News & Notes 628:Monsoon 2015
This was a monsoon we will remember. For Chennai, Cuddalore and other places, it was disastrous. For Auroville and it bioregion it was a blessing, as all its water bodies filled up and even spilled over. All the granite and concrete dams, mainly from Sukhavati till Bommyarpalayam, from Certitude, Aspiration canyon till Quiet and Auromodele functioned well. Newly made earth dams and bunds in Aurodam, International Zone, Hermitage and others had some top erosion and some broke, but had relatively little damage.
The percolation of the watershed Sukhavati, Aurogreen, Bommyarpalayam, goes very fast. The last big basin near Bommyarpalayam and the end of the canyon filled up after receiving 264 mm in 24 hours and spilled over. The last time was 5 years ago. Then the dam was raised by 1 meter. This was made to catch exceptional rainfall. Within 8 days this water percolated. Here we lost hardly any water. The settlement at the end of the canyon was safe.
This monsoon shows very clearly that water bodies are important and should be maintained, monitored and improved if necessary. For Auroville it means that many water bodies should be cleaned, some bunds and dam raised and spillways widened or deepened.