Masters Thesis Abstract: David Kuru
Assessing and quantifying causes of foreshore erosion on the township beaches of Lake Te Anau.
Lake Te Anau represents a highly valuable resource for New Zealand. Firstly, it acts as a focal point for tourism within the Fiordland area. An area of natural pristine beauty, that serves as the entry to Fiordland National Park and Milford Sound. Secondly, Lake Te Anau has been “put to work” and performs an important function of a water storage facility for New Zealand’s hydro-electric power through the Manapouri Power Station.
As is common to alpine lakes in New Zealand, Te Anau presents beaches that are formed from a range of sediments supplied by a combination of hill-slope processes, rivers and streams and glaciers (Kirk, 1985). These beaches have developed their current morphology over thousands of years in response to wave conditions acting across a range of water levels. The range of water levels vary as a response to seasonal and storm conditions in the catchments, as well as being artificially manipulated to meet the needs of hydro-electric power generation.
With the shoreline surrounding Te Anau continually evolving, an understanding of coastal processes and acceptance of continual natural coastal change is essential. A realisation of the need to accommodate constant coastal change is important as it leads to sound planning and management techniques. Usual beach processes like onshore/offshore transport of sediment; longshore drift of sediment and erosion are continuous and result in a dynamic coastal environment around Te Anau. Quantification of these processes would greatly aid management of the lakeshore.
This research is directed at assessing shoreline change of the beaches of Lake Te Anau between the Upukerora River and the Waiau River. This thesis was conducted with two particular aims in mind. Firstly, to assess the current state of foreshore erosion on Lake Te Anau beaches from Blue Gum Point to the Real Journeys (previously Fiordland Travel) Wharf. The second aim was to ascertain the current state of the sediment budget of the Lake Te Anau shoreline from the mouth of the Upukerora River to Steamer Beach.