Storing water outside?

Are there any tips, tricks, or rules of thumb for storing water outside (in barrels, etc) or is it best avoided when possible?

Some of my thoughts/questions:

  • If you opt for a rain-barrel collection system, where its not perfectly sealed from the outside and water-overflow might be a concern, is there any way to avoid various gross things from growing in a rain barrel?
  • If storing in a sealed container, are there containers/materials that are more freeze-tolerant?  Should you avoid filling an outdoor container to 100% to give ‘freeze’ expansion somewhere to go?
  • Is freeze expansion so problematic that you can only do outdoor storage in more temperate environments, or empty your outdoor water storage prior to the freezing points in winter?
  • Are underground (below the freeze line) storage solutions/cisterns viable in suburban environments, or is this more for homestead type operations, where you have a few acres at your disposal and fewer code enforcement agencies to worry about?

To clarify, my use case here is secondary water storage and/or replenishment (with possible need for filtering?).  I’m also curious if this might be useful for small scale garden applications – especially in a scenario where public water isn’t always turned off but potentially intermittent/less reliable.


  • Comments (4)

    • 8

      Rich, We have a rainwater harvest system.  Gutter cleaning is ongoing.  The water first flows into a “roof washer”, which “wastes” the first ten gallons of rainfall, helping to rinse contaminants off the roof before they enter the tank.  That doesn’t keep everything out.  There is a float that holds the outflow 4″ below the surface of the water, which is the cleanest.  The inflow goes to the bottom.  We have a small pressure tank and pump  on the 3500 gallon storage tank.  Yes, the inside of the tank gets a little gross but the water comes out clear.  Before use, we treat the water with Clorox (1 tablespoon-5 gallons), then run the water through a Big Berkey tabletop filter.  We’ve recently installed a sediment pre-filter to keep the Berkey cartridges as clean as possible (they are very expensive).   Rainwater harvesting is illegal in some states, and frequently regulated by local codes.  Also, I don’t think it’s recommended to drink rainwater from a composition roof, but the Berkey would take contaminants out. There’s great information available about installing a good rainwater system. We’ve had the tank since 2009 and never cleaned it, but we are going to do so this year when the rainy season returns.  Our original information said that the biological filter that establishes at the bottom of the tank would generally keep the water clean, but we’ve since read we should be cleaning the tank annually. The weather never gets cold enough here to worry about freezing too much.  Your use for gardening would depend entirely on rainfall, and your irrigation methods.  We water the two horses with it all winter, but conserve it during the dry season for emergencies. We use it year round for coffee making and aquarium fish.  Have plans to install another tank this summer, but plan on filling with well water, though we could convert it to rain later.  Much cheaper than buying a bigger generator to operate our deep well pump.

      We had some remote property where we installed a 1500 gallon underground cistern, specifically made for burial.  Water was delivered by tanker truck.  Installed correctly, freezing was no concern at all.

    • 7

      @Rich has done it again! You beat me to the punch, man!

      Not too long ago, (nerd trigger warning!) I was watching a PBS documentary (I think the show was called “H2O: The Molecule That Made Us”) about water scarcity and how, within the next decade, freshwater would become scarcer. So, naturally, I felt that prepper drive to look into this, weigh options, and get prepping.

      Thanks for bringing this up!

    • 2

      I have some of the same questions that the OP asked but don’t feel like they got answered. Hopefully commenting on this will bring more people to this post and we can get some answers. 

      How do you store sealed water barrels outside without them freezing? How about your rain catchment barrels, do you have to drain those and just not use them during the winter?

      How do you properly clean a rain barrel? Don’t they have very small inlets which prevent getting your arm down in there to scrub? I’m sure they will build up quite the thick layer of algae over the years.

    • 1

      Store the water in only food grade approved containers, NEVER store containers directly onto the ground or concrete floor to prevent leaching of chemicals into the water, Always keep the tank covered up and protected rfrom sunlight to prevent black or green algae growing, if you live where there is proper winters never fill the container to the top, leave enough room for ice expansion. Only used fully sealed containers. many people flush and change the water every 3 or 4 months to keep it fresh tasting.