Wairarapa water project enters new phase

A project investigating the potential for the Wairarapa valley to store water in the winter and distribute it for a variety of community and agricultural uses during the dry season has entered a new phase.

Subject to meeting the environmental, social and cultural needs of the community, the Wairarapa Water Use Project aims to improve the productive capacity of the Wairarapa valley land, and the subsequent economic return through water storage and irrigation opportunities.

A significant area of farmland could be irrigated by the project which would maximise water storage opportunities to provide a reliable water supply.

Engineering consultant Tonkin and Taylor has been commissioned to undertake a range of work, including water availability and demand, and to identify a range of potential water storage sites and distribution options and the environmental effects of these.

This work will be undertaken over the next 10 months alongside exploration of investment options. In September next year a short list of potential schemes will be developed for consideration by the project’s Leadership Group, in what is likely to be a staged approach.

“The current work builds on previous Wairarapa studies carried out over the last decade, all of which have been reviewed,” Leadership Group chair Fran Wilde said. “The project is now looking at all potential water uses and opportunities, not just irrigation. A wide range of storage options are available and we have taken off the table any prospect of using our four main rivers (Ruamahanga, Waingawa, Waiohine, Tauherenikau). The priority however is to identify locations where water can be stored off-river in natural valleys with on-river storage possible for smaller tributaries. Rivers will also be considered as part of the water distribution network but only where environmental effects are positive.”

The Leadership Group which represents district and regional councils, iwi, environmental, agricultural and economic interests, met last week and endorsed the work plan.

In work to determine the likely demand for irrigation water, a pilot study east of Carterton last month found that 90 per cent of farmers on non-irrigated land said they would like to irrigate. Indicative results showed that when existing irrigators were added, the farmers wanted to irrigate about half of the total land area. The results of the pilot will be compared with the results of a theoretical demand assessment currently being made by Landcare Research over the whole of the Wairarapa valley.

High-level environmental assessments will be made of the potential issues and threats to the environment of any water scheme. Part of this work will be to identify areas where the soil is not suitable for irrigation. Once they are short-listed, potential storage schemes and distribution methods will be further assessed for environmental effects, benefits and efficiency.

Last week representatives of 13 interested organisations met with the project team to consider how they would like to be involved in the project. The group’s terms of reference will be confirmed in the New Year and will include information sharing, jointly addressing issues and providing feedback and ideas.

Earlier this year Greater Wellington Regional Council allocated $750,000 in its current annual plan to assist project investigations. The project will also apply for funding from central government’s new Irrigation Acceleration Fund (IAF) next year. The fund provides $35 million nationally over five years to unlock the economic growth potential of primary sectors by developing more efficient and effective water infrastructure.

The potential for high-value land uses such as horticulture or specialist crops, which might also attract processing facilities, will be investigated as well as liaising with local councils on opportunities for urban and recreational water use.

The work runs parallel to Greater Wellington’s Regional Plan review including its review of regional water allocations.