Internal Drainage Districts (IDD)

Drainage districts are typically found in low-Iying land where boundaries are determined by physical, not, political attributes. Districts vary in nature and size, from the mainly agricultural (such as Conwy, Llanfrothen and Towyn) to the semi-urban (such as the Gwent Levels). Drainage districts are at risk from various sources of flooding. Without flood risk and water level management, drainage districts would be unsuitable to live in and would not protect and provide for the variety of agricultural land, utilities and transport networks that have developed within their boundaries.  This dataset shows the location of the boundaries of IDD's within Wales including the maintained watercourses, tidal flaps, pumping stations and for for Caldicot & Wentlooge Levels & Lower Wye and Powysland it also shows locations of sluices. Current Drainage Districts as of 2022: Afon Ganol Ardudwy Marsh Borth Bog Caldicot & Wentlooge Levels & Lower Wye (Gwent Levels) Dysynni Valley Glaslyn - Pensyflog Harlech & Maentwrog Llanfrothen Malltraeth Marsh Mawddach & Wnion Powysland River Conwy Towyn