By PNA and U.S. News Agency / Asian

The coastal towns of Calumpit and Hagonoy are still being deluged by rising waters as back floods from Nueva Ecija and Pampanga continue to surge, inundating low-lying villages where many residents were trapped on rooftops and trees days after Typhoon “Pedring” left the country.

The flooding is also being aggravated by the continuous release of water from Angat Dam whose critical level of 212 meters was breached after the water level rose to 213.26 meters as of 8 a.m. Friday.

At least 754 families or 3,255 persons from different villages in Calumpit were rescued and brought to government evacuation centers while 437 families in Hagonoy were evacuated, the Provincial Disaster Risk Reduction and Management Office (PDRRMO) reported Friday.

The PDRRMO said that 29 villages in Calumpit and 26 villages in Hagonoy are submerged under five to six feet of rising floodwater.

Helicopters from the Philippine Army joined rescuers in rescuing residents trapped in flooded villages.

Maj. Gen. Jessie Dellosa, commander of the Northern Luzon Command, said that at present, three Army helicopters are conducting aerial rescue operations for residents trapped on rooftops.

He said he had already requested for two more helicopters from General Headquarters as many residents are still trapped and the floods are still rising.

Dellosa also accompanied Governor Wilhelmino M. Sy-Alvarado to Hagonoy and Calumpit to personally supervised massive relief and rescue operations in the flood-stricken municipalities.

Alvarado earlier called the National Power Corporation, operator of Angat Dam, to temporarily stop the release of excess water from its reservoir to give time for the back floods to subside.

He said the continuous release of water from the dam is aggravating the back floods in the two coastal towns, which has become the perennial catch basin of floodwaters from Nueva Ecija and Pampanga.

Meanwhile, a study made by Bulacan Environment and Natural Resources Office (BENRO) chief Rustico de Belen showed that many parts of Bulacan, particularly the coastal municipalities of Calumpit and Hagonoy, are “sinking.”

De Belen said that this phenomenon is called “ground subsidence,” in which land sinks primarily because water that occupies the ground below is being extracted by humans faster than it is being replenished by nature.

He also said that the flooding is an effect of climate change.