15. A PART OF RAINWATER GETS
ABSORBED BY GROUND AND
SEEMS TO DISAPPEAR IN THE
SOIL IS KNOWN AS GROUND
WATER.
16. IN THIS SYSTEM THE RAIN
WATER IS COLLECTED FROM
THE ROOF TOP TO STORAGE
TANKS THROUGH PIPES.THIS
WATER MAY CONTAIN SOIL
FROM THE ROOF AND NEEDS
FILTERING BEFORE IT IS USED