Our Beautiful World
The Northern Negros Geothermal Power Project
A Case Study
by Simon Peter Gregorio
The Northern Negros Geothermal Power Project is an 80-mw power plant to be constructed
in the slopes of Mount Kanlaon Natural Park (MKNP) in the province of Negros Occidental.
The project actually consists of two power plants, each generating 40 mw.
One plant would be located in Barangay Minoyan, Municipality of Murcia
and the other in Sitios Pataan and Hagdan, Brgy. Mailum, Bago City.
In the original plan, the whole development area would cover around 4650 hectares,
of which 1850 hectares would be located in the Mount Kanlaon National Park.
A protected area.
Mt. Kanlaon is the highest peak in the central Philippines. The mountain sits almost at the
center of Negros Island. It forms the north westernmost tip of the border dividing the Island
into the two provinces of Negros Occidental and Negros Oriental. Jurisdiction over the
volcano is disproportionately shared by the two Negros provinces and by four cities and two
municipalities that have their common boundaries on the slopes of the volcano.
These are the cities of Bago, La Carlota, San Carlos, and Canlaon and the municipalities
of La Castellana and Murcia. Of the six, only Canlaon City is located in Negros Oriental.
Mt. Kanlaon is one of the six most active volcanoes in the Philippines.
Though it has not had a major eruption in the last 50 years or so,
the volcano is prone to unpredictable pyroclastic explosions.
Mt. Kanlaon is an important watershed area. It slopes are the origins of three Negros river
systems. These are the Bago, Nahalin, and Ilog river systems. Seventy-five percent (75%)
of the total land area of the MKNP or 18,418.2 has. are part of the Bago watershed.
The Bago River originates from the northeastern part of the mountain. The Bago and Bilibago
Irrigation Systems irrigates the province's so-called rice bowl. In 1990, the Bago Irrigation
System was watering 15,000 hectares of agricultural land. Around half a million people in
Negros Occidental are said to benefit from the waters of the Bago and Binalbagan river
Along with the Northern Negros Forest Reserve on Mts. Mandalagan and Silay, Mt. Kanlaon
hosts the remaining rainforests of the province. A Swedish Satellite Corporation survey
showed that rainforests cover an estimated 11,475 has. or 46.73 percent of the park's area.
The rainforests host a number of endangered plants like the Pitcher plant, staghorn fern,
and orchid species like the Maripusa and Waling-waling and others. Plants endemic to the
park are Cyrtanda cyclopum (Gesneriaceae) and two varieties of grasses that grow near the
crater: Isachae vulcanica and Miscanthus depauperatus.
There are also 50 species of animals distributed into 40 genera, 81 species of butterflies
classified into 32 genera and belonging to four families, and 22 families of birds inside the
park. Among the birds is the Yellow-backed sunbird which is found only in four islands in
the CentralPhilippines (Sibuyan, Tablas, Panay, Negros, and Cebu).Other rare
and endangered birds in Kanlaon are the Blue-crowned racquet-tailed parrot (Prioniturus
discursus), Visayan tarictic hornbill (Penelopides panini), Flame-templed babbler (Stachyris
speciosa), White-winged cuckoo-shrike (Coracina ostenta), and White-throated jungle
flycatcher (Phinomyias albigularis). These birds inhabit the forest of the western portion
of the mountain.
De-vegetation and the Subsequent Fragmentation of the Area: The plant would clear
forests and vegetation where endangered species of flora and fauna might be living. Roads
leading to the project would attract settlers and residents who would then encroach on the
remaining rainforest. As a consequence, the animals would be disturbed from their habitats,
thereby disrupting their breeding patterns. The incidence of soil erosion would increase,
and the watershed would be compromised. There would be drought in the lowlands during
the dry season and flash floods during the wet.
Subsidence of the Surrounding Land: The geothermal plant would use up ground water
faster than nature could replace them; creeks and streams would dry up and the surrounding
land would sink. In Tiwi, Albay, where a geothermal plant is operating, several of the hot
springs dried; in their place, new "hot spots" emerged in unlikely places like lawns,
bedrooms, and kitchens. A number of families had to be evacuated.
Water Pollution: Opponents argue that geothermal exploration and operation would pollute
watershed catchments, the ground water, river catchments, and tributaries with toxic
effluents, chemical wastes discharges compromising the quality of drinking and irrigation water.
Hot water discharged into the rivers and streams would raise the temperature of the water and
damage fisheries and encourage the growth of weeds.
They claim that in Tongonan, Leyte where PNOC operates a geothermal plant, rice yields
declined from 29 cavans per hectare to four cavans per hectare because of the plant's
In Tiwi, Albay, discharges from the plant allegedly contained concentrations of arsenic, barium,
cadmium, chromium, copper, and lead that surpassed safety standards. Closer to home, the
Palinpinon geothermal plant had supposedly polluted the Okoy River. Life forms in the river
e.g. fish and shellfish had allegedly ceased to exist because of the high sulfuric content of the
water. Some springs had also dried up as the geothermal plant sucked surface and ground
water for its operations.
Air Pollution and Acid Rain: Air emissions from geothermal plants contain hydrogen sulfide
(H2S) and sulfur dioxide (SO2). SO2 in the atmosphere is the cause for acid rain.
H2S at certain concentrations is known to harm the olfactory nerves (nerves in the eye) and
even paralyze them. H2S is not easily removed from a place. Because it has a greater density
than air, it is not easily carried by the wind and tends to remain at low-lying areas near the
Go to part I
Wildlife in Canlaon NP