the Sandbanks peninsula?

  The entrance to Poole Harbour
• What could happen to the harbour entrance due to longshore drift (LSD)?

  It could become clogged and shallow
• What is the predicted sea level rise in Sandbanks over the next 100 years?

  0.6 meters
• What could be the consequence of flooding in Sandbanks?

  Damage to properties estimated at £18 million
• What is the lowest and narrowest point of the peninsula?

  2 meters above sea level and 50 meters wide
• What could happen if no management strategies are applied in Sandbanks?

  It could cut off from the mainland
• What strategy has been implemented to maintain a deep and wide beach?

  Rock groynes
• What are the reasons for managing Sandbanks?

  • Protect high-value commercial properties
  • Maintain residential property values
  • Preserve beach as a tourist attraction
  • Provide shelter for Poole Harbour
  • Mitigate effects of climate change and flooding
• What do rock groynes do to maintain the depth and width of the beach?

  Minimise movements of sediment along the beach at Sandbanks (by LSD) = prevents sediment from entering harbour entrance (keeps access free to ships) and absorbs wave energy (reduces rates of erosion)
• What would rates of erosion be without rock groynes?

  About 1m per year
• What other strategy is in use to conserve beaches?

  Beach recharge
• What is beach recharge?

  Sand dredged from offshore is sprayed onto the beach ('rainbowing') adding to its size
• How much does beach recharge currently cost?

  £20/m3
• What is a cheaper alternative to beach recharge?

  [2015 trial]

  1. Dumping sediment dredged from the harbour just offshore involves a much cheaper alternative (only £3/m3)
  2. Natural currents transport sand onshore where will help to build up beaches

  BUT 2018 review = only 3% of the 30,000m3 sediment dumped off-shore had reached the beach after 18 months

  1. In total, + 3.5 million m3 sediment has been added to Poole Bay beaches
• How has the management of Sandbanks been successful?

  Sediment budget surplus on the beach (beach profile widened = can absorb more energy) - NB: important due to climate change and resultant sea level rise
• Unintentional impacts of management at Sandbanks

  1. Dredging = deeper water in offshore zone = less friction = more energy (more erosion in future)
  2. Sediment deficit further along the coastline (i.e. Barton Cliffs) = base of cliff unprotected = more susceptible to mass movement (slumping) = spatially limited success