Rohnert Park will open its first homeless housing site today. The $15-million, 60-unit facility will be opening its doors to its first residents. Those living in the new facility will use it as temporary housing, while working with a case manager to find more permanent homes. Rohnert Park expects to serve about 100 people per year at the housing site. The city has an estimated 250 homeless people. A large number of them live in an encampment off Roberts Lake Road.