HUGE slices of Victoria's premier irrigation districts could be mined for coal-seam gas.

Farm groups are seething, worried that mining could deplete or pollute aquifers. A Weekly Times investigation has revealed:

A MASSIVE swathe of the Macalister Irrigation District in Gippsland is covered by an application to explore for CSG.

MUCH of the Werribee irrigation district, in Prime Minister Julia Gillard's electorate, is under a CSG exploration licence.

HUNDREDS of square kilometres of Gippsland, stretching from west of Warragul to Yarram in South Gippsland, is covered by several licences.

The Macalister irrigation district is worth $500 million to the local economy, while the Werribee irrigation district brings $120 million to its region.

Victorian Farmers Federation president Andrew Broad said Australia should not "rip up prime agricultural land just to sell gas to the Chinese".

"We've got massive wealth in agricultural production and that's where our focus should remain," Mr Broad said.

AusVeg public affairs manager William Churchill said applications in irrigation areas were a significant risk and should not go ahead if water sources were at risk.

MID consultative committee chairman Graeme Anderson said local farmers were sensitive about mining because offshore oil rigs had depleted aquifers so much that some farmers could no longer reach bore water.

"This is a vital food production area for Victoria and Australia," he said.

A spokesman for the Victorian Department of Primary Industries said there were no restrictions on the depths exploring miners could drill to. Plans were assessed individually.

Agriculture Minister Peter Walsh did not return calls. A spokesman for Ms Gillard said CSG was regulated primarily by state governments.