2020 will forever be remembered for COVID-19. However, as COVID (hopefully) recedes, what is likely to emerge are increased issues with water supply. Recent monthly weather statements from Met Éireann report that following an exceptionally wet February, rainfall was below average in March and April, with drought conditions reported at many stations for April. Thus far, May has also been largely dry and with increasing air temperatures there is even less chance of any meaningful effective rainfall. Recent discussions with the EPA highlight that river flows and water levels are lower than the long term monthly average and are falling quickly, with many rivers showing lower river flows in April 2020 than were observed in April 2018. More direct impacts are now starting to be seen: Irish Water have started announcing water conservation messages.
A simplistic and perhaps over-generalised description of our physical system can be described as follows. A cursory look at the river system indicates a dense, largely extensive, hierarchical network of watercourses. This extensive network is an expression of our geology, topography and climate, and our own efforts to control it. The combination of these factors and the relatively frequent Atlantic westerlies keep this system wet and flowing, promoting run off. Our water system might be described as ‘flashy’ for a number of reasons – presence of poorly draining soils and subsoils, large areas of low transmissivity, poorly productive bedrock aquifers, and the low storativity of our major aquifers. This is reflected in the flow indices of the watercourses and in water level variations in our monitoring wells; usually quick to rise and quick to drop. There are some exceptions, such as the areas underlain by sand and gravel. The somewhat simplistic nature of this description does not draw out the regional differences nor do justice to the significant science databank and wealth of knowledge that exists in this country. However, the broad point is that we have a natural surface water and groundwater system that is inherently generally poor at storing the rainfall that sweeps across the country. Not only do we rely on the volume of rainfall, but we rely heavily on frequent events to keep that ‘flashy’ system topped up. This has significant implications for all water users whether they are humans, plants or animals. Balancing the various competing needs is complicated.
There are many people representing various entities that are working on, investigating, and studying the natural system here in Ireland and how that is changing with climate change. These endeavours should lead to an improved holistic, optimal and sustainable approach to looking after our waters and working towards sustainable supply for those users.
At TOBIN, and with our partners and clients, our team of geologists, hydro(geo)logists and ecologists are working on national based projects to advance the understanding of the countries water resources to inform decision making. These include projects on climate change, groundwater resource assessments, and protection measures around sensitive receptors.