MARTINEZ -- Following a last-second flurry of negotiations between Antioch and Contra Costa officials, county supervisors on Tuesday gave the go-ahead to a complex pair of financial agreements that clears the way for a 678-acre annexation.

The land located to Antioch's northeast is divided into three swaths: 481 acres of industrial waterfront that includes two natural gas-fired power plants, 94 acres for marina and storage uses, and 103 acres of established rural properties off Viera Avenue.

"This was not been an easy process to go through; there are some unique circumstances here," Catherine Kutsuris, the county's director of conservation and development, told the board.

St. Claire Drive in Antioch, has been a quaint quiet area in unincorporated area of Antioch for years which might change in the coming year in Antioch,
St. Claire Drive in Antioch, has been a quaint quiet area in unincorporated area of Antioch for years which might change in the coming year in Antioch, Calif., on Friday Dec. 14, 2012. Close to 200 people that live in the unincorporated area off Viera Avenue may soon become Antioch residents whether they like it or not. Mitosinka feels there will be change to the neighborhood that will take away the country feeling it has now. (Dan Rosenstrauch/Staff)

A couple of recent hang-ups have centered on plans detailing how estimated millions in future tax revenue generated in the area would be split and how both agencies would cover costs for water, sewer and storm drain improvements in the Viera area, which drew international attention in 2009 because of the Jaycee Dugard kidnapping case.

City and county staff and legal counsels met early Tuesday morning to negotiate while the Board of Supervisors meeting was in session. By 1 p.m., amended versions of the tax transfer and infrastructure improvement documents were considered by the board.

The changed language deals with how improvements would be added to the Viera area and financial protections.

The agreement also calls for the county to handle application processing, plan review and building inspections for 114 acres of waterfront land that Forestar Real Estate is looking to develop for the city, while Antioch would retain land use authority.

"I think what's before us is very reasonable. It's really important at the end of the day, the partnership of Antioch and the county as we serve our mutual constituencies," county Supervisor Mary Nejedly Piepho, of Discovery Bay, said.

The city and county will contribute $3 million over 10 years to add water, sewer and storm drains to residential areas, with Antioch covering the rest with grants and loans. Antioch estimates it would cost about $10.7 million, and nearly $5 million more in other engineering and contingency costs, to add the infrastructure.

Property tax revenue in the area would be split 62 percent to the county and 38 percent to the city.

Antioch estimates the area could yield about $900,000 in net tax revenue each year and provide other economic opportunities on the waterfront. Both parties will also set aside $500,000 over the next five years to boost area economic development initiatives.

The approved documents will now go before the Antioch City Council for consideration at its Nov. 26 meeting, city officials said. If it is approved that night, the Local Agency Formation Commission, which has final say on all annexations, would likely consider annexation in January, Executive Director Lou Ann Texeira said.

Contact Paul Burgarino at 925-779-7164. Follow him at Twitter.com/paulburgarino.