Last month I teased about a new water harvesting project at the farm. As you recall, we had issues getting gutters on an old tobacco barn and we ultimately had to scrap our original design all together. This challenge turned into one of the most simplistic, yet functional designs we have implemented to date.
Several weeks passed and Dr. Higgins called me. “I have an idea for Field 60 but you’re not going to like it” he says, clearly anxious to present me the idea. The conversation that followed sounded like it would work just fine to me.
An artifact from a previous project, Dr. Higgins had found an unused pvc pond liner. This pond liner was 40x80 foot in size and was folded up and waiting for someone to think up something to do with it. It was perfect for our water harvesting needs in this challenging location of the farm.
The design Dr. Higgins found for this project was in an old book dating back to the 1950’s. The simple concept was to lay the pond liner on the ground, sloping it down hill slightly so that the rain water that lands on it will flow to the lower side. The lower side is laid down in a trench and funnels the water to a collection box in the corner of the rain water capture area.
From the collection box the water travels using gravity, via 6 inch pipe, to a partially submerged 3,000 gallon tank. Once the 3,000 gallon tank is full, the water is pumped using a solar powered pump up into the pasture and fills another 3,000 gallon tank. This pasture tank gravity feeds water into an 8 foot tire water tank directly below it.
Once installed, the effective area of the pond liner is about 35x70 foot. A four inch rainfall is enough to completely fill this system giving us 6,800 gallons of stored rain water. This is enough water to effectively graze this pasture with 30 pairs for 10 days at a time as part of our rotational grazing program. When the cattle leave this location, we have 4 weeks to allow the system to refill before the cattle are back in this field.
We have not watered cattle in this location yet, but the system is currently capturing water and functioning as designed. As I mentioned earlier, it is a very simplistic design that functions efficiently.