Manuherekia River

The Manuherikia climate is considered to be the most continental type in the country with cold winters and warm summers. It is away from the effect of the sea and has the surrounding mountains which shelter it from rain-bearing storms. Average annual rainfall in the Manuherikia Valley is between 400 and 500mm.

The low rainfall has led to the development of extensive water storage and irrigation schemes. Three reservoirs have been established in the Manuherikia catchment to provide water for irrigation. Poolburn Reservoir was constructed in 1931, with a capacity of 26 Mm3. Falls Dam was built in 1935 to capture the high rainfall water supply in the northern high-altitude part of the catchment and has a capacity of 11 Mm3. Manorburn Reservoir was built in 1935 and has a capacity of 51 Mm3. 
The irrigation distribution system consists of a network of manually controlled, unlined, open water races. 
        
The Blackstone Hill, Ōmakau, Manuherikia, and Galloway irrigation schemes take water out of the Manuherikia River, which is partly controlled by the releases of Falls Dam, and distribute the water through a network of open water channels to irrigate the Manuherikia Valley bottom. The Poolburn Reservoir is used to store water to irrigate Ida Valley. Water from the Manorburn reservoir is partly diverted into the Manuherikia Valley over an open water race to irrigate the upper Galloway Irrigation Scheme. The rest of the Manorburn water is used for irrigation in the Ida Valley.

Land use in the upper catchment of the Manuherikia and Ida Valley’s is primarily extensive sheep and beef grazing. Due to irrigation, the mid and lower reaches of the catchment are dominated by comparatively higher intensity farming with smaller farms and higher stocking rates relative to the upper catchment. In the past few years there has been an expansion of wintering dairy herds and in June 2009 the first dairy platform was established near Omakau. Over the last decade extensive vineyards have been established on terrace sediments in the lower part of the catchment

The most significant active recreational pursuit carried out on the Manuherikia River is angling. The Manuherikia River and tributaries as having high natural value particularly for brown trout fry habitat, trout spawning habitat and adult trout habitat. The Manuherikia River is a popular fishery with local and visiting anglers.

During the summer there is weekly monitoring at some sites.