By
Dino Balabo
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| Angat Dam's spillway as photographed by Napocor while discharging water on Sunday. |
MALOLOS
CITY—Water elevation at the Angat Dam climbed to 213 meters above sea level
(masl) on Sunday, leading the National Power Corporation (Napocor) to discharge
water through its spill way for the first time this year.
This
came a day after Super typhoon Yolanda move out of the Philippine Area of
Responsibility (PAR) but left heavy rainfall infl ow into the dam reservoir.
Gladys
Sta. Rita, president of the Napocor, told PromdiNews that Angat Dam started
discharging a total of 190 to 200 cubic meters per second (cms) of water. She
said that Napocor opened its floodgate by one meter to discharge at least 130
cms through its spillway.
In
addition to that, Napocor is also discharging 61 cms through its tunnels to
power its hydroelectric turbines that generate electricity. As of yesterday
morning, water discharged by Napocor through Angat Dam’s spillway was raised to
265 cms, while Bustos Dam on the Angat River downstream is discharging 285 cms.
The
discharge through the dam’s spillway is the first this year, after months of
clamor from Bulacan officials for Napocor to start “pre-emptive release” of
water. On Saturday, water elevation at the dam climbed to 211.25 masl, but
Engineer Rodolfo German said they would not spill water yet.
German
is the general manager of the Angat River Hydroelectric Power Plant (ARHEPP) of
the Napocor which manages the Angat Dam. German later said that they can spill
water anytime, while the Napocor central office issued an advisory within the
next 24 hours as they monitored situation at Angat Dam.
Based
on data gathered by PromdiNews on Saturday, Yolanda’s rains left an infl ow of
at least 568 cms, while the regular discharge of Angat Dam towards Ipo Dam is
only 61 cms. This means more than 500 cms of inflow that caused water elevation
to climb.
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| Angat Dam's spillway. Photo from Tonkin & Taylor |
Yesterday,
the inflow dropped to around 300 cms, and water elevation dropped to 213.51
masl from Sunday’s 213.65 masl. As this develop, the Provincial Disaster Risk
Reduction Management Offi ce (PDRRMO) of Bulacan allayed fears of possible
floods.
Liz
Mungcal of the PDRRMO said that the 130 cms discharge to Angat River is almost
negligible noting that there is not much rains in the last 24-hours and that
rivers are shallow because of low tide. For his part, Engineer Precioso
Punzalan of the National Irrigation Administration (NIA) said that Bustos Dam
can accommodate water spilled from Angat Dam.
Operated
by NIA, Bustos Dam is an after bay regulator dam of the bigger Angat Dam.
Punzalan said they have been discharging 60 to 90 cms from Bustos Dam since
Thursday in preparation for the Angat Dam discharge.
On
Saturday, Gov. Wilhelmino Alvarado expressed disappointment over the refusal of
Napocor to spill water despite the fact that its 210 spilling level was
breached on Friday night. But Napocor officials like Engineers Romualdo Beltran
and Russel Rigor explained that the 210 masl is not their spilling level but
the normal high water level during flood season.
As
head of the Dams Management Division of the Napocor, Beltran noted that the
month of November normally marks the end of rainy season and the start of the
summer. However, he said that Napocor is also considering typhoons that can hit
the country between the end of November to December and January next year.