Trivia no. 6: Lluvia to Rain: Extreme Rainfall in Manila during the Colonial Era

Did Manila experience flooding during the Spanish and US colonial eras?

By Rancho Arcilla
19 May 2020

Yes, Manila did. And it was hit hard.

Extreme weather has been a common feature of everyday life in Manila since time immemorial. When typhoons are formed, rains particularly strong, or when tides are unnaturally high, the limitations of natural drainage ceases to cope up and starts to give in, resulting in streets turning into rivers and entire districts turning into temporary lakes, forcing the people to travel by bancas or canoes, and making people imaginative in some respects—i.e. the workers of the cigar factories along Arroceros in Manila of the early 20th Century, for example, were distinguished by high-heeled shoes (Bankoff, 2003).

So how often was Manila subjected to extreme rainfall during the Spanish and American period? This question can be answered thanks to data from the Manila Observatory, which covers a period from 1865, the year when the observatory was founded, to 1940. The Manila Observatory, a research institute established by the Society of Jesus, has served in many capacities including weather forecasting and earthquake research. The institution is now based in the Ateneo de Manila University in Quezon City. 

What is extreme rainfall? A year of extreme rainfall is defined as having one standard deviation above the yearly average rainfall. To give context, the average yearly rainfall in Manila during this 75 year period was roughly 2,091 millimeters with a standard deviation of 502 millimeters. So basically, anything higher than 2,593mm of rainfall in a year is considered as extreme. From 1865 to 1940, there were a total of only nine (9) recorded incidents of extreme rainfall. These fluctuations in the 75 year period chronology are caused by various factors, such as typhoons or monsoon seasons. 

These were recorded in (Gaerlan, 2012): 

• 1867 (2,977.86mm); 
• 1899 (2,793.36mm); 
• 1919 (3,919.66mm);
• 1921 (2,620.16mm); 
• 1923 (3,424.06mm); 
• 1931 (2,950.36mm); 
• 1934 (2,691.66mm); 
• 1935 (2,860.86mm); and 
• 1937 (3,026.06mm).

Note that only one of these extreme years was recorded during the Spanish period; the Americans during their occupation, on the other hand, experienced the brunt with a total of eight.

1867

1867 was perhaps one of the deadliest years during the Spanish period in terms of rain. Jesuit Miguel Selga, the last Spanish director of the Manila Observatory, published in 1935 his Catalogue of Typhoons 1348–1934. Selga’s chronology contains a total of 524 reports about typhoons before the 20th century, and in this list, the deadliest was recorded from 20 to 26 September 1867.

From the 20th to the 26th of September, Manila experienced a violent storm which caused the flooding of all the city suburbs. The Malacañang Palace, residence of General Gandara, became isolated, and the officials had to make use of boats to reach the place, all adjacent barrios (city districts) being surrounded temporarily by a lake. This typhoon passed to the north of Manila. Seventeen ships were dashed against the Santa Lucia and Tondo shores. The waves in Manila Bay were mountainous. The Ayuntamiento, with the consent of Gandara, distributed P3000 to aid the sufferers of the storm (Ribera, 2008).

A total of 1,800 people died during this typhoon, and the amount of rainfall caused the annual level for that year to skyrocket. Manila (the Walled City), and all the surrounding suburbs (Quiapo, Sta. Cruz, San Miguel, Binondo, Sampaloc, Malate and Ermita) were completely flooded. This incident was so negatively memorable that it became a yardstick for succeeding typhoons. 737mm of rain was recorded during that seven-day period—25% of the total rainfall for the entire year.

1899

In 1899, American newspapers carried news about flooding in the City of Manila. Despite the absence of a typhoon, the Salt Lake Herald reported that Manila was flooded after two days of continuous rains from 10 to 11 August with people being forced to use bancas in the flooded streets. The gutters of Manila were under 12 inches of water, with the district of Sampaloc submerged totally in flood, completely forcing residents to move to their upper floors. Policemen were forced to continue their foot patrols under two feet of water. (Salt Lake Herald, 1899)

1919

Among the nine extreme annual rainfall years, the highest rainfall was recorded in 1919. The Manila Observatory Annual Report for 1919 reported:

Manila rainfall has broken all our records since the foundation of the Observatory in 1865, both as to the monthly and to the annual amount of rain. The total monthly rainfall for August was 1,983mm, the monthly maximum ever recorded before having been 1,469.7 mm in September, 1867… Out of the 31 days of August, there were six (6) days of extreme daily rainfall (August 2, 5, 7, 11, 12, 25) with a total rainfall of 912.20 mm or 46% of the total rainfall for August. (Manila Observatory, 1919)

The rain that fell during that month of August was a whopping 48 percent of the total rain for the entire year, although no exceptional typhoon was recorded. According to the same 1919 Annual report, the lower areas of Manila and the western part of Central Luzon were practically flooded from end July till middle of September. The maximum height of the flood in Manila was observed on August 12 and 26. The heavy rain period which began during the last part of July was the more remarkable as the first part of the year had been rather dry throughout the Archipelago: in fact, while Manila was drowning, Visayas and Mindanao were completely dry.

1923

In 1923, the South Australian Register recorded 12 inches of flood in Manila after a deadly typhoon hit the capital on 23 November.

A typhoon from the Pacific swept Visayas (and) Luzon Island. Railway and cable communication has been suspended as a result. The crops were destroyed by torrential rainfall. Manila is partially under water, and boats have replaced motors in several of the streets. (The Barrier Miner, 1923, p. 1)

1934

In 1934 the rain that was caused by the typhoon was so heavy that a terrifying 50 mm of rain was recorded in just 30 minutes on November of that year (Boombard, 2007). 300 people were reported killed, and the town of Mauban was reportedly “obliderated.”(Longshore, 2008)

1937

The last of the series of extreme annual rainfall was in 1937. In early November, twin typhoons ravaged Manila and the surrounding Bulacan province within a week of each other, killing 277 people and destroying hundreds of crops. (South Australian Register, November 22, 1935, p. 274).

It may not be surprising for some, but the average rainfall during the American period was higher versus the levels during the Spanish period. During the Spanish colonial period, annual rainfall averaged 1,916.16mm compared with the 2,232.98mm of the succeeding period.

Conclusion: Water has memory and Manila is a sitting duck

Perhaps to better illustrate and to provide better context for the modern reader, data from the World Bank shows an average rainfall of 2,348mm from 2005 to 2014 (World Bank, 2014); clearly higher than the averages of the Spanish and American period. In 2009, Typhoon Ketsana (Ondoy) dumped over 455mm of water in just 24 hours, only to be out-figured four years later on 20 August 2013 with a deadly 600mm of water over the same one-day period (Inquirer, 2014). The record from 20 August, if compared vis-à-vis with that of the annual average in the Spanish period, would mean that four months’ worth of rain would’ve been dumped in just one day!

With these gradual increases in average rainfall comes an equally distressing flood problem which seems to worsen every year. Context wise, Manila is a sitting duck.  Metropolitan Manila is located in a semi-alluvial floodplain formed by sediment flow from the Meycauayan and Malabon-Tullahan river basins in the north and the Marikina river basin in the east. The city is open to Manila Bay on the west and to Laguna de Bay, a large lake, on the south-east. As such, this strategic location for flooding and disaster now constitutes a vast urbanized drainage basin that experiences frequent floods from overflowing rivers and storm waters.

Manila was formerly a group of islands separated by esteros. The districts of Manila (Walled City), which were then referred to as suburbs, were separated and bounded by these esteros. In the 1900s City Planner Daniel Burnham himself planned for the filling of some of these waterways, and in a span of more than a century, most of the waterways during the Spanish period were already filled by earth and concrete, worsening the problems of flooding. The usual places where flooding is worst, such as the University Belt area in Sampaloc, are the same areas where waterways once existed. It seems water has a memory of its own and still knows where it once flowed.

Texts and Illustrations by Rancho Arcilla
All rights reserved by the author.
19 May 2020 (updated 31 May 2020; 03.31)

References:
– Bangkoff, Greg. Constructing Vulnerability: The Historical, Natural and Social Generation of Flooding in Metropolitan Manila
– Boomgard, Peter (2007). A World of Water: Rain, Rivers and Seas in Southeast Asian Histories. KITLV Press.
– Gaerlan, Martin. (2012). Rain, Rain, Go Away: Manila’s Rainfall During the Spanish and American Colonial Period 
– Inquirer. (2014). Who dumped more rain? ‘Mario’ or ‘Ondoy’? 
– Longshore, David. (2008). Encyclopedia of Hurricanes, Typhoons, and Cyclones, New Edition.
– Manila Observatory. (1919). Annual Report 1919. Manila: Manila Observatory.
– Ribera, P., Garcia-Herrera, R., & Gimeno, L. (2008). Historical deadly typhoons in the Philippines. Royal Meteorological Society, 194-199.
– South Australian Register. (1935, November). 
– The Barrier Miner. (1923, November). 
– The Salt Lake Herald. (1899, August 11) Retrieved from Salt Lake Herald 
– World Bank. (2014). Average precipitation in depth (mm per year)