Preheat oven to 350°F and spray a 9x13-inch baking dish with cooking spray.
Brown the ground beef in a large skillet over medium-high heat, breaking it up as it cooks, then drain excess fat.
Add taco seasoning and water to the beef, simmer for 3-4 minutes until thickened, then stir in salsa, black beans, and green chiles.
Spread a thin layer of meat mixture on the bottom of the prepared dish, then layer with 3 tortillas (overlapping as needed), half of the remaining meat mixture, and 1 cup of cheese.
Repeat with 3 more tortillas, remaining meat mixture, and another cup of cheese.
Top with remaining 2 tortillas, spread sour cream over the top, and sprinkle with remaining cheese.
Cover with foil and bake for 25 minutes, then uncover and bake 5 more minutes until cheese is melted and bubbly.
Let stand 10 minutes before slicing and serving.