Heat 2 teaspoons oil in a large nonstick skillet over medium-high heat.
Add zucchini in a single layer; increase heat to high and cook until golden, about 2 minutes a side. Sprinkle red pepper flakes (a little goes a long way here) while finishing, last minute or so.
Remove zucchini to a plate with a slotted spoon.
Heat remaining teaspoon oil in same skillet.
Add shrimp; sauté 1 to 2 minutes. Add tomatoes, oregano, salt and pepper; sauté until shrimp are almost just cooked through, about 1 minute.
Stir in garlic and water; sauté, stirring to loosen bits from bottom of pan, until shrimp are cooked through and tomatoes are softened, about 1 to 2 minutes more.
Return zucchini to skillet; toss and serve.