Televised ducts under slab floor. Ducts are concrete with metal connections and fittings. Concrete is in good condition and metal is only showing slight signs of rust. Plenum also has very little rust. Customer had water in ducts after a heavy rain fall. All the downspouts are properly extended away from the house. Believe this wTerinsystem was an isolated event due to the condition of the ducts. Suggest spray lining the ducts with Duct Armor duct lining material in order to encapsulate the concrete possibly Transite ducts.