Brown ground beef in a large skillet over medium-high heat for 8-10 minutes or until no longer pink. Drain excess grease as needed.
Add the taco seasoning and water to the browned beef. Stir to mix and bring to a boil. Reduce heat to low, and simmer for 3-4 minutes. Set aside to cool.
While the taco meat cools, wash and chop the lettuce. Add to a large serving bowl.
Dice the tomatoes and drain and rinse the kidney beans. Dump the tomatoes, beans, and shredded cheese into a mixing bowl. Stir to combine.
Add the vegetable and cheese mixture to the lettuce. Then add the taco meat and crushed Doritos. Pour dressing over the top and toss to combine. Serve immediately.