Water Wairarapa


Q. Why do we need a water storage scheme in Wairarapa?

A. Our natural supply of water is increasingly unpredictable and not available when it is needed most. This causes uncertainty and limits the opportunities in our local community and wider region. This problem can be solved by harvesting water during times of high rainfall and then storing it for use when it is needed most.

Q. What are the climate change predictions for Wairarapa?

A. Climate studies indicate that average temperatures will rise by 1°C in 30 years’ time and 2°C by 2080. The current 1 in 20 year droughts are predicted to occur 4 times as frequently by 2080. Establishing a more reliable source of water will help address the effects of climate changes.

Q. Apart from climate change, why do we need a managed water regime?

A. Water that is allowed to be taken from waterways across much of the Ruamāhanga catchment is fully-allocated. Dry summers mean that stream and river flows can be very low. Rapidly growing pressure on existing water resources over the past decade needs a different approach to ensure ground and surface water can be sustainably managed.Q. How can water storage help manage the water resources in the Ruamāhanga catchment?

Q. How can water storage help manage the water resources in the Ruamāhanga catchment?

A. Water storage creates long-term security of supply to meet environmental, cultural, economic and social needs. It is an infrastructure tool that assists the efficient allocation and use of water and the overall management the water resource.

Q. What are the potential benefits of the scheme?

A. A greater, more reliable water supply would grow and diversify the region’s primary production base and create longer-term inter-generational economic and social development. An independent study suggests that the regional economy would grow by $157 million per year and 1,200 new jobs would be created. A further $90 million in growth and another 1,100+ jobs for one year would be created as a one-off result of farmers converting to irrigation.

Employment and industry growth retains younger people in the region and builds stronger rural communities. Population-based services, schools, clubs and community facilities benefit from greater employment, income and confidence in the area’s future prosperity.

Water storage and a catchment-wide approach to water use and management provides opportunities to augment summer river and stream flows, enhance quality in waterways, supplement urban water supplies and create new recreational uses.

Q. How could the stored water be used?

A. Uses include irrigation of land used for agricultural and horticultural production, supplementing low summer river/stream flows, supplementing town water supplies, recreation, stock drinking water and electricity generation.

Q. What stage of development is the scheme currently in?

A. The scheme is currently in the feasibility stage with the main focus on assessing viability. Activities during this phase include assessing demand for water from farmers and other potential users, work on financial viability, and further geotechnical investigations at proposed storage sites.

Q. Why is the scheme taking so long to be established?

A. Based on similar New Zealand experiences, it takes at least 10 years for these types of schemes to be established. That time depends on many factors such as availability of funding for investigations, the resource consent process and scheme complexity. The Wairarapa scheme is over halfway through this process. Subject to viability, attracting the necessary investment and resource consent, construction could start in 2020.

Q. Where are the proposed water storage sites?

A. The proposed storage sites are at Black Creek (located in the Kaituna area west of Masterton) and Tividale in the Tauweru catchment northeast of Masterton.

Q. Why have these sites been chosen for further study?

A. Investigations to date show these are the optimal sites to construct water storage reservoirs. Both sites have the potential to collect and store water from nearby waterways that have enough water available for storage refill, and are within range of the areas of the demand for water.

Q. Will both of the proposed storage dams be built?

A. It is possible that both storage sites could be used, depending on their viability. However, construction is likely to be staged with only one dam being built initially. Depending on demand for water, the second dam may be constructed.

Q. Where will the water come from?

A. The Black Creek reservoir would be filled by a combination run-off and river flows from the Wakamoekau and Black Creek catchments, and water harvested from the Waingawa River at times of high flow. The Tividale reservoir would source water from its own catchments - the Tauweru River and the Mangapurupuru Stream.

Q. How much of the valley is irrigated already?

A. Currently about 12,000 hectares in Wairarapa are irrigated using water taken under consent from rivers, streams and underground bores.

Q. How much of the valley could be irrigated and is there enough water?

A. Currently, about 12,000 hectares of the Wairarapa valley are irrigated. An additional 30,000 hectares could be irrigated using water from the proposed storage scheme (using both storage sites). This would require approximately 100 million m3 or around 2-4% of the volume of water flowing from the valley per year.

Q. What is the demand for irrigation water and where is it needed?

A. Initial interviews with farmers in the proposed supply area suggest that about 62% are interested in either extending existing irrigation or converting to irrigated land use if water was available at an affordable price. The indicative supply area covers from north of Masterton to south of Greytown.

Q. How many farmers will need to sign up to the scheme?

A. The scheme isn’t asking farmers to sign up at this stage. Ultimately, a critical mass of farmers and other users would need to commit to buying water for the scheme to become a reality. The number of farmers that would need to initially commit will be determined by the current feasibility study. Others may have the opportunity to join the scheme at a later date.

Q. What are the environmental risks of the scheme?

A. More intensive agricultural and horticulture production made possible by irrigation presents environmental challenges in managing nutrients that affect water quality. The community engagement, consenting and design phases of scheme development will need to ensure both economic and environmental sustainability.

Q. How would environmental values be protected?

A. The Government’s National Policy Statement for Freshwater Management requires regional councils to ‘maintain or improve’ water quality by setting policies and rules. These include limits on what can be taken from or discharged into waterways, based on community values. In the Greater Wellington region, the regional council’s Regional Policy Statement and new Natural Resources Plan govern this. Farmers would be supported to ensure good management practices accompany any move to irrigation. Wider community use would also need to be in line with national and regional standards.

Q. Who is setting the policies and rules for Wairarapa’s Ruamāhanga catchment?

A. The community, through the Ruamāhanga Whaitua Committee, is setting the policies and rules which will form part of the new Natural Resources Plan. It has developed a vision for the future and has described what the community values and wants from land and water. This will help the committee to make informed decisions about goals for future land and water management.

Q. What is the relationship between Water Wairarapa’s proposal and the Whaitua process?

A. They are separate initiatives that are both currently are being led by Greater Wellington Regional Council. The Whaitua Committee will use scientific, cultural and community knowledge to model future scenarios that will include water storage. The results will help the committee to recommend water quality and quantity limits that are acceptable to the community, based on community values.

Q. How is the scheme going to affect the waterways?

A. Water will only enter the reservoir/s at times of high water flows i.e. winter and that it will help reduce the pressure on river levels in summer by providing an alternative source. The scheme has the potential to augment low summer river/stream flows and provide flushing flows when needed.

Scientific modelling by independent experts will provide evidence-based information about effects on waterways. These will be based on assumed land use and water flow scenarios.

Q. Who will own the scheme?

A. A range of ownership options are possible for the scheme - community, cooperative, private, or a mixture of these. Interest in scheme ownership is being assessed as part of the current feasibility stage through discussions with community representatives and farmers.

Q. What about including the irrigation of treated wastewater in the scheme?

A. The scheme is working closely with district councils in the region to understand how the scheme could support environmental and community uses. These include looking at opportunities to work collaboratively with councils on irrigation of treated urban wastewater.

Q. Is hydro-electricity generation possible as part of the scheme?

A. Micro generation may be possible but is not a focus for the scheme. This could be part of future scheme developments if the wider community wanted it investigated further and the potential benefits indicated it was worth considering.

Q. What lessons has the Wairarapa proposal taken from other schemes?

A. Water Wairarapa has studied existing schemes in other regions and has close ties with them and other developing schemes. It is able to draw on their experience and factor this into the Wairarapa scheme’s design and development.

Q. How is Water Wairarapa involving the community in its investigations?

A. Conversations with all parts of the community with an interest in water have been a priority for since scheme investigations began. A wide range of community interests have been involved in the development of the proposal through the Water Wairarapa Governance, Leadership and Stakeholder Advisory Groups who provide feedback and input into project design and decisions.

Q. Where can I get more information and how can I have my say?

A. Contact us if you would like more information and subscribe to our newsletter to get regular updates.