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Cheap water level/piezometers data loggers for sand dams

Orlando Avis
related country: Kenya
KnowledgePointAdmin
RedR CCDRR
related country: Kenya

Hi all. I’m looking for a cheap way to measure water level data in sand dams over an extended period of time to monitor functionality. I want it to be pretty automated. I found the "heron logger" which costs about £335. And that’s not including the actual installation costs (the distributor puts the total installation cost at over £1500, which is way above budget though I’m sure it can be done cheaper)

I was wondering if anyone knows a cheap alternative solution. I really don’t need great accuracy. Even logging at three heights in the dam would be fantastic.

A friend sent this fantastic article about modifying other loggers to make a presence absence logger but I need at least 2 heights and I thought I would check my options before attempting it. https://onlinelibrary.wiley.com/doi/10...

I was thinking of just putting a tube into the sand and getting someone with a string and a float to check it but it seems undesirable to the org.

Again great accuracy is not essential.

Thanks for your advice.


2 Answers

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Prajwal Shrestha
Practical Action

Dear Orlando,

please check in youtube.com using keyword "DIY water level sensor" you can get lots of videos on that. Hope some trick might work in your case.

Regards,

prajwal

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The cheapest option would be to construct a peak level gauge using a vertical piezometer housing pipe, and adding granulated cork. The cork will float on the surface of the water and will adhere to the sides as levels drop. Cost approx. 15 Euro

A little more complicated would be to fix a tape measure to the inside of the piezometer pipe with some form of friction fit slides on the tape, pieces of foam or neoprene cut to size could be used. If you use 3 slides, with a rigid connection between the float and the centre slide you can measure minimum and maximum water levels. A standard globe from a cistern ballcock could be used as a float in the pipe below the slides. As the float rises it will push the centre slide via the rigid connection, which will push the upper slide. The upper slide will remain at the max level, held by friction. As the float drops the centre slide will pull the bottom slide down with it, giving you the minimum level. There is nothing special about the float, you could use a PET drinks bottle, or a ping pong ball, whatever is appropriate to the size of pipe you are using. Depending on how much time and patience you have you can embellish the design by fitting guide rails on each side of the tape, depending on what is avaialable locally. Now that I think about it, rigid plastic markers would probably be the best option, running between to guides. Depending on how sophisticated you get the cost is approx. 100 Euro.

Next option would be an Ott ecologer 500. Simple to install and can be barometrically compensated,. The logger is integral with the sensor, and can monitor EC and temperature. A steal at approx. Euro 1,800.

Hope this helps, and happy times in your shed.

Regards

John Cody