Final presentation

For our final presentation, Siruthuli were spreading the news and invited their trustees, APEXmembers and volunteers. When we started our presentation there were about 25 people in the audience. When the light was switched on at the end there were about 40 people.

We talked about the as is situation which we discovered during our field trips.

We needed to disillusion a bit since there is no one time solution for the water hyacinth. The only option left is to combine different control strategies and to adjust them to the local situation and facilities in Coimbatore.

One hour before our final presentation we met Prof Dr. Kalyanasundaram, from the Institute for Entomology, Tamil Nadu Agriculture, Coimbatore. And to our surprise his institute has the skills and facilities to rear the critical amount of weevils needed for biological control of water hyacinth. What a good news and even for a reasonable price.

We recommended not to do anything about the water hyacinth at Valakulam tank for now. With the current volume of daily sewage inlet the growth rate of water hyacinth is too excessive and the harvesting effort would be a waste of money and real a Sisyphus operation. Actually at the moment water hyacinths have a positive effect on the water quality of Valankulam tank since the plant has the ability to treat sewage water.

We recommended starting water hyacinth control at a medium or low invested tank, to prevent the tank to become as bad as Valankulam and to test the new control strategy. We recommended a combination of biological and manual control were we also highlighted options to make harvesting smarter and less cost intensive. As usage option we recommended to make briquettes out of the water hyacinth. These can be used by dwellers for cooking and replace the firewood. Getting firewood gets more and more hard the faster the city grows.

In parallel a thorough water analysis needs to be carried out. Only on basis of water analysis results a sound decision can be made how the sewage water of Valankulam should be treated. For this experts and funds will be needed. We recommended Siruthuli to build knowledge partnerships and to start applying for funds. We did an in depth research of possible partners and were already able to establish first contacts. Now unfortunately our time is over. It is time for us to say good bye and start packing. We hope that Siruthuli will be successful, so that we can come back soon and take a swim in Valankulam tank.