五大湖
Voinovich sponsored legislation aimed to protect the Great Lakes from foreign species and preserve "our ultimate jewels, the five Great Lakes". He lobbied his colleagues in the Senate as well as Great Lakes governors and administration officials to take real action. Working with Senator Carl Levin, he introduced legislation to ratify the Great Lakes Compact, a bipartisan agreement among the Great Lakes states to protect the Great Lakes through better water management, conservation, and public involvement.