48% of European Rivers are exposed to Hydromorphological pressures – Source: EC Environment.
Hydromorphology considers the physical character and water content of water bodies. Good hydromorphological conditions support aquatic ecosystems (i.e. hydromorphological elements such as water flow and substrate provide physical habitat for biota such as fish, invertebrates and aquatic macrophytes).
While hydromorphological impacts are not as severe compared to other European countries, it is an area that requires more attention in Ireland.
Significant pressures have been identified for waterbodies that are at risk of not meeting their water quality objectives under the EU Water Framework Directive. While there are a multitude of pressures in every waterbody, the significant pressures are those pressures which need to be addressed in order to improve water quality. Many of our waterbodies have multiple significant pressures. Impacts from hydromorphology include sediment/siltation pollution and alteration to the physical environment.
- impoundment (i.e. dams and weirs)
- land drainage
- bank erosion
Hydromorphological risk assessment approach for rivers, lakes, transitional and coastal water bodies
- Preliminary Risk Screening: incorporating information on water bodies with known hydromorphological issues based on expert opinion, along with evaluating national monitoring data in order to identify any indications of other pressures other than eutrophication. This will help identify water quality issues that need to be addressed first; it is vital to tackle water quality pressures prior to implementing hydromorphological measures. These water bodies, along with water bodies with known impacts caused by hydromorphological pressures, will be given high priority for the next stage.
- Initial Hydromorphological Characterisation: this will involve a GIS based desktop assessment to identify the screened water bodies that may be impacted by various hydromorphological pressures.
- Further hydromorphological characterisation: this can include actions such as field assessments to finally assign a risk category to the water body. This will allow the identification of appropriate mitigation and rehabilitation measures. Screening water bodies throughout the process will allow for a streamlined focused approach.