Water bodies are the basic management units for reporting and assessing compliance with the Water Framework Directive (WFD) environmental objectives. There are 571 water bodies in Northern Ireland of these 496 are surface water bodies: including 450 rivers, 21 lakes, and 25 transitional and coastal waters (Marine); the remaining 75 are groundwater bodies.

This layer displays the river waterbodies boundaries based on surface water flow hydrological units. This is a 2016 revision of the earlier 2009 hydrological unit split. Future revisions are not planned.

Water bodies are the basic management units for reporting and assessing compliance with the Water Framework Directive (WFD) environmental objectives. There are 571 water bodies in Northern Ireland of these 496 are surface water bodies: including 450 rivers, 21 lakes, and 25 transitional and coastal waters (Marine); the remaining 75 are groundwater bodies.

This layer displays the river waterbodies boundaries based on surface water flow hydrological units. This is a 2016 revision of the earlier 2009 hydrological unit split. Future revisions are not planned.