I have the experience of ...

I have the experience of building a very inexpensive ground water re-charge system for a colony in Gurgaon without the possibility of natural drainage. It used normal drains and sewage system as/rules of HUDA. However the drainage water was diverted to a network of shallow pits in the green areas. The pits were about 2 m deep and 2m in diameter and were filled with brickbats and covered with earth so that the ground became available for normal use. This worked well without any maintenance for about 15 years after which the pits needed to be de-silted or perhaps abandoned and replaced by new pits. The system really cost peanuts and required no extra land. The project was a zero rainwater discharge project. To avoid pollution of underground water, the pits did not have a vertical pipe connecting to UG water level, such as is recommended for clean water from roofs.