Roof water harvesting: A Case study

Abstract

The study was conducted at Shri Ram college, Muzaffarnagar- 251001 located at 29° 28’N, 77°41’E at 272 meters MSL. The climate of Muzaffarnagar is subtropical characterized by much hot summer and cooler winter. The average temperature of the area is 24.2°C which range from 45°C to 0.9°C. The average rainfall of the area is 929 mm. The dries month is November with 8 mm of rain and highest rainfall in July with an average 261.4 mm. Shri Ram College is spread in more than 5.7 hac lands. For this study the roof of block B having 894.14 square meter area was selected. Based on last thirty years rainfall data (maximum 40 mm rain in a day) a rain water collecting well of 36 m3 was manufactured to store water. The study indicates that from 894.14 m2 catchment area 35.78 m3 water is generated which required almost 36 m3 well size for storing the water. The 9 feet depth of collecting well with 6 feet diameter was found appropriate if 40 mm rain in a day occurs. To drain out 36 m3 water stored on the roof of 894.14 m2 area 7 pipes of 10cm diameter required. The study also found that 3x4 feet size two siltation tank may be sufficient before the rain water enters into the collecting well. The 6 inch (15 cm) perforated pipe was found suitable to percolate the water into ground.