Quarrying Seen To Cause Dam Collapse

Quarrying seen to cause dam collapse

Inquirer

13th November 2006

PILA, LAGUNA -- More than 2,300 farmers in five Laguna towns stand to lose their livelihood after unhampered quarrying on a river and after Typhoon "Milenyo" (international name: Xangsane) caused irreparable damage to an irrigation dam in Liliw town, officials said recently.

Mayors of the affected towns and officials of the National Irrigation Authority (NIA) said more than the effects of the typhoon, the continuous quarrying along the Sta. Cruz River was behind the destruction of the Calumpang Diversion Dam.

The dam, built in the 1970s, is a source of irrigation water for 2,185 hectares of ricefields in Pila, Sta. Cruz, Liliw, Victoria and Nagcarlan towns. Its walls and other parts were destroyed during the height of "Milenyo" on Sept. 28.

During a dialogue at the NIA office here, local officials led by Sta. Cruz Mayor Dennis Panganiban said the typhoon damage could have been minimal if not for the destructive effects of quarrying on the dam structures in the last 20 years.

The dialogue was also attended by farmers' groups in Laguna.

Although the mayors were against the quarrying in the area, Panganiban said, they could do nothing to stop it because it had permits from the Department of Environment and Natural Resources.

He lamented that even the provincial government maintained a quarry site in the area.

Efren Roqueza, NIA-Calabarzon director, said that as early as 1994, they had notified the DENR about the damaging effects of quarrying in the riverbed of Sta. Cruz River, the only source of water of the dam.

He said while the quarry operations were located beyond the dam's 1-km radius, the continuous collection of rocks in the lower portion of the area caused erosion in the riverbed.

Roqueza noted that a survey they recently conducted showed that the riverbed had dropped by 12 meters because of erosion.

He said that aside from commercial quarrying, there were also several small quarrying activities in the river.

"The dam is really beyond repair. All the structures were destroyed. We have to build a new dam now," Roqueza said.

Virgilio Yorro, NIA assistant provincial engineer, said it would take 11 months to two years to build a new dam. "[It] depends on the availability of funds.

This means that our farmers may not be able to plant rice for two years," Yorro said.

The new dam, he said, could cost between P100-P160 million.

Panganiban and all the other mayors present during the meeting sought the help of President Macapagal-Arroyo to immediately release the funds.

Roqueza said the National Disaster Coordinating Council had pledged P10 million to help them construct a new dam.

Marlon Ramos, Inquirer Southern