How to Revive a RWH Pit

Maintaining a Rain Water Harvesting Pit is very easy 
Explained in 3D - Front View

Picture 1 # is a rain water harvesting pit on day one. Its when constructed. All layers are clear.

Picture 2 is after few rains. When we see the cross section of sand we can observe that
silt is mixed with sand. Silt is a chocolaty layer that stops the rain water to seep.

Sand Layer Silted - Closeup

Picture 3 explains all the sub layers in sand layer in closeup.

Layer 1 # Pure silt - mud + garbage + dead live plants, plastic

Layer 2 # silt / mud mixed with sand. ( 80% silt + 20% sand)

The above layers 1 & 2 have to be removed completely

Layer 3, 4 # Silty water mixed with sand. You can wash the sand and reuse

Picture 4 is RWH pit (top view in practical.)

Picture 5 suggests a silt trap to be constructed for an existing RWH pit.
By adding silt trap we can decrease the frequency of maintenance task. Absorption Power of the Pit will also increase.

Silt trap is a simple cement tank or plastic drum of size 200 litre


Sizes are : length is 14 to 18 inches. width 12 to 16 inches. Depth is 4 feet. Bottom should not be cemented. So leftover water will be seeped in a day.
How silt trap works. We have to release rain water into this tank first
All heavy particles, objects and silt will be settled in silt trap. Then
semi pure water will go to RWH. Cleaning Silt trap is easier than cleaning RWH pit.




Few tips and suggestions to public

1. Keep the roof and surroundings clean as much as possible.

2. These days it is raining 10 months in an year. So its better to keep the RWH Pit ready always. 3. If RWH is on road then construct a small dam-like breaker to guide water into pit.Just 2 to 3 inches height is also enough so that its not a trouble to vehicles. ratio of height x breadth is 1:12.
4. Keep a sign mentioning that its a RWH Pit. Not a garbage pit. 5. Even if you constructed your pit 20 years back you can repair and make it like new within few thousands.Gold is inside the earth you have to sharpen.
6. Because ground in urban areas is very dry and we created vacuum in the aquifers by extracting the ground water,even a small pit with a size of 2'x2'x6' can seep lot of water in small houses. (in case there is no space)
7. If you don't have a recharge pit in your colony till now, you can plan and pool up for a big pit for anacre at lowest point in that acre. A properly constructed pit can absorb water in an acre or more. Maintaining big pit is easy



If public has any doubts they can join in my telegram group "rainindia" or telegram channels of Rain India.
Telegram Channel https://t.me/rainindia. Telegram Channel in telugu https://t.me/inkudugunta
Ranga Prasad, Project Head, Rain India Project, Gachibowli, Hyd, T.S