The social impacts of irrigation

Irrigation in the Lower Waitaki and Amuri brought changes in land ownership, land uses, farming systems, and farm size. Photo: Dr Mike Mackay.

A Building Better research team has recently looked at the social impacts of irrigation developments in the Waitaki Valley (North Otago) and Amuri (North Canterbury) as part of evaluating the success of regional regeneration initiatives, along with developing methods and capability in assessing social impacts. The work is important to see how the actual impacts line up with the predicted Social Impact Assessment of such work: What worked well, and for whom? What patterns of change were not anticipated and how were these addressed? What can be learnt from these experiences?

The team have been conducting after-the-fact analyses of a number of initiatives for regional social and economic regeneration in Aotearoa New Zealand’s South Island. The research confirms that regeneration typically is a complex, incremental process involving multiple stakeholders over a lengthy period. Part of Building Better’s “Thriving Regions” work stream, the first tranche of research examined the social impacts of tourism infrastructure developments, including the Alps to Ocean (A2O) National Cycle Trail in the Waitaki Valley. The second tranche is looking at strategies for primary production, especially irrigation, and housing for a changing workforce and population.

Social Impact Assessment (SIA) analyses the intended and unintended consequences of policies, plans, programmes, and projects on people and communities. SIA is a predictive endeavour, occurring before something is implemented. SIA also generates recommendations to mitigate anticipated (negative) effects in plans for monitoring and managing social change, generally referred to as impact assessment follow up. For sound ‘if-then’ propositions of social change and useful plans for social impact management, SIAs can draw on SIA follow-up and comparative after-the-fact social-impact research.

The researchers say that irrigation development has objectives of economic regional regeneration and positive social impacts in the minds of planners and development communities. But the use of water resources and subsequent changes in land use creates a complex set of positive and negative social impacts. Their assessment and management has implications for net social wellbeing over time.

“The search for enhanced social wellbeing is not simple. Taking water for irrigation normally triggers an environmental impact assessment because of the impact on river flows and the impacts of new infrastructure such as dams, storage lakes, and canals. These assessments should include SIA. But irrigation development also requires strategic SIA for planning land and water use in a region,” says researcher Dr Mike Mackay from AgResearch.

Researcher Dr Nick Taylor, from Nick Taylor and Associates, says social changes with irrigation are usually in relation to changes in land use and land ownership.

“Initial thinking by proponents of community irrigation projects, such as the Lower Waitaki and Amuri irrigation schemes, was to avoid the depressing effect of successive droughts on dry-land framing systems and rural communities. One Amuri farmer reported ‘you could see a mouse running’. Positive economic regeneration from irrigation with associated social benefits was expected for rural people and communities, but the extent of land use changes and subsequent social changes was not fully anticipated.

“Irrigation in the Lower Waitaki and Amuri brought changes in land ownership, land uses, farming systems, and farm size. There was early evidence of phases of changes in farm ownership: from land conversions, often associated with farm family succession, to sales of land to new owners from outside the district, who then introduced new land uses and farming systems such as dairy farming.

“Recent irrigation projects such as the North Otago Irrigation Company scheme, in which farmers jointly built infrastructure to take water from the Waitaki River, confirm that changes in land use now happen in just a few years post irrigation. In this scheme an increase in dairy farming was soon evident, along with an increase in dairy and beef production and a reduction in sheep numbers.

“Early adoption of new land uses was facilitated by farmers who had already converted parts of their farms through point sources of water. Accompanying new land uses were new methods to apply water: a shift from mainly border dyke (flood) irrigation systems to centre pivot and to other types of spray irrigation. These more efficient technologies resulted in re-distribution of water in catchments, particularly impacting down-stream farmers who previously extracted surface water boosted by increased run off from flood irrigation upstream. They also impacted amenity values and recreational users,” says Nick.

Impacts on employment and population

The team’s analysis confirms irrigation causes a change in the type and number of jobs on and off farm, which in turn affects the size of the population and demand for housing and other services. These changes are often significant in small rural communities previously experiencing a decline in population under dry-land farming systems. At the same time the composition of the population changes, with a younger age structure. Changes in the size and composition of communities were identified in the Amuri, the Lower Waitaki, and other parts of Canterbury. The key driver of these primary social effects is the change of land use to dairy farming and some horticulture.

The assessments shows marked increases in the number of dairy farmers and farm workers in the farmer and farm worker occupation group over the main periods of land use change. The more intensive land uses attract younger, more mobile workers including farm workers, share milkers, contract managers, and their families. The cohort effect in these younger, incoming populations is reduced by the ongoing movement of younger farmers and farm families into dairy areas due to the demand for contract milkers and farm workers. Some of these newcomers stay in farming, build their asset base, and progress towards higher levels of farm ownership. They will in turn hire younger workers and contractors.

“Intensive farm operations also bring an underlying change in the social structure of farming with a marked increase in the number and proportion of paid employees and a reduction in self-employed farmers. These changes are associated with the increasing size of irrigated land holdings and scale of production with irrigation and over time – indicated by the average herd size. For instance, in the Amuri irrigation area the average herd size was 832 cows, double the national average of 414. This type of intensive farming, with its corporate farming systems, is indicative of a super productivist landscape,” says Nick.

Intensification of farming in these landscapes was also found to bring higher qualifications and technical skill levels amongst farmers and farm workers and associated communities. Relevant qualifications and ongoing learning are necessary for large, high-tech farms and corporate-structured operations, and many farm operators have utilised migrant workers to fill the skills gap that they have faced with the expansion of intensive farming. In addition to the changes brought by irrigation, the research also found an underlying trend of structural ageing in many rural areas and communities, such as the Waitaki, due to their attractiveness for retirement, including the presence of amenity migrants. This puts an onus on environmental policy and management to ensure intensive farming does not reduce amenity values and adds to, rather than reduces, outdoor recreational opportunities such as freshwater angling. Overall, an increased population in rural areas and small settlements was found to bring significant benefit to community wellbeing, through the effect of increased school rolls, better supported health services, organised sports, and a range of community organisations and facilities that all require sufficient numbers of people for funding purposes and to build social capital.

Impacts on environmental quality, recreation and amenity values

Irrigation has transformed landscapes with shelter, other trees, and hedges removed to facilitate centre pivots, bringing what a local newspaper described as “alien” landscapes and public concern about loss of visual amenity, more uniform landscapes, physical changes in water ways and old drainage systems, and increased on and off-farm water storage areas – some of which are now used for recreation purposes. Non-point discharges of nutrients into water from intensive farming have reduced water quantity and quality, and subsequently ecological, cultural and amenity values in lowland streams, coastal lakes and lagoons. Nick and Mike say the research recognises negative effects on the socio-cultural values of freshwater bodies, cultural uses by Māori, and outdoor recreation by a range of people, including farmers themselves.

Waitaki Alps to Ocean cycle trail alongside irrigated rural farmland. Photo: Mike Mackay

Impacts on health

“The impacts of reduced water quality on human health are a concern in catchments affected by intensive farming. Domestic drinking water wells in rural Canterbury are relatively shallow and there is an increase in the level of nitrates in wells close to areas of intensive farming. A report by the Canterbury District Health Board notes a direct potential effect on human health. Also, low quality surface water affects the health of humans and their pets engaged in water-based recreation through the presence of cyanobacteria. In addition, reduced quality and quantity of surface water and associated amenity reduces the level of healthy, active outdoor recreation,” says Nick.

The management of change

Given the extent of social changes found by the team’s after-the-fact analysis of the social impacts of irrigation, Mike says it is notable the changes were largely unanticipated in project planning.

“As a result there is little in past impact assessments about proactive management of social change. Ad hoc initiatives focus on integration of newcomers, including migrant workers, into communities. Solutions to social issues such as finding housing for workers are largely left to individual businesses and contractors.

“Another aspect is the move towards collective environmental management, as issues arise from water abstraction and nutrient discharges, affecting cultural uses, outdoor recreation and drinking water. Farmers have adopted collective, farmer-driven approaches to forming farm environment plans and an adaptive approach to environmental management, recognising the importance of social licence if future developments are to proceed in an increasingly contested arena. But rural communities seeking to balance economic, social, and environmental outcomes require capacity to monitor and document social impacts and consequences for social wellbeing. In this respect, the research programme is currently preparing guidelines on SIA in rural communities,” says Mike.

Read the research

Taylor, N. & Mackay, M. (2021). Ex post analysis of irrigation development for future SIAs. International Association for Impact Assessment Annual Conference.
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Date posted: 29 July 2021