Indiscriminate river sand mining, due to the recent boom in the construction industry in Sri Lanka, has created a number of environmental and social problems. Within this context, this study attempts to identify policy options for sustainable river sand mining that minimize environmental degradation while meeting the requirements of the construction industry and local people.
The study followed four separate analyses: comparison of annual costs and the benefits of selected mining sites, analysis of miners’ views and preferences using choice modeling, evaluation of expert opinion using multi-criteria analysis, and a comparison of alternative sources of river sand.
The comparison of the costs and benefits of sample mining sites revealed that the social cost of river sand mining exceeds the private costs; however, the fact that social benefits were still found to be non-negative at the study sites may be due to the under-reporting of environmental effects and the exclusion of off-site costs. It was observed that although the increased costs of restoration and other costs of overmining are borne by government institutions, government income has remained at a very low level. The results of the discrete choice experiment with the miners indicated that they believe the negative effects of sand mining can be partly mitigated by increasing government revenue towards an environmental trust fund (ETF) with some level of co-management. Strict rules, regulations and awareness programs, as suggested by the media and environment groups, were not found to be productive. Alternative policies for sustainable sand mining in three major rivers were ecologically, economically, socially and technically evaluated using multi-criteria analysis. The restriction of mining at vulnerable sites was found to be the best management alternative followed by the establishment of an ETF for the Ma Oya River, where there are more than 70 mining sites. Community-based management was found to be the best option for the Mahaweli and Deduru Oya rivers.
Using off-shore sand was found to be the best way to decrease pressure on rivers for sand. However, at present, the price of off-shore sand is slightly higher than that of river sand and it is less popular because there is the possibility that shells and chlorides are present in it. Prices could be brought down further by expanding offshore sand mining operations because off-shore dredging is sensitive to economy of scale. This could be achieved by mandating the compulsory use of off-shore sand for large construction projects and landfilling, especially in Western Province.