Hydro Electric power In the Mackenzie Basin

Some useful sentences to include…. The Mackenzie Basin is located at the centre of the upper Waitaki Power Scheme. The natural landscape has been majorly changed by interactions from the HEP developments. These interactions have resulted in a river and lake system that is one of the most modified in NZ. Peoples interactions with the landscape to create the HEP scheme have altered landforms and changed the landscape significantly.

Specific changes Before the HEP scheme these lakes naturally fed water into the Waitaki River system. Dams have been built this has resulted in lakes being artificially raised and lowered which leads to changes in the natural lake/river system. The raising and lowering of lakes has increased erosion around the lake edges. Rivers are controlled with gates so the Pukaki River bed is often dry resulting in major changes for the natural ecosystem which operated before this.

Benmore dam under construction

New lakes have been created – Ruataniwha and Benmore Canals have been constructed to provide a consistent supply of water to the HEP stations. In the Mackenzie Basin the constructions of 50kms of canals involved the largest earthmoving project ever carried out in NZ. The building of Benmore Dam resulted in the formation of the largest human-made lake in NZ – Lake Benmore. “The massive earth dam is 957 x 118 metres, and used around 12 million cubic metres of material.” (Te Ara) Go to pages 52 and 53 in The Geography on the edge textbook. Do a quick sketch map of fig 58 – include labels.

Read page 54 in Geography on the Edge and construct a 4 stage flow diagram to show how the HEP scheme in the Mackenzie created Twizel. Underneath your diagram write down how Twizel has changed since the completion of the HEP scheme. (bullet points) INCLUDE SPECIFIC DATES AND STATS. twizel

The end of the hydro era – The Clyde dam

1986

Money now being put into other sources of renewable energy such as wind farms. Hydro no longer really viable as have used most of the lakes and rivers suitable in SIHC. Also strong environmental opposition due to the huge changes Hydro can cause.