Lanka Rainwater Harvesting Forum was established at the beginning of 1996 by a small group of interested persons. They are from a range of government and non-government institutions, including the National Water Supply and Drainage Board (NWSDB), Intermediate Technology Development Group Sri Lanka (ITSL), Community Water Supply and Sanitation Project (CWSSP), Church of Ceylon, Board of Women’s Work, NGO Water Supply and Sanitation Decade Services, Agrarian Research and Training Institute (HARTI) and the Open University.

Lanka Rain Water Harvesting Forum was officially launched on the 19th of March 1997 by the then Minister  for National Housing and Public Utilities, Hon. Nimal Siripala de Silva as the chief guest. The Forum is registered under the companies act No. 17 of 1982 as a non-government, non profit making organization under the Ministry of Social Services.