A proposed 1,285-home development that would become the largest subdivision on Johns Island received final approval Tuesday from Charleston County Council.

Kiawah River Plantation, across the river from the gated island community of Kiawah, also would have 450 guest rooms, 80,000 square feet of commercial space and up to 36 holes of golf.

The site is a 1,428-acre tract on the Kiawah River marsh with access from Betsy Kerrison Parkway and Mullet Hall Road.

The development is expected to take shape over the next 20 years, and the county is expected to consider early next year a request for tax incentives aimed at getting the project started.

A financial analysis of the project prepared for The Beach Co. estimated that Kiawah River Plantation would generate 850 to 900 jobs in the county and create $1.3 billion in taxable property value. Homes would, on average, sell for $1 million.

Approved Tuesday night were zoning changes to the properties involved, and a development agreement between The Beach Co. and Charleston County that spells out planning and zoning requirements and sets some conditions for the plan.

For example, the development agreement says that 20 units of "work-force housing" will be created for every 200 units of market rate housing, up to a maximum of 117 units. Work-force housing is typically rented or sold at less than market rates to occupants with limited incomes.

The agreement also says the developer will provide up to $800,000 toward the purchase of a new ladder truck for the St. Johns Fire District because they could need one if multi-story hotels are built at Kiawah River Plantation. Also, 3 acres of high land will be provided as a site for needed government services, such as a magistrate's court and a fire station.

In the 20 years after development begins, according to the developer's financial analysis, which the county has reviewed, the county's general fund would gain $30.1 million.

County services related to the development would cost an estimated $20.3 million during that time.

Next year, The Beach Co. is expected to request the creation of a tax-increment financing district for the development, which would allow some portion of the anticipated property tax revenues to be used to pay for public infrastructure, such as public roads.

In other business Tuesday, council approved the details of a federal stimulus grant that will help pay for solar panels on the expanded county Detention Center.

Council did not continue a discussion from last week dealing with pending state legislation that could change the way properties are reassessed when sold, but expects to consider taking a position on the issue in January.

Reach David Slade at 937-5552 or dslade@postandcourier.com.