La Mesa Dam
Also known as: La Mesa Reservoir · La Mesa Weir · La Mesa Watershed dam
Definition
La Mesa Dam is an earthfill impounding dam in Quezon City, Metro Manila, Philippines, forming the La Mesa Reservoir at the terminal of the Angat–Ipo–La Mesa water supply chain. Raw water that has passed Ipo Dam arrives here for final regulation before treatment at the La Mesa and Balara treatment plants, which serve millions of metropolitan water consumers under Manila Water and Maynilad concessions. (Wikipedia)
Identities (Wikipedia/Wikidata/DBpedia)
- Wikipedia: La Mesa Dam (https://en.wikipedia.org/wiki/La_Mesa_Dam)
- Wikidata: Q6463849
- DBpedia: http://dbpedia.org/resource/La_Mesa_Dam
Also Known As
- La Mesa Reservoir
- La Mesa Weir
- La Mesa Watershed dam
Examples and Analogies
- System role: La Mesa functions like the municipal water tank on a hill, holding a buffer of treated-supply-ready water so that daily demand swings do not directly stress the faraway Angat source.
- Watershed pair: The dam sits within the La Mesa Watershed Reservation, the last major forest patch of Quezon City, often called the city’s lungs.
Usage Scenarios
1. Supply buffering
Operators modulate reservoir releases so the La Mesa and Balara treatment plants receive steady inflow despite hourly demand fluctuations.
2. Recreation and education
The watershed’s eco-park and reforestation areas host nature education trips, subject to access regulations protecting raw water quality.
Strategies
- Reforestation and protection of the watershed reservation reduce sediment and pollution loads reaching the reservoir.
- Concessionaire programs for tunnel and aqueduct maintenance keep conveyance from Ipo reliable year-round.
Security and Safety Measures
- Restricted access and patrolling of the watershed guard against encroachment and dumping near the raw water source.
- Dam safety monitoring, including instrumentation and emergency spillway protocols, is coordinated with NDRRMC ahead of typhoons.
Historical Context
The La Mesa Dam and watershed were developed as part of Manila’s expanding waterworks in the twentieth century, with the reservation long serving as the city’s northern forested catchment. Intense reforestation campaigns from the 1990s onward, supported by public-private partnerships, restored degraded portions of the watershed surrounding the reservoir. (Wikipedia)
Challenges and Controversies
Encroachment
Informal settlements and land claims within and around the watershed repeatedly threaten raw water quality.
Drought vulnerability
During strong El Niño episodes, falling Angat allocations quickly draw down the La Mesa buffer, triggering supply alerts.