The power company was granted resource consents two years ago to install a pair of turbine generators at the Lake Hawea dam - which is used as a storage release system to control downstream flows to Contact's Clutha River hydro scheme.
The planned Lake Hawea hydro-electric scheme would be capable of producing about 17MW of electricity - enough to power about 4000, or half, of the Upper Clutha's residential households, Contact spokesman Jonathon Hill said.
Contact Energy's hydro development manager Neil Gillespie said "uncertain time-frames" existed about when installation of the planned hydro-electric generators will begin.
Technical design and engineering plans were still being worked on.
"It has taken some time, but it is a very complex project which we need to get right," he said.
The Hawea generation scheme is "a completely separate project" from existing consultation with Clutha River communities about potential hydro-electric dams.
"Neither one has a priority over the other," Mr Gillespie said.
Contact was working towards finalising design plans for the Hawea turbine generators, before a decision would be made about the "right time" to start construction, he said.
Contact has separate resource consents from the Queenstown Lakes District Council and Otago Regional Council for the installation of the turbines.
The QLDC consent must be exercised within five years, while the ORC consents last until November 2017.
Contact also has the right to apply for renewal of the resource consents.
Contact Energy will hold a workshop with Clutha District Council staff and councillors today as the company increases consultation over building up to four dams on the Clutha River.
The power company has devoted 2009 to talking to affected communities about plans to revisit the chances of building hydro-electric dams at Queensberry, Luggate, Beaumont and Tuapeka Mouth.
Mr Gillespie will hold a workshop with council officials this morning but the event is unlikely to yield any new information.
He said the council workshop was one way it could engage with communities.
It was also open to meeting other groups in areas that could potentially be affected if any of the dams gain approval.
