Table schema:
CREATE TABLE table_name_67 (rank INTEGER, capacity___mw__ VARCHAR, type VARCHAR, name VARCHAR)

Question: what is the lowest rank when the type is hydro, the name is grand rapids generating station and the capacity (mw) is more than 479?
SQL: SELECT MIN(rank) FROM table_name_67 WHERE type = "hydro" AND name = "grand rapids generating station" AND capacity___mw__ > 479