By retooling existing farm fields to use a closed loop NFT (Nutrient Film Technique) design, we can use less than 10% of the traditional amount of water needed to irrigate the same square footage. In addition to the water savings, NFT allows a higher growing density which can help offset some of the costs of retrofitting an existing farm.
In order to build a system that can span significant acreage, multiple NFT systems will need to be implemented. Each system will use opposing channel runs at 30m length, with the tank and sump pump between each run. Implementing a large tank (10,000) allows the use of many channels, grouped by the bed width of the existing field. Depending on the row spacing, you should be able to fit 3-5 channels per row.
Because the NFT systems are being built upon dirt, it's important that the footing be secure. Regular footing could shift, and cause ponding within the channels. Instead, use stakes driven-in securely to provide an adequate foundation.
Initial seed of Sketchup drawing showing a potential system design. More to follow...