500MW Wawa Pumped-Storage Hydropower Project

An Environmental Impact Statement (EIS) was prepared in order to secure an Environmental Compliance Certificate (ECC) for the 500MW pumped-storage hydropower plant project of Olympia Violago Water and Power, Inc. (OVPI). The power plant is located within the Wawa River Basin and Montalban Riven Sub-Basin and covers the municipalities of San Mateo and Rodriguez in Antipolo, Rizal. The EIS prepared by Aperçu Consultants Inc. for this project received the Exemplar Environmental Impact Assessment (EIA) Report in Environmentally Critical Reports award from DENR-BMB. 

As part of the preparation of the EIS, Aperçu Consultants Inc. was engaged in the following activities:

Land Module

Land Use

The major land use conversion of the project site was the conversion from a terrestrial environment to an aquatic environment. The discrepancy between the proposed project with the current land use classification of the site required a reclassification of the existing land use through a Sanggunian Bayan Resolution. A Special Use Agreement in Protected Areas (SAPA) was also secured since the project is located in a protected area.


A thorough assessment of both regional and site geology was done by studying the following: regional tectonic setting, regional stratigraphy, geomorphology, topography, slope, and all relevant geologic hazards (i.e. seismic hazards, ground shaking and acceleration, ground rupture, liquefaction, etc). An assessment of each individual basin affected was also done. The results provided insights on the possible hazards and its impacts on the project. It also served as a basis for the mitigating measures and monitoring plans made. 


Soil type and quality, soil erosion susceptibility, and sediment sources and riverbank stability were assessed in order to make the proper preventive and mitigating measures. 

Terrestrial Ecology

The flora of the project site was assessed for historical occurrences of pest infestation, forest or grassfires, and other similar incidences. It was sampled during the wet and dry seasons through various ecological measures (i.e. species dominance, diversity and evenness, threatened status etc). This helped to identify all possible issues and problems that may arise from the project as well as select the best solution for this specific site. 

A faunal assessment of avian, mammalian, amphibians, and reptiles in the site were assessed during the wet and dry seasons. This was important as the conversion from a terrestrial to aquatic environment would have a large impact on these species. Mitigating measures and monitoring plans were made based on the results of the faunal assessment.

Water Module


Drainage morphology, hydrogeological setting and aquifer identification, rainfall and stream flow measurements, and water resources were assessed to identify all impacts of the project to the hydrology during the construction and operation phases of the project. A hydrology monitoring plan was made for both phases to prevent and mitigate impacts. 

Water Quality 

Water quality baseline conditions were determined through sampling surface waters and ground/spring waters within the project site. All water samples were assessed for pH, temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), oil and grease, and total suspended solids (TSS). Results served as a basis for monitoring plans. It also helped identify potential impacts of the project construction and operation to the water quality. 

Freshwater Ecology

Aquatic biota characterization of plankton communities, zooplankton, macroinvertebrates, and fish communities was done. Results were used to identify, reduce, and mitigate impacts on the provisioning, regulatory, and cultural services of the various water resources of the project site.

Air Module


Primary and secondary data were used to assess the project’s air pollution impacts and contribution to climate change in terms of greenhouse gas (GHG) emissions. Results were used to identify climate change projections on the rainfall and temperatures.

Ambient Air Quality

Air quality was assessed and compared to the Clean Air Act ambient air quality standards. Air dispersion modeling was done to predict the indicative ambient air quality impacts of the project during the construction phase. 

Ambient Noise

The existing sonic profile at the project site and noise impacts during the construction phase were determined. Results of sound measurements and predicted sound levels were compared to the Environmental Quality Standards for Noise in General Areas. Construction noise control strategies were used to control sound at the source. 

People Module

Existing Conditions in the Host Province, City, and Municipalities

The socio-economic description of the host community and host barangays were assessed. The province of Rizal was assessed through identifying the population, households and housing units, migration, agriculture, aquaculture, other industries, education, telecommunication, power generation, and water supply. The city of Antipolo and municipalities of San Mateo and Rodriguez were assessed through identifying the physical and demographic characteristics, social profile, proximity to basic services and service institutions, barangay programs and services, and project perceptions. 

Indigenous Peoples

Out of the 115 households surveyed, 22 were considered an IP household belonging to the Dumagat and Agta tribes. As such, various Information, Education and Communication (IEC) and consultation activities were held to ensure proper communication with IP communities regarding their Ancestral Domain. Focus group discussions with the IP communities also informed the plans made to protect and conserve cultural heritage and archaeological sites. Benefits from the project were also identified.

Traffic Study

Existing transportation and the traffic situation in the vicinity of the project site was evaluated. Sampling was done for both weekdays and weekends. No traffic congestion as a result of the project was predicted but management and mitigation plans were still made for the construction and operational phases. 

The Environmental Compliance Certificate (ECC) for the project was issued by the Department of Environment and Natural Resources (DENR) on June 2016 with ECC Reference No. ECC-CO-1601-0006. The ECC is available at the following link.

A copy of the Environmental Impact Statement is available at the Environmental Management Bureau (EMB) website at the following link.