5856_LH - Living Here - MARCH 2017_WEB

Uniquely braided
In Canterbury, the seven alpine rivers that contribute 88% of the
flow within the region – Clarence/Waiau Toa, Waiau, Hurunui,
Waimakariri, Rakaia, Rangitata, and Waitaki – are all braided.
Other foothill rivers are also braided or
have braided reaches.
Braided rivers are iconic natural features,
found in only a few places around the
world, such as Alaska, Canada, the
Himalayan region, and New Zealand.
‘Braiding’ refers to the multiple water
channels that flow around gravel islands.
These unique features of the Canterbury
landscape started life during the last major
ice age 25,000 to 10,000 years ago, when
huge glaciers pushed millions of tonnes of
rock off the spine of the Southern Alps. As
the ice began to retreat, streams and rivers
carried this alluvial outwash down the
valleys of the east coast and deposited it
to form flat basins between the mountains
and the coastal plains.
Braided rivers are characterised by their
multiple, shifting channels, varying
flows and shingle substrate. The rivers
are an abundant supply of food and
support many species that can’t be found
anywhere else, including 26 species of
native bird, with the majority classified
as threatened and facing increased
pressures as the natural character of
their home changes.
It is recognised that the habitats provided
by braided river systems are becoming increasingly vulnerable as we
place pressures on them for water use, such as irrigation and hydro
schemes and recreation. They also face pressures from increased
pests, weeds and pollution.
Working together
In February, the Environment Canterbury Council
resolved to make Plan Change 4 of the Land &
Water Regional Plan (the ‘Omnibus’ plan change)
operative. Among other things, this plan change
strengthens the rules regarding removal of
vegetation from braided river beds and defines
those beds to make it easier to understand how
to comply with stock exclusion rules.
Many agencies have come together to ensure
an aligned approach to protecting the braided
rivers. Environment Canterbury, local councils,
Te Rūnanga o Ngāi Tahu, Federated Farmers, the
Ministry for Primary Industries, Land Information
New Zealand, Department of Conservation,
Braided River Aid (Braid), Forest & Bird and many
other local groups are already driving work on
the ground that can be built on for the future.
Specific management plans are also being
considered for individual rivers, like the Hurunui.
The Canterbury Water Management Strategy (CWMS) aims to halt the
decline through its targets and goals with its focus on the integration
of water and land management including the protection of indigenous
biodiversity and water quality.
This is also integrated with kaitiakitanga
or guardianship by Ngāi Tahu which
applies to the ecological health of all
waterways.
A number of projects are underway
to protect and enhance braided-river
ecosystems and species. Such projects
include, weed control (e.g. preventing
weeds, surveillance, removal); sustained
predator control; rules for habitat
protection (e.g. legal protection of
waterways, firewood cutting rules);
adequate environmental flows to
sustain fauna; protected areas networks
(e.g. to protect a representative range
of rivers); community conservation
initiatives; recreation management (e.g.
restricted access for four wheel drives);
communication and education for river
users (e.g. improved signage); subregional
(zone) action plans; inventories
of current state; fencing of stock to keep
them out of waterways. Many of these
activities are methods for achieving the
CWMS targets.
The unique protection issues of
our braided rivers is explained at
www.ecan.govt.nz/cwms-braided-rivers.