Rotomairewhenua / Blue Lake is a small

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 ...

Nelson Lakes National Park Nelson Lakes National Park is in the South Island of New Zealand, at the northern end of the Southern Alps. It was created in 1956 (one of four created in the 1950s). The park contains beech forests, multiple lakes, snow-covered mountains and v ...

, in the northern reaches of

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) are a mountain range extending along much of the length of New Zealand, New Zealand's South Island, reaching its greatest elevations near the range's western side. The n ...

. Sacred to local

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

, it has the clearest natural fresh water in the world.

Description

The Blue Lake is drained by the west branch of the Sabine River, which is part of the

Buller River The Buller River () is a river in the South Island of New Zealand. The Buller has the highest flow of any river in the country during floods, though it is only the 13th longest river; it runs for from Lake Rotoiti (Tasman), Lake Rotoiti throu ...

system. It is fed by a short upper segment of the Sabine, which in turn is fed by underground seepage through the landslide debris impounding the much larger

Lake Constance Lake Constance (, ) refers to three bodies of water on the Rhine at the northern foot of the Alps: Upper Lake Constance (''Obersee''), Lower Lake Constance (''Untersee''), and a connecting stretch of the Rhine, called the Seerhein (). These ...

. Blue Lake is roughly boomerang shaped, running north then northwest, with each arm of the lake stretching some . Its waters are cold, ranging from .

Clarity

The lake has extremely clear water, and is the clearest natural body of fresh water yet reported. A 2011 study found its

visibility In meteorology, visibility is the measure of the distance at which an object or light can be clearly discerned. It depends on the Transparency and translucency, transparency of the surrounding air and as such, it is unchanging no matter the amb ...

ranged from , clearer than the measured for Te Waikoropupu Springs, a previous record holder. For comparison, laboratory measurements show

distilled water Distilled water is water that has been purified by boiling it into vapor then condensing it back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the origin ...

has a visibility of approximately . Scientists attribute the lake water's clarity to its passage underground from Lake Constance, which filters out nearly all the particles suspended in the water. Its clarity reveals water's natural blue-violet colour.

Facilities and access

Blue Lake is most often reached as a side trip from the

Travers-Sabine Circuit The Travers-Sabine Circuit is a popular tramping route in Nelson Lakes National Park, New Zealand. The full circuit takes about five to six days, although many side-trips are possible for longer tramps. The circuit involves both bush-walking ...

, although a marked route to the south, over the Waiau Pass and another to the West, via Moss Pass continues beyond the lake. The nearby Blue Lake Hut, with 16 bunks, provides accommodation for more than 700 trampers each year.

Māori history

Blue Lake lies within the

rohe The Māori people of New Zealand use the word ' to describe the territory or boundaries of tribes (, although some divide their into several . Background In 1793, chief Tuki Te Terenui Whare Pirau who had been brought to Norfolk Island drew ...

(tribal area) of

Ngāti Apa ki te Rā Tō Ngāti Apa ki te Rā Tō is a Māori people, Māori iwi (tribe) in the upper South Island of New Zealand. Its rohe (tribal lands) include the areas around Golden Bay / Mohua, Golden Bay, Tākaka, Tasman Bay / Te Tai-o-Aorere, Motueka, Nelson, Ne ...

. As part of the

iwi Iwi () are the largest social units in New Zealand Māori society. In Māori, roughly means or , and is often translated as "tribe". The word is both singular and plural in the Māori language, and is typically pluralised as such in English. ...

's 2010 treaty settlement, the lake passed into tribal ownership and was then given back to the Crown. The lake was traditionally used in ceremonies to cleanse the bones and release the spirits of the dead, so they could begin their journey to

Hawaiki (also rendered as in the Cook Islands, Hawaiki in Māori, in Samoan, in Tahitian, in Hawaiian) is, in Polynesian folklore, the original home of the Polynesians, before dispersal across Polynesia. It also features as the underworld in man ...

, and the iwi regard its waters as tapu (sacred). (Blue Lake was used only for males; Lake Constance was used for females.) Its Māori name, ''Rotomairewhenua'', means "the lake of peaceful lands". In August 2014, the official name for Blue Lake was altered to Rotomairewhenua / Blue Lake, following the Ngāti Apa ki te Rā Tō treaty settlement with the Crown.

References

{{Tasman District Lakes of the Tasman District Sacred lakes Nelson Lakes National Park