Header Image

Rainwater Systems

Rainwater Collection Systems

Gathering rainwater for use in the garden and home has a never-ending list of advantages and values.

For the young and old, it is educational to learn that water does not just come out of the tap in your kitchen or bathroom. Because most municipal water systems are chlorinated, rainwater is actually preferable for your garden and plants. In weather emergencies or some crisis, your rainwater is very fresh water that can be treated for more potable use.

Inside Rain Collection Tank
This 1,000 gallon tank when empty needs a ladder to climb down in.

A poly 55-gallon drum is an easy way to start.

You can just shorten the downspout and run the water over a piece of screen before it goes into the tank. In my city, the garbage system changed from recycling square bins and the usual variety of trash cans to uniform wheeled containers that can be picked up by a mechanical arm of the newly outfitted garbage truck. My personal award for ingenuity went to a family that flipped the recycling bin upside down to support their trash can that became a rain barrel! Hooray for them.

1,000-gallon rainwater systems

The photos shown are for a 1,000-gallon rainwater system that is freeze-protected for year-round use in the house for flushing toilets and use for house plants. It utilized an insulated copper pipe 4 ½ feet below ground with temperature sensitive heat tape where it goes above ground into the house and to the tank. It turns out wonderfully to be a gravity flow system into the house basement. That is not a basic system. In a very efficiently insulated shed, electric heat provided freeze protection from November to May with only about a dollar’s worth of electricity. Of course, it could only turn on if the space dropped below 38 degrees Fahrenheit. The copper “mandala” coil seen in one of the pictures was my outrageous design how solar panels could keep the water and plumbing from freezing.

Rainwater Collection System
This base has to support almost 5 tons of water solidly. Coil will be able to heat the tank and water from solar thermal panels in the future.

First Flush

One important lesson is that the first flow of water off the roof into your rainwater tank will be the dirtiest water. Gallery pictures show a “first flush” system where the first flow fills up the vertical PVC pipe and then flows into the tank. This system has a floating ball that rises up to seal the pipe for the cleanest flow and to isolate the “dirty” water that can slowly drain out the drain tube to automatically empty the system. You can glue up PVC pipe and fittings to have a simpler flush system that is manually drained using a hose bib valve. I also use a “sock” filter that the rainwater goes through before it goes into the big tank. If your tank is large enough, the next refinement is to have the pipe for water usage drawing through a flexible tube attached to a screen that rides some distance below a float at the water level. I have been surprised how clear the water has been. The gutters that collect the rain from off the roof can either be mechanically “screened” to minimize the seeds, leaves, etc that flow into your rain water system or you need to devise some way that this debris does not get into your tank excessively.

I bought my rain “diverters” from a non-profit organization in Madison, Wisconsin, that had an engineer design the plastic devices that basically send the debris down the gutter downspout and collect the water by surface tension and flow. I believe the design has gone public as the “rain reserve” available at certain big box stores.

I also use a lot of gray electrical conduit PVC pipes and fittings because that material is made to resist degradation from sunshine and to exist in outside weather. Finally, if you move on to some larger and more sophisticated rain water system, your smaller system does not go to waste but can be moved to some other roof drain of your house or the garage.

Many large cities have extensive and very large, complex underground systems to store rainwater runoff so that it does not overwhelm the required sewage treatment plants that residents pay for through their water bills. I read in past years that Philadelphia, Pennsylvania, opted for a different route to some extent. That city planned to advertise and somewhat subsidize urban rainwater collection and use the design of rain gardens, porous paving, ponds, and irrigation storage systems. I do not know how successful that effort is but it is certainly admirable.

Finally, keep in mind that people in many countries collect and use rainwater for human use routinely. I remember using Google to research “rainwater tanks” and found many inventive and interesting designs that caught my imagination but were only available in Australia. Especially interesting was the 3,000-gallon tank that was meant to go under the outdoor porch!

If you are ready to do your part, why not try harvesting rainwater? This idea may sound expensive or confusing, but Janesville Home & Solar is at your service!