Brooklyn Garden Center - Sub-irrigated raised bed planters like these will typically produce in the range of 50% more produce than top watered traditional raised beds while saving in the range of 90% of the water. It is a closed system and there is no runoff.
Lengths of perforated, corrugated drain pipe create the water and air reservoir. The plants receive an optimized supply of both water and oxygen via the reservoir system. This is a major benefit for the plants. You might think of this type of planter as an "intensive care unit" (ICU). Mother nature supplies the light for photosynthesis and technology supplies the water and oxygen.
I did not make this planter and there was a mis-communication. The sheet plastic lining should have been installed all the way to the top to make the planter watertight. It does not diminish the functionality of the planter but the wood will not last as long.
Perforated. corrugated drain pipe with a fill tube is a universal way to make any watertight container into a sub-irrigated planter (SIP). Read more about corrugated drain pipe sub-irrigated planters (SIPs).