In a large pot or Dutch oven, brown the sausage over medium heat until it is cooked through. Break up any large pieces with a wooden spoon.
Add the onion to the pot and cook for 3 minutes, stirring occasionally.
Add the chilli powder, cumin, garlic powder, tomato sauce, kidney beans, diced tomatoes, and water. Stir to combine all of the ingredients.
Bring the chilli up to a low boil over medium-high heat, reduce the heat to low and simmer for 20 minutes, stirring occasionally.
Taste the chilli and adjust the seasoning with salt if needed. Simmer for an additional 10 minutes.
Serve the chilli in individual bowls, topped with shredded cheese, sour cream, and chopped cilantro (if desired).