A rain barrel for your raised beds

People collect rainwater for all kinds of things, up to whole houses that run on it. This isn’t about any of that. This is about the simplest version there is: a barrel under a downspout, and a watering can for your beds.

Why bother

The rainwater itself is free. It’s close to neutral pH, it has no sodium, and it has nothing added to it on the way. Garden plants and vegetables love it, and every can you fill from the barrel is one you didn’t pay the water company for.

How much your roof can catch

More than you’d think. Work out the footprint of your house, its length times its width, in square feet. The number of stories doesn’t matter and neither does the shape of the roof. Then:

So one inch of rain on a 1,000 sq ft roof gives you 623 gallons. That’s eleven 55-gallon barrels from a single decent storm, which tells you the real limit isn’t the rain. It’s how much you can store. One barrel on one downspout will fill fast and overflow often, and that’s fine.

What you need

A whole-house system has six parts. A garden barrel only needs four:

1. A roof. The catchment surface. You already have one.
2. A gutter and downspout. To bring the water down to the barrel.
3. A screen. A piece of window screen over the barrel’s opening keeps leaves out, and keeps mosquitoes from laying eggs in the water.
4. A barrel with a spigot. An old 55-gallon drum works. Make sure it once held food or water, not chemicals.

Filters, pumps and purification are for drinking water. Your tomatoes don’t need any of it.

Setting it up

1. Cut a hole in the top. Big enough for the downspout to empty into, then cover it with your screen.
2. Put a faucet in near the bottom. High enough to get a watering can under it.
3. Set it up on blocks. The barrel works on gravity, so every bit of height helps the water come out faster. Make the base level and solid. A full barrel weighs over 400 pounds.
4. Put it under the downspout. Cut the downspout to length if you need to. When the barrel’s full, the extra spills over the top, so make sure it spills away from your foundation.

Using it

Fill the can, go water your vegetables. Water the soil rather than the leaves, and use it up between rains so the barrel’s ready for the next one.

Some states and cities have rules about collecting rainwater, most of them aimed at bigger systems than this. It’s worth a quick check for where you live before you set one up.

I started off wanting to write a quick article on how to cut a hole in the top of an old 55 gallon drum, stick a faucet in it, put it under your downspout and then go water your vegetables. This time, that’s the article I wrote. Until next time, How Do!