by Yolanda Sotelo
The spillway of the San Roque Dam where millions of cubic meters were released at the height of typhoon “Pepeng” in October last year, is dry at present. (Cesar Ramirez)
SAN MANUEL, PANGASINAN – There are no guarantee that Pangasinan will not submerge once more, similar to the kind of flooding that occurred at the height of typhoon” Pepeng “in October last year.
Virgilio Garcia, hydrologist of the National Power Corporation, said if four factors under the dam discharge protocol of NPC and related agencies, the San Roque Dam in San Manuel will open its gates to release water that can no longer be contained by its reservoir.
Garcia and other officials involved in the flood forecasting and warning activities, presented to the reporters on Friday the “dam discharge protocol” to be followed when releasing excess water from the San Roque Dam.
These are when the reservoir elevation has reached 280 meters above sea level (masl), there is typhoon in “typhoon marking area I (area around Luzon and Visayas), the inflow (water entering the reservoir) is 500 cubic meters per second or more, and the rainfall is 60 mm or more in one day.
“The absence of one of the factors would mean there will be no release of water. We will not necessarily release water if the reservoir reaches 280 masl,” Garcia said.
At the height of typhoon Pepeng, when the dam ‘water level was 289 masl, the gates of San Roque dam were all opened to release 5,300 cubic meters of water per second, breaking dikes along the Agno River and inundating 36 towns and cities in Pangasinan.
Garcia said the protocol has been in place since the dam started operating in 2002, although an interim protocol lowering the water elevation to 278 masl was issued after typhoon “Pepeng” by the National Power Corporation.
The officials said the interim protocol was only for typhoon “Ramil” which threatened to hit northern Luzon right after typhoon Pepeng.
Garcia said as of present, the Nacopor would welcome a typhoon that can bring rain as much as typhoon “Pepeng” did because of the dam’s very low level of water.
Tommy Valdez, San Roque Power Corporation’s vice president for corporate social responsibility, said there was a need to adopt to weather changes because of global warming, but did not answer if the dam managers have taken into consideration the global warming in its operations.
The agencies concerned conducted a seminar-workshop among mayors and disaster action office of the 17 towns downstream of San Roque Dam, on Thursday, primarily to “address the gaps in the information dissemination scheme which is being followed by the Pagasa and the NPC in their flood forecasting and warning activities.
Among the action plans are the establishment of additional warning system and checking of the workability of the warning stations, improvement of warning information, installation of warning sirens, and strengthening the provision of direct warning to the communities along the Agno River Basin.
http://northernwatchonline.com/2010/...release-water/
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