Ireland’s rivers require greater protection and more effective management
Ireland’s rivers are a vital resource and an integral part of our landscape and culture. They are the basis of famous folklore stories, such as the great warrior Fionn Mac Cumhaill and the mythical “Salmon of Knowledge” that was caught on the River Boyne. In the past many of our rivers have facilitated the transportation of goods, and were an important source of food (e.g. salmon and eels). Today our rivers comprise a unique renewable resource providing us with drinking water, fisheries, energy and an outlet for our wastes. They drain our countryside and urban areas and are a centre-point for a range of recreational activities. They are highways which transport water, sediments and nutrients, and are pathways through which wildlife can migrate. Our major towns and cities are invariably located on rivers, highlighting the historical and functional importance of waterways. River corridors provide ecological commuting routes through these urban areas allowing the wilder areas of our countryside to be connected thus facilitating the migration, dispersal and genetic exchange of wild species. The ecological services that rivers provide uniquely meet the requirement of Articles 3 and 10 the EU Habitats Directive. Irish rivers have a number of significant pressures however, resulting from physical, chemical and biological sources.
Drainage and channelisation works have been a key physical impact. The major catchment-wide arterial drainage schemes of the 20th century greatly increased water conveyance in affected rivers, but also resulted in unimaginable ecological destruction. The aesthetic and recreational value of these rivers was also severely compromised. Many of these schemes have also been counter-productive and have simply transferred the problem of flooding further downstream. The predicted economic benefits of these schemes were also rarely realised. In an attempt to repair some of the physical damage to our rivers a programme of instream enhancement commenced recently. However, to date these works are almost exclusively focused on enhancing rivers for salmonids, and improving angling, and are having their own significant environmental and ecological impacts.
Although the major catchment-wide arterial drainage schemes are over, there are a large number of more localised schemes being progressed. Recent ones in Kilkenny, Ennis and Clonmel affected Natura 2000 Rivers. It was claimed at the time that these schemes would avoid all instream works to protect these designated areas, however this did not happen. River walls built within these towns required major temporary instream works and resulted in the loss of most of the juvenile lamprey habitats within the works areas. A scheme planned for Bandon in Co. Cork will require extensive lowering of several kilometres of river corridor and the construction of river walls and bank armouring. Again this scheme will hit lampreys the hardest, and the River Bandon is thought to hold the best River Lamprey population in Ireland.
Water quality remains a significant pressure on Irish rivers, with almost 50% of Irish rivers failing to meet Good Ecological Status in the last national survey. Issues resulting from diffuse pollution sources are an increasing problem, even as point discharge pressures are brought under control. The intensification of agricultural activities has profoundly affected our rivers. Although the protection of our rivers has largely been driven by EU Directives, most notably the Water Framework (WFD) and Habitat Directives, it is also EU supports for agriculture in areas which would be otherwise uneconomic that has had been one of the greatest drivers of the deterioration of Irish rivers.
Our rivers have long been source of energy from small watermills to the ESB’s major hydroelectric developments. Very few of our rivers have not been affected by the weirs, diversions and other modifications required to harness the power of running water. Dams and weirs have also been used to impound water to facilitate abstraction for drinking water and industry, for ornamental reasons, to count migrating fish and measure flows. Dams and weirs interrupt the river continuum, interfering with the transport of bed material and the movements of fish and other wildlife. Some species are affected more than others by these barriers. Lamprey species are particularly vulnerable, with two of the three species which occur in Ireland even unable to get pass the crump weirs that are put into rivers to count salmonids and measure flows, for example. Hydroelectricity may be a renewable energy source, but it has not proven to be a sustainable one in Ireland. On rivers such as the Shannon, Erne and Lee which have hydroelectric schemes, salmon runs are only around 5% of the historical levels on these rivers.
The introduction and spread of non-native invasive species is a major threat to the ecological integrity of Irish rivers. This includes the spread of plant species such as Japanese Knotweed Fallopia japonica and Himalayan Balsam Impatiens glandulifera, along our river corridors along with aquatic invaders such as the Asian Clam Corbicula fluminea and Zebra Mussel Dreissena polymorpha. The arrival of others appears almost inevitable.
Ireland’s rivers have many problems and face a challenging future. Climate change and non-native species are perhaps the most serious emerging threats, however mismanagement is also a key issue. According to ‘A Celebration of Salmon Rivers‘, published by the North Atlantic Salmon Fund in 2007, “the salmon is no longer an image associated with the Boyne, nor is wisdom a quality to be associated with the management of this natural resource“. It is clear that this comment applies to most rivers in Ireland, even though the information and technology required to manage our rivers sustainably is available. We could, for example, easily restore significant salmon runs to the River Shannon with some effective management. We should be looking at back-to-nature flood schemes and restoring floodplains and wetlands, rather than walling and dredging our rivers. We should be enhancing and restoring our rivers for all wildlife, and not blanket filling them with gravel and rocks to favour just salmonids and angling interests. We should be removing barriers from rivers and providing fish passes and eel passes on all weirs that are still required. We need to keep livestock, housing and other developments back from our rivers and their riparian zones. All payments to landowners should be used to incentivise environmental and ecological improvements.
Our rivers are an intricate part of our natural heritage and an important renewable resource. We need to protect and restore these vital natural commuting and transport networks and manage them sustainably.
This article was featured in An Taisce’s Summer Magazine 2015, which can be downloaded here.