An easy way to check the water level in your rain barrel.

I've already written numerous times about some the challenges with rain barrels.  (How to keep debris out.  How to still use them when it doesn't rain.  How to keep them from overflowing when they aren't the same height.)  I still have the issue of now knowing how full they are.  I could always just unscrew the lid and look, but that's a nuisance.  I'd also like to be able to move water from the barrels in my back yard to the barrels in my front yard (using only gravity).

In a previous post I put a clear vertical tube in my garden.  That worked, but only if I was in my garden and only if I remembered to look at it.  It still wasn't ideal.  What it didn't offer was a gauge.  It was easy to tell if it was empty, but I couldn't really tell how close the barrel was to being full. 

Anyway, I decided to use the same idea but expand on it.  I got a section of clear tubing, attached it to a garden hose, and ran it vertically along a fence post.

Then I attached the garden hose to the rain barrels at the front of my house.

Front yard rain barrels which are attached to the drip irrigation that waters the garden.

I opened the valve on the barrel and allowed it to fill the hose.  Then I put a mark on the fence showing the height of the water when the barrel is nearly full.

Then I took the hose off of the barrel in the front yard and attached it to the barrel in the back yard.

I marked the post with the height of the water for the back yard barrel and measured the difference between it and the front yard barrel.  It was 12.5" (meaning that the back barrel is a foot lower than the front one).  Then I moved the garden hose back to the barrel in the front yard.

This clear tube along with these two marks tell me how I can move water between the barrels.  Water will flow downhill (from high to low).  So if the water level in the front yard barrels is lower than the height of the water in the back yard, I can move the water from the back yard to the front yard.  If the water is higher than the line on the post I can move water from the front yard to the back yard. 

Water level in the front yard barrels is lower than the back yard barrels.

Moving the water is as simple as turning a valve.

The valve on the right connects the front yard barrels to the back yard barrels.

Since the back yard barrels are lower, it's impossible to move all of the water in them to the front yard (without an additional energy source like a pump). 

Back yard barrel level after it reaches the same level as the barrels in the front yard.

When front yard barrels got empty I marked the post with that level as well.

Empty barrel level mark.

Empty barrel

This isn't a perfect solution.  I still have a garden hose running across my yard.  I'll probably end up relocating the clear tube to someplace else, but for now it's good enough. 

I'm real happy with the fact that this allows me to get a few more days of irrigation in my garden without having to fill the barrels from the house water.