Place bacon in a skillet. Cook over medium high heat until evenly brown. Keeping drippings in the skillet, remove the bacon and drain on paper towels. Crumble the bacon.
While the bacon is cooking, mix the eggs, milk, water, salt, and pepper in a bowl until combined.
Add potatoes to the bacon drippings and cook until semi-soft. Stir in the onions. Cook and stir for 1 minute. Pour the egg mixture into the skillet. Stir in the crumbled bacon and the butter. Cook until the eggs set to your desired firmness. Spoon mixture into tortillas and serve.