In a 5-quart Dutch oven or heavy pot, heat oil over medium-high. Add onion and garlic; season with salt and pepper. Cook, stirring occasionally, until beginning to soften, about 4 minutes.
Add zucchini, carrots, chili powder, and cumin. Cook, stirring occasionally, until carrots are crisp-tender, 6 to 8 minutes. Add beans, tomatoes, corn, and 1 cup water. Simmer until slightly thickened and carrots are soft, 8 to 10 minutes more.