Omaka River

Many of the streams draining the Southern (Wairu) Valleys are intermittent and tend to dry up in the lower reaches during the summer. As a result groundwater for the irrigation of crops and for domestic drinking water is in high demand on the lower plains. Viticulture is the dominant land use on the plains, historically dairying also occurred, but has nearly disappeared. Over the last ten years viticulture has grown from 900 hectares to over 9,000 hectares.

The high country areas are predominately pastoral with some exotic forestry. The lower tributaries of the Omaka (the Taylor and the Opaoa) flow through Blenheim, the biggest urban centre (approx. 25,000 population) in Marlborough. Water quality in the lower reaches is affected by stormwater runoff from the town. The Taylor River and Lower Opaoa are valued as recreational rivers with swimming and kayaking being popular during the summer months. In addition there are numerous reserves through which the rivers flow which are popular with walkers and picnickers.