The government is being accused of picking favourites over a proposal to put a water sporting facility in Christchurch's red zone.
The government and the Christchurch City Council have asked Regenerate Christchurch to look at turning part of the damaged land into a lake for water sports.
The crown spent $1.5 billion buying the 700 hectares of damaged land after the 2010 and 2011 earthquakes.
Avon Rowing Club president and olympic gold medalist Athol Earl said there had been talk of building a sports lake in Christchurch for 20 years, and the idea was thrilling.
"Even without the earthquake we needed it, Kerrs Reach is so dangerously over crowded during the week there are hundreds of school kids there.
"The earthquakes have made the river more narrow and shallow - that, combined with the low water quality, makes it really dangerous," Mr Earl said.
He said Christchurch could hold international water sports events if the facility was built.
"At this stage we are at bursting point with the growth in rowing, we need to to look to the future and plan ahead ... Having this facility right in the heart of a city, near an international airport, will bring thousands of people here and encourage more kids into water sports."
But Greening the Red Zone, a group which wants a native forest and wetlands created in the empty space, isn't happy.
Its chair, Ashley Campbell, said the government was not considering all of the options for the land.
"Every proposal put forward for the land is on the back of thousands of hours of volunteers. For the government to then say to Regenerate Christchurch 'do a feasibility study on one option' is really, really disappointing."
Ms Campbell said the public needed to see the costs and the benefits of all the ideas for the red zone.
"Just like the people who are proposing a rowing lake, we believe the best outcome for Christchurch will only be got if every option is looked at and every proposal has the opportunity to highlight the benefits for their case," Ms Campbell said.
Another idea pitched for the land is an attraction based on Britain's Eden Project.
Regenerate Christchurch is expected to make an announcement on the future of the red zone in the next 12 to 18 months.