Changing rainfall patterns, rapid urbanization, and sustained population growth have intensified flooding risks in the Philippines, particularly in densely populated and low-income communities where drainage and sanitation systems are often overstretched.
Flooding and urban pressure in Greater Manila
The Greater Manila Area is the Philippines’ primary hub for business, culture, and economic activity and is also its most populous and densely developed region. It includes Metro Manila and the neighboring provinces of Bulacan to the north, Cavite and Laguna to the south, and Rizal to the east.
Covering approximately 8,000 square kilometers, the region was home to around 28 million people as of 2020, with a population density of nearly 3,500 residents per square kilometer.
This rapid concentration of people and development has placed immense pressure on existing water and wastewater infrastructure. Inadequate sewer coverage and untreated wastewater contribute to clogged waterways, increasing flood risks during heavy rainfall and typhoon seasons.
Expanding sewer networks to improve sanitation
Two private concessionaires, Maynilad Water Services, Inc. (Maynilad) and Manila Water, provide water and wastewater services across the Greater Manila Area. Their concession agreements were originally signed in 1997 following privatization, each with a 25-year term, and later extended in 2008 by 15 years through 2037.
In September 2025, Maynilad announced that it had expanded its sewer network to more than 650 kilometers, completing the latest phase by the first half of 2025. This represents a significant increase from 425 kilometers in 2006. The expansion supports the development of wastewater facilities to improve sanitation and reduce pollution across the West Zone.
“We continue to expand our wastewater infrastructure to help meet long-term sanitation needs and environmental standards,” said Engr. Zmel Grabillo, Maynilad’s Head of Wastewater Management. “Beyond treatment plant construction, the installation of underground sewer lines is a critical component of this effort.”
As of 2025, Maynilad operates 24 Water Reclamation Facilities (WRFs) with a combined treatment capacity of 743.5 million liters per day. The company plans to add five more WRFs, increasing capacity by an additional 314 million liters per day, along with 60 kilometers of new sewer pipelines.
Looking further ahead, Maynilad plans to construct 10 additional WRFs and install more than 300 kilometers of sewer lines through 2047, in support of its goal to achieve 76% sewerage coverage by 2046. Remaining areas will be served through scheduled sanitation services.
Parallel investments by Manila Water
Manila Water has also reported strong progress in expanding sewer services in the East Zone. As of September 2025, the company added 43,604 new sewer service connections, one of its highest monthly increases of the year, according to the Philippine Daily Inquirer. This brought the total number of sewer connections to more than 360,000, serving residential, commercial, and industrial customers.
Manila Water’s continued expansion of sewerage infrastructure supports regulatory requirements for comprehensive sanitation coverage and plays a key role in improving public health and protecting waterways from pollution.
Building resilience through wastewater infrastructure
The combined efforts of Maynilad and Manila Water to expand sewer networks and wastewater treatment capacity are critical to addressing both flooding and sanitation challenges in the Greater Manila Area.
As climate change intensifies rainfall patterns and urban growth continues, resilient wastewater infrastructure will be essential to reducing flood risks, protecting public health, and supporting sustainable development.
Strengthening these wastewater infrastructure systems is not only a response to today’s challenges but also a long-term investment in the resilience and livability of the Philippines’ economic and cultural center.
Sources:
Maynilad expands sewer network infrastructure to over 650 kilometers. (2025, September 18). Maynilad. Retrieved from https://www.mayniladwater.com.ph/maynilad-expands-sewer-network-infrastructure-to-over-650-kilometers/
Ecosio, J. (2025, November 12). Sewer expansion surges as Manila Water adds over 43,000 new connections. Inquirer.net. Retrieved from https://newsinfo.inquirer.net/2139066/sewer-expansion-surges-as-manila-water-adds-over-43000-new-connections?
Our Company. (2023). Maynilad. Retrieved from https://www.mayniladwater.com.ph/our-company/
The Manila Water Story. Manila Water. Retrieved from https://www.manilawater.com/about-us/our-story
Leave a Reply