The Rising Concern of a Blocked Tullahan River.

Understanding the Full Course of the Tullahan River.

• Starts at La Mesa Dam / Reservoir in Quezon City, where excess water spills into the Tullahan, especially during intense rain and potential overflow events.

• Flows through Calоocan, then Malabon, Valenzuela, and Navotas, before emptying into Manila Bay.

• Entire length estimated at approximately 27.1 km (16.8 mi), though some sources note up to 36.4 km when including connected tributaries.

Blocked Tullahan River: Impacts on Metro Manila’s Key Transport Routes.

The Tullahan River is a river in the Philippines. It is located to the north of Manila and has an approximate length of 27.1 kilometers.

It starts at the La Mesa Reservoir in Quezon City and flows through Caloocan, Malabon, Valenzuela, and Navotas and empties into Manila Bay.

River Course Summary:

• Source: La Mesa Dam / Reservoir (Quezon City)

• Passes through: Caloocan → Malabon → Valenzuela → Navotas

• Empties into: Manila Bay

The Critical Role of Tullahan River in Flood Prevention Across Metro Manila.

Critical Transport Nodes Along the Blocked Tullahan River

In Malabon (nearest points):

• Franco Clinic & Hospital (Letre Road) – 3 min walk (approx. 128 m)

• Letre Road / Dagat-Dagatan Avenue – 4 min walk (approx. 250 m)

• Malabon City Square (C-4) – 7 min walk (approx. 481 m)

• Circumferential Road 4 stop – 8 min walk (approx. 565 m)

• Pagamutang Bayan ng Malabon (Dagat-Dagatan Ave, Caloocan) – 10 min walk (approx. 729 m)

• 5th Ave LRT‑1 Station – 19 min walk (approx. 1,482 m)

From La Mesa Dam to Navotas: The Tullahan River’s Vulnerable Path.

In Navotas (river delta area):

• Circumferential Road 4 (Navotas side) – 3 min walk (approx. 110 m)

• M. Naval / Tanganahan Intersection – 5 min walk (approx. 217 m)

• Circumferential Road 4 / Gen. P. Borromro – 8 min walk (approx. 518 m)

• San Ildefonso, M. Naval – 10 min walk (approx. 668 m)

• Abad Santos LRT‑1 Station – 10 min walk (approx. 774 m)

Blocked Tullahan River: The Overlooked Risk in Urban Planning.

Impacts of a Blocked Tullahan River on Infrastructure and Transit

Flood Risk and Drainage Failures

• River blockages—caused by sediment buildup, debris, or infrastructure failure—can lead to severe flooding in low-lying areas of Quezon City, Caloocan, Malabon, Valenzuela, and Navotas. Overflow from La Mesa Dam during heavy rains already amplifies the risk.

• Disrupted drainage affects key transport access points: bus stops and LRT stations become unreachable or dangerous during floods, paralyzing commuter movement along the corridor.

Transport Network Disruption

• Blockages compromise the reliability of bus and train services, particularly those closest to the river like Franco Clinic, Letre Road stops, Circumferential Road 4 stops, 5th Ave LRT, and Abad Santos LRT.

• Infrastructure risk extends to bridges along the river corridor—e.g. MacArthur Highway, NLEX crossings, C‑4 and Pinoy rail overpasses—which may sustain damage or require closures if the river is blocked.

Tullahan River Blockage Risks to Circumferential Road 4 and Key Bridges.

Delays in Transit Expansion Projects of a blocked Tullahan River

• Ongoing infrastructure schemes—such as NSCR or PNR expansion—depend on stable river crossings. A blocked river could delay bridge construction or the opening of key stations in Valenzuela and surrounding areas.

Environmental Degradation and Urban Planning Concerns

• Blockage leads to worsening water quality, stagnation, and ecosystem decay—compounding pollution in Manila Bay.

• Impacted areas face higher long-term planning risk, particularly when factoring in urban resilience and future infrastructure expansion.

Blocked tullahan river summary table.

The blocked Tullahan River is more than just an environmental concern—it is a pivotal factor that influences flood control, transportation stability, and the success of infrastructure projects from La Mesa Dam to Manila Bay.

By recognizing the risks and addressing them through proactive river management, Metro Manila can safeguard communities, protect vital transit routes, and ensure that future urban development is both resilient and sustainable.

Continuous monitoring, timely interventions, and collaborative planning are essential to prevent the far-reaching consequences that a blocked Tullahan River could impose on the region’s progress.

The Tullahan River Connection: From La Mesa Dam to Manila Bay