Abstract: This data shows Arterial Drainage Scheme (ADS) Channels constructed under the Arterial Drainage Acts 1945 & 1995, that OPW has a statutory obligation to maintain. These channels are either modified watercourses or constructed channels/drains to enhance the conveyance or constructed to modify the flow regime in an area. The average channel is requiring maintenance every four to six years. However, this varies with some channels requiring maintenance annually and others only requiring maintenance every twenty years. Circa 2,000 km of channels are maintained annually and nearly all of the 11,500 km of channels will have been maintained at least once over the Programme cycle of six years. Arterial Drainage Schemes were carried out under the Arterial Drainage Act, 1945 to improve land for agricultural purposes. The Act was amended on a number of occasions, for example to transpose EU Regulations and Directives such as the EIA, SEA, and Habitats Directives and the Aarhus Convention. The Arterial Drainage (Amendment) Act, 1995 further allows for the implementation of localised flood relief schemes to provide flood protection for cities, towns and villages. Statutory Arterial Drainage Maintenance entails the maintenance of completed Arterial Drainage Schemes and completed Flood Relief Schemes. The OPW are responsible for the maintenance of 11,500km of channel, 800km of embankments, some 19,000 bridges and further ancillary structures such as weirs, sluice barrages, sluices, pumping stations and tidal flap gates.

Purpose: This data has been developed to support the maintenance of Arterial Drainage Schemes carried out under the Arterial Drainage Acts 1945 & 1995, that OPW has a statutory obligation to maintain. These schemes were carried out to improve land for agriculture and to mitigate flooding in urban areas.