Christchurch's city council is signing up for the Government's 761 million dollar Three Waters funding

Councillors have voted to proceed with the paperwork for a more than 20 million dollar grant to upgrade drinking, waste and storm water systems.

The Council would access some of 50 million dollars for Canterbury - as long as councils agree to work together.

Mayor Lianne Dalziel says it's a good move - as long as cost-sharing agreements don't come back to hurt the city.

She says they've signed in good faith and can still revisit where they go with water in the future.

Dalziel says she's concerned that Maori weren't involved in Government talks with the reforms.