Managing Coastlines

Victorian Coastline Section a) Answer these questions: Only 4% of the Victorian coastline is privately owned. The remaining 96% of coastal land is held by the Victorian Minister for Environment on behalf of the Crown for all Victorians. One third of Victoria's coastal Crown land is reserved as national park under the National Parks Act 1975 and managed by Parks Victoria Section a) Answer these questions: 1) Have you been to any Victorian beaches? 2) What is your favourite beach and why? 3) Why do you think beaches and coasts need to be managed by government?

Who is responsible for coastal management? All levels of government have some responsibility for coastal management. Traditionally, under the Australian Constitution, the states have the greatest power over the use of the coastal zone. However, responsibilities are fragmented and often overlap. People have different and often conflicting perspectives about how the coast should be used and managed. There are various stakeholders, including local, state and federal governments, the community, environmental groups, local businesses, and recreation and sporting associations.

A spectacular coastline One of the most spectacular coastlines in Australia is located near Port Campbell in western Victoria. The rapidly eroding coastline is exposed to the strong seas and winds of the Southern Ocean, and is characterised by sheer cliffs, rock stacks, gorges, islands, arches and blowholes. This sensitive coastline is protected within the Port Campbell National Park and managed by Parks Victoria. Section b) What do you think can be done manage erosion of coastlines?

Groynes Task: Explain in your own words how groynes “work”. Groyne are an artificial structure designed to trap sand being moved by longshore drift, therefore protecting the beach. Groynes can be built using timber, concrete, steel pilings and rock. Traps sand and maintains the beach. Groynes do not stop sand movement that occurs directly offshore. Task: Explain in your own words how groynes “work”.

Beach/Sand Replenishment This is the artificial placement of sand on a beach. This is then spread along the beach by natural processes. Sand is used that best matches the natural beach material. Low environmental impact at the beach The sand must come from another beach and may have an environmental impact on that location. Must be carried out on a continuous basis and therefore requires continuous funds. Task: Explain the advantages and disadvantages of this process in managing erosion.

Offshore breakwater A breakwater is a structure parallel to the shore and placed in a water depth of about 10 metres Waves break in the deeper water reducing their energy at the shore. Task: Explain how a breakwater helps to give protection to the coastline.

Sea wall A sea wall is a structure placed parallel to the shoreline to separate the land area from the water Prevents further erosion of the dune area and protects buildings. Task: Find three images of local sea walls and explain where these sea walls are. Research the cost of building a sea wall.

Sand Dunes Dunes are an integral part of our coastal environment and support valuable communities of plants and animals. The plants in turn stabilise the dunes, preventing them from being blown inland. Dunes are ‘nature’s sea walls’. They are flexible structures which provide protection by sacrificing themselves at times of storm attack. Without the protection of the dunes, the beaches themselves are more at risk of erosion. Task: Explain what is meant by “Dunes are nature’s sea walls”.

Backshore and Foreshore 1) What is a low tide. 2) What is a high tide Backshore and Foreshore 1) What is a low tide? 2) What is a high tide? 3) Where might be the safest place to swim? The foreshore or the backshore? Why?

If you need a refresher about EROSION, please read the next slide…

How erosion works… Coastal landforms are produced by two major processes — erosion and deposition. Erosion is the wearing away of the Earth’s surface by agents such as wind and water. Wind and waves create the energy that erodes the rocks along coastlines. You will be aware of this energy if you have ever been dumped by a large wave! Waves are constantly striking against a coastline. When the weather is windy, the waves are larger and more powerful. As the waves hit the coastline, the energy in them is used to erode rocks and move sand, pebbles and other material. Some rocks are more resistant to erosion than others and will not wear away as quickly. Waves carry sand and other material on and off the shore. When a wave breaks, the water from it runs up the beach. This is called the swash. The movement of water back down the beach to the sea is called the backwash.

Managing Coastlines Task: Make a PowerPoint Presentation about Coastline Management. Include the following: Why do we need to protect our coastline/beaches? You need to explain about “erosion”. A slide for each of: breakwater, sea wall, sand/beach replenishment, groynes, boulder barriers, and include a description of how each works (your own words). Research a Victorian beach and include three images that show how this beach is being “protected/managed”.