Preheat oven to 400 degrees. In a medium bowl, whisk together chili powder, garlic powder, onion powder, cumin, salt, lime juice, olive oil, and water. Stir in corn, onion, peppers, chickpeas and cauliflower florets. Place seasoned chickpeas and cauliflower on a greased baking sheet. Roast for 30-35 minutes, stirring occasionally during cooking, until chickpeas are slightly crispy and cauliflower is tender. Remove from oven and set aside.