Paoay Lake

Lore & Background

According to local tradition, the lake was once the site of a prosperous barangay called San Juan de Sahagún (Saint John of Sahagún) that sank after an earthquake. This historical account is preserved in the lake's former name, Lago de Nanguyudan. The lake has no tributaries; its inflow comes from groundwater and surface runoff from surrounding hills during the rainy season.

The lake covers 386 hectares with an average depth of 6 metres. It is bounded by the barangays of Suba, Nanguyudan, Pasil, Sungadan, and Nagbacalan, and lies about 3 kilometres from the sea. Its formation resulted from coastal progradation and the development of a sand dune barrier during the late Quaternary Period.

The park hosts diverse biota, including phytoplankton, macrophytes, zooplankton (8 species of copepods, 8 cladocerans, 11 rotifers), fish such as tilapia, catfish, and mudfish, and aquatic plants like water spinach, water hyacinth, tape grass, and Buntót-pusà. On the slopes grow ipil-ipil, acacia, gmelina, and banaba. Avifauna includes white-collared kingfisher, brahminy kite, Philippine duck, and migratory birds like grey heron, osprey, and great egret.

Reader's Guide

Paoay Lake is a significant natural and cultural landmark in Ilocos Norte. Its designation as a national park in 1969 and later as a Protected Landscape in 2025 underscores its ecological importance, particularly as a habitat for diverse aquatic life and migratory birds. The lake's formation through coastal progradation and its lack of tributaries make it a unique hydrological feature. Economically, it supports tourism—with attractions such as the Malacañang ti Amianan, Paoay Golf Course, and Fort Ilocandia Resort—and small-scale aquaculture, primarily tilapia fish pens. The protected status allows government monitoring to prevent misuse of resources. The lake's legendary origin as a sunken barangay adds cultural depth, linking it to local history and the name San Juan de Sahagún. Its accessibility via Paoay Lake Road and Laoag–Balaccad Road from Laoag International Airport makes it a key destination for visitors to the region.

Did You Know?

• Paoay Lake is locally known as Dakél a Danum, meaning 'Big Water' in Ilokano.
• The lake was historically called Lago de Nanguyudan and was supposedly the site of a sunken barangay named San Juan de Sahagún.
• It has no tributaries; its water comes from groundwater and surface runoff.
• The lake is home to migratory birds such as the grey heron, osprey, and great egret.