Accident-proof Water Tank

This is the main water tank for the farm troughs, gardens, trees etc. It holds 15,000 litres when full but when a horse or cow trips over a pipe it tends to hold zero water fairly quickly. After finding an empty tank last night it was time to fix the problem.

I needed a system to keep the tank usable, but limit the loss of water when the inevitable happens. Until all the fencing is finished, there will always be temporary plastic troughs floating around and they are easy to trip over or disconnect.

My trusty cordless drill made short work of the plastic tank side – drilling a hole half way up.

Here’s the tank fitting in the hole. Rubber gaskets seal it from both sides between the two halves. Thankfully, what you can’t see is me having to climb into the tank in my boxers to push the fitting through from the inside. Luckily the water was only knee-deep (thanks to the horses).

The finished job  – you can see we now have two exits for water, both with valves. If the bottom valve is shut then water can only drain as far as the halfway point before running dry, but we still have half a tank safe in reserve for when the problem is fixed (and a few days of water in which to refill).


  1. Rob Says :
    25 November, 2008 at 10:31 am

    I’m disappointed! Such a low-tech solution – I was expecting wireless mesh devices tracking flow rates and alerting you via Farm PDA/SMS when flow rate exceeds x for longer than y, perhaps also automatically activating a servo to shut the valve off until reset by a return SMS :)

  2. Kay Says :
    25 November, 2008 at 10:35 am

    Nice tidy solution to one of those ongoing problems…

    We fixed ours by filling the troughs out of a 1000 litre tank – that way the most we lose is the 1000 litres. However we do have to refill the small tank from the large tank.

  3. John Says :
    25 November, 2008 at 10:53 am

    Your solution sounds sexy Rob (and don’t think I haven’t thought about something like that :) but mine requires no batteries.

    That said, there IS a mechanical solution that does the same thing as yours – a valve that shuts off if preset flow rate and time are exceeded. It’s set with pins and uses the movement of the water to actuate the closing mechanism (presumably some sort of screw/spring thing). I knew a guy in Auckland that imported them from Belgium I believe, must track him down…

  4. Martin H. Says :
    19 December, 2008 at 12:17 am

    John is right. You should try a safety valve used for inlet hoses of washing machines. It is mounted between the hose and the tap and shall close when the hose breaks or comes loose from the washing machine.
    They are marketed under the names Aquastop or Waterblock in Germany.

  5. Lifeboat Farm » Arduino water level gauge Says :
    28 December, 2009 at 2:18 pm

    [...] Our main water tank for the farm is out of view of the house so a visual water level gauge wouldn’t be much use. Most of the time we can only tell when the tank is empty the hard way, although I’ve added some plumbing to the tank so we always have some water in reserve. [...]

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