Hydropower: To build or not to build

By Gerry T. Estrera
On January 29, 2014, the San Lorenzo Ruiz and Developers, Inc. wrote a letter to Davao City Mayor Rodrigo Duterte about the firm’s proposition of building a 160-megawatt (MW) hydropower project in the city. 
 The proposed hydropower project will “involve a run-of-river-flow low diversionary weir with a height of 25 meters at the confluence of the Davao and Tamugan Rivers” and then connected “via a 10-kilometer combination of tunnels, open canals and penstock to a powerhouse located at the Lapunan area.”
 The construction and operation of the proposed project is pegged at US$500-US$600 million.  It will be built at elevation 210 meters, which is below the 300-meter threshold for recharging zones of the Davao underground water aquifers.
 “The proposed project is not in conflict with Hedcor’s power project since it is to be built below the elevation proposed by Hedcor and will utilize only the water released from Hedcor’s proposed project,” said the document obtained by this author.
 According to the document, the Department of Energy “has already reviewed and certified the worthiness of San Lorenzo Ruiz Builder’s Davao hydropower project.”  In fact, the energy department itself “has issued a Letter of Endorsement addressed to the Honorable Davao City Mayor.”
 The proposed hydropower project was referred to Councilor Louie John J. Bonguyan, who chaired the Committee on Energy.  Some hearings were conducted by the said committee on the project.
 “Based on the reactions of the participants in the hearings conducted by the Committee on Energy, all participants including barangay officials of Tamugan, Davao City have expressed elation and approval of the proposed project,” the document said.
 But last May 23, 2014, Councilor Leo Avila told Oscar I. Violago, the chief executive officer of San Lorenzo Ruiz and Developers, Inc. that the proposed hydropower project “has to be referred to the Davao City Watershed Management Council” as per “pursuant to Davao City Ordinance Number 03-10-07.”
 In a news report dated May 29, 2014, Davao City Vice Mayor Paolo Duterte was quoted as saying that, based on the committee hearings conducted, “the proposed hydropower plant will be using massive water from Davao River and Tamugan River and that it will also be diverting the used water to other areas instead of returning it to the rivers.”
 The vice mayor’s concern is that the proposed hydropower project will greatly affect the water level of the two rivers.  This is especially true in the case of Tamugan River, a protected watershed area and source of drinking water for the people of Davao, according to the news report.
 Water covers over 70 per cent of the earth’s surface. Electricity produced by water movement has been used for decades.  About 16 percent of the world’s electricity is generated by hydropower.
 According to the Washington-based Worldwatch Institute, the world’s top five producers are Canada, China, Brazil, the United States and the Russian Federation.   Several countries, including Brazil and Norway, obtain almost all their electricity from this one source.
 Hydropower can be generated by water falls (the first hydroelectric plant was built on Niagara Falls in 1878), rushing rivers and streams, and manmade dams, all of which allow a controlled amount of water to pass through the pipes that spin turbines – creating electricity.
 Electric power is measured in units called watts.  A watt is equal to one joule per second.  The total generating capacity of a power plant is measured in kilowatts (kW) for 1,000 watts and megawatts (MW) for one million watts.
 A World Bank report in the 1980s showed the Philippines as one of the “thirteen largest additions to hydroelectric capacity in developing countries.”  From an operating capacity of 940 megawatts in 1980, it went up to 2,195 megawatts in 1985.  In 1998, the total hydropower capacity stood at 2,304 megawatts or almost 20 percent of the country’s total installed capacity.
 Mindanao, the country’s second largest island, gets its power from four major sources: hydropower, coal, geothermal, and oil. The bulk – 662 MW or 52% – comes from hydropower. Oil contributes 24% of the power supply (311 MW) while geothermal is the source of 8% (98 MW). The remaining 16% (203 MW) comes from coal.
 “We are heavily dependent on hydropower which is coming only from one source, Lake Lanao,” says Manuel ‘Bobby’ Orig, first Vice President for Aboitiz Power Corp. in Mindanao. “This is the reason why during summer months or during long dry spell, when water level in Lake Lanao is very low, the power supply in Mindanao is gravely affected.”
 Most of the hydropower plants in the country are in the form of a dam that backs up the water and raises the level.  Smaller hydropower plants, however, do not necessarily require dams.  They use a series of pipes with turbines inside which are turned by the current. 
 But are hydropower plants really environment-friendly?   Some scientists believe that hydropower from manmade dams produce significant amounts of carbon dioxide and methane, which are greenhouse gases closely connected to climate change.
 “Large amounts of carbon bound up in trees and other plants are released when a reservoir is initially flooded and the plants rots,” Worldwatch points out in a recent report.  “And as plant matter settling on the reservoir bottom decomposes without oxygen, it leads to a buildup of dissolved methane, which is released into the atmosphere when water passes through the dam’s turbines.”
 To operate well for many decades, hydro projects require sound management, not just of equipment, but of entire watersheds.  “Hydroelectric power will not be truly renewable until the functions of flood control, irrigation, transportation, power production, tree planting, fisheries management, and sanitation are coordinated within the overall goal of maintaining healthy and productive rivers,” writes Cynthia Pollock Shea in Renewable Energy: Today’s Contribution, Tomorrow’s Promises.
 In the final analysis, however, “hydroelectric power creates virtually no pollution problems,” writes H. Steven Dashefsky, the man behind Environmental Literacy: Everything You Need to Know About Saving Our Planet.  “Small-scale projects cause little harm to the environment, but larger projects are environmentally destructive.”