Bring a large pot of lightly salted water to a boil. Cook pasta shells in the boiling water, stirring occasionally until tender yet firm to the bite, about 12 minutes. Drain.
Preheat oven to 350 degrees F (175 degrees C).
Combine turkey, chopped green chiles, water, and taco seasoning in a large saucepan; cook and stir until turkey is cooked through and moisture is absorbed, 8 to 10 minutes. Remove from heat.
Spread salsa in the bottom of a 9x13-inch baking pan.
Stuff each pasta shell with some of the turkey mixture and arrange on top of the salsa in the baking dish. Sprinkle Cheddar cheese on top. Cover pan with aluminum foil.
Bake in the preheated oven until cheese is melted and bubbly, about 30 minutes.