CHARLOTTE, N.C. – Environmentalists are concerned about what they are calling a threat to the Charlotte area’s water supply.

They are concerned about a bill that has already passed the Senate in the General Assembly that would end requirements for a 50-foot buffer zone at the edge of the water along the Catawba River.

“This is a serious threat,” said Catawba Riverkeeper Sam Perkins, who says developers could now build right up to the edge of the water.

Perkins says the vegetation the grows in the buffer zones helps protect the river and its lakes and streams from erosion and runoff.

He and other environmentalists, including the chief of water quality for Mecklenburg County are worried because Lake Norman and Mountain Island Lake provide the bulk of the drinking water for the Charlotte area.

“For Charlotte-Mecklenburg, for Gaston County, for Mooresville and Lincoln County, it supplies water for a lot of people,” said Perkins.

The effort to remove the buffer restriction comes as development on the Catawba River is about to explode.

Developers have plans for 14,000 acres of wooded land just west of I-485 at the Charlotte Douglas International Airport.

To be called “The River District,” the project would include office and residential housing and would be bigger than Ballantyne.

Developers of the project have already said they will take steps to avoid runoff into the Catawba.

The bill to remove buffer requirement passed the Senate this week and now moves to the House.

On NBC Charlotte’s Flashpoint program to air this Sunday morning, Republican State Rep. Andy Dulin says even though Republican control both houses of the General Assembly, he will go against his part and vote against the bill.

Said Dulin, “We need be able to let local communities, local county commissions to regulate that, and the state government ought to stay out of it.”