Water Supply development dates back to the mid 1870's, but the first comprehensive potable water development plan was developed in 1963 by the Government of Dominica. As part of the plan an Act of parliament established the Central Water Authority (CWA) in October 1967. It remained as CWA until 1986 when the name was changed to National Water Services (NWS). In 1989 the NWS was dissolved and Dominica Water and Sewerage Company Limited (DOWASCO) was created under the Companies Ordinance of the Laws of the Commonwealth of Dominica.
Development of the sewer infrastructure started around the 1920's. In 1993 the Roseau Water and Sanitation project commenced. This included the study, design and construction of sanitation systems so as to improve the sewerage collection and disposal systems in Roseau.
DOWASCO has the mandate to provide potable drinking water and sewerage services to communities throughout Dominica.