Tayabasan Multi-basin System Project (IEE Checklist)

The Tayabasan Multi-basin System project was led by WawaJVCO and served as a response to the growing water demand and recurrent flood woes of Metro Manila. It will deliver 80 MLD of water by 2021 to Manila Water’s treatment plant. The multi-basin system is located in Barangay San Rafael, Rodriguez, Rizal and Sitio Apia, Barangay Calawis, Antipolo City, Rizal. It is considered a category B project (non-environmentally critical project) and as such required an initial environmental examination (IEE) checklist in order to secure the Environmental Compliance Certificate.

As a part of the preparation of the IEE checklist, Aperçu Consultants engaged in the following activities:

Baseline Survey

Water Quality

A baseline assessment of the physical and chemical properties of the water in the three (3) rivers covered by the project: Montalban, Tayabasan, and Sapa Bute-bute was done. The specific parameters assessed were temperature, pH, salinity, conductivity, dissolved oxygen, turbidity, biochemical oxygen demand, total suspended solids, total dissolved solids, and oil and grease.

Freshwater Ecology

Existing conditions of the river system in terms of ecological parameters such as abundance, richness, diversity, and evenness of planktons and microfauna was studied.

Terrestrial Flora and Fauna

The site is classified as a forest area, as such the tree species were identified and the biodiversity index of regeneration species for the area was assessed. Avifauna was assessed by listing and counting all species seen or heard. Rodents were captured from various areas of the project site. Reptiles and usual fish type and catch were

 identified through interviews with representative guides and key informants. 

Ambient Air Quality 

Existing air quality at the site vis-à-vis applicable Clean Air Act ambient air quality standards were assessed. Impacts on the air quality as a result of the project’s construction and operation phases were also projected. 

Ambient Noise Quality

Existing ambient noise levels at the primary impact zone, Sitio Apia were taken. The sound measurements were compared with the criteria values in the NPCC Memorandum Circular No. 002. Impact predictions showed that only the construction phase will contribute to the ambient noise, as such, mufflers were installed on the construction equipment.  


The income and economic activities the host province, Rizal was evaluated. While the population, indigenous peoples, economic activities, tourism, social services, and poverty profile of the host city, Antipolo was evaluated. Local benefits to the host local government unit and community as a result of the project included job generation, increased business opportunities for locals, decrease in unemployment, and decrease in poverty incidence.  

Traffic Study

Pertinent traffic routes were observed to evaluate the traffic situation and count the vehicles plying on these routes. Sampling was done during the weekday and weekend to get a complete traffic study. 

Environmental Impact and Management

All impact assessments and mitigating measures were grounded on the baseline studies and done for both the construction and operation phases. 

The Environmental Compliance Certificate (ECC) for the project was issued by the Department of Environment and Natural Resources (DENR) on September 2019 with ECC Reference No. ECC-OL-R4A-2019-0559.