Priorities. When you design deep you must take in mind first: safety. Ponds with too vertical sides can be very dangerous for toddlers and pets. Evaporation

Priorities. When you design deep you must take in mind first: safety. Ponds with too vertical sides can be very dangerous for toddlers and pets. Evaporation depends on climate, shadow location, covering of the surface by plants, rains and extra income of new water. In very dry places with minimum work, you could desire a temporal pond, and let it dry naturally each year. If you want fishes and live in an arid place use killies, specially the native species. Take in mind that fishes in a pond are totally optional. Carps are normally too big and behave as a bunch of piglets so better not in very small ponds. If your water is cold and from snow take a look to the (non american) Tanichthys albonubes. If you live in UK use crucians and Gasterosteus