In California, we are finally starting to get a bit of rain. Not enough to break the drought, but enough that you should start thinking about how to collect rainwater. When I was a child living in South Africa, we drank rainwater all the time. It was collected in a large galvanized tank into which the rain gutters emptied.
Now you may wonder how we treated the water. The truth was we didn’t. The roof was galvanized sheet metal and it went straight to the gutters and into the tank. The only attempt at treating the water was that the tap was about 18 inches from the bottom. This allowed the heavy particles that washed in, to settle to the bottom. Yes, the birds lived on the roof
Now I am not telling you to collect untreated rainwater and drink it. Using untreated rainwater is not something that I would do today. However, I would collect rainwater today. One of the problems of collecting rainwater to drink is that most of us have composition roofs. These are largely made from petroleum-based products. I would be concerned about what chemicals would leach into the water. I have also seen the rainwater collection systems that they use in Bermuda and I notice that these are all tile roofs, no composition.
So my first advice would be that if you are going to collect water off a building for drinking don’t collect it from a composition roof without proper treatment. However, water collected from a composition roof can be used for many other things, including sanitation and gardening.
Rainwater collection can be as simple as setting buckets out to catch the rainwater, or it can be a complicated underground systems. Me, I stay on the simple side.
In an emergency you can build a improvised cistern for storing water fairly easily. You can build one with a minimum of 3 sheets of ¾ inch plywood, a large plastic tarp and a number of 2x4s and 4x4s or larger fence posts. Build a simple box measuring 4x4x8 feet and lined with heavy plastic. This will hold approximately 950 gallons of water. One inch of rain from a 2000 sq ft roof will equal about 1200 gallons. Remember you are dealing with a lot of weight so the 2x4s and the fence posts will be needed to reinforce the box. This amount of water will weight over 7000 pounds, if you completely fill it. You can store the materials until needed.
Now the above box would not by any means be my first choice, it is hard to construct and would take a lot of bracing. If it was not properly braced and collapsed, it could kill someone. But it does give you and idea of just how much water could be collected in an emergency.
Take a look around your yard and see what you could use to take an improvised water collection system. Get the extra downspouts, fittings and other items you would need to complete the system. Plan ahead.