Irrigation system design help

[Buzzaro]

Hi,
I am trying to figure out the best way to put together an irrigation system. Maybe I am trying to do too much or approaching it wrong. I made a quick sketch to illustrate the basic property layout. There is around 50' of elevation change from the top of the property to the bottom with an irrigation canal that supplies the water up at the top. So the option is there for a full gravity fed system, which works OK down at the bottom but not enough pressure for the orchard up at the top. I'd like to install a pump to increase the pressure (especially for the orchard) but I'd also like to be able to use gravity and not pay to pump it when I don't want to or when the demand isn't necessary. The system is limited currently to 1 inch (11.3 gpm) but I am looking to increase it to 2 inches (22.6 gpm). I don't yet have the storage tank so the size is flexible but looking at something in the 2500gal range. What would be best option for a low water shut off and on in the tank to protect the pump? The head is approximate but good enough for rough design. Currently the entire system is gravity with an option to run a gas pump on the orchard when desired. If possible I'd like the system to be mostly or fully automatic but I can't think of a way to make it happen with my limited knowledge. Any direction for the best approach would be most appreciated.
Thanks

 

[WorthFlorida]

For the orchard level and depending on the size and watering needs, use a drip irrigation system. Drip can run all day or a few hours without a pump. An irrigation pump could be used to overcome friction lost in the piping. Since the lower level has sufficient pressure from gravity, still use drip and keep the two zones separate. You can control the zone with a typical irrigation controller and zone valves. If you have areas of mainly turf, rotor sprinklers are the way to go but a pump is needed.

From your layout I would install one pump to fill the tank and use a float switch to shut the pump on and off as needed. A second pump with a float switch to irrigate the orchard area and maybe near the home. At very bottom use gravity feed and it will need its own controller to operate the any zone valves if needed. Irrigation controllers have a MV terminal to operate a motor start relay for irrigation pumps.

Usually the biggest problem I read on this forum is getting power to the pumps and float switches. If you have to bury a wire for power from the home to the tank, also bury a CAT 5 cable. There are many controllers that are WiFi and some might be direct wire but I don't know of any. I have a Rainbird WiFi controller and I can program it, manual turn on zones and set timers from anywhere.

 

[Sponsor]

 

[Valveman]

You can use a pump down float switch at the bottom of the tank to protect the pump from running dry. It will be wired to the booster pump while the upper "pump up" float switch will control the pump in the canal. Or, you can use a Cycle Sensor instead of a pump down float switch, and another Cycle Sensor will protect the pump in the canal from running dry.

If you turn off power to the pump the water will gravity flow right though the pump and controls when needed.