The Great Moss Swamp is located in Otago

Otago

Otago is a region of New Zealand in the south of the South Island. The region covers an area of approximately making it the country's second largest region. The population of Otago is...

, New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, at 45°33'S, 169°56'E. It lies in the Maniototo

Maniototo

The Maniototo Plain, usually simply known as The Maniototo, 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 the north and the Rock and Pillar Range to the southeast...

, close to the former gold mining route of the Old Dunstan Road, 85 kilometres to the northwest of Dunedin

Dunedin

Dunedin is the second-largest city in the South Island of New Zealand, and the principal city of the Otago Region. It is considered to be one of the four main urban centres of New Zealand for historic, cultural, and geographic reasons. Dunedin was the largest city by territorial land area until...

 city centre.

The swamp lies on the upper surface of the Rock and Pillar Range

Rock and Pillar Range

The Rock and Pillar Range of high hills is located in the Maniototo, an area of inland Otago, New Zealand. They are surrounded by the Taieri River, which has its source in the range, flowing out across the scroll plain at Paerau, before almost doubling back on itself at Waipiata and flowing back...

 (the Rock and Pillars are a horst range, and thus have a very flat top). Originally an actual swamp

Swamp

A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...

, a dam to store water for irrigation

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 and hydroelectricity

Hydroelectricity

Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...

 has turned the 'swamp' into a lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

. The swamp is drained by the Logan Burn, which feeds into the Taieri River

Taieri River

The Taieri River is the fourth-longest river in New Zealand and is located in Otago in the South Island. Rising in the Lammerlaw ranges, it initially flows north, then east around the Rock and Pillar range before turning southeast, reaching the sea 30 km south of Dunedin.The upper reaches meander...

 at Paerau

Paerau

Paerau is a small settlement in inland Otago in New Zealand's South Island. It is located in the upper valley of the Taieri River), at the foot of the Rock and Pillar Range...

.