After three decades of operation, the National Irrigation Administration-Magat River Integrated Irrigation System (NIA-MARIIS) Dam, which irrigates 83,000 hectares of farmlands in Isabela and Quirino provinces, will soon undergo optimization works. The irrigation dam is located just after the Magat hydroelectric plant operated by SN Aboitiz Power (Snap).
The MARIIS Reservoir Optimization Project (MROP) is a joint undertaking of the NIA and Snap, which aims to increase the storage capacity of the MARIIS reservoir.
“With the addition of another set of stop logs on the MARIIS Dam, it is expected to create an additional 8-million-cubic-meter-storage capacity for the MARIIS reservoir, which certainly helps the NIA store more water and makes both irrigation and power generation flexible,” Snap Vice President for Corporate Services Michael Bon Hosillos said.
The optimization project also includes refurbishment and improvement of MARIIS Dam structures, with the replacement of the 30-year-old gantry crane with two brand-new ones to provide redundancy during flood-season operations and the modification of the right sluice gate to serve as fine-flow control gate for more effective reservoir level control improving irrigation water delivery and dam safety.
“The project will include full automation using digital controls of the irrigation dam to ensure accurate water management,” NIA-MARIIS Operations Manager Mariano Dancel said.
The fabrication and installation of new stop logs, including refurbishment and improvement works on the irrigation dam, started August 2014 and will be completed in March 2016.
“The project is fully funded by Snap at no cost to the national government,” Hosillos said.
Thirty-two years after its inauguration on October 27, 1982, by the late President Ferdinand Marcos, the Magat Hydroelectric Dam, which straddles Ramon, Isabela and Alfonso Lista, Ifugao, and spans the mighty Magat River, has been the biggest multipurpose dam in Southeast Asia.
Many describe the multipurpose dam as the NIA’s “most daring” infrastructure project and the former president’s gift to his fellow Ilocanos in the Cagayan Valley region.
“About 350 kilometers north of Metro Manila, it has a power-generation capacity of 360 megawatts and could irrigate 83,000 hectares of rice lands, covering parts of Quirino province, Santiago City and the rest of Isabela downstream,” said Engr.Wilfredo Gloria, manager for Engineering and Operations of the NIA-MARIIS.
Under the Electric Power Industry Reform Act of 2001, however, the Magat Dam hydroelectric plant underwent privatization bidding, which was won by Snap in 2006.
Rice farms irrigated by the dam allow farmers to produce an average of 100 cavans per hectare. Each sack could be sold at P1,026, which is equivalent to P102,600 per hectare.
While Dancel’s group was able to irrigate rice lands in Isabela, including Santiago City and Quirino province regularly covered by MARIIS, the agency has managed to come up with a number of diversion dams that can catch wastewater from farms upstream.
“After painstaking years of thorough research, we were able to construct seven minidiversion dams that could preserve waste-water from creek tributaries that normally exit to the Cagayan River downstream but now being reused to irrigate towns formerly deprived of farm water,” Dancel informed.
Recently inaugurated, the Patanad Diversion Dam in San Isidro, Isabela, which tapped water from the Patanad Creek, was designed to irrigate some 200 hectares of farmlands in town.
“With an area of 200 hectares it can irrigate, the diversion dam is expected to yield an average of 1,900 metric tons of palay per cropping season, benefiting 235 farmers from the village,” MARIIS Division II Manager Pedro Dalawampu said.
After irrigating 81,000 hectares of rice lands, with an estimated production value of P8.3-billion from rice harvests last cropping season in the province of Isabela and the rest of the Cagayan Valley Region, the NIA-MARIIS has announced the operation of a 45-kilowatt mini hydropower plant in San Mateo, Isabela.
“We don’t tap water just for irrigation, we also run mini hydro-electric plants that could generate power to maximize our resources in serving both our farmers and people in the countryside,” said NIA Administrator Florencio Padernal during recent inauguration ceremonies at the power plant.
Implemented by the Japan International Cooperation Agency (Jica), through the Department of Energy, the mini-hydropower plant straddles Lateral B of the Mariss main canal traversing Barangay Villafuerte.
“While we drive water to irrigate our farms, the 45-kilowatt capacity mini hydropower plant could be replicated nationwide as a preemptive move to answer the projected power crisis next year,” Dancel said.
With Padernal were Energy Undersecretary Zenaida Monsada and Jica Senior Representative Eigo Azukizawa, who attended the recent launching ceremony of the pilot project, which was completed in October 2014.
The first of its kind in the country, many see the feasibility of utilizing existing irrigation canals for power generation.
“The NIA would like to replicate such a project in other areas. That is precisely the reasons why all of our irrigation managers from the different regions in the country are now here,” Padernal said after the inauguration ceremonies.
Padernal eyes the construction of around 50 hydro power projects of various generation capacities around the Philippines the soonest possible time.
“We are looking into the possibility of another mini-hydro power plant in Barangay Sinamar Sur, also of this town, with a generation capacity of 500 kilowatts, or something like 10 times stronger,” Dalawampu added.
San Mateo Mayor Crispina Agcaoili lauded the project, saying it is an added value to her town.
“If we could only replicate the project in more areas here, then our town can have more sources of power and revenues,” Agcaoili said.