There are several points you need to consider before building your pond or water feature. Should it be formal or informal, natural or modern? Do you want to keep fish, grow plants or attract wildlife? Are there children to keep safe?
Once you have answered these questions you need to decide where you want to site the pond or water feature. A pond should be kept away from big trees and shrubs so ensure their roots don’t puncture the lining. If you want to keep fish you need to have a pretty deep pond to stop it freezing over the winter. The smallest you should build a pond is 60cm (2ft) deep and 1 x 1.5m (3 x 5ft) across. However, the bigger the better.
If childrens’ safety is and issue or you prefer not to have to maintain a pond then a water feature is an excellent compromise. You could build a wall fountain or a pebble pool which can be sited in sun or shade near to a power supply. If you do not have external power then a wide plant container or half a barrel, without drainage holes, is ideal. You can still grow small aquatic plants or use floating oxygenators such as water hyacinth. You will need to protect them during winter or empty the container and start again in the spring.