Flooding in the City usually happen when there is a strong rainfall intensity and coupled with a high tide. Based on the City old folks accounts, the deepest flooding that occurred in the City is when typhoon Gading struck sometime in 1997 where a very extensive inundation happened as the result of overflow from the Alaminos River. (Map of the Extent of Water Inundation During Typhoon Gading in 1997).
As far as the existing flood control structures is concerned, common civil works measure includes concrete revetment, riprap slope protection and concrete sheet piles. These structures were distributed along the river system which serves as protection to build-up and agricultural areas.
Meanwhile line canals drainage system has already been established within the Central Business District to capture excessive surface run off that happens when there is a strong rain or during typhoons (Map of Line Canals in the Central Business District)