The Jakarta Post, Bantul, Yogyakarta Fri, 06/15/2012
Seawater has found its way further inland in coastal areas in southern Bantul regency, Yogyakarta, killing dozens of fish and contaminating dozens of residents’ wells over the past month.
“This intrusion results from global warming that has increased the sea levels,” Maritime Affairs and Fisheries Agency head Edy Machmud Hidayat said on Friday.
He said the global warming had melted polar ice caps and caused the sea level in waters south of Bantul, part of the Indian Ocean, to rise by 15 centimeters.
Not only has the sea-level rise caused erosion, but it has also caused seawater to diffuse from the ocean into freshwater aquifers, he said.
The situation has become worse because many residents use water from shallow wells to irrigate their paddy fields and plots of agricultural land along the coastline, according to Edy, and excessive exploitation may result in acceleration of the decline of groundwater levels and of seawater intrusion.
Southern Bantul at the moment has some 1,000 hectares of red onion and vegetable production, with five to 10 shallow wells used to irrigate each hectare.
“Just imagine if they tap groundwater every day. But this is a very difficult situation because plants will go die without [water supply from] those wells,” Edy said.
Yogyakarta-based Gadjah Mada University (UGM) is currently studying the threats of saltwater intrusion to Bantul.
According to UGM’s preliminary study, southern Bantul’s groundwater bed is shaped like a bowl, Edy said.
“Seawater intrusion threatens many people if it contaminates [groundwater] even only at one spot,” he said.
“And saltwater cannot get out once it gets in because of the groundwater bed’s bowl-like shape and contamination could harm thousands or even tens of thousands of southern Bantul residents.”
Tens of thousands of fish that relied on brackish water wells were killed in dozens of ponds near Samas beach, Srigading, Sanden, Bantul, because of the seawater intrusion, according to Mugari, a member of fish farmers’ organization Mina Laguna in Samas beach.
Residents also find difficulties in meeting their daily water needs because of the seawater intrusion.
“It feels sticky when we use water from our wells to take a bath. The water that we boil [for drinking water] also tastes salty,” a resident, Tri Jawawanto, said.
vr 15 jun 2012 - 17:37