KERI: Years after the water resources department completed the construction of a chain of check dams called 'vasant bandharas' on the Mhadei to meet the state's water needs during summer months, the ecological fallouts of these well-meaning structures are coming to light. Studies are now showing that damming of the river is affecting breeding of various indigenous fish, including shellfish, many varieties of which are no longer easily available in markets.
"During the summer we would catch tamso, kalundra, malaye, kharchyani and fresh water prawns like shivod or chingul. The area was also known for local varieties of shellfishes, like mandolyo and kale khube. However, today, the vasant bandharas have affected breeding of local fish species," Zilu Gaonkar, 63, from Savarshe says.
Environmentalists from Karnataka raise a similar red flag. "A chain of dams across the Sharavathi and its tributaries has seriously affected breeding of fresh water fish species thereby leading to extinction of some species and decreasing yield of others," environmentalist Janna Janni says.
In Goa, along the Mhadei, Kotakadali Kond in Nanus, Madhlo Devno in Savarshe, Tarikadali Kond in Bhironda, Rajgyachi Kond in Khadki-Velguem and Gothnivaili Kond in Dabos were known for indigenous fishes. During the summer, when the water level decreased, the local community living in and around the Mhadei and its tributaries would depend on their catch of indigenous species of fish. However, this has all changed with the check dams stopping the natural flow of the river, disrupting fish migration patterns and, thus, breeding.
Environmentalists add that damning of the river increases water salinity which also affects the fish. Shellfish, which need flowing water, are also impacted.
WRD constructed vasant bandharas as environment-friendly structures across the river. However, no environment impact assessment was carried out before constructing these check dams.