30,000 gallon modular, underground rainwater harvesting system | Innovative Water Solutions 

Of course Waldo. We are here to help and educate. Thanks for recognizing our dedication to responding to our video comments.

It's certainly worthy of recognition with how uncommon it is these days. May you find success :)

#Innovative Water Solutions LLC can we apply the same method in the cold mountain regions to collect melted snow along with rain water? i hope you understand what i mean to ask

You certainly can collect the melted snow after the winter thaw into a cistern. The main thing to design your system for is to weather the freezing weather during the winter time. Therefore, you would want to investigate underground cisterns or having the ability to drain and bypass an aboveground cistern during the winter if an underground cistern is not feasible.

Thanks!!

+ManitobaScott Very interesting application and additional benefit of rainwater harvesting in northern climates. Thanks for posting!!!

doesn't have to be rainwater, just water for seasonal solar heat storage

Bob Wood Yes we think that same way. Actually it comes down to commitment and the price of water. If the building owner isn't committed to conserving water no matter if it does pay off now or later, then they certainly won't employ rainwater harvesting. They will have the federally mandated water fixtures (water conserving) installed in the building and leave it at that. Also, since the price of water is so relatively cheap (yes even in drought stricken California water is still cheap but it may be rationed out for the use of irrigation purposes) it doesn't push building owners to think about using rainwater harvesting systems to reduce their water use. Thanks for the comment!!

Innovative Water Solutions LLC Don't get me wrong, I'm not a big tree hugger but I do see the advantages of a system like this and the use of solar and wind energy. Imagine if the roof of each Walmart, Lowes, Home Depot, large school buildings etc. were covered in solar panels, especially in highly sunny areas like the south west. Every bit helps, even domestic rain barrels or similar rain catchment systems. Keep up the good work.

Bob Wood Oh, I think about their potential every single day. Those larger roofs could become water and energy generators for their localized area around the buildings because they would probably harvest more energy and water than the actual building needs. It would be great for the environment but maybe the energy and water providers would have a different opinion since we wouldn't be purchasing more energy and water from them.

Thanks for the comment. Yes, I would be worry about the liner developing a hole, but with the recommended installation method by the manufacturer, that chance is lessen due to the thickness of the liner and the special backfill requirements. But the chance is still there. As for the cost of water, that is a debate that has many factors that are hard to bring out here. Rainwater systems do have long paybacks if you only compare to the implicit cost of water now. When you bring in other factors to the analysis, rainwater can have just as good or better paybacks than solar. As for using another tank material, you are definitely correct about fiberglass or concrete being a better material if you don't want to chance a hole but you will not get a 30k gallon underground fiberglass or concrete tank for less than $3 per gallon. So that would make just the tank cost around $90k and that doesn't include the excavation or other costs. Bottom line, there are lots of options, tanks, and decisions that need to be made by the project owner to determine what is the best rainwater harvesting system for them.

Thanks for the comment. I really like to respond to the comments here because it can be helpful for people to learn about rainwater harvesting. To size a system, one variable that you didn't include is the average rainfall for your area. If you were in central Texas (32 inches annually), then with a 3000 sf collection surface, you could collect about 60,000 gallons per year. Now, you will probably not collect that much due to the timing of rainfall, usage, etc. For irrigation use, I always a rule of thumb of being able to capture a 2" or 3" rain event in order to efficiently collect rainwater. So in your case, it would mean a cistern size of 5,000 gallons or so. I hope this helps!

While there is definitely a possibility of adding a sand filter to a rainwater system, the best place to do that is after the storage volume, when you are pumping the water to use. The issue with using a sand filter to filter the rainwater from the roof is the flow rate required to collect the rainwater without causing waste. As you pointed out, it would take maybe 2 or 3 weeks to filter 30,000 gallons of rainwater. Where would that rainwater be stored while waiting for the rain to be filtered prior to entering the rainwater storage tank? Off this roof, there could be flows of up to 350 gallons per minute of rainwater flowing off this roof.

Ok, you are right. 350 gallons per minute would easily overwhelm a small slow sand filter, even a relatively large slow sand filter would be overwhelmed by that flow. Your storage system looks really nice. Thank you for posting it.

Thank you!

+Fernando Cosso Yes, I never got back to the site to get a picture after the grass had established itself. It would have made for a better ending. Thanks for the comment.

+Innovative Water Solutions LLC you do this for home systems? Underground?

+Spiorad Krieger Yes, but underground systems on a residential project can be rather pricey when compared to an aboveground system. Now if surface space is a premium then, yes, an underground system may be worth it.

I wouldn't suggest this particular water storage system for potable water supply for a household. One of the main reasons is the cost of an underground rainwater storage versus an aboveground rainwater storage system. An underground system is a lot more expensive partly due to the need for excavation. Another reason why this system may not be appropriate is because it essentially can't be cleaned out due to the plastic matrix that makes up the boxes. Over time, with potable rainwater systems, you will want to clean the tank. I hope this helps. Thanks for the question.

+dethmaul The roof of the building is what is collecting the rainwater so there will be a minor amount of dirt but not much. What we didn't show in the video is an inground inlet filter that the rainwater collection pipe from the roof goes through before connecting to the underground tank system.

justgivemethetruth In comparison to underground cisterns, this system can be a cheaper alternative, but it depends on the volume desired. If you only want a few thousand gallons then an underground poly tank or two will work. The largest underground poly tank is around 2500 gallons. The other underground cistern options are fiberglass or concrete (either tanks or cast-in-place). The great thing about this modular system is the cost savings of shipping big empty tanks to a job site. This type of system has been around for some time. Obviously, as with any other structural system, the site should be analyzed to determine if this is the best solution.

Innovative Water Solutions LLC At what volume does this start to make sense, and what about comparisons of repair and maintenance, or breakage? Is there enough of an install base of these things to tell how well they work in the long term?

justgivemethetruth Something under 10,000 gallons of storage may be less expensive to use multiple underground poly tanks than this modular system. We have only gotten the opportunity to install 3 of these systems (we don't do many underground installations here in Austin due to the presence of bed rock close to the surface). I think that if care is taken in the installation of the base materials and the backfill material around the units, then you can minimize the danger of a leak in the liner.

E Devos Thanks for the comment. This music was created by the band of one of our long time employees. We wanted to showcase their music as well as rainwater harvesting. It is typical to find many people in Austin, working their day jobs, but also are part of a band or aspiring musician. We just wanted to support them in anyway we can.

Innovative Water Solutions LLC God damn youre going green in every direction aint you ;)

dethmaul Grimy Styles: facebook.com/pages/Grimy-Styles/79017934355

+E Devos I thought the music was great and matching the video. :-)

+Innovative Water Solutions LLC I personally liked the music, and I reloaded this video just to find the artist info. Two thumbs up =-) Please pass it on to the musician.

The "tarp" is actually a impervious liner material so no water can get through it. We are piping rainwater collected from the building's roof into the "cistern". The liner keeps the harvested rainwater in the cistern. To figure how much a rainwater collection system can harvest, multiply the rainwater collection area (square foot) by 0.623 by the amount of annual rainfall for your area. Thanks for the question!