Barangay Lower San Agustin

Classified as a small barangay, Barangay Lower San Agustin is one of the administrative divisions of Bauang in La Union, Ilocos Region, Philippines.

According to the 2020 Philippine census, Barangay Lower San Agustin had a population of 1,054. This made it the 35th largest of 39 barangays in Bauang by population, placing it among the smaller barangays of the municipality. Residents of Barangay Lower San Agustin accounted for approximately 1.34% of the total population of Bauang, which stood at 78,449 in the same census year.

The barangay recorded 1,085 residents in the 2015 intercensal count and 1,054 residents in the 2020 Census — a net change of -2.9%, consistent with a contracting settlement. Barangay Lower San Agustin is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Bauang is a municipality comprising 39 barangays, and serves as the governing unit directly responsible for local services in Barangay Lower San Agustin, including public health, sanitation, peace and order, and civil registration. Within the wider province of La Union, which contains 576 barangays across its component cities and municipalities, Barangay Lower San Agustin ranks 329th by 2020 population. La Union is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay Lower San Agustin is governed by an elected Sangguniang Barangay composed of a Punong Barangay and seven kagawads, with the Sangguniang Kabataan representing the youth. The next BSKE, set for Monday, November 2, 2026, will elect officials to four-year terms as provided under Republic Act No. 12232.