I was unable to put our barrels very high above the level of our garden boxes so the gravity feed worked only the lower level garden and I was only able to use the top half of each barrel in the garden boxes. I too used 5 gallon buckets mostly. Each was raised only about 6" on their individual wood bases. On the 10 acres I just moved to near Spokane, I am building small (20'wx10'lx4'deep) rainwater cachement basins that will be fed by buried 6" pipe from the gutters to the basins and by diverting my grey water into the same pipes. I live on a hillside so have engineered basins using existing swales and cut banks. My shop, chicken coop and guest house will also have gutters to feed basins. These will be about 5'-6' hijgher than the level of our hugelkultur beds so I can use gravity.
