Up to £1.5 billion could be raised to help fund improvements in Northern Ireland's water network, the Green Party has said.
Public bonds should be issued to prevent a repeat of shortages which faced householders last winter, the party said at its Belfast manifesto launch.
Temperatures rose quickly on Boxing Day and frozen cracked pipes began to haemorrhage water, leaving thousands without supplies for days.
Leader Steven Agnew also called for metering, allowing people to have 90 litres of water per day free, with fees introduced for wastage.
Other proposals included a pause in new road building.
The manifesto said: "By issuing low yield bonds £1.5 billion could be raised to fund the necessary improvements to our infrastructure to ensure we don't have a repeat of the water shortages that we faced over the winter.
"The Green Party believes that water is a right but we have no right to waste it."
Mr Agnew is standing in North Down where he hopes to take the Assembly seat of Brian Wilson, who represented the Green Party but is not standing this time.
The Green Party in the Republic of Ireland failed to win any seats in the recent Dail elections after it was a minority partner in a government many voters blamed for the economic collapse.
Mr Agnew insisted this would not prevent the party from growing in Northern Ireland.