The
La Mesa Dam is a dam in Quezon City in the Philippines.
It is part of the Angat-Ipo-La Mesa water system, which
supplies most of the water supply of Metro Manila. The La
Mesa Dam is an earth dam whose reservoir can hold up to
50.5 million cubic meters occupying an area of 27 square
kilometers.
Metro
Manila and its surrounding areas are divided into two water
concessionaires.Metro
Manila and its surrounding areas are divided into two water
concessionaires.
The
water collected in the reservoir is treated on-site by the
Maynilad Water Services, and at the Balara Treatment Plant
further south by the Manila Water Company. Both water companies
are private concessionaires awarded by the Metropolitan
Waterworks and Sewerage System, the government agency in
charge of water supply.
Angat Dam
The Angat Reservoir and Dam are located
at the Angat River in San Lorenzo, Norzagaray, Bulacan.
The facilities were constructed from 1964 to 1967 and have
been operational since 1968. They have multi-purpose functions:
-
To provide irrigation
to about 31,000 hectares of land in 20 municipalities
and towns in Pampanga and Bulacan;
-
To supply the domestic
and industrial water requirements of residents in Metro
Manila;
-
To generate hydroelectric
power to feed the Luzon Grid; and
-
To reduce flooding to downstream towns and villages.
The
principal river, Angat River, originates from the western
flank of the Sierra Madre Mountains. It then cuts through
the mountainous terrain in a westerly direction to the dam
site. The elevation within the watershed rises to a maximum
of 1,115 meters at the Sierra Madre Mountain range and is
lowest at the dam site at 100 meters.
It has three major tributaries, namely, the Talaguio, Catmon
and Matulid Rivers. The Angat Watershed has a moderate to
intensive forest cover and has a drainage area of about 568
square kilometers, which receives an average annual rainfall
of about 4,200 millimeters.
The
Angat Dam is a rockfill dam with a spillway equipped with
three gates at a spilling level of 219 meters. Its storage
capacity is about 850 million cubic meters. Water supply to
the MWSS is released through five auxiliary turbines where
it is diverted to the two tunnels going to the Ipo Dam.
Ipo
Dam
The
Ipo Dam is a gravity concrete dam located about 7.5 kilometers
downstream of the Angat Dam near its confluence with the Ipo
River in Bulacan. It was completed in January 1984 with a
maximum storage capacity of 7.5 million cubic meters, an increase
of about 2,500 million liters per day (MLD) from the old Ipo
Dam, which used to be located 200 meters upstream of the new
dam.
The
spill level of the dam is at an elevation of 101 meters and
it has seven radial floodgates. The watershed topography is
characterized by mountainous terrain similar to the Angat
Reservoir Watershed with moderate forest cover. The watershed
has an area of about 70 square kilometers and receives an
average annual rainfall of 3,500 millimeters. Tributaries
to the Angat River at this section include the Ipo, Sapa Pako
and Sapa Anginon Rivers. These tributaries drain into the
Angat River from the eastern section of the watershed.
Water
from the dam is diverted to the Novaliches Portal and the
La Mesa Dam through three intake structures going down to
three connecting tunnels into five connecting aqueducts.
