Slow Cooker Corned Beef and Cabbage

6 to 8 medium potatoes, peeled and cut into(about 1/2 inch)slices
3 medium carrots, thinly sliced
2 ribs celery, thinly sliced
1 corned beef brisket, about 3 pounds(I use 'Boyles' brand,it comes   with corned beef seasoning packet)
1 cabbage, about 2 pounds
1/2 teaspoon black pepper
1 1/2 cups water

Directions:

Lightly butter or spray a 5 to 6 quart slow cooker Layer potatoe slices over bottom of cooker with carrots. Place corned beef on vegetables. Slice cabbage into 8 wedges and arrange around meat. Sprinkle with the pepper and add water. Cover and cook on LOW 7 to 8 hours, until meat and vegetables are tender.
Remove meat to a platter. Cover with foil and rest for 10 to 15 minutes before slicing.