9 Tips On Collecting Rainwater

June 23, 2015

Rainwater Harvesting


I still remember the feeling of utter joy I used to have every Saturday at around 2 PM when I would take my bath with rainwater that I warmed up myself with nothing but the sun. My grandpa and I (I was 6 at the time) used to take out this huge tin bathtub from the shed, put it in the middle of the yard at around 10 AM, fill it with previously harvested rainwater and let it warm up for 3-4 hours.

This was exciting for me for several reasons. First, because everyone passing by could see me (we didn’t have any other place to put it) so I had to lay low when I heard footsteps down the road and hide from them. Second, since our chickens ran around freely, it was fun splashing them as they approached.

But the one thing I didn’t care much about as a kid is the one that appeals to me today, as a prepper: that rainwater is 100% free. There’s nothing stopping you from starting your disaster water stockpile or even using it starting today and save money. Heck, as you’re about to see at the end of this article, you can even do this if you live in an apartment building.

So let’s get started with some of the best tips you need to know before installing your first rainwater harvesting system.


Tip #1: If you’re going to drink it, filter it first

Yes, there will always be preppers who tell you they’ve been drinking unfiltered rainwater all their life and they turned out just fine. But this doesn’t mean we can all do it… or should do it. A lot of variables are at play here and one of them is your immune system. I’m no doctor so I can’t vouch that a tiny, slender woman who can barely eat fast food without getting sick can drink rain water without a problem. What I’m trying to say is… why risk getting sick?

There are numerous options to make your water safe to drink: using Berkey water filter, boiling it and adding bleach – you probably know these already. The key is to stockpile on them as well because after the world as we know it has ended, finding them is going to be very difficult.


Tip #2: Don’t worry about acid rain

All water is acidic so there’s absolutely no need to worry about it unless you’re looking to wash your car and you live in a polluted area. Since most rainwater has an almost neutral pH, the one that’s a little acidic is still not as much so as some of the foods we eat. Other things such as bird poo, insects and dirt are more problematic when we’re talking about drinking rain.

The only water you shouldn’t be drinking is the one around radioactive sites and volcanoes but do keep tip #1 in mind and filter it before you do that.


Tip #3: Know your state’s rainwater harvesting regulations

You probably heard the story of Gary Harrington from Oregon who went to jail for collecting too much water on his own property. I’ll spare you the details, the lesson here (whether you agree with him or not) is that you need to check the laws in your state before you do anything.

Right now, it is legal in most states to collect rain water but there are exceptions. For example, Nevada doesn’t allow harvesting without a water permit. Colorado is another notable exception because it doesn’t allow it even in small quantities. Ponds are, in fact, a great idea but, since we’re talking about larger volumes, here, you need to do your due diligence before attempting to have one in your back yard.

Of course the best and easiest way is for you to contact your local authorities directly to find out exactly what you need to do, if you need to.

Tip #4: Consider these uses for rainwater (you may not have thought of)

You don’t need to drink rainwater, there are plenty of other uses for it. The following are some of the things you can use rainwater and you don’t need to wait for the end of the World to do it, you can cut your utility bill as soon as you set up your harvesting system:

  • watering your garden
  • watering fruit trees
  • doing laundry (you can even use it with your washing machine)
  • taking baths and showers
  • washing your car (if you live in a polluted area and you have acid rain, it’s best to treat that water first as, in time, it will affect your vehicle’s paint)
  • flushing your toilet
  • for your pets, your backyard and your farmyard animals
  • against possible house fires and wildfires
  • for an outdoor pool so you and your kids can have fun on weekends
  • for your bug-out location’s water supply


Tip #5: Use gravel or asphalt shingles for your roof

Indeed, this study by P.C. Van Metre and B.J. Mahler suggests that these two will result in a lower concentration of heavy metals inside the harvested rainwater. This isn’t that big of a problem as long as you use a water filtration system but it will prolong the life of your filter since it’ll have less bad stuff going through in the ling run.



Tip #6: Use a collection screen

Although you don’t need this as long as you’re not drinking the water, it’s a good idea to have a screen that won’t allow things such as bird droppings or flies inside your containers.

Ideally, you should look for a screen with an aperture of no more than 1mm so you can filter out even tiny insects like mosquitos. The price of these filters is low, anyway, so they’re worth every penny.


Tip #7: Get a tank that suits your needs

Not because you should restrict how much water you can harvest but because there may not be enough water for you to collect. Keep in mind that your roof typically collects about 80% of the amount of water that rains directly on in, the rest is being lost due to leaks, rain drop splashes and overflows. Once you know how much falls, on average, where you live, you just have to multiply that by 0.8 to get to the amount you can collect in one year and thus decide how big a tank you need.


Tip #8: Use a first wash diverter

This is actually a pretty neat addition to your harvesting system. See, the first few gallons of collected water are always low-quality and a diverter, using simple mechanics, allows you to only store what comes after that.

The way it works is this. The first few gallons of water gather in the diverter chamber showcased above. In that chamber there’s a ball that floats up and seals it when that chamber fills with water. Once the chamber is full, the rest of the coming water passes right over it and continues to flow into your collection tank.


Tip #9: You can do this even if you live in an apartment building

A balcony is all you need. The bigger the better of course, because then you’d have a bigger surface for your plastic containers.  Sure, you won’t be able to collect much compared to someone living in a rural area but it’s better than nothing and it will teach you about frugality. One other thing to consider is stopping collecting excess water once it reaches a certain level. The last thing you want is an inundated balcony.

Well, those were it. I hope my tips helped you avoid some mistakes and that now you have a much better idea on how to collect rainwater. Sure, others are gonna be able to some rainwater from their rooftops inside barrels but the quality of that water won’t even get close to yours if you apply all my tips. This is going to be of utmost importance post-collapse because your water is going to be of the highest quality, which means you might even be able to sell it after you treat it!

About Dan Sullivan

Growing up in a small 2nd world country, Dan learned from a young age to love nature, animals and living with little or no money. He started writing about survival when he got tired by the lack of quality information and realized people just need the facts. Dan has declared war on fluff and is winning battle after battle with each article that he writes on www.SurvivalSullivan.com

View all posts by Dan Sullivan

18 Responses to “9 Tips On Collecting Rainwater”

  1. Ric Says:


    Not all water has a pH less than 7. Water from limestone or dolomitic aquifers, or which pass over limestone or dolomites can have a pH up 7.8; but more usually in the region of 7.2 – 7.5.

    Any pH greater than 7 is not acid but alkali.


    • Bob Says:

      The author is taking about the pH of rain water. Once it’s on the ground it becomes surface water and is subject to any and all environmental conditions.


  2. Ray Says:

    I don’t see it but I believe your first flush diverter needs a restricted drain so that it can “reset” between rains.


  3. Meathead Says:

    Good information. I rigged a section of gutter across my rear roof with two downspouts. One is for the “dump” and the other is for the collection. I used a flexible section so that I can fill two 55 gallon barrels and a 20 gallon barrel, one after the other.

    The 20 gallon barrel is painted black and mounted on a stand 6′,4″ off the ground with a shower head extended from it. The sun heats the water and allows us to shower under it after being in the pool or getting dirty doing yard work. We get sweaty and grungy in East Texas this time of year.


  4. Larry Clifton Says:

    I use the American made Pro Pur filter and the Berkey…the Pro pur is less expensive and has, I believe, better filters…just a thought. God article and sound advice…kudos


  5. Larry Clifton Says:

    Those of us in Texas are pretty lucky because the State of Texas has been promoting Rainwater harvesting/catchment for a long time. I hope they don’t go too crazy and change this attitude and the laws. These days …who knows what our gov reps will do next. Hope for the best but prepare for the worst…


  6. Henry Roop Says:

    I too collect and store rainwater, I use cleaned 1 gal. milk jugs, and I have over 800 gallons in my underground bunker. I run it through a 1 micron filter before bottling it up, and after 2 years it is still very good tasting. Also I use my shower and laundry water to water my garden. I flush only when its brown. If its yellow, I leave it for the next fellow. My water bill is always the minimum, and I have reduced my electric to less than $50 a month, even with A/C.


  7. Nicholas Says:

    I put knee high nylons (available at dollar stores) over the end of my downspout between the elbow and the downspout so it stays put. This filters out most of the junk/debris. I then filter through a Birkey and I use it mainly for drinking and cooking. I have several rain barrels, and they all still seem to get mosquitoes, but i filter it once again as I am adding it to my Birkey. This is without a doubt the best water I have ever had, and it makes really good coffee.


    • Diana Says:

      Mosquitoes are a problem here, too. In my garden rain barrels and critter troughs I keep feeder goldfish. They eat the larvae and green stuff that tries to grow. But for water I would plan on drinking I figure a lid would work better on keeping mosquitoes out, or maybe a screen?


  8. bob johnson Says:

    Utah requires a license but you can get it online. limited to around 250 gallons


  9. ed vodochodsky Says:

    Knowing the Law (Tip #3 Harvesting regulations) is a MUST these days. It almost seems like TPTB WANT us to fail at surviving any coming disaster, – maybe to “thin-the-herd” – as the Georgia Guidestones reflect? Oregon (a blue-state) is trying to convince the states around it to also follow it’s archane laws,…… what will they try to regulate next? Air? Sunlight? Readers – don’t laugh! Who would have EVER thought that RAINWATER could be regulated? I lived in Washington state for many years – and a man there was FINED & had to pay unrealistic reparations ($$ tens-of-thousands)- for tearing down a dilapidated (UNSAFE) boating dock,….. (wait for it!)…… on his OWN PROPERTY!!! All because a semi-rare little fish decided the sand-n-gravel beneath his dock was an ideal spawning-ground! The state claimed he destroyed thier ‘habitat’ – and they could now be on the verge of extinction. What if a school of salmon happened by – and ate them – ALL? WHO would the gov’t blame then? It’s a little rediculous…


  10. Rambuff Says:

    Well-done article…..except PLEASE, PLEASE render them in PDF so’s we can copy them off instead of having to cut’n’paste.
    A quick comment to Larry, above: You’re on the right track with the Berkey..however, the Pro Pur is NOT a better filter; it is in fact a Berkey knock-off. It’s not BAD one per se, but bet your life on the real winner.

    Suggest you check for yourself as I did many years ago: contact both companies and have them send you their MSDS sheets on their filter elements. Berkey’s is right on their website; compare with the PUR.

    Good advice in the article… the prohibition on rainwater collection in Colorado is one of the big reasons I left there. The state is NOT benign on their enforcement of said statutes, either, particularly in the arid/desert areas where you would REALLY need it.


  11. Bobby Deems Says:

    Great Message. BEST TIP: “KEEP-UP-WITH” ALL of your “Local LAWS”! It’s “AMAZING” HOW-FAST “Things Change” when some “POL” Gets-a-GOOD(?)IDEA”! ANY “POLITICIAN” can really “Sc….”, well, you know!


  12. Mona Houser Says:

    There’s no need to put a floater in the stand-pipe. All leaves or other debris will be above the ball, and go right into your tank. A simple stand-pipe is adequate. Of course, some debris will still float, but a goodly amount will go to the bottom of the stand-pipe.


  13. Laura Says:

    Isn’t a metal roof the better choice. Seems like asbestos would not be healthy.


  14. Jim Says:

    Amazing that some places have restrictions on how much rain water you can collect. We’re fighting just to be able to burn wood in our stoves for heat so I guess if it isn’t one thing it’s another.


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