This whisky barrel holds 50 gallons.
Hubby adapted spouts for each. Our water comes from a well with an electric pump. During the summer we use a lot of water for the garden and watering the animals. We haven't done the math but we know that we are keeping our electric bill down by keeping the well pump from turning on every time we need water outside. The first summer here, we just had the whiskey barrel. It ran dry for one week at the height of the summer and we used it mainly for watering the animals. Last summer we hooked up the biggun' and were able to water the garden and the animals from them all summer. We did have a very wet summer last year. We felt guilty emptying them of water once the really cold weather set in.
We live in a fairly wet region of the country so the need for water saving is not as necessary as other regions of the country. But we do lose power on a regular basis so this also serves as a backup water source when the power is out in the summer.