State water quality regulators have given Raleigh four months to adopt new development rules for about 5,000 acres in North Raleigh, including the neighborhoods of Wakefield Plantation, Falls River and Bedford at Falls River.

The notice of violation, approved last week by the state's Environmental Management Commission, could end a four-year effort by Raleigh officials to convince state regulators that the new restrictions aren't necessary.

For the 4,994 property owners located within northeast Raleigh's Richland Creek Watershed, the changes would make it harder to add a deck or build an addition.

Mitch Silver, Raleigh's Planning Director, said the regulations would apply to any building permit issued after the new zoning restrictions were in place, which is expected to be this fall. The city will send letters to all affected property owners explaining what's happening, he said.

The new rules are designed to protect a possible source of drinking water on the Neuse River at the old Burlington Mills textile plant off Capital Boulevard. Nobody is using the water now, though Franklin County has expressed interest in tapping it.

The state reclassified Richland Creek as a water supply watershed in 2004. In the intervening years, Raleigh has mounted several unsuccessful attempts to get the classification changed.

City Manager Russell Allen called the EMC's notice of violation "unwarranted" at Tuesday's City Council meeting. During the same meeting, the council agreed to send David Moreau, the EMC's chairman, a four-page letter explaining the city's position.

The letter states that Raleigh has been working to comply with state requirements and that the notice of violation "gives the misimpression that Raleigh had flouted the EMC's prior action and did nothing to protect a water supply source that was proposed to serve a public water supply system."

Raleigh officials have argued that it makes no sense to restrict thousands of people's property rights to protect a water source that is unlikely ever to be used.

City officials also note that if the water source had been in use during the drought, the Army Corps of Engineers would have been forced to release more water from Falls Lake to meet flow requirements in the Neuse River, hastening the lake's decline.

"Any water drawn has to be made up by additional releases from Falls Lake," said Dale Crisp, Raleigh's public utilities director.

Last week's move by state regulators was supported by the Upper Neuse River Foundation, a private group that guards the river against pollution.

Dean Naujoks, the foundation's head, said he worries about letting Raleigh or any other municipality declare another user's potential water source unnecessary.

"We felt that it set a really dangerous precedent that a municipality would want to reclassify someone else's potential drinking water because it hurts development," Naujoks said.

If Raleigh fails to adopt an adequate watershed protection program within 120 days, it could face fines of $10,000 a month.

Allen submitted a timeline to the EMC on July 1 that outlined when Raleigh hoped to have such a program in place. Under Allen's plan, the city would not apply a water supply watershed protection overlay district to the property until May 2009, long after the state's deadline.

At Tuesday's City Council meeting, Mayor Charles Meeker suggested that the city schedule special public hearings as part of an alternative timeline that would meet the state's 120-day deadline.

"What they're telling us is they are tired of waiting and they want us to get moving," Meeker said.