In the end, the decision to let a developer build nearly 200 homes near the Yellow River in Lilburn came down to what’s best for the health of the waterway, Gwinnett officials said.

County commissioner Lynette Howard said when she saw the opportunity to expand sewer service, she had to take it. That area of Gwinnett County, near Five Forks Trickum and Lake Lucerne roads, has a “sea of septic” and very little access to sewer, planning director Bryan Lackey said.

But nearby residents believe the homes that developer Inland LLC wants to build on Oleander Drive likely will be underwater at the next big flood.

Tom Shillock, Georgia’s flood plain manager with the state Department of Natural Resources, agreed. Shillock said the commissioners’ flood maps are from 2006, and have not yet been updated to include the high water marks from the 2009 flood.

“The Yellow River has a history of flooding,” Shillock said. “It’s a flood-prone area.”

But commissioners said they were required to abide by the flood maps on file.

“According to the maps, the development proposed is acceptable,” commissioner John Heard said.

The homes, which were approved unanimously, will be part of what is known as an open space conservation subdivision. Of the 93 acre property, 39 acres will be preserved as green space, said Eric Johansen, who represented the developer. The subdivision also will have a boat ramp for public access to the Yellow River and a swimming pool and tennis courts.

To help appease flooding worries, each home will have a personal cistern that can hold 300 gallons of water.

Michael Shapiro, who lives nearby and who tried to get commissioners to delay their vote, said he is in favor of development, but thought the project could be harmful to the environment. Residents had asked the county to buy the land for a park — at the recommendation of a planning commissioner, who referenced the county’s purchase of Simpsonwood in Peachtree Corners — but Howard said there was not a need for additional park land nearby.

“I’m impressed with the passion in the area,” she said. “There are serious issues in the area that really need to be addressed, but they have nothing to do with this zoning.”