The county promises are not yet fully fleshed out, however. One Scott Homes tract remains vacant because of ground contamination problems that the agency says will take millions of dollars to clean up. The county housing agency says it is building about 500 additional subsidized units in partnership with private developers in the vicinity to make up the balance.

“We are committed to making sure that area does not lose affordable housing units,’’ said county housing director Gregg Fortner.

The completion of the new development comes four years after the county, under intense public pressure, hurriedly had Habitat for Humanity construct 52 detached houses on one of the old public housing tracts; 41 of the homes were purchased by former Scott Carver tenants who helped build them under Habitat’s famous “sweat-equity’’ formula.

But that was preceded by years of protests and lawsuits, and a scandal over housing officials’ bungling and waste.

Miami-Dade’s housing agency, long castigated for poor maintenance and management of its properties, first announced its intention to replace the deteriorating Scott and Carver homes in 1999, when it received a $35 million grant from the Clinton administration’s Hope VI initiative. The program aimed to replace obsolete housing projects, criticized for concentrating the poorest of the poor in hopeless, crime-ridden communities, with mixed-income neighborhoods better integrated into their surroundings.

The county issued 1,100 Section 8 vouchers — portable subsidies that can be used in qualified private housing as well as affordable housing projects — to Scott Carver residents, allowing them wide latitude in choosing where to live.

Though tenants and their legal representatives say many were left to fend for themselves by housing officials and lost their vouchers and housing, Fortner says the great majority retained their subsidies. Some elected to move to other public housing projects.

Six years later, after the projects had been demolished, a Pulitzer-winning investigation by The Miami Herald, called “House of Lies,” revealed the agency had spent half the Hope VI grant but built just three homes. The series documented millions of dollars in fees paid to architects and project managers, staggering overhead costs, and payments to a consultant who double-billed the county. The agency, meanwhile, could not account for the whereabouts of hundreds of former Scott Carver residents.

The scandal, coupled with other fiscal and operational problems, led to a temporary takeover of the agency by the federal government. New leadership has since been installed.

Former tenants, organized as Low-Income Families Fighting Together, meanwhile staged protests, sued the county for discrimination and launched a campaign to locate scores of former residents. The group eventually lost the court battle, but won a commitment from the county commission to replace the lost housing and tender offers for new homes to former Scott Carver tenants first.

The county reached a deal in 2008 with St. Louis developer McCormack Baron Salazar, which packaged together what remained of the original Hope VI grant with tax credits, private financing and new federal grants, including stimulus money to build in energy-saving and other environmentally friendly features. The developer, which has extensive experience developing and running Hope IV projects, owns the buildings and improvements and will maintain and manage them.