Here's how we built the 3rd layer. Big stones in the front, small stones right behind them, medium size stones at the back, and soil in between the two columns of stones. This is nearly two feet thick at the base, around two feet high.
View at the back of the third layer. Dried leaves and branches of mostly mahogany trees which changed all their leaves this February-March. The soil, where did we get it?
From the trapped top soil and organic materials that decomposed and became soil. See how deep this small waterway is. Our caretaker Nong Endring standing. He was about eight meters from the third layer of stones.
The view from where Nong Endring was standing. The height should be about seven feet or more than two meters high. He said that last year during heavy rains, this structure would trap rain water for three to four days. Meaning if there was heavy rain today, the water would remain in this pond for 3-4 days. Which means flash flood has been significantly minimized, eroded top soil has been impounded, and a mini-spring water is created in this area, slowly released at the first layer of stones hours and days after a heavy rain has stopped.
We measured how deep the trapped top soil has been since about three or four years ago when we first built the structure. About one foot deep, about eight meters from the 3rd layer of stones. About two to three meters from the 3rd layer, depth of trapped top soil could be about 1.5 to 2 feet.
