Explain briefly, how rainwater harvesting is done from open spaces around the buildings in city areas.

For rainwater harvesting from open spaces around the buildings in city areas, percolation pits are constructed and covered with concrete slabs having holes in it. They are connected to a recharge well via a pipe. The rainwater goes into the percolation pit through the holes of the slab cover. It gets filtered in the pit and enters the recharge well via an outlet pipe and then, slowly, seeps into the soil.