Water Management: Digging a Pond


Three things prompted us to dig a pond at Aanandaa. i) Our neighbour had taken over the village pond, and cut off our access to it. ii) A significant amount of water was still running off our property during the rains which we could harvest and store and iii) We thought it would be a pretty feature, that would provide a home to ducks, fish, birds and geese.

Having avoided getting an earthmover on the property all this while, we finally had to bring a JCB on site. We calculated, that an appropriate size of the pond would be about 100ft x 85 ft x 15 ft. The displaced earth would be used to fill in the ravine, which at the moment had general bushes harbouring snakes. And we would place a concrete overflow pipe for the water to leave the pond. The overflow would go into the village pond after running down a path planted with bananas, bamboos and grasses. Also we would need some sort of a liner for the pond to stabilise its slopes and establish the eco system.


We started with marking out the pond outline with lime markings, and the earthmover started digging and depositing the excavated soil into the ravine.


The trickiest part was placing the overflow pipe. If placed too high, we ran the risk of flooding our entire orchard and the inlet channel. If placed too low, the pond would start overflowing without hitting the 15 feet mark. Using the good old pipe filled with water we matched the levels of the inlet channel to the proposed overflow pipe. Then we dug out a channel into the berm area and placed 3 pipes one after the other in line and sealed them with cement. However, we would not know for sure, till it rained and the pond filled up completely, whether the overflow was at the right height or now.




We continued to dig the rest of the pond, and use the soil to reclaim the ravine and also secure the pipe in place with compressing soil on either sides. The tractor trolley did countless trips to the ravine and back and piled up the rest as a berm on the south side of the pond.



It took about 65 odd hours of earthmover work to dig the pond and restore the soil in the ravine. After that we put a layer of clayey soil all over the slopes of the pond. The clay was a bit chunky, and we tried to break it down into smaller pieces. But most of it just melted away with the first sprinkle of water.



And finally, we added the eco fibre lining, which had been specially sourced all the way from Bangalore. 85% coconut fibre and 15% polyester, it was the best material we could find, to provide a natural lining to the pond, and ensure the pond would be a living breathing body. The liner was held in place with metal staples that came with it.




After the first layer of liner, another layer of clay was added, and then a second layer of fibre was rolled out to line the pond. With this, we now had a pond ready to receive the monsoon showers, and storm water run off that flooded the farm! The soild around the south side of the pond was compressed, stabilised, and over 75 Frangipani trees were planted. In addition the reclaimed land (after filling up the ravine) allowed us to plant another 50 odd trees there and created one of the more beautiful spots on the farm today!

Final pictures of the pond. Isn't it quite a feat!

#ponds

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