Gabion walls don't need any kind of drains because they are porous throughout. Gabions can be customized to make them more useful in public spaces. Gabions can be filled with any heavy material--diverse stones, metal artifacts, obtanium, etc.
This is great since we don't have any outdoor hose hookups! How to Build a Rain Barrel. A dual barrel system that uses atmospheric pressure to equalize the water volume in both rain barrels. Use the water from your rain barrels to water your plants.