Irrigation from water butts
Using a simple timer attached to the tap on your water butt can create a simple drip irrigation system to water a raised bed or pots automatically when you are away on holiday etc.
Installing the water butts or connected water butts so the tap is above the level of the pots or raised beds will create a gravity watering system with the timer which runs on batteries set to water as required. To raise the water butt stacking some concrete building block will create a solid base.
In tight spaces the water butts can be easily disconnected from the houses or buildings downpipes and moved to allow access for maintain etc