Televised ducts under slab floor. Ducts are a combination of pvc corrugated pipes and plastic coated galvanized metal. Metal ducts are very rusted as is the plenum. Downspouts need to be run out and some grading needs to be done. If that does not solve water issue a sump pit should be installed in the garage ear the furnace. After water issue is resolved the ducts should be spin cast mortared then spray lined with Duct Armor.