BC Hydro's proposed Site C dam in the Peace River region could force as many as 20 property owners to move and affect another 80, an environmental impact study says.

The utility has filed the study with federal and provincial regulators on the massive hydroelectric project that would be built on the Peace River at a estimated cost of $7.9 billion.

The five volumes of the study include thousands of pages of environmental documentation covering everything from agriculture and aboriginal rights to the relocation of parts of Highway 29.

David Conway, with Hydro's Site C community relations, says the plan also includes the benefits the dam would provide to customers, First Nations, northern communities and British Columbians.

Hydro's Site C Clean Energy Project would be the third hydroelectric dam on the Peace River in B.C.'s northeast.

Conway says public environmental review hearings about a year away and if the project goes ahead it will start generating electricity in 2021.