It is a bit confusing at this time of year with the thick foliage and hard to take photos. But basically...
The bottom (wildlife) pond pumps water up to the large ornamental (fish) pond. It then runs into the small but very deep (wildlife) pond. From there it runs down a waterfall back into the bottom pond with the pump.
The bottom (wildlife) pond pumps water up to the large ornamental (fish) pond. It then runs into the small but very deep (wildlife) pond. From there it runs down a waterfall back into the bottom pond with the pump.