Rural Water Infrastructure

Description

Background and history

209. Large-scale irrigation in New Zealand began in Otago and Canterbury in the late 19th century and consisted only of small-scale, private irrigation schemes. During the Great Depression of the 1930s, many large-scale storage and irrigation projects, such as the Rangitata Diversion Race, were built using government funding. The graph that follows shows areas of irrigation that were committed at the date of scheme approval:

Areas of irrigation that were committed at the date of scheme approval

Source: Ministry of Agriculture and Forestry (MAF)[51]

210. Most schemes were constructed after 1960 in the Canterbury and Central Otago regions. The following map shows government-owned irrigation schemes prior to 1989, and the number of hectares they irrigated. It excludes on-farm irrigation owned by private individuals or entities[52].

Source: Selwyn District Council and Christchurch City Council; 2000: ‘Appendix 4: Social Impact of Irrigation: Literature Review', quoted in Internal MAF background paper “Water in New Zealand Agriculture: Resilience and Growth”, (2004), by Morgan, M., Harris, S. & Smith, W., of Lincoln Environmental; Harris Consulting; University of Auckland.

211. In 1988, central government began to transfer ownership of the Crown schemes to commercial operators. It was left with only one scheme, the Beggs Scheme in Central Otago, on which no offers of purchase were made.

212. Major irrigation schemes developed since the 1980s include the Opuha schemes (1998, 16,000 ha), Waimakariri (1999, 18,000 ha), North Otago Stage 1 (2006, 10,000 ha), and the Wai-iti Valley Augmentation (800,000 m2 dam opened 2006).

213. Rural water infrastructure is economically beneficial to New Zealand’s farming and food production industries, and energy production. Used for water capture, storage, distribution, and drainage, it can play an important role in increasing rural land productivity and in maintaining our competitive advantage. It does this by:

• smoothing the variability of water supply (due to intermittent rainfall and seasonal snow melts), which increases the amount and reliability of production per hectare, and allows exporters to take advantage of higher-value markets that require a reliable supply of high-quality products; and
• helping New Zealand adapt to climate change, as some areas are subject to increasing frequency and intensity of droughts and others become wetter.

214. Since their environmental and social costs can be significant, irrigation projects need to be carefully planned and managed in order to maximise benefits and minimise and mitigate negative impacts.

215. Irrigation projects support a variety of agricultural industries such as horticulture, dairying, sheep, beef and cropping. They are often used in conjunction with, or are dependent on water capture and storage infrastructure. Examples of which range from large-scale dams and reservoirs to smaller-scale water tanks (on-river and off-river) and groundwater extraction facilities.

216. Irrigation accounts for the largest proportion of water use in the country. Of all the resource consents for water takes in New Zealand in 2006, 77 per cent of allocated water was used for irrigation, as is illustrated in the chart below[53].

Use of allocated water in New Zealand, 2006

Source: Ministry for the Environment, 2007

217. Irrigation schemes exist in Northland, Auckland, the Waikato, Bay of Plenty, Hawke’s Bay, Taranaki, the Wairarapa, Nelson, Marlborough, Canterbury, Otago, and Southland[54]. Most are on the east coast of the North and South Islands, as New Zealand's mountainous topography means more precipitation falls on the west coast[55]. Around 500,000 hectares of land is irrigated in New Zealand, approximately 350,000 hectares, of which is in Canterbury[56]. The following table illustrates the area of irrigated hectares across regions as at 2000, according to a Nimmo-Bell report[57].

218. The majority of irrigation water is taken from surface water sources: rivers, lakes and streams. Around 41 per cent of irrigation water is extracted from groundwater sources, stored naturally in aquifers.

219. There are several types of irrigation which vary in terms of efficiency of water distribution, water wasted as run-off, or of energy consumed. Over time, more efficient technologies have evolved with the development of border dyke, spray and micro irrigation. The most efficient irrigation technique for a particular region depends on a variety of factors, such as soil type and density, topography of the region, and the surface or groundwater take. The use of computers and technology advancements have also allowed greater specificity in water use, reduced waste, and diminished the labour demands on end users.

Institutional arrangements

220. Historically the Crown played an extensive role in developing, subsidising and maintaining community irrigation schemes, initially through the Public Works Department and then the Ministry of Works, eventually owning 50 odd community irrigation schemes. The rationale for government involvement changed from period to period:

• Between 1910 and 1935, New Zealand government involvement followed the history of government assistance of irrigation by colonial governments in Australia. It aimed mainly to prevent drought, take advantage of existing water rights and reclaim mining land;
• After 1935, the first Labour Government expanded the irrigation programme to boost employment, and make greater use of the water resource;
• In the 1950s, while concerns were raised about the financial implications of the schemes, a Select Committee concluded that direct government intervention was necessary because individual farmers could not obtain the required finance, technology and labour; and
• From the 1960s to 1980s, community schemes were increasingly viewed as a farm management tool to intensify agricultural production and new irrigation schemes were justified as being in the national interest by virtue of having economy-wide benefits (Audit Office[58] 1987).

221. In 1989, the national benefits started to be questioned, along with central government’s ability to set and recover realistic costs. It also became apparent that the assistance was causing inefficiency in resource allocation in the agricultural sector, for example by favouring pastoral farming over other forms of agricultural development such as horticulture, or subsidising particular irrigation methods over potentially more efficient ones.

222. Under the Resource Management Act 1991, local government is now responsible for approving the development of rural water infrastructure. Central government has focused its efforts on funding science and technology development, and on facilitating the planning and proposal development process, through initiatives such as the Sustainable Farming Fund and the Community Irrigation Fund.