The 35MW station, which would provide electricity to power up to 10,000 average households, would be built on the Pukaki-Ohau Canal, near State Highway 8.
The canal carries water from the lake to the Ohau A Power station further south.
When contacted yesterday, Meridian spokeswoman Claire Shaw said the proposal was in its very early stages.
The concept was a modification of the existing dam structure, and it was too early to comment on how much it would cost.
Resource consent applications had been filed with the Mackenzie District Council and Environment Canterbury.
Meridian was waiting for feedback from those councils on how they wanted to proceed with the applications, Ms Shaw said.
In July, Meridian said there was no definite plan to develop a hydroelectric project on Lake Pukaki after The Timaru Herald reported it could be looking at plans surrounding Pukaki Gate 18 dating from the late 1970s.
An information sheet on Meridian's website said it had "long identified" the canal intake structure at Lake Pukaki as having potential to increase the generation capacity from the lake.
According to the consent applications, the construction period was likely to be 28 months, with the workforce estimated to reach 200.
The main engineering components, including a power house capable of generating up to 35MW, and a bypass channel, would be located close to the existing Pukaki canal intake structure.
Construction activities would be contained within Meridian-owned land.
Net transfer of energy northwards had been trending down as a result of increasing South Island demand, particularly over the past four years.
It was estimated that by 2015, South Island demand could have risen by 2300GWh above today's levels.
That would put the South Island increasingly exposed to the risk of insufficient supply during periods of low rainfall, inferring increasing reliance on northern power transmission.
Additional South Island generation would provide ongoing alternatives to supply a growing South Island demand.
The net effect on recreation and tourism would be represented by a minor temporary loss to trout angling in the Pukaki and Ohau canals as a result of dewatering, but it was unlikely angling amenity in the upper Waitaki catchment would be reduced in any measurable way, Meridian said.
While there might be some losses of adult and juvenile trout in the canal during drawdown periods as part of the construction phase, it should be minimal, provided the salvage operation was well planned and organised, the company said.
