Water Harvesting

We live in a rain shadow region, so a sustainable approach to water management has to include rain water harvesting and tapping the shallow aquifer, along with a bore well.

At farm hill, we are in a rain shadow region where the average rain fall is closer to 800mm. There are no major surface water sources like rivers nearby; and the one there is, comes from Bangalore, full of waste water.

Naturally, most of the agriculture here depends on ground water. Vegetables and green leaves are grown, but it is not uncommon to see water guzzling crops like rice too. Suffice it to say that the average depth of a borewell in this region has gone up by about 200 feet in the last three years.

In such scenario, our long term water management strategy needed to include surface water harvesting and some way of tapping the shallow aquifer, in addition to a borewell.

Considering the roof size and the rainfall, we could potentially harvest 250,000 liters of water annually, which is about a third of our current water requirement. Taking various factors into consideration, we invested in building an underground water harvesting tank of about 85,000 liters.

The last ten days of cyclonic weather meant the tank is nearly full. Right now, we estimate about 75,000 liters in the tank. That’s a happy thing.

On the other hand, these rains have been unseasonal, and heavy, causing a lot of damage to crops and devastation. Also, even here in the rain shadow region, about 30% of the entire annual rainfall happened in a single week, after a prolonged near dry spell during the monsoon, and that’s not great.

It’s a mixed feeling, I guess.