Household Willingness to Pay for Constructed Wetlands as Nature-Based Solutions for Wastewater Treatment in Bayawan City, Philippines

Constructed wetlands are globally recognized as effective nature-based solutions to wastewater treatment providing significant ecological and socio-economic benefits. This study aims to identify the ecosystem services provided by the constructed wetlands and evaluate their economic value. This study administered a survey questionnaire to 270 households of Fishermen’s Gawad Kalinga Village in Bayawan City, Negros Oriental, Philippines and employed a contingent valuation method to investigate their willingness to pay for the constructed wetlands. Respondents identified several ecosystem services of the constructed wetlands including the provisioning (water supply and biomass), regulating (wastewater treatment, water purification, climate regulation, flood prevention), supporting (habitat formation, nutrient cycling, hydrological cycle), and cultural (tourism, educational and research, recreation, aesthetic) services. Results showed that 96.3% of the respondents were willing to pay for the ecosystem services, with a mean of PHP 107.28. In terms of socio-demographic characteristics, age group and sex have no significant impact on WTP; while positive, weak, monotonic association for highest educational attainment; and positive, very weak for monthly income. The findings hold a significant promise for the government and other stakeholders to adopt a constructed wetland in achieving more human ecological and sustainable peri-urban communities.