Water surplus vs water shortage
In terms of water supply for the Philippines and many other tropical countries, we have a mixture of news. First the good news — we have too much rain water yearly, floodings damage lots of public and private properties, crops, and drown or kill many people.
Second, the bad news — we do not have enough deep and wide lakes, or dams (man-made) to catch, “harvest” and store those huge volume of rain water.
Third, the worse news — some natural water catchments like rivers, streams and low-lying areas are often silted if not covered with soil to become new residential, commercial or industrial zones.
Let us check some numbers to prove the good news, that our problem is not lack of water but lots of water.
In 2014, the Philippines has naturally produced an estimated 479 billion cubic meters (bcm), higher than those in S. Korea, Thailand, Vietnam and Japan. In terms of per capita production, we have 4,757 cubic meters per year (see table 1).
Need more proof? In terms of annual freshwater withdrawals, the Philippines in 2009 has produced nearly 82 bcm, at par with Vietnam and Japan and higher than Thailand, S. Korea and Malaysia. But in terms of water productivity, ours is low, only $2.3 per cubic meter of freshwater withdrawals (FW), see table 2.
What the numbers imply would be the following.
One, we should have more dams to store lots of flood waters yearly. This will greatly reduce flash flooding that damage some midland and lowland areas, while storing water for the dry months of March to May.
Two, conduct regular, largescale dredging of heavily silted rivers and lakes. Like the many
rivers and streams in Bulacan, Pampanga and Tarlac that are silted with lahar from Mt. Pinatubo since the 90s. PHIVOLCS estimate that lahar deposits in the mountains can continue to flow downstream for the next 30 years or so.
Three, encourage more private sector participation and investments in building more dams. The reversal from integrated PPP (construction then O&M done by one private entity) to hybrid PPP (construction via ODA/budget then O&M by another entity) of Kaliwa Dam is a big mistake that resulted in delays in construction and lead to some P18.7 B of new loans to China.
Four, have more open pit mines, not less, then when they are mined out, do not cover them with soil and reforest. Leave them as deep and wide man-made lakes that will help store flood waters. The new lake can be used for fishery, tourism and water sports, etc.
Five, allow private ownership of man-made lakes, like the mined-out open pit mines. The artificial lake should be under management and control by the private mining company or consortium of private firms.
The current water shortage problem in many parts of Metro Manila is totally unnecessary and avoidable. El Niño and La Niña are natural phenomena that occur in predictable cycles, alternating usually every two years per episode. There should be less politics, more private sector investments and management of water resources.