Preheat the oven to 400°F (200°C) and grease a casserole dish.
In the prepared dish, stir together the chicken, water, rice, cream of chicken soup, cream of celery soup, and cream of mushroom soup.
Season with salt and pepper.
Dot the top of the mixture with butter.
Bake for about 1 hour, until the rice is tender and the chicken is fully cooked.
Let the casserole cool for 10-15 minutes before serving.