A group of 68 farmers, members of the Amuri branch of Federated Farmers, signed a petition to the Minister of Works asking for an irrigation survey in their district. A survey was completed in 1952.

The Labour Government’s 1973 Irrigation policy allowed the scheme to move from paper onto the ground. New irrigation schemes were seen as being in the national interest by having economy wide benefits as well as fitting neatly into the “Think Big” philosophy of the Muldoon era. This attitude may have overshadowed the need for more economic analysis on the viability of the scheme, which became evident when the 1980s brought ‘worst case scenario’ conditions for farmers.

An application was made by local farmers in January 1974 and approval was granted in February 1975. A poll of 85 local farmers voted to proceed with the scheme. It would become a major community project designed under the supervision of the Ministry of Works with advice and lending from MAF and the Rural Bank. Construction went ahead on the basis that the Government would subsidise 100% of the costs of the off farm earthworks and structures.

The first of the Amuri schemes to open was Waiareka Downs in 1976, which sits east of the Waiau township. This took water from the Waiau River and irrigated 420ha of land by borderdyke on eight farms.

Construction of the Balmoral scheme commenced in 1979.

The intake gates of the main water race at the Leslie Hills Bridge were opened on 25 November 1980 by Hon. W L Young, Minister of Works and Development in front of a large crowd.

During the summers of 1980-83, the district suffered successive droughts. Most farms were partly developed with raw borderdyked land but only a few were able to receive water. Escalating construction costs, inflation and declining farm gate prices meant that the farmers could not afford to pay the high water charges and development slowed as it became more unaffordable for farmers.

In 1985, the Amuri Plains Irrigation Committee began a long process of lobbying Central Government for more sustainable water charges. In 1986, Cabinet initiated a review of all community irrigation schemes. This review suggested that the selling these schemes might solve the ongoing problems created by them.

In 1987, the Government declared that farmers should be given the first opportunity to purchase the schemes. The Committee began a long process of negotiating with Central Government. This process was fraught with problems as the Amuri schemes were given a value of $22-26M by Treasury - an amount that the farmers could simply not afford. The Committee insisted that these works had no value if irrigators could not afford to pay the water charges.

When the larger Lower Waitaki scheme was sold for around $1M, the Committee knew their scheme was worth less. Amuri Irrigation Company Limited (AIC) was formed in 1990 and the Government agreed to sell the three Amuri schemes to AIC that same year. It was a company wholly owned by farmers, all of whom were shareholders.

In September 2016, AIC began installing pipe to upgrade much of the current open race network over five distinct branches, Waiau 1-3 and Balmoral 1-2. This included approximately 131km of buried GRP and HDPE pipe and 180 offtakes. Completed in 2017, 24,000 hectares are now supplied with water by pressured piped water and 4,000 hectares are supplied from the existing main water races. Eleven combined pump stations boost scheme lateral pipelines and 31 individual stations boost after the farmer offtake.

The Pahau River is awarded the Supreme prize for Most Improved River at the annual Cawthron New Zealand River Awards. The top prize was based on the river showing the most declining levels of the bacteria E coli over the last 10 years, achieving reductions of 15.6% a year.

Today, AIC has 131 shareholders and supplies 147 farms, of which 60% of the irrigated land is used for dairy farming and the remainder is dairy support, cropping, sheep, beef and arable farming. 99% is spray irrigated and 1% is border dyke irrigation.