Rainwater Collection-Clean, Free Water for the Homestead

In 2004 my husband and I experienced a night that we will never forget. During an unprecedented spell of abundant rain our property flooded. No one expected it, least of all us, yet there we were at 3:00 a.m. frantically trying to get horses, goats, sheep and chickens to safety in chest deep (on me, I am 5' 4") water.
For the past several years our area has been growing by leaps and bounds. There has been development all around us, small zero lot properties with lots of sidewalks, driveways, and alleys. A large Super- Walmart was constructed not far away, and then a Home Depot..and on and on. What was once a small farming community has turned into a bustling suburb and no-one planned for it. The effect on the creek that runs behind our property has been unbelievable. The city has started requiring retaining ponds and other measures but it does not seem to be enough. While we have not flooded to that extent since 2004 we have seen the creek come out of it's banks. The cost in erosion, loss of habitat, and just plain stress has been enormous.

This was our pasture the morning after the flood. Some of the buildings you see floated on to our property from downstream. 

 

If even half of the houses in our town had rainwater collection systems in place there would be virtually no flooding and it's residual negative effects on the environment. If rainwater collection systems were in place the drought and dropping water tables that we face every summer in North Central Texas would not cause undue problems. Farmers could still water their animals, people could still water their yards and gardens...and all for free.
Rainwater is the cleanest water available. Until you have been in a flood you don't truly understand the amount of water that can fall in 6 hours on a rainy day! A rain water collection system is not that expensive to install and once the initial investment is recouped everything is free. Initially the system will cost anywhere from $200.00 to $20,000.00 depending on whether you are going to use it for just watering plants or whole house water supply and whether or not you are going to do all or part of it yourself.
The basic system contains five main parts. As you understand the function of each part you can see how easily this would be to implement.
The first part is the catchment system. This is where the rain is initially going to be caught- the roof. The very best roofs for catchment are metal roofs because they do not absorb water or add toxins to the water the way traditional shingles can. The water falls onto the catchment system and then runs to the conveyance system. This system is made up of gutters and downspouts that divert the water to the third part of the system, the holding vessels or cisterns. There should also be a roof wash system in place to divert the first 10-20 gallons of rainwater away from the cistern. This first few gallons of water would carry with it bird droppings, twigs, leaves, bugs, and other things that might be on the roof that you would not necessarily want in your water. Once the first water is diverted then the cistern starts filling with the clean rainwater. The next part of the system is the delivery system or pump. This is what is used to get the water from the cistern to where you want it inside or out. It could be as simple or as complex as you need it to be. The last part of the system is the treatment system. This is where the water is purified before use.
You will need to contact your local government for specific codes and permits. In Texas an air-gap must exist between the public water and the rainwater if a backup system is used, a city water line feeding into a rainwater cistern, for example. The Health Department requires a covered cistern, to avoid mosquito breeding. Also in Texas there are tax breaks for installing rainwater collection systems so be sure to look in to that.
How much rain will you harvest? Here is a formula to calculate just that. [Catchment area of building] x [inches of rain] x [.75] x [600 gallons] / 1000
The catchment area of the building is the size of the footprint of the building. If your house is 30'x 60' for example then your catchment area is going to be 1800 sq ft. Basically 600 gallons per inch of rain per 1000 sq ft of catchment area. We have about a 2000 sq ft catchment area...so we would expect 2400 gallons +/- when we got 2 inches of rain.
Amazing, isn't it? The possibilities are exciting! Add a barn to the catchment area and you have increased your harvest by that much more. Not only is this a good thing for the budget but it is also a good thing for the environment, decreasing the devastation caused by excessive run off.
This is truly one of the first steps anyone can take in becoming self sufficient, and restoring their homestead green.