Explore your local river or lake through our interactive map

Interactive Map

The Source to Tap Mapping Portal provides you with an exciting opportunity to explore your local water environment from the comfort of home.  The Mapping Portal gives you online access to a selection of datasets, or layers of information, about your local rivers and lakes, that can be turned on and off, to allow you to view different aspects of the water environment.

When you click on the map image the Mapping Portal will open in a separate window called ArcGIS Online.

Why a mapping portal?

Data and evidence are a critical part of integrated catchment management,

whereby coordinated planning and management of a river catchment takes place by a group of stakeholders operating under agreed terms of engagement. Thus, helping to engage a wide audience, agree on the priority issues and solutions, and monitor outcomes.

Effective visualisation of data through maps, infographics and other media helps develop an understanding of complex environmental systems, builds confidence and eases communication between a wide range of people and organisations who need to work in partnership to improve the water environment.

Source to Tap Story Maps

The Source to Tap Story Maps are interactive maps that allow you to explore the Erne and Derg river systems and the Source to Tap Project through images, text and multi-media content, clipped to a map of the area.

You don’t need to be an expert in geography or even be able to read a map to enjoy the Source to Tap Story Maps. We have designed them so that they can be used and enjoyed by anyone who wants to learn more about our precious rivers and lakes and the water world around us.

A 'catchment' is an area where water is collected by the natural landscape. In a catchment, rainwater run-off will eventually flow to a stream, river, dam, lake, ocean, or into a groundwater system.

The Erne Catchment

The Erne Catchment Story Map

The River Erne rises in County Cavan and flows for almost 100 kilometres through Lough Gowna, Lough Oughter, Upper Lough Erne, Lower Lough Erne and Lough Asseroe before entering the sea at Ballyshannon, County Donegal.

The total catchment area of the Erne is 4374 km2. For almost 50km from Crossdoney (south west of Cavan Town) through to Enniskillen in County Fermanagh, the River Erne can be difficult to distinguish as it winds its way through interconnected loughs nestling among the Drumlin hills of Cavan and South Fermanagh.

Click to view Erne Story Map

The Derg Catchment

The Derg Catchment Story Map

The River Derg and its tributaries have a channel length of approximately 60 kilometres and a catchment area of 369 km².  The River Derg emerges from Lough Derg in County Donegal and flows for approximately 12 km before merging with the Mourne Beg River, 2.5 km above Castlederg in County Tyrone. The Derg River continues through the lower Derg Valley and merges with the River Strule just below Ardstraw to form the Mourne River. The Mourne River subsequently flows into the River Foyle just below Strabane.

The other notable tributaries of the Derg catchment in addition to the Mourne Beg include the Killen Burn, Leaghany River and Glendergan River. Notable tributaries on the Mourne Beg which flows from Lough Mourne in County Donegal include the Garvagh Burn, Croagh Burn and Bunadowen River.

The Killeter Forest which is one of the largest areas of coniferous woodland in Ireland is located within the upper sections of the Derg Catchment.

View Derg Story Map

Introduction to the Erne and the Derg Catchments