On the coastal islands of the State of Georgia, where there is no causeway or other means of land transportation and where essential services are not otherwise provided, the department is authorized to contract for or to provide essential services and water transportation for the employees of the department and their families, other state employees and their families, and any permanent residents of the islands. This authorization is applicable only to those islands owned or controlled by the State of Georgia and upon which the department has facilities located, or on other islands where an emergency condition is found to exist.