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Pasac-Guagua watershed

A sanctuary for wildlife and people

By IW:LEARN

October 9^th, 2024

Located in the central region of northern Philippines, the Pasac -Guagua Watershed is a critical source of water and livelihood that supports, at least, 10 municipalities (Bacolor, Floridablanca, Guagua, Lubao, Macabebe, Masantol, Minalin, Porac, Santa Rita and Sasmuan) with approximately 888,560 population (Philippine Statistics Authority 2020 Census), over 566,576 live along 152 villages within the watershed. It is one of the major river systems that drain to Manila Bay, considered the main harbor of the country that is connected to a larger marine ecosystem, that is, the South China Sea.

Map generated and developed by the Province of Pampanga.

The Pasac-Guagua Watershed stretches 80.61 kilometers[1] down to its main basin outlet in Manila Bay. Aside from providing livelihood and water supply, the river is also a local transportation channel. In fact, in the municipality of Guagua, it is still considered one of the faster and cheaper ways to reach isolated villages through wooden or motorized bancas. During the school year, students from far-flung communities who attend school in the town are paid only PhP 5-10 per trip (USD 1=PhP 56.36 using September 10, 2024 exchange rate).

[1] Estimated from the delineated boundaries of Pasac-Guagua Watershed for the preparation of State of River Basin report

Local fishers rely on the aquatic resources of Pasac-Guagua Watershed and Manila Bay for their livelihood.

A wildlife refuge and haven

The Pasac-Guagua Watershed has 78.75 hectares of mangrove forest cover in Lubao, Sasmuan, and Macabebe municipalities. And nestled in the downstream of Pasac-Guagua Watershed is the Sasmuan Bangkung Malapad Critical Habitat and Ecotourism Area (SBMCHEA), part of the larger Sasmuan Pampanga Coastal Wetlands (SPCW), a recognized Ramsar Site or Wetland of International Importance. This wetland area, the 8th Ramsar Site in the country, includes mudflats, mangroves, and riverine habitats that serve as essential stopover points for migratory waterbirds on the East Asian Australasian Flyway.

In Guagua, wooden banca is a cheaper option for students to go to school and to return home

The Sasmuan Bangkung Malapad Critical Habitat and Ecotourism Area has become a haven for tourists and migratory birds and other marine animals.

According to Ms. Irene Marie Villar, Assistant Department Head of Provincial Government Environment and Natural Resources Office (PGENRO) of Pampanga, the formation of SBMCHEA was first observed after the eruption of Mt. Pinatubo. The lahar sediments settled in the area while there were mangrove propagules from nearby mangrove forests that started growing from the year 2010. The SBMCHEA is approximately 14 hectares of patches of mangrove forest, with at least nine (9) recorded species of mangroves, according to the 2017 Mangrove Assessment of the Department of Environment and Natural Resources (DENR) Office – Pampanga.

Five coastal villages in the Municipality of Sasmuan rely on SBMCHEA for coastal protection against flood and storm surge. According to the locals, fish catch has increased since the mangroves have grown and protected the area.

The mangrove boardwalk leading to the outpost in Sasmuan Bangkung Malapad Critical Habitat and Ecotourism Area

In the Municipality of Lubao, the local government established the Bamboo Hub and Eco-Park along the riverbanks, which serves not only as a local tourist destination but also as a mitigating measure against soil erosion. The mature bamboo also offers alternative lumber and a source of income for the locals, who can sell it commercially in the market.

Aside from providing protection against soil erosion, the Lubao Bamboo Hub and Eco-Park also employs locals and contributes to local tourism in Pampanga Province.

Addressing threats in the watershed

Among the identified issues in the watershed were conflicting and competing water uses for available freshwater and impairment of environmental flows, which can lead to biodiversity degradation and loss and increased susceptibility to climate-related impacts. To address these, the Province aims to advance sustainable forestry, fisheries, and aquaculture.

Bamboo along the riverbanks are harvested as an alternative source of lumber for construction and furniture.

Lahar is one of the identified threats in the SPCW, located downstream of Pasac-Guagua Watershed, according to its management plan. The municipalities of Lubao, Guagua, and Sasmuan are located downstream and are thus affected by lahar sediments from the Pinatubo eruption.

“The lahar deposits from nearby upstream towns, following the Mt. Pinatubo eruption has contributed to the siltation of rivers. The degradation of coastal ecosystems due to siltation could result in reduced fish populations, thereby affecting fisherfolks’ fish catch and income. Additionally, the altered river flow due to siltation can lead to an increased vulnerability to flooding, which damages fishing equipment, homes, and coastal infrastructure, further threatening their livelihood,” said Ms. Villar of Pampanga PGENRO.

There are dredging stations along the 80.61-kilometer stretch of the Pasac-Guagua Watershed to regularly manage the sediments/lahar from the upstream.

Pampanga Province also heavily relies on groundwater for domestic and industrial use. Coastal municipalities in the province, including Macabebe, have been reportedly affected by seawater intrusion from Manila Bay based on the initial survey conducted by DENR-Mines and Geosciences Bureau,which was supported by a study to determine the possible origin/sources of salinity in the groundwater samples taken from the province.

Houses including stilts are common sights along the coastal villages in Sasmuan.

Wastes from domestic sources, including untreated sewage discharge from heavily populated areas, also contribute to the decline of Pasac-Guagua Watershed's water quality. There is no existing sewage treatment plant in the watershed, and most of the local governments within it dispose of their solid wastes in the Metro Clark Sanitary Landfill located in Tarlac City.

Aquaculture also heavily impacts the water quality of the Pasac-Guagua Watershed. In 2010, 3,200 hectares of fishponds were constructed along the riverbanks, where tilapia, shrimp, and milkfish are cultivated. There have been incidences of fishkills in the area, which negatively affected the livelihood of local communities.

In heavily populated areas, wastes from domestic and industrial sources contribute to the decreasing water quality of the river

The pollutants and other issues affecting the water quality of the Pasac-Guagua Watershed adversely impact Manila Bay, which connects to the South China Sea—an important marine ecoregion, major fishing ground, and global shipping route. This connectivity emphasizes the importance of addressing the watershed's management concerns within the source-to-sea framework, as espoused by the IRBM Project.

The Integrated River Basin Management (IRBM) Project aims to strengthen the existing governance mechanism of the Pasac-Guagua Watershed under the auspices of the Subcommittee on Environment of the Sectoral Committee on Economic Development of the Regional Development Council of Region 3 (RDC-3). The subcommittee serves as a venue for discussion and resolution of issues, review, and validation of outputs of the plans and projects related to Region 3's environment in general and the Pampanga River Basin in particular, which includes the Pasac-Guagua Watershed.

Through the IRBM Project, the awareness and understanding of the land-to-sea ecosystem linkages will be enhanced, emphasizing the impacts of watershed-based activities on the coastal waters of Manila Bay. The Project will also promote partnerships between government, businesses, and communities through a participatory process and facilitate knowledge sharing to successfully transfer best practices, technologies, and skills among the ASEAN Member States.

Beneath the green waters of the Pasac-Guagua Watershed is a thriving aquatic ecosystem that provides food and livelihood for the people in Pampanga and its nearby provinces. On the sideline, the tall bamboos and lush mangroves provide shade and protection for communities, as well as home for different wildlife. With a more robust governance mechanism in place, a healthy source-to-sea connection will weave through the river, coastal waters, and their communities.

About the project

The Reducing Pollution and Preserving Environmental Flows in the East Asian Seas through the Implementation of Integrated River Basin Management (IRBM) in the ASEAN Countries project aims to set-up functional management mechanisms in priority river basins of six ASEAN countries to reduce pollution and sustain freshwater environmental flows as well as adapt to climate change vulnerabilities. IRBM Project is supported by the GEF, implemented by UNDP in Asia and the Pacific and executed by PEMSEA, in collaboration with ASEAN.