Since the 1970s, the Maha Oya is one of the most popular sources of high quality river sand in Sri Lanka. Over the time, due to the free economic policies and the construction boom the pressure on the river as sand provider has dramatically increased. Therefore, since the late 1980s, the sand mining in the Maha Oya and clay mining in the hinterland have been exacerbating, giving rise to a number of environmental and socio-economic problems.

Excessive sand mining activities in the Maha Oya cause reduction of sand supply to the coastline, breaking the natural sand equilibrium of the beaches. The indiscriminate sand extraction from the river leads to lack of sand availability for replenishing the beaches which are naturally washed away by the wave action. The coastal stretch from Negombo to Chilaw has been identified as the most eroded coastline in Sri Lanka by the Coastal Zone Management Plan in 2006, of which 80-85% of the degradation is attributed to exacerbate sand mining in the Maha Oya. At certain places such as Katuneriya and Lansiagama, the erosion rate is 12-15m/year. Due to the coastal erosion in Wennappuwa and Nattandiya DS divisions, over 1,000 of families lost their properties over the span of a 20 year period giving rise to a number of adverse impacts including loss of homes and other properties, and loss of livelihoods. Some of these displaced communities have been living in temporarily built sheds for nearly 3 years since 2009.

By the Maha Oya River there are more than 1,000 people engaged in traditional mining activities. Due to the sharp increase of sand price during the last decade, today there are many business groups interested in such profitable activity. Following the Environmental Foundation Limited, these business groups carry out illegal mining using heavy mechanical equipment. Mechanical River Sand Mining (RSM) in the Maha Oya has been completely banned since 2004 because it causes more damage to the riverine environment than traditional artisan mining and because the extraction rate of the sand is far higher than that of artisan mining causing bank erosion and depletion of sand deposits.

The banning of Mechanical RSM is the outcome of a conflict involving the local communities engaged in traditional sand mining against the mentioned business groups.

Tensions within communities occurred as the benefits of RSM were passed on to private players engaging in the sand mining business and to urban communities who enjoyed the benefit of better infrastructure. Local communities had to manage the negative impacts of extractions for which they were not compensated in any way.

This led the communities living along Maha Oya to file Public Interest Litigation (PIL) with the legal support of the Environmental Foundation Ltd. (EFL). As a result of the PIL, sand mining was completely banned. The court also demanded periodic reports from the police to ensure progress was made.

In addition to this positive outcome, two local organizations, SLWP (Sri Lanka Water Partnership) and NetWwater (Network of Women Water Professionals) launched a campaign against illegal sand mining in 2005. Therefore the legal efforts to confront the practice of indiscriminate sand mining have been accompanied by SLWP creating awareness and further mobilising communities to take concerted action. As a result, the Ministry of Environment and Natural Resources issued a 'Draft National Policy on Sand as a Resource for the Construction Industry' in 2005. [1][2][3]

The coastal stretch from Negombo to Chilaw has been identified as the most eroded coastline in Sri Lanka by the Coastal Zone Management Plan in 2006, of which 80-85% of the degradation is attributed to exacerbate sand mining in the Maha Oya. At certain places such as Katuneriya and Lansiagama, the erosion rate is 12-15m/year [1].