Preheat oven to 400 degrees F (200 degrees C). Grease sides and bottom of a casserole dish.
Stir chicken, water, rice, cream of chicken soup, cream of celery soup, and cream of mushroom soup together in the prepared casserole dish; season with salt and pepper. Arrange butter evenly over the top of the chicken mixture.
Bake in preheated oven until the rice is tender and the chicken is cooked through, 1 hour to 75 minutes. Cool 15 minutes before serving.
