Heat the oven to 350° F.
Brown the ground turkey on a skillet over medium-high heat until no longer pink and a temperature of 165 degrees F. is reached.
As it cooks, sprinkle on the garlic powder, mixing it into the meat. Break up the meat with a wooden spoon or spatula into small crumbles.
Once it's browned, drain any excess grease and return the meat to the skillet.
Add the marinara sauce, then add the water to the skillet to thin out the sauce.
Stir the sauce until it's combined, then turn off the burner.
In a large mixing bowl, combine 1 cup mozzarella, 1/4 cup grated parmesan, all of the ricotta, and the egg.
Pour enough meat sauce to lightly coat the bottom of a 13"x9" pan.
Top with a layer of tater tots, then the ricotta mixture, and a layer of meat sauce.
Cover with another layer of tots, add more meat sauce, then sprinkle on the remaining mozzrella and parmesan cheese.
Bake in the oven for 45 minutes, or until the cheese has melted and the tots are lighly browned.