Projects For Solving Big Water Problems

We’re looking for solutions to problems that matter and water waste is high on that list. This week we challenged you to think about Big Water; ideas that could help conserve the water used in agricultural and industrial applications. Take a look at some of the entries, get excited, and start working on your own idea for the 2015 Hackaday Prize.


smart-dewpoint-harvesterThat’s right, windtraps. Like the Fremen of Arrakis there were a few hackers who propose systems to pull moisture from the air.

The RainMaker is targeted for urban farming and explores the possibility of passive systems that water themselves automatically. [Hickss] admits that there are some limitations to the concept. Small systems would have limited ability to collect moisture and a need for direct sunlight in order to be solar powered. However, if you’re growing food we figure direct sunlight was a pre-requisite anyway.

On a bit grander scale is the Smart Dew-Point Water Harvester which is shown off in this diagram. The proof of concept at this point is a desktop system that collects moisture on a small heat-sync. Scroll down to that project’s comments and read about the possibility of building the system underground to take advantage of the naturally colder area.

For us the interesting question is can this be done in conjunction with traditional irrigation? Is a lot of irrigation water lost to evaporation and could reclamation through these means make an impact?

Moisture Sensing

water-sensing-orb-thumbSimple but powerful: only water when the plants need it! Here are several entries focused on sensors that make sure fields are being watered more efficiently.

The Adaptive Watering System focuses on this, seeking to retrofit current setups with sensor pods that make up a mesh network. We found the conjecture about distributing and retrieving these pods using a combine harvester quite interesting.

Going along with the networked concept there is a Moisture Monitoring Mesh Network which proposes individual solar-powered spikes. Much of the info for that project is embodied in the diagram, including a mock-up of how the data could be visualized. One thing we hadn’t spent much time thinking about is that fields may be watered unevenly and a sensor network would be a powerful tool in balancing these systems.

Wrapping up this concept is the Soil Moisture Sensor for Agriculture. [JamesW_001] rendered the image seen above as his concept for the sensor. Toss the orbs throughout the fields and the rings of contacts on the outside make up the sensor while the brains held safely inside report back wirelessly.


solar-water-pumpTwo projects tackled plumbing. The first is the Solar Water Pump seen here. Focused on the developing world, this array provides water for multiple applications, including agricultural irrigation, and can be used for wells or surface water sources.

Once that pump gets the water moving it will be taking a trip through some pipes which are another potential source of waste. When buried pipes leak, how will you know about it? That’s the issue tackled by the Water Pipeline Leak Detection and Location project. When the water pipe is buried, two sets of twisted-pair conductors in permeable sheathing are also buried along with it. These redundant sensors would use Time-Domain Reflectometry (TDR) to detect the location of a short between conductors. We’re a bit fuzzy on how this would detect leaks and not rain or irrigation water but perhaps the pipe/wire pairs would be in their own water-shedding sleeve?

This Week’s Winners


First place this week goes to the Smart Garden and will receive a DSLogic 16-channel Logic Analyzer.

Second place this week goes to Soil Moisture Sensor for Agriculture and will receive an Adafruit Bluefruit Bluetooth Low Energy sniffer.

Third place this week goes to Solar Water Pump and will receive a Hackaday robot head tee.

Next Week’s Theme

We’ll announce next week’s theme a bit later today. Don’t let that stop you from entering any ideas this collection of entries may have inspired. Start your project on and add the tag 2015HackadayPrize.

The 2015 Hackaday Prize is sponsored by:

24 thoughts on “Projects For Solving Big Water Problems

  1. I dunno the prospect of pulling moisture out of the air seems absolutely terrible.

    Yeah it will probably work and solve some smaller localized issues but when applied in large scale (and I’m sure it will be) it seems like it would cause far greater wide spread issues. Just look at what wide spread irrigation has done to rivers. Rivers that flow at a fraction of what they used to and no longer reach the ocean. Now people are going to start sucking the water out of the atmosphere before it ever makes it to the tributaries…. what could possibly go wrong…..

    The best bet seems to be adaptive watering, make the best use of what you have instead of trying to pull more out of an already stretched system.

    1. That’s the same conclusion I came to when I first heard of this idea (it’s not a new one).
      Like you said, sure it solves the local problem, but what about those downwind? Industrial water harvesting will quickly deplete moist air just as it does with wells and reservoirs. Now we’ll get artificial deserts thanks to rainshadows created by Pepsi and their new bottled water factory.

      We’ll have the same legal issues, California will be suing Vegas and Colorado for overharvesting atmospheric water like has been done with rain water and rivers.

      This is another example of fighting the system (ie; weather) rather than working it to our advantage.

    2. I am not sure that this would be a problem. You see, this does not work everywhere equally well, if the air is pretty dry to begin with, this wouldn’t make much sense.

      But if you have large water bodies (sea) nearby, then the air is usually saturated (for the current temperature) and people would actually prefer if it was dryer. I know that for sure because I live in such an area: We have high temperatures, high humidity, but still rely largely on rain.

      Taking moisture out of the air would be a good thing here – but still the air wouldn’t really become dry, because the sea will replenish any missing moisture. So, for many (sub)tropical islands (up to the size of the Japanese islands) this would be a good idea, and also for coastal areas.

  2. I work for We’ve been working on a remote sensor project for the past few years with the help of a grant from Google. We just open sourced the hardware and software files. You can read more about the challenges, find links to the source repos, and see pictures at:

    While it’s not specifically designed to conserve water it might prove useful to projects that are being designed with that in mind.

    1. Very cool design! If I understand right, you’ve built a multi-point capacitance level probe and you’re using this measurement (along with a few calculations on head pressure) to figure out flow rate. No moving parts and low power consumption!

      What kinds of accuracy and turndown have you seen from your sensor? Do you have to calibrate the unit to each individual well?

  3. The problem is not water or any other resource, it is population growth. I don’t care how much you ‘save’ you are still going to see total quantities increase as long as population increases.

    If you want to control use of a resource, there is a simple solution. Let the market price that resource freely. If that is done, you will see consumption decrease considerably as supply decreases. As an Example, all users of water in California should probably be paying $10-$20 a gallon for water. And at that cost level, the supply can easily be supplemented by desalination plants. No need to continue stealing water from other Southwestern states…

      1. Sadly we already have large numbers of the people who caused all of the problems in California moving to places like my state, Texas, and trying to convince us we should be doing the same stupid things that caused them all of the problem they are running away from.

  4. Peltier elements aren’t really powerful enough to pull water out of air.

    For starters, you’re mostly cooling air instead of the water in it. There’s only a tiny amount per cubic meter, so 99% of your energy is actually going to waste. Secondly, for the water you do get you need to pull ~600 Watts of heat off for every liter of water per hour.

    Even with a proper compressor, the energy required to pull water straight out of the air is enormous.

    1. I have a feeling from the design that the air moving into the reduced pressure zone is supposed to put it closer to the dew point. This may be a physics mistake. Certainly the system would seem to benefit from a heat exchanger.

    2. This is California: They’re already using air conditioners. So what if it takes 0.6kWh of electricity to produce a liter of water? That’s one liter of water they have at 1 o’clock that they didn’t have at noon.

      Here’s the trick: Instead of the condensate from the AC dripping on the ground or into a sump to be pumped up-hill to drop into a storm sewer, simply have it fill up a bucket instead. And then use that bucket of water for something productive.

      Also, get rid of industrialized evaporative cooling: It only makes sense when water is plentiful, and it isn’t.

      (Where’s my prize?)

      1. The bulk of water used in California is for Agricultural purposes. Your proposal amount to changing the number after the second or third decimal point… In short it changes nothing. Of course the California politicians can’t do the math either since they are focusing on regulating the folks who use only about 5% of the state wide consumption and ignoring the primary consumers… Perhaps because they donate large amounts to campaigns…

  5. It’s been possible for quite a while to recycle and purify 100% of waste water to clean, potable standard. It’s time to Just Do It.

    All the technology has existed for at least 20~30 years to build a fully automated system that could take in unsorted muninciple, industrial and medical waste and output cleaner air, clean water, electricity and sorted metals and glass. It would also be possible to separate out chemicals to send to a refinery to be re-fractioned/re-refined. Even various types of plastics can be sorted by automatic methods.

    The first step would be to dump all the waste and contaminated water through big grinders and mixers.

    After all the desired recyclables are removed, the remaining ground up waste and de-watered sewage could be mixed with a small amount of a clay that will vitrify at high temperatures. Extrude that mix into gravel size chunks and use waste heat from the burner exhaust to dry it, with the end of their trip spiraling down around the outside of the burners. Feed the waste fuel pellets into the bottom of cyclonic burning chambers, the feed air being drawn in from the waste intake area so any smelly fumes get pulled in and burned.

    As the pellets fuel load burns they get lighter and spiral up and out the top then pour down a cooling tumbler (same design as used to cool wood pellets made with rotary pellet mills). Heat from that would also be used to help dry the incoming fuel pellets. The vitrified, highly porous pellets would work very well as concrete and asphalt aggregate. The pores would bind much better with the cement and tar than ordinary rock.

    There would be many places in the process where waste heat would be used to evaporate excess water. The burning process would also produce water vapor in its exhaust. Collect all that and there’s the clean water. The problem of distilling water contaminated with chemicals that have a lower vapor transition temperature than water has long been solved. Do a first step where the water is heated to just below its vapor transition point. Then do a second step where the water is evaporated, leaving behind anything with a lower transition temperature than water. Adjusting the pressure can also be used to control evaporation of various components of a mixture.

    Build enough of these all in one plants and it should eventually be possible to be running 100% of the waste through them, then start mining the landfills.

  6. The issue isn’t one of technology, but rather of cost. Third world countries will be unable to afford the vast majority of this tech (some are only just getting solar lamps) and first world countries have little interest in supporting them. Hell, UKIP want to get rid of the foreign aid budget entirely

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