The Great Moss Swamp (much of which is also known as the Loganburn Reservoir) is located in

Otago Otago (, ; ) is a regions of New Zealand, region of New Zealand located in the southern half of the South Island and administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local go ...

, New Zealand, within the

Maniototo The Maniatoto Plain, usually simply known as The Maniatoto, is an elevated inland region in Otago, New Zealand. The region roughly surrounds the upper reaches of the Taieri River and the Manuherikia River. It is bounded by the Kakanui Range to ...

region. It is located on the

Rock and Pillar Range The Rock and Pillar Range (), is a range of high hills is located in the Maniototo, an area of inland Otago, New Zealand. The range is surrounded on three sides by the Taieri River, which has its source in the Lammerlaw Range. The river flows ...

, near the

Old Dunstan Road Dunstan Trail, also known as Old Dunstan Road, is a historic route in Otago, New Zealand. The road was created during the Central Otago gold rush of the 1860s. At the time of the road's creation, it was the shortest route from the city of Duned ...

, a former gold mining route, approximately northwest of

Dunedin Dunedin ( ; ) is the second-most populous city in the South Island of New Zealand (after Christchurch), and the principal city of the Otago region. Its name comes from ("fort of Edin"), the Scottish Gaelic name for Edinburgh, the capital of S ...

city centre. This area is classified as a regionally significant wetland. The Rock and Pillar Range are a horst range, and have a very flat top. Originally a

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

, the upper surface of the Rock and Pillar Range was transformed through the construction of a dam to store water for

irrigation Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...

and

hydroelectricity Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

. This has turned the 'swamp' into a

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

as part of the Maniototo Irrigation Scheme. The swamp is drained by the Logan Burn, which feeds into the

Taieri River The Taieri River (a misspelling of the original Māori name ''Taiari'' ) is the fourth-longest river in New Zealand and is in Otago in the South Island. Rising in the Lammerlaw Range, it initially flows north, then east around the Rock and Pill ...

Paerau Paerau is a small settlement in inland Central Otago in New Zealand's South Island. It is located in the Strath Taieri, the upper valley of the Taieri River, at the foot of the Rock and Pillar Range. "Paerau" is a Māori-language name meaning "on ...

. Despite the transformation, there are still significant areas of swampy wetland at the southwestern end of the lake. The Loganburn Reservoir was completed in 1983, with a capacity of of water. In 2014, the dam was raised by , which included adding an 80 cm-high spillway and increasing the height of the coping wall along the top of the dam. This modification increased the storage by some . The dam is located on the southern end of the Rock and Pillar Range, about south of

, providing irrigation for 60 farmers and , and power generation when water is released for irrigation.

References

Wetlands of Otago Lakes of Otago Reservoirs in New Zealand {{Otago-geo-stub