Exploratory drilling has started at two sites as part of the feasibility study into storing and distributing water in Wairarapa.
Drilling programmes at Black Creek and Tividale will provide core samples for geotechnical assessment as part of further investigations into the viability of locations as possible dam sites.
Black Creek is located in the Kaituna area west of Masterton and Tividale in the Taueru catchment northeast of Masterton.
The drilling activity is the latest phase in the Wairarapa Water Use Project, which is investigating how water could be collected, stored and distributed to support the sustainable management of the region's land and water and contribute to regional prosperity.
Project director Michael Bassett-Foss said the drilling programme marked an important milestone in the project's work to secure a more reliable source of water for agricultural, municipal, environmental, recreational and cultural use in Wairarapa.
"After nearly five years of investigations and work with a wide range of community interest groups, it's exciting to be one step closer to meeting our region's ongoing needs and creating wider opportunities for water use."
He said the two potential schemes could between them irrigate almost 30,000ha between north of Masterton and south of Greytown and provide water for a range of other uses.
Drilling will take about two months to complete.
Other fieldwork over the coming months would assess the land-based and aquatic ecology of the storage sites and surrounding areas.
Mr Bassett-Foss said the feasibility stage also includes further assessing the potential demand for water and farmer interest in investing in irrigation.
"We will continue to talk with farmers about the opportunities a regional water use scheme will provide and about the various options for ownership and operating structures."
Upcoming activities would include sharing information about land use studies on three local farms to investigate the viability of using irrigation in different situations, and an independent survey of local farmers to understand their preferences for scheme ownership, buying water, and land use.
Later this year, an assessment would be made about whether to proceed to the next stage which would see the project move into a new commercial entity to develop the scheme.