DIY unpowered drip irrigation on sloping land with 95% uniformity
The attached article demonstrates how drip irrigation on sloping land from a header tank can use NPC (non pressure compensated) drippers without compromising dripper uniformity throughout the irrigation application. The irrigation controller is an Unpowered Terracotta Irrigation Controller.
Some key features are listed below.
1. The installation cost is a fraction that for an equivalent PC system.
2. Excluding the refilling of the header tank, the irrigation system is completely unpowered (no batteries, no solar panels, no electronics, no computers, and no WiFi).
3. A small low pressure water transfer pump may be required to refill the header tank between irrigation events.
4. The water discharge from each irrigation dripper during the irrigation event is approximately the same.
5. Provided that the control dripper has the same emitter discharge exponent as the irrigation drippers, the water discharge from each irrigation dripper during the irrigation event is independent of the water level in the header tank.
6. Provided that the irrigation system is designed so that frictional head loss along each lateral is negligible, the dripper uniformity throughout the irrigation application is better than 95%.
7. You can adjust the water usage rate by adjusting the control dripper on the Unpowered Terracotta Irrigation Controller.
8. You can adjust the interval between irrigation events by adjusting the float on the Unpowered Terracotta Irrigation Controller.
9. The irrigation system responds automatically to on-site evaporation and rainfall.
10. Simple, unpowered, and low tech, and therefore fewer things can go wrong.
11. Provided that you have a continuous water supply, you can leave your irrigation application unattended for weeks on end.
12. If the header tank runs out of water, the irrigation system starts again automatically as soon the header tank is refilled.