Tuwharetoa is pushing for Mighty River Power to pay several million dollars a year for using the tribe's property.
The central North Island iwi wants to charge the company which takes water for its turbines from Lake Taupo.
The tribe owns the lakebed and has the right to charge commercial users, under its Deed of Settlement with the Crown.
Talks have been going on for nine months, but the issue has surfaced in the share offer document for the partial sale of Mighty River Power and is identified as an investment risk.
He said they don't want to drive commercial operators "under water" - they are just after what is fair.
Mr Lloyd would not specify exactly how much the iwi wants for the use of Lake Taupo, but agrees with the share document's reference to several million dollars.
He described discussions with Mighty River Power as positive and hopes to reach an agreement in four to six weeks.