A new study say there are huge untapped water reserves in the Pilbara, which could drive a massive agricultural expansion in WA.

Western Australia's Pilbara region is known mostly for its arid natural wonders and active mining industry, but the State Government has seen the figures, and says it wants to make a bold expansion of towns, agriculture and industries.

Researchers probed the content of underground reservoirs of the West Canning Basin, near the town of Sandfire.

Their reports suggest the aquifers could supply an additional 50 gigalitres of water a year, on top of 50 gigalitres discovered in other recent surveys.

They also found a source for 30 gigalitres per year, from groundwater in the Hamersley Ranges.

The lack of water has been a major tumbling block for population and industrial development in the Pilbara, but buoyed by the new findings, she State Government is fast-tracking moves to make use of the supply.

Irrigated agriculture is among the plans, tied-in with long-running efforts to create new industries for the sparsely populated parts of the country.

The groundwater in the Hamersley Range has already been earmarked for agricultural development, under the WA Government's Water for Food program. 

Meanwhile, resource firms owned by local billionaires Gina Rinehart and Andrew Forrest have already moved into the area, but Pilbara MP Brendon Grylls says he wants to see the water used to diversify away from mining industries.

WA Water Minister Mia Davies has told ABC reporters that investigations will continue.

“The State Government is trying to stay ahead of the curve with this investigation program so that we can meet the expansion of our Pilbara.... to prove over the next couple of years exactly this 50 gigalitres so that we know what is sustainable in terms of take, it will become part of our allocation plan.”