30 Years of River Quality

Transcription

1 30 Years of River Quality A Retrospective and Prospective View EPA National Water Event Galway Bay Hotel June 2013 John Lucey

2 Presentation Outline Overview of past 30 years river quality Problems solved and those remaining Future challenges and possible solutions

3 Alien Species

4 Alien Species Are alien species a real problem in water quality? Or can the cure be worse than the disease? Glyphosate and Triclopyr being applied to control Gunnera on Achill and Dichlobenil - highly toxic to zooplankton and moderately toxic to fish - being used to control Lagarosiphon in Lough Corrib.

5 Siltation A study of suspended sediment (suspended solids) results (2010, 2011 and January-March 2012: n=960) for designated salmonid rivers in the south-east, which also support pearl mussels, showed a mean concentration of 9 mg/l (annual average guideline standard of 25 mg/l). The study concluded that, despite siltation being a problem at some sites, current nitrate levels in south-east Irish rivers would appear to be a more widespread risk for pearl-mussel survival. ies.html The EPA has commissioned, under the STRIVE programme, a large-scale project Measurement of silt flux in rivers and benefits of enhancement measures (SILTFLUX).

6 Acid Rain Acid rain has come and gone! Worldwide reductions of sulphur dioxide. In Ireland some waters were impacted in the past, e.g. Lugaduff River (Glendalough) and is now much reduced. Investigations began 30 years ago show little change in acid status of other waters. The global problem is now CO 2 rather than SO 2

7 Native Woodland Establishment Scheme Forest Service proposal to plant native trees within designated acid-sensitive areas will help greatly. Will return to topic of trees and rivers later in presentation.

8 Rivers 30 years Ago 40 years ago we joined the EU (then EEC). 30 years ago CAP had kicked in leading to an agricultural revolution. Fertiliser use increased in both pasture and tillage areas. Large increase in animal numbers led to slurry and silage waste reaching rivers - in rural areas - already polluted in towns.

9 River Quality 30 Years Ago In or below many towns were grossly or moderately polluted for a short stretch which dissipated with travel downstream as the river acted as a WTP breaking down the sewage.

10 Some Rivers 30 years Ago

11 Fish Kills Some Attitudes At a meeting on river quality with farmers in the 1980s an IFA local rep asked what is the difference between us killing a few fish and anglers doing the same? The only thing more expensive than education is ignorance Benjamin Franklin

12 Fish Kills A marked upsurge in fish kills had occurred in Irish rivers in the 1970s coinciding with the intensification of agriculture. In response to this situation, a nationwide public information campaign was launched and an enforcement strategy was put in place by the then Regional Fisheries Boards and Local Authorities. There were 127 fish kills in 1987 and only 10 in the lowest on record.

13 Fish Kills Sources: CFB, RFBs and IFI (Fiona Kelly)

14 Seriously Polluted River Sites

15 Trends in River Water Quality

16 High Status River Sites

17 Water Quality Management Plans There is nothing new in the concept of catchment management in Ireland. The first such Plan was published 30 years ago in 1983 for the Barrow catchment with others following. One of the main outcomes of the Plans was the commissioning of new WTPs. These would now need upgrading after 30-year lifespan.

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19 Integrated Catchment Management Is a process of decision making and action involving multiple interests aimed at integrating the different uses of land, water and related environmental resources. A planned pilot project with Kilkenny County Council on small River Nore sub-catchment (Nuenna).

20 Constructed Wetlands ICWs seen as the panacea for all our ills! Adequate for polishing - nutrient removal - but certainly not for treating municipal or agricultural waste. Unless they are lined the groundwater may be contaminated. If discharging to watercourse then should be licenced.

21 Constructed Wetlands

22 Riparian Buffer Zones Intercept sediments and nutrients. Reduce erosion/bank stabilization. Reduce flooding. Carbon sinks.

23 Riparian Buffer Zones Zone 1 functions mainly to shade the water source and act as a bank stabilizer. Should include large native tree species that grow fast. Zone 2 should be an important transition between grassland and wood. Should include native shrub species. Acts to slow and absorb contaminants missed in Zone 3. Zone 3 serves primarily to slow water runoff and begin to absorb contaminants before they reach the other zones. Should consist mostly of native grass species.

24 Riparian Buffer Zones Source:

25 Riparian Buffer Zones Teagasc study summary Study on farmers attitudes to riparian buffer zones: Buckley et al., Supply of an ecosystem service Farmers willingness to adopt riparian buffer zones in agricultural catchments. Environmental Science & Policy 24

26 Tree-lined River 1800s

27 Tree-lined River 1900s

28 Tree-lined River 1900s

29 Tree-lined River 2000s

30 Future Challenges and Possible Solutions To meet objectives of WFD Some progress but not enough - almost 30% of river channel remains polluted to some degree. To preserve at least the status quo ante with Food Harvest 2020 coming on stream Has Anaerobic Digestion a Role? Riparian Buffer Zones? Integrated Catchment Management? Nutrient Management Artificial Fertiliser Use.

31 River Quality - Overall Situation The problem in Ireland is largely low-level river pollution of enrichment with nutrients. Other EU MS would be quite happy to have this type of river-quality problem as a challenge. Rivers where anglers would expect trout and hope for salmon. Best Mayfly fishing recorded on Lough Sheelin in over forty years with more than 1,000 trout recorded. We have come a long way in the past 30 years and the prime task now should be to restore those enriched sites to at least good ecological quality while at least also preserving the existing high quality habitats.