The Nevis River hearings will begin in Cromwell today before a special tribunal.
The New Zealand and Otago Fish and Game Councils have sought a change to the existing water conservation order on the Kawarau River, asking for a ban on damming the Nevis River.
Most of the 248 submissions received about the application have opposed dams on the river.
The hearing was to have started yesterday but the proceedings were delayed by a medical matter involving a tribunal member, tribunal administration officer Alex Miller said.
The hearing is expected to take about four weeks and the tribunal will report its findings to the minister for the environment.
