Bake the pie shell at 350 degrees until brown. Pour half the blueberries into the cooled pie crust.
Combine the remaining blueberries, sugar, cornstarch, salt, orange peel, water, nutmeg and butter in a saucepan. Cook until thickened. Pour the filling over the blueberries in the crust.
Chill until serving time. Top with whipped topping.