LA MESA DAM

The La Mesa Dam is located in Novaliches, Quezon City, Metro Manila (MM) across the Tullahan River as shown in Figure 3.1.  It is one of the two major dams whose primary purpose is water supply for the entire Metro Manila area.  Construction of the dam began in 1926 and was completed on June 1929; but with the increasing demand, the Metropolitan Waterworks and Sewerage System (MWSS) decided in 1957 to increase the capacity of the reservoir by raising the dam.  The project was completed in 1958.  In 1991, the dam was again raised to a new elevation of 80.15 meters to serve as a buffer zone for flood control.  The La Mesa Dam has a watershed area of 27 km2, a height of 33 meters and a crest length of 326 meters.  It has a dependable water supply capacity of 110 million liter per day (MLD), augmented by water from the Angat Multi-purpose Dam.

Main Features of La Mesa Dam

Location

:

Brgy. Novaliches, Quezon City, MM

Coordinates

:

14°40’15” N

 

 

121°03’ E

Name of River

:

Tullahan River

Owner

:

MWSS

Purpose

:

Water Supply

Period of Construction

:

1926 – June 1929

Date of Operation

:

June 1929

 

 

 

Dam

 

 

Type

:

Storage, Earth fill

Drainage Area at Dam site

:

27 square kilometers

Foundation

:

Solid Rock

Crest Elevation (Parapet)

:

El. 82 m.a.s.l.

Height

:

33 meters

Crest Width

:

6.0 meters

Crest Length

:

326 meters

Base width at maximum section

:

180 meters

 

 

 

Embankment

 

 

Impervious Fill

:

630,000 cubic meters

Filters

:

99,000 cubic meters

 

 

 

Reservoir

 

 

Gross Storage Capacity

:

51.03 million cubic meters

Dependable Supply

:

110 million liters per day

Maximum Reservoir level

:

El. 80.15 m.a.s.l.

Minimum Reservoir level

:

El. 71.00 m.a.s.l.

 

 

 

Spillway

 

 

Length

:

236.50 meters

Type

:

Concrete Overflow Structure

Sill Elevation

:

El. 80.15 m.a.s.l.

 

 

 

Penstocks

 

 

Type

:

Plate Steel embodied in concrete

Dimension

:

3 – 2.45 meters dia. for the horizontal part then reduces to 2.30 meters dia. for the vertical part

 

 

 

Project Cost (original project)

:

P 1,875,000 (at 1929 price level)

1st dam raising

:

P    950,300 (at 1929 price level)

2nd dam raising

:

P 3,110,300 (at 1929 price level)

 

 

 

Source of Fund

:

Corporate Funds of MWSS

Construction By

:

Dimson Construction Co. – For raising of the dam and spillway (1958)

 

 

Galauran & Pilares Const. Co. – For raising of the dikes (1958);

 

 

Pacifico Austria Co. – For raising of the dike and spillway to El. 80.15 m. (1991)