Rotomairewhenua / Blue Lake is a small

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

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 formed after the passing of the National Parks Act in 1952. It was created in 1956 (one of four created in the 1950s). The park co ...

, in the northern reaches of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

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

. 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 C ...

, 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 ( mi, Kawatiri) is a river in the South Island of New Zealand. One of the country's longest rivers, it flows for from Lake Rotoiti through the Buller Gorge and into the Tasman Sea near the town of Westport. Within the Bulle ...

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 (german: Bodensee, ) refers to three Body of water, 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, ca ...

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

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 boiled into vapor and condensed 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 original container. Thus, di ...

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

tramper Tramping, known elsewhere as backpacking, rambling, hill walking or bushwalking, is a popular activity in New Zealand. Tramping is defined as a recreational activity involving walking over rough country. Trampers often carry a backpack and we ...

s each year.

Māori history

Blue Lake lies within the

rohe The Māori people of New Zealand use the word ''rohe'' to describe the territory or boundaries of ''iwi'' (tribes), although some divide their rohe into several ''takiwā''. The areas shown on the map (right) are indicative only, and some iwi ...

(tribal area) of

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

. As part of the

iwi Iwi () are the largest social units in New Zealand Māori society. In Māori roughly means "people" or "nation", and is often translated as "tribe", or "a confederation of tribes". The word is both singular and plural in the Māori language, an ...

'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 In Polynesian mythology, (also rendered as in Cook Islands Māori, in Samoan, in Tahitian, in Hawaiian) is the original home of the Polynesians, before dispersal across Polynesia. It also features as the underworld in many Māori stories. ...

, 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