Line a 6-qt. slow cooker with a double thickness of heavy-duty foil. Coat with cooking spray., In a large skillet, cook beef over medium heat until no longer pink, 6-8 minutes, breaking into crumbles; drain. Stir in soup, water and taco seasoning. Bring to a boil. Reduce heat; simmer, uncovered, until slightly thickened, 3-5 minutes., Cut each biscuit into 4 pieces; gently stir into beef mixture. Transfer to slow cooker. Cook, covered, on low until dough is cooked through, 3-4 hours. Sprinkle with cheese. Cook, covered, until cheese is melted, about 5 minutes longer. Serve with toppings of your choice.