By Dr. Ernesto Hofileña, a retired anesthetist and an agriculturist from Iloilo
At first sight, building the Jalaur Multipurpose Project Phase II (JRMP II) seems like a good idea. One of the biggest problems facing any small island environment is fresh water. Panay Island, which has borne the brunt of chronic water shortages through the years, is no exception. Proponents claim that the building of the Jalaur Mega Dam will finally solve the water crisis plaguing Iloilo province. The mega dam is supposed to provide year-round irrigation and potable water while augmenting the province’s power supply with a 6.6 megawatt hydroelectric plant.
Historical records show many of Panay Island’s major rivers to be navigable by ships. Today, these rivers — including the 123-kilometer-long Jalaur River which is the island’s second largest river — have been plagued with low water levels. Having no aquifer or that subterranean layer of impermeable rock that stores water, Panay Island only have underground water which is dependent on rain and which is in danger of salt water intrusion if too much fresh water is sucked out.
The Jalaur Mega Dam is being touted as the answer to Panay and Iloilo’s perennial water woes, which has been made worse in recent years by the wanton destruction of the environment and climate change. A deeper investigation of the issue, however, will show that building a mega dam in the mountainous barangays of Calinog cannot give enough water promised by the proponents. In fact, it is only enough to irrigate rice paddies and cannot provide for the planting of sugar and other crops. This is on top of the dangers of flooding and landslides which critics say will be worsened by the mega dam.
There are alternatives that are simpler and more practical. Instead of building a mega dam upstream where the catchment area that collects rain and run-off water is only 107 square kilometers, we can do better by maximizing the 1,500 square kilometer catchment area downstream. The average annual output of the Jalaur River is 1,197,504,000 cubic meters. If we can save this using a series of small dams, reservoirs, and deep lateral canals crisscrossing the farmlands across the Iloilo plain we won’t need a high dam with a storage capacity of less than a billion.
Today, all the rain water will just rush down the sea when it rains hard. We cannot conserve water because our rivers are too shallow and heavily silted. This also results in the destruction of the marine life near the mouth of the river where the silt and debris from upstream eventually settle. Now if you put a mega dam, the heavy rain volume results in the water simply overflowing and causing floods downstream. However, if you rehabilitate the river and have the deep canals, rain and run-off water will simply flow through the network of waterways to the farms and recharge the groundwater system.
If we compare this to the human body, we can liken the source of our rivers in the mountains of Panay as the heart of the island, with rivers like Jalaur acting as arteries and the canals serving as capillaries that will bring water to agricultural areas. In order to store more water, the Jalaur River can be deepened by digging up the silt in the river and use it to raise the embankments along its length. Beside the building of canals that are deep enough to absorb water, this will regulate water levels, confine the flow along waterway and prevent flooding. The area near the mouth of the river can be dammed so that salt water will not intrude, ensuring that the entire length of the river is all fresh water.
In fact, all these are not new, and have been done in Thailand and China where low dams in rivers and deep canals are used not only for irrigation but also as means of transportation for their produce. Farmers will then not have to hand carry their harvest across the fields but use boats to transport their produce from farm to market. Early in the Industrial Revolution, products in Great Britain were carried by horse. But these can only carry so much tons so they developed a canal system so boats can carry more produce from their factories. In more recent years, Singapore’s efforts to reduce its dependence on imported water from Malaysia through a system of rainwater catchments and freshwater reservoirs is also worthy of emulation.
By developing the Jalaur River in this manner, we not only get more freshwater. We can save marine life, and later on, we can get more fish from the river. We can get boats to once more traverse a longer portion of the river and, in time, even allow ships to ply the river. We can also use the river not only for irrigation but also for recreational purposes. Fish ponds, which need more water during hot season when the salinity goes up in the ponds and stunt the growth of bangus and shrimp, will also benefit.
Why in good conscience borrow Php8.96 billion from the Export-Import Bank of Korea to build an expensive mega dam when there are cheaper, safer, and more effective ways of providing water for Ilonggos? For too long we have ignored our rivers and allowed our agricultural sector to deteriorate. For the sake of the younger generations, the administration of President Rodrigo Duterte must seriously review the JRMP-II and carefully study alternatives that help the people with lesser cost./PT