Lower Waitaki River

The geographical area of the lower Waitaki River begins below the Waitaki dam, where the lowland section of the river starts to braid. The video above shows how badly the river is affected by introduced weed species including willow and gorse. Some islands have been cleared of weeds as part of a (now completed) research project to create suitable habitats for braided river birds, primarily black-fronted terns.

Primarily fed by the  the Upper Waitaki, an additional 2% of water flow comes from the Hakataramea River, Elephant Hill and Waikakahi Streams, Awakino River, Otekaieke River, Maerewhenua River, Welcome Creek/Whakapapa Ariki, and Wainono lagoon and its tributaries including the Waihao and Hook Rivers and the Makikihi and Otaio Rivers.

The Zone includes all of the Waimate District and part of Waitaki District (including the rural towns of Duntroon and Kurow).
lower-waitaki-map

Biodiversity & cultural significance

Extract from the Lower Waitaki Zone Implementation Programme (page 8): ‘Small rivers and streams (including the Hakataramea River, Elephant Hill and Waikakahi Streams, Awakino River, Otekaieke River, Maerewhenua River, and Welcome Creek/Whakapapa Ariki) flow into the main stream. Collectively these tributaries, which have peak flows in winter, provide two percent of the river flow…

The Lower Waitaki River is noted for its indigenous fisheries, including tuna (eel), inaka kōkopu and kōaro (whitebait), kanakana (lamprey) and waikōura (freshwater crayfish), with aua (yellow-eyed mullet) and mohoao (black flounder) being found at the mouth…

Native fish found in the catchment include long-finned and short-finned eels, kanakana/lamprey, kōaro, common river galaxias, common bully and upland bully. The Hakataramea valley provides important habitat for New Zealand’s most threatened and rarest fish, the Lowland longjaw galaxias (Galaxias cobitinis). This galaxis is currently only known from two locations in the Hakataramea Valley.’

Important Bird Areas on the Waitaki River – 7-page PDF file that includes maps, habitat types, and threats relevant to this river. This document was extracted from Forest & Bird’s 177-page 20Mb file on all rivers, lakes, and coastal areas.

Lower Waitaki downstream of the Waitaki Dam with Lake Waitaki in the background
Lower Waitaki downstream of the Waitaki Dam with Lake Waitaki in the background

Conservation activities

As can be seen in the (filmed July 2017 ) and photo (Google Earth) in spite of its significance, large stretches of the lower Waitaki are covered in willow, gorse, and other invasive weeds. This is due in part to the relatively low river flow, a consequence of damming the upper reaches for hydro-electicity production and water abstraction for irrigation. Floods that would normally be able to remove small weeds no longer occur, and woody weeds have now become so entrenched that the character of the river has vastly changed.

A key conservation project was to try removing weeds from islands in the river just below the town of Kurow, in order to provide suitable nesting sights for critically endangered black-fronted terns. The cleared islands are visible in the video. The project, which formed part of a now completed PhD thesis, is outlined below:

Lower down the river towards the coast, work is also being undertaken by the Lower Waitaki River Management Society to improve mud fish habitats.

Water flow

Lower Waitaki river mouth
Lower Waitaki river mouth

References & research material