Add tomato sauce, water, tomato paste, salt and oregano to meat; mix well.
Spread 1/4 of meat sauce in an ungreased 5-qt slow cooker.
Arrange a third of the noodles over sauce, breaking noodles to fit in cooker if needed.
Combine the cheeses in a medium bowl, spoon 1/3 of cheese mixture over noodles.
Repeat layers twice. Top with remaining meat sauce.
Cover and cook on low for 4-5 hours or until noodles are tender.