Water level sensor?

Hi all, I live on a farm with a borehole. Said pump from borehole stores water in a large tank. Borehole pumps fail eventually and with warning I will have a day of water left! Any idea of the best way of doing this - maybe outside of SmartThings as the borehole is about 150 metres from the farm and will not be covered by my present hub (any way that I could extend the distance?) My initial though was a door sensor, but wondering how to stick the plastic container that would house the ‘magnet float’, and the fact that the tank lining may make the 2 parts of the sensor too distant. Thanks in anticipation.


The door sensor probably won’t work for multiple reasons, one being that you should never put a battery operated device into an airtight container, including a plastic bag, unless it is specifically designed for that purpose. Batteries can and do outgas and it becomes a fire hazard. And as you noted if you try to put the sensor on the outside of the tank it can be tricky to get the magnet inside to line up just right.

That said, there are several flood sensors which work via an attached probe and those can probably be used for the kind of use case you describe. For example, people use these to test whether a Christmas tree well has run dry. You mount the radio part of the device up out-of-the-way so it stays clean and dry (if necessary, you can put it inside a vented project box like people use for outdoor electrical outlets) and then run the probe down to the point where you want it to alarm.

See, for example:

Looking for a way to monitor/notify me when a water/wet sensor is dry

For the distance aspect you’ll probably get the best results with a wifi-enabled water sensor and extending your wifi range via an outdoor wireless access point such as the TP-Link EAP225 Outdoor.

AFAIK most Z-wave range extenders have a maximum of 150m so you’d be pushing the envelope. WiFi range is a lot better (with the right equipment) especially if you have unobstructed line of sight.


Good point on the range, I actually missed that the first time through. Technically, 150 m is within range of zwave plus outdoors although signal might not get through on a rainy day.

It would be far enough for Wi-Fi, but the problem with Wi-Fi is how are you going to power the sensor? There are very few battery powered Wi-Fi sensors because they use about 10 times the power of zigbee or Z wave so battery life ends up being about two months.

The Wi-Fi extender you link to is powered although it’s POE. If there is a power source out in the yard, not uncommon with pumps, it may be just as easy to put a Z wave repeater partway across if you need one, although again, I suspect you probably wouldn’t. A Z wave light bulb is often good for this purpose if there does happen to be a light fixture in the area. Then again if that’s the set up, you could probably run the Wi-Fi sensor off of power. :thinking:

use a water sensor and wit doesnt sense water ave it sound a siren.

Is it potable water? If so, you may need to be a bit more cautious about what gadgets/sensors you put in the. Honestly not sure if that matters but may be worth looking into.

A contract sensor may still work. If there is any kind of float with an arm, you could attach the magnet to that and it would be up out of the water.

Since there is a pump there, I’m assuming there is also electricity there so you could plug in a smart outlet (or other repeater) to extend the range beyond what a battery powered sensor could handle? Then also make sure you have another repeater on the outside of the house as close to the pump as is feasible.

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What actually you want to monitor? Water level? Pump status?

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Hi All, To confirm I am trying to monitor if my water level drops in a storage tank at the borehole. This ill then inform me of any issues with the pump, electrics etc 1 day before we run out of water. It is potable water and hence my thought of just having an inert magnet inside the tank with the functioning part of a door sensor on the outside of the tank. I am waiting to get wifi inside to see if this works. Electric is present at the borehole, and I will soon get wifi present using Ubiquiti Airmax devices. I tried to use Powerline, but they did not like the distance and the RCBOs on the consumer units. Additionally the very poor signal I did get was shot to bits when the circuit was under load from the pump. Having thought and googled this further an Ultrasonic Water level sensor is probably the thing to go for, BUT they look expensive and one that uses an app by Kingspan to monitor oil levels (assume this would work with water), mentions annual subscription which I would not want. Anyone seen a reasonable low cost one? Thanks Paul

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Ok, if you want to monitor the water level at storage tank, that can be easily done using esp8266 and integrate to SmartThings / blynk app with some programming, material wise it’s cheap.

Take a look on this example.

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Many thanks CSC. I had seen this on the web and thought it looked interesting. I know nothing about the esp8266 board or Blynk, but the two look very interesting. I love a computer challenge, especially if I have a problem to solve and so this looks the ideal ‘toy’ for the early part of winter - especially with lockdown. If anyone can give me any pointers then it would be helpful. Quick question - I see that this board has now been superseded by the ESP32 and hence wonder if I should be going for this instead??? Has anyone on here made this water level sensor and can give some advice?? Will post back if I sort it!

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I am still using esp8266, you can get a nodemcu, it is easy to use and to connect to computer, it can directly connect to the sensor as well with simple wiring.

To load the code into nodemcu, you need arduino IDE.

Hope that help.

I’ll post a picture of my setup later, I use it to check the water level of my balancing tank.

Many thanks - look forward to seeing the picture.

Basically it’s a D1 mini Pro (can use nodemcu as well), and a ultrasonic sensor (this set not water proof but I hanging it some height from water), in a 3D printed box. I added temperature sensor for another purpose

Just to update on this. I have just completed a prototype sensor system for our borehole using 2 ultrasonic sensors and a temperature sensor. The ultrasonic sensors will monitor the salt tablet chamber level and the water level. Temperature is to warn me if it gets near to freezing point inside. This will save me from having to check the water level on a daily basis to ensure that my main pump has not failed. Once it does we have one day of water before we run out until it is fixed!! Many thanks to all for their input. Will re-post when I have tried this in the ‘wild’. A bit of a learning curve with Arduino programming on a nodemcu and then using Blynk to display on an iPhone, but fun and kept me amused!

I use this for a similar application, if it helps: