About the River
The Clutha Mata-Au is New Zealand's
largest river and one of the swiftest and most unspoiled high
volume rivers in the world. It is the longest river in the South
Island, flowing 338kms (210miles) from Lake Wanaka in the Southern
Alps, through the Central Otago semi-desert - the driest region in New
Zealand, to the Pacific Ocean.
The river's course is diverse and
spectacular. We know and love the entire river, but our eco rafting
home is on the upper reaches. Lake Wanaka, at the head of the river,
gathers primarily glacial and snow-melt waters, and acts as a
rock-flour filter, providing the Upper Clutha Mata-Au with unusually
clear, turquoise-tinted water - a very rare characteristic for a large
river. This stunning water rushes away from the mountains through a
spectacular, golden semi-desert landscape of ancient glacial terraces.
Mata-Au's average discharge into the Pacific is estimated at 614 m3/s,
comparable to many much larger but slower flowing rivers (the Nile is
650 m3/s). This heavy flow, concentrated into a relatively confined
river channel, makes the Clutha Mata-Au notoriously fast flowing. It is
the swiftest river in New Zealand and is often listed as one of the
swiftest rivers in the world, alongside Australia's Macleay and Fitzroy
Rivers, the Amazon and Atrato Rivers in South America, and the Teestra
River in the Himalaya.
original Maori name 'Mata-Au' refers to the
formidably 'swift current' with its unusual turquoise 'green' colour.
When Captain Cook sighted its impressive flow entering
the Pacific, he named it 'Molyneux' after Robert Molyneux, Master of
Later, during the gold-rush, the miners increasingly
called it the 'Clutha' - Gaelic for 'Clyde'.
The following classification is based on the
system. Grades, sometimes referred to as Classes, are approximate
rather than definitive measures of a rapid's seriousness or difficulty.
The nature of a rapid can alter quickly due to increased or decreased
flow, new obstacles, and changes in the riverbed:
Rapids have small regular waves. The passage is clear and easy to
recognize. Care may be needed to avoid obstacles like trees and rocks.
Grade 2. Medium
Rapids have regular medium sized waves up to 1 metre, easy ledges,
drops and eddies, and gradual bends. The passage can be recognized and
is generally clear, though there may be rocks or tree strainers in the
main current, and over-hanging branches.
Grade 3. Difficult
Rapids have fairly high waves of 1-2 metres, broken water, stoppers and
strong eddies, exposed rocks and small falls. The passage may be
difficult to recognize and manoeuvring to negotiate the rapid is
Grade 4. Very Difficult
Powerful rapids with high, irregular waves, broken water, often boiling
eddies, ledges, drops and dangerous exposed rocks. The passage is often
difficult to recognize and precise and sequential manoeuvring is
Grade 5. Extremely Difficult
Very powerful rapids with very confused and broken water, large drops,
violent and fast currents, abrupt turns, difficult powerful stoppers
and fast boiling eddies, with numerous obstacles in the main current.
Complex, precise and powerful sequential manoeuvring is required. A
definite risk to personal safety exists.
Grade 6. Unrunnable
All previous difficulties increased to the limit of practicability.
Extremely confused and violent water so difficult that controlled
navigation by raft is virtually impossible. Significantly life
threatening if swimming and unrunnable by all but a few experts.
Eco rafters encounter a variety of bird species
throughout the 'Summer'
rafting season. These include the friendly and playful Fantail
(Piwakawaka), Kahu (Australasian Harrier Hawk), White-faced
Heron, Paradise Shelduck (Putangitangi), Grey Warbler (Riroriro),
Oyster Catcher (Torea), Spur-winged Plover, White-fronted Tern (Tara),
Rock Pigeon, Kawau (Black Shag), Karoro (Dominican Gull), California
Quail, and Bellbird (Korimako).
The river corridor is home to many
uniquely adapted native plants able to tolerate the extremes of the
semi-desert climate. The dominant native is Kanuka (White Tea-Tree),
interspersed with other small-leaved hardy natives such as
Olearias, Matagauri and some Manuka (Red Tea-Tree).
Fascinating ground cover natives include the cushion plants, Raoulia
Australis, R. Hookeri, and R. Parkii. Introduced species include Crack
bordering much of the river, and on the riverbanks Lupins, St. John's
Wart, and California Poppies are common.
The Clutha Mata-Au is the second richest
gold-bearing river system in
the world, the richest being the Yukon. New Zealand's greatest
gold-rush began on the Clutha Mata-Au in 1861, continuing through many
stages over the years. When alluvial gold became scarce, massive
gold-dredges were employed to scour the riverbeds and banks. In 1900,
some 187 gold-dreges were operating, the last finally ceasing work in
the early 1960's.
Today, gold is still mined in some areas, but
Resource Management laws and public land beside water (the Queen's
Chain), require the protection of waterways. Floods periodically
release and spread new gold into the river from the quartz reef veins
in the tributaries. The swift Clutha Mata-Au soon breaks this down into
fine alluvial gold, which averages 98% pure. The ancient terraces along
the river also contain gold-bearing quartz. Your Guide knows where to
Clutha Mata-Au River Parkway
The outstanding natural, recreational and cultural
values of the Clutha
Mata-Au have remained remarkably intact despite a range of
historical and recent development pressures. The more remote reaches of
the river, such as the Upper Clutha Mata-Au, retain an impressive
wilderness quality which may soon be lost if the river
corridor is not better protected. In 2003, Pioneer Rafting Guide Lewis
"Finn", initiated a project to create New Zealand's largest river
Parkway, with a river-length trail, along the entire Clutha Mata-Au
corridor from Lake Wanaka to the Pacific Ocean. In 2009, Contact Energy
released proposals for four large hydro dams on the Upper and Lower
Clutha. The Clutha River Forum, an alliance of conservation groups,
opposed all four dam proposals, which were abandoned in 2012. Local
groups are now working to make the river-length trail a reality.