Industrial pollution and the management of river water quality: a model of Kelani River, Sri Lanka Asha Gunawardena & E. M. S. Wijeratne & Ben White & Atakelty Hailu & Ram Pandit Received: 27 June 2016 /Accepted: 9 August 2017 # Springer International Publishing AG 2017 Abstract Water quality of the Kelani River has become a critical issue in Sri Lanka due to the high cost of maintaining drinking water standards and the market and non-market costs of deteriorating river ecosystem services. By integrating a catchment model with a river model of water quality, we developed a method to estimate the effect of pollution sources on ambient water quality. Using integrated model simulations, we estimate (1) the relative contribution from point (industrial and domestic) and non-point sources (river catchment) to river water quality and (2) pollutant transfer coefficients for zones along the lower section of the river. Transfer coefficients provide the basis for policy analyses in rela- tion to the location of new industries and the setting of priorities for industrial pollution control. They also offer valuable information to design socially optimal econom- ic policy to manage industrialized river catchments. Keywords Transfer coefficients . Industrial pollution . Integrated river model . Kelani River . Water quality Introduction The degradation of water quality in major rivers due to rapid urbanization and industrial development has be- come a major issue in developing countries (Schaffner et al. 2009). The development of infrastructure facilities supporting this expansion lags behind population growth and economic development (Biswas and Tortajada 2009; Qin et al. 2011). As a result, the inadequate capacity of drinking water supply, sewer and wastewater treatment systems pose a serious threat to surface water resources and water quality. Poor water quality has adverse effects on the economy, human health and eco- systems (Schaffner et al. 2009). More effective manage- ment of surface water quality in developing countries is needed if the benefits of industrial development are not reduced by social and economic cost. Water quality management is challenging due to the complexity of river dynamics and the influence of both natural and anthropogenic processes. Lack of systematic Environ Monit Assess (2017) 189:457 DOI 10.1007/s10661-017-6172-3 Highlights •We configured an integrated model of catchment and river water quality. •Relative contribution of pollution sources on river water quality was estimated. •We estimated river zonal transfer coefficients using experimental simulations. •We show that industrial parks have more influence on ambient BOD and DO levels. •Transfer coefficients provide the basis for policy analyses in river management. A. Gunawardena : B. White : A. Hailu : R. Pandit Agricultural and Resource Economics Discipline, UWA School of Agriculture and Environment, University of Western Australia, Perth WA 6009 Western Australia, Australia A. Gunawardena (*) Agricultural and Resource Economics Discipline, UWA School of Agriculture and Environment and Institute of Policy Studies of Sri Lanka, Colombo, Sri Lanka e-mail: asha.gunawardena@uwa.edu.au e-mail: asha1oct@gmail.com E. M. S. Wijeratne School of Civil, Environmental and Mining Engineering and the UWA Ocean Institute, University of Western Australia, Perth, Australia