2. Coastline management Gold Coast Shoreline Management Plan Queensland, Australia Why was a management plan needed?
3. Longshore drift was leading to deposition of sandbars at the mouth of the river Tweed causing a shipping hazard. Ship aground at Tweed Heads, 1914
4. Groynes were built at the river mouth to reduce longshore drift and stop the development of sand bars. Mouth of the Tweed 2005 seandigger
5. Surfer’s Paradise: The Gold Coast is one of Australia’s most important tourist destinations. The economy is based around the beaches. Spellcast
6. I n 1967 a series of storms eroded most of the sand from the beaches. The problem was exacerbated by the groynes at the mouth of the Tweed preventing longshore drift.
7. Management strategies had to take into account the importance of the sand and surf culture… Gold Coast beach 1930’s
8. 5 options for coastal management: Not an option because economy relies on tourism Not an option due to the size of the urban area Expensive, requiring hard engineering Adverse impact on surfing conditions Adverse impact on beach activities Some creative thinking was needed. The plan was to widen the beaches and reduce erosion while improving recreation opportunities.
9. A combination of strategies were deployed… Tweed Sand Bypass (Beach nourishment) Source Sand pumped from beach to east of river Tweed Sand passed under river via pipes Sand deposited on beaches to the west of the river Tweed Longshore drift gradually returns sand to the Gold Coast beaches 1 2 4 3
10. A combination of strategies were deployed… Has the Tweed Sand Bypass scheme worked? 1990 – 2000 Webcams constantly monitor the beaches. How to keep the sand on the beach during storms?
11. The Narrowneck artificial surf reef 1. PUMPING SAND INTO TERRAAFIX MEGA BAG 3. OPEN HOPPER TO DROP BAG 4. BAG DROPPED 2. BAG FULL OF SAND Giant sandbags create a structure that creates a surfing wave. How does this reduce beach erosion? Constructing the artificial reef
12. The Narrowneck artificial surf reef: video The reef protects the nourished beaches by as waves break offshore. The reef resulted in a new habitat for fish and marine plants As well as a new surf break, Narrowneck has become a popular diving and fishing location An example of soft or hard engineering?
13. Control points and sand dune stabilization source Dunes are a natural reservoir of sand. Eroded dunes are restored by planting dune-fixing vegetation, and controlling access to the beach to prevent damage by people and vehicles. Another example of soft engineering
14. Gold Coast sea wall The last line of defence for urban areas along the Gold Coast is the seawall. Private home owners have to pay the costs of protecting their own property, while the Council constructs walls to protect public land.
15. Gold Coast shoreline Management Problem Plan Solutions River Tweed mouth groynes led to reduction in beach width along the Gold Coast Gold Coast beach erosion and loss of recreation facilities Potential for serious storm damage to beach-front property To widen all Gold Coast beaches Stabilise the nourished beaches and improve surfing conditions Tweed Sand Bypass project Artificial reef at Narrowneck Dune stabilization and control points Gold Coast sea wall Successes?