Ōhau River
Ōhau River upstream of Lake Ruataniwha
Location
Country	New Zealand
Physical characteristics
Source	Lake Ōhau
• coordinates	44°17′06″S 169°56′11″E / 44.2851°S 169.9365°E / -44.2851; 169.9365
• elevation	540 metres (1,770 ft)
Mouth	Lake Benmore
• coordinates	44°20′39″S 170°12′17″E / 44.3441°S 170.2048°E / -44.3441; 170.2048
• elevation	380 metres (1,250 ft)
Length	27 km (17 mi)
Basin features
Progression	Lake Benmore→ Lake Aviemore→ Lake Waitaki→ Waitaki River→ Pacific Ocean
Tributaries
• left	Twizel River
• right	Wairepo Creek
Waterbodies	Lake Ruataniwha

The Ōhau River is river in the Mackenzie Basin of New Zealand's South Island. It is the primary outflow of Lake Ōhau, from which it flows in a roughly eastward direction until reaching the artificial Lake Benmore after a distance of roughly 27 kilometres (17 mi). In 1981, the artificial Lake Ruataniwha was created along the river's length to power a small hydroelectric power station as part of the Waitaki hydro scheme.^[1] Prior to the creation of the Waitaki hydro scheme, the river flowed directly into the Waitaki River rather than through a series of lakes.^[2] The river forms part of the traditional boundary between Otago and Canterbury regions.^[3]

Prior to European settlement of the region, the river was a traditional mahinga kai (food gathering site) for Māori travelling through the Mackenzie Basin, providing valuable food sources such as weka, tuna (eels), and pora (Brassica rapa subsp. sylvestris)^[4][5]

References