Environmentalists want to reopen the debate, but the province and town planners are ready to allow housing development to proceed on a controversial portion of the Oak Ridges Moraine in Richmond Hill.

The province decided not to be represented at Ontario Municipal Board hearings that reopened this week. The proposed developments are on moraine land that is not included in an area set aside for provincial protection, said Jim Miller, spokesman for the Ministry of Municipal Affairs and Housing.

"We have determined the principle of development has been established," Mr. Miller said. "The protection of water and environmental features has been set up through legislation."

The ministry's view is that it is now up to the OMB and the town of Richmond Hill to work out the scope of development and the zoning of the subdivisions.

"This is absolutely insane. The province is rubber-stamping the building of 6,800 houses on the moraine," said Glenn De Baeremaeker, president of Save the Rouge Valley, an environmental group that led the opposition to moraine development.

He said his group and others who contend such large-scale development will permanently alter the ecology of the area in northwest Richmond Hill that is the source of ground water in much of the Toronto area were never allowed to present their evidence before the OMB. They want the board to allow expert witnesses to make presentations before the panel.

After years of legal battles, the environmental groups cheered last November when the province announced a deal with developers to swap lands near Yonge Street and Stouffville Road they held for development in Richmond Hill for provincially owned land off the moraine. Protected land on the east side of Yonge Street is slated to become a large park.

But maps produced for the province's legislation identified areas, mostly to the west of Yonge Street, where large-scale urban development could continue.

"Now, they are throwing the moraine to developers like a big, juicy steak," Mr. De Baeremaeker said of the province's pullout from the hearings.

"We're absolutely frustrated because even if the province thinks building all these houses is such a good idea, they should be at the hearings to explain why," he said.

The OMB hearings are expected to be concluded before Christmas, a spokesman for the board said.