The power of rains and streams

How much water flows in a stream in an hour?

The tiny stream next to farm hill has been flowing this year, for the first time since we came here four years ago. Neighbours say this hadn’t happened in the ten years before as well.

Today, we asked how much water could actually be flowing through the stream. Considering it’s a small stream, the initial estimates varied between 10 to 20 buckets per hour. That’s about 200 to 400 liters per hour.

It’s a really small stream and it’s hardly a foot across at the narrow point where it flows out of a small pool we dug last season. That gave us the idea of putting a bucket in the stream, completely stopping it for a few seconds, and measuring the time and the water.

So we did it. We noticed that the ideal time to stop the stream is for about five seconds. We caught the water for 4.63 seconds. When we measured the water, it turned out to be 7.5 liters.

What does that mean? 7.5 liters in 4.63 seconds is 1.6 liters per second. That’s good math, but it didn’t mean anything to any of us.

Then we played around with the numbers, asking how much water per minute? Turns out 60 * 1.6 is about 100 liters. So it’s about 6000 liters per hour.

And that’s about three tanks like the ones we have at farm hill. Usually when we fill all the three tanks, the water lasts for about two days!

So an hour of water in the tiny stream is enough for us for two days. And in a day, it pumps out 1,44,000 liters of water, which is close to double the size of the ten foot deep rain water harvesting tank we have. And the water will last us a month and half!

Needless to say, the kids were blown away. That’s the power of rain, surface water and small streams.