The state of water resources in the Philippines - Greenpeace

E. Other threats to water availability
The situation presented earlier clearly shows how various problems on water use
and distribution lead to water scarcity in different areas in the country.
There are other factors, however, that need greater attention now as these affect
not only the supply but the availability of water resources itself. One of these is
the significant decline and deterioration of watersheds. Excessive logging and
shifting cultivation in the watersheds trigger widespread degradation and
subsequent erosion and siltation of rivers, lakes, and reservoirs (Santos 1997, as
cited in Jose and Cruz, 1999).
Reports from several studies mention that most of the watersheds in the
Philippines are in critical condition as manifested by recent and recurring
calamities such as flashfloods in Southern Leyte and Northern Mindanao and an
increase in frequency of El Niño events in Luzon which reduces water levels in
dams. The World Bank also cites deteriorating watersheds as one of the reasons
for the increase in flooding in recent years (WB, 2003).
The report Crisis or Opportunity cites data that shows how extreme climate
events/variability, such as floods, droughts, forest fires, and tropical cyclones
have increased in temperate and tropical Asia in the past few decades. In some
regions, such as parts of Asia and Africa, the frequency and intensity of droughts
have also increased. The El Niño phenomenon has been more frequent,
persistent and intense since the mid-1970s.
The report also presents data on extreme climatic events that occurred in the
country since 1970, impelling us to recognize that earth’s climate is indeed
changing.
• The Great Luzon Floods in 1972 is a typical example of heavy flooding
caused by heavy, persistent precipitation.
• The Southern Mindanao Drought of 1998 was one of the most severe El
Niño Southern Oscillation to hit the country.
• Landslides, triggered by earthquake or heavy rainfall, were aggravated by
man-made causes, i.e. forest denudation, modification of slope of the
terrain, and others. From 1989 to 1999, landslides occurred almost every
year in the Cordillera Administrative Region. The highest number occurring
during the La Niña period of 1996 to 1999, which recorded annual total of
17 to 29 events that followed after a heavy rainfall.
• The Ormoc catastrophic flash flood in 1991 wherein more than 5000 people
perished was also cited
• Camiguin flashflood in 2001, Southern Leyte, and Surigao disaster in 2003,
and the Aurora/Infanta floods which came after 20 days of moderate to
heavy rainfall were caused by four successive tropical cyclones towards the
end of 2004.
Based on this study, it is anticipated that flood magnitude and frequency are
projected to increase, affecting many regions as a consequence of repeated
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