Gravity Water Feature

Garden water feature's are becoming more popular, many of these use a pump to recirculate the water, wasting electricity and usually running all the time. If enough rain water was collected in a tank this could be used to keep the water feature running for a reasonable amount of time each week.

Small garden pump generates a head of 0.5m and pumps 100l/hr, tank at eaves level could easily generate greater pressure than this. Most pumps run continuously.

Minimum (average) monthly rainfall in my city is 50mm/mth, if the water feature was connected to a timer so it only ran say 4hrs each weekday and 8 hrs each weekend day, and you store around 2 weeks of rainfall for the feature a tank of 7200L volume is required, this could be captured off a roof area of 140m2, easy to do off a regular house.

A smaller tank could be used but will be less dependable, a compromise needs to be made based on the month with the least rain in your area and the tank size (as well as the number of rain days in a given month).

Runoff from the far end of the water feature would be directed into agricultural pipe (plastic pipe with holes in it) to allow the run off to soak into the soil acting as a fairly permanent water supply for the garden.