Whether a pond waterfall freezes depends largely on the local temperature and the flow rate of the water. In 2026, the common advice for pond owners in cold climates is that moving water is much harder to freeze than still water; however, during extreme or prolonged "deep freezes," ice can still accumulate. This often begins as "ice dams" where moving water splashes onto rocks and freezes, gradually building up until it restricts the flow or diverts water out of the pond entirely, causing a leak. While some experts suggest keeping pumps running to maintain a hole in the ice for gas exchange, others recommend shutting down waterfalls in sub-zero regions to prevent super-cooling the water, which can stress or kill fish. If you choose to keep it running, you must monitor it daily for ice buildup. A peer-to-peer tip is to utilize a pond de-icer or air stone to keep a small area of the surface open while shutting the waterfall itself to protect your equipment and plumbing from freezing and cracking.