Cath Hassell on Calculating Monsoon Rain

On Thursday 29th September, Cath Hassell of ech2o Environmental Consultancy ran a fantastic  workshop for students in DS18 on urban rain water management and harvesting. This was framed by a discussion of water politics in Tamil Nadu and traditional ways of retaining rainwater in South India. Her presentation covered problems that arise from combined storm water / sewage systems in urban areas and showed precedents of more sustainable drainage systems (SUDS), storage systems, green roofs and green walls. She then discussed the annual monsoon rainfall cycle in India and Chennai in particular, which is in the unusual position of receiving rain from both the south west and north east monsoons, but frequently experiences either water shortages or flooding. This has implications for the collection, storage and distribution of water throughout the year. Cath’s presentation was punctuated with short group discussion periods, when students were asked to consider questions such as why harvest rain water and what issues should be taken account of in Chennai. The workshop ended with a quick exercise in calculating the amount of ran falling on a roof of a certain dimension during an average monsoon year in Chennai.

This was an extremely informative workshop for students, opening up questions and providing tools and concepts that will be of use later in the year.

Cath’s presentation can be viewed below.