Some bounds on this 1) yes you can have a small 100l tank catching rain water for your garden, but you can not drink it. If it became a big tank it would beco

Some bounds on this 1) yes you can have a small 100l tank catching rain water for your garden, but you can not drink it. If it became a big tank it would become subject to planning and building control. 2) you need a permit to harvest ground water by digging a well or borehole. 3) you need a permit to entrap water in a pond and to build a dam for this purpose