of typhoons and dams
sept 27 sunday, around two o’clock in the afternoon, dzmm teleradyo
tail end of a live presscon of gma and gibo and the national disaster coordinating council (ndcc) trying their darndest to appear like they have been and continue to be on top of the situation, doing the best that can be done given the unexpected unprecedented unbearable volume of rainfall that ondoy brought.
dost director graciano yumol was in the middle of a hardsell that typhoon ondoy was in many ways different from hurricane katrina. among other things, he gave the impression that the ndcc was prepared for, having seen, that huge flood coming. say niya, “…early in the afternoon we were already telling them to evacuate…” at noong hurricane katrina daw, ang response time ng u.s. government was two days. ang ndcc? “first thing in the morning ndcc was on the scene. that’s how quick ndcc responded…”
3:45 p.m. gibo was back for another presscon. caught him saying that the news of ondoy coming was duly reported in the papers. we were warned. but of course daw there was no predicting so much rain pouring down steadily for hours on end. on top of that, september has been a rainy month, 4 weather disturbances daw before ondoy, kaya saturated na ang lupa and could not absorb any more of the rainwater.
gibo should have gone on to talk about the dams, angat and ipo in bulacan, and la mesa in quezon city. instead government has been avoiding the question and would have us believe that no water was released, the dams were not full from the same september rains.
flashback to 13 september 09
about angat dam in particular, but which could apply to ipo and la mesa dams as well in terms of how full of water they were:
MALOLOS CITY, Philippines – Water elevation at the giant Angat Dam is about to reach its spilling level of 210 meters as rains continue in Central Luzon, and local officials fear that it might break if pressure mounts.
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) yesterday afternoon raised public storm warning signal no. 1 in nine provinces in northern Luzon with the arrival of tropical depression “Nando.”
. . . Records from the Provincial Disaster Management Office (PDMO) obtained by The STAR showed that water elevation at the Angat Dam climbed to 209.65 meters as of 8 a.m. yesterday.
Officials said the steady rise of water elevation at the giant water reservoir that supplies 97 percent of Metro Manila’s water requirements is caused by constant rainfall over the past weeks.
On Sept. 1, PDMO records showed that water elevation was only 204.89 meters.
High water elevation at the dam means enough water for Metro Manila but the continued rains might breach the dam’s spilling level that would require the release of water to ease pressure on the dikes.
In the past, the National Power Corp. (Napocor) managing the Angat Dam watershed usually released water from the dam through the Angat River when water elevation breached its spilling level of 210 meters.
Bulacan officials have demanded that the rehabilitation of the aging Angat Dam be prioritized over the proposed multibillion-dollar construction of Laiban Dam in Rizal.
Without repair, they said the 41-year-old Angat Dam poses danger to millions of residents of Bulacan and neighboring provinces, citing documents from the Metropolitan Waterworks and Sewerage System (MWSS) that the dam is sitting on a geological fault line and has already developed cracks.
forward to september 14
about angat dam’s condition, more than 40 years after it was built and commissioned.
MANILA – The Angat Dam management assured the public that the dam does not have any cracks, dispelling the feared disaster that could happen if the dam crumbles.
During a survey of the Angat Dam in Bulacan on Sunday, local officials and the dam’s management showed some media members that the dam is safe.
The survey of the area, which took almost one hour, did not see signs that there is danger in the area.
“Sabi ng MWSS [Metropolitan Waterworks and Sewerage System]… normal na merong seepage… pero walang crack,” said Neri Amparo, regional director of the Office of Civil Defense-Region 3.
Authorities have also pointed at the seepage from which the water is released from the dam.
But the Angat Dam management maintained that the seepage is normal in dams that are made of earth and rockfill. They also believe that the dam will last long.
“Kaya pang tumagal nito ng 50 years, except kung magkaroon ng earthquake,” remarked Romualdo Beltran of the dam’s reservoir and management division, National Power Corp. (NPC).
On Saturday, the Sagip Sierra Madra Environmental Society expressed alarm that continuous rains could aggravate the reported seepage in the Angat Dam as a portion of the dam is located on the Marikina West Valley Fault Line.
The environmental group members feared the possibility of an earthquake that could cause the dam’s destruction and lead to a flashflood.
They noted that if the seepage expands, water will forcibly be released from the dam.
This could submerge 11 towns in water, namely Norzagaray, Angat, Bustos, San Rafael, Baliuag, Plaridel, Malolos, Calumpit, Paombong and Hagonoy in Bulacan, and Masantol in Pampanga.
In addition, the reported cracks in the dam pose a threat to the water supply in Metro Manila as 97 percent of its water supply comes from the dam.
The Angat Dam management, however, downplayed such fears.
NPC plant manager Rodolfo German said: “Matagal ng isyu yan… ginagawan nila ng dam remediation.”
“Nagkaroon ng 2 major earthquakes… wala kaming nakikitang signs na nag-deteriorate ang dam structure natin,” noted Jose Dorado, principal engineer from the MWSS.
Despite the continuous rains, the management said it is not yet time to release water from the dam because the water level is still safe. –
forward to sept 25 and ondoy
it rained all night and most of the next day. all three dams must have been spilling water after all that rain. by noon there may have been great fear that the structures (angat, at least) would give way under the immense pressure and release the water in one humongous wave. infinitely safer to release the water little by little, sort of. and so it happened.
The Bulacan Provincial Disaster Management Office (PDMO) reported the Angat dam commenced spilling operations at about 1 p.m. on Saturday with the initial opening of its radial gate, releasing one cubic meter of water every 30 minutes until total outflows reached 500 cubic meters per second.
The state media said reports from the Bulacan Provincial Disaster Management Office (PDMO) showed that hardest hit by the raging floods were the towns of Marilao, where waters rose to as high as 9 feet; Bustos, 7 feet, and Bocaue, 5 feet.
Gov. Joselito Mendoza of Bulacan said the flooding, the worst to hit the province since October 1978, was compounded by the release of water from the overflowing Angat dam and Ipo dam in Norzagaray town.
i have no idea, there are no similar reports, about how much later, or sooner, water was released from the ipo and the la mesa dams. i suspect it all happened that saturday afternoon, around the time when the water started rising swiftly and inexorably,and reaching places never before touched by flood waters.
. . . Valenzuela Rep. Magtangol “Magi” Gunigundo blamed the inefficient handling of the Metropolitan Manila Development Authority (MMDA), Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), local government units (LGUs) and officials of the La Mesa Dam for the worst flood that hit Metro Manila.
“The Metro Manila calamity was aggravated by poor coordination of MMDA, PAGASA, LGUs and La Mesa Dam authorities. No effective dissemination of information on rainfall, no warning by La Mesa Dam authorities on their decision to release impounded water. Delayed MMDA and LGUs response,” an irate Gunigundo said in an interview.
what were they thinking? that all that additional water would drain directly out to the manila bay? nakalimutan nila, o hindi nila alam, that rivers along the way are all silted up because of land erosion, thanks to deforestation, and esteros are all clogged up with nonbiodegradable plastic trash, thanks to an mmda that’s apparently given up on the garbage problem? no wonder kung saan-saan nakarating ang baha.
of course it’s quite possible that government officials just didn’t want to cause panic. imagine the hysteria, and the horrendous traffic once people started evacuating. but, hey, in such a crisis a good leader should have no trouble addressing the people, explaining the situation, allaying fears, offering advice, and mobilizing the media and the internet to assist and facilitate.
anc’s pia hontiveros is so right to ask, bakit walang warning? maybe authorities were correct to release the water in controlled increments, maybe it was the lesser evil. but but but the public should have been seriously warned. the people deserve to be given adequate information on matters that affect their lives so that they can make the right decisions, that is, whether to stay and brave the elements, in which case, walang sisihan! or whether to go and seek higher ground while there’s time, with at least some possessions and their dignity intact.
meanwhile, let’s pray really hard that typhoon peping pepeng changes course.