Bangladesh polders under threat

IRIN: Changing weather patterns, poor maintenance and lack of investment are taking their toll on Bangladesh’s extensive polder system, viewed by many as a first line of defence for coastal communities against tidal surges, experts say.

“Many of the polders are in various states of disrepair,” Wahida Ahmed, former disaster risk reduction manager for ActionAid, told IRIN, citing extensive damage by cyclones Sidr (2007) and Aila (2009). “This puts millions of coastal residents at risk.”

Her comments come one month after Cyclone Mahasen struck southern Bangladesh, killing 17 people and resulting in the evacuation of more than one million, the government’s Ministry of Disaster and Relief reported.

Cyclones strike Bangladesh’s coastal regions almost every year, in early summer (April- May) or in the late rainy season (October-November), while a severe cyclone (wind speeds of 90-119km per hour) strikes every three years on average.

In the 1960s, 123 polders (low-lying tracts of land enclosed by earthen embankments), including 49 sea-facing polders, were constructed to protect low-lying coastal areas from tidal floods and salinity intrusion in southern Bangladesh. Instrumental in the region’s agriculture development, they have also played a key role in mitigating the loss of life and damage during tidal surges.  “Polders play a crucial role in avoiding waterlogging from tidal surges. The recent Cyclone Mahasen was low in intensity, but the damage could have been significant from the resultant tidal surges and flooding. But the polder networks allowed the water to run off, avoiding long-term flooding,” said Delwar Hossain, executive engineer of the Bangladesh Water and Development Board which maintains an extensive database of coastal polders, including their length, location, construction year and cost....

A mugger crocodile in Bangladesh, shot by Dhruvaraj S, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license