Aerial image of the Ulster Blackwater, an EREP study catchment.

Environmental Drainage Maintenance Research Programme | EDMRP

The Environmental Drainage Maintenance Research Programme (EDMRP) will build on existing good practice developed between IFI and the Office of Public Works (OPW) over many years, previously under the Environmental Drainage Maintenance (EDM) programme, which was further developed into the Environmental River Enhancement Programme (EREP). These programmes have provided an avenue for environmental research by IFI in OPW maintained catchments, establishing baseline datasets where they are absent, or building on existing datasets through repeat surveying and monitoring, which in turn feeds into OPW’s environmental decision-making with regard to Arterial Drainage Maintenance activities.

Measuring river flow using acoustic Doppler current profiling (ADCP) on the River Liffey.

Historical drainage and flood relief works

Natural channels contain a variety of physical habitats, all interacting together to create ecological diversity. In the 1940s, extensive arterial drainage works were undertaken by the OPW to reduce flooding and improve land drainage. These works were carried out on whole river catchments and involved substantial physical changes to the channels.

Surveying the Stonyford River.

Destruction of natural processes

The deepening, widening and straightening of river channels completely altered their natural beds and flow patterns and destroyed important habitats. Though positive for land drainage, these changes dramatically impacted the ecology of our rivers, leaving many with unnaturally high, steep banks and cut off from their natural floodplains.

Preparing for boat electrofishing.

High maintenance and further impact

Expensive, on-going channel maintenance is required by law to retain the flood-management and land-drainage gains of the original drainage works. Maintenance involves removing obstructions within the channel, such as fine sediment deposits, vegetation and fallen trees, with the maintenance process itself posing an additional risk to the river.

Stonyford 2020 after restoration works.

Guiding practice & more sustainable solutions

In 1990, the OPW began the EDM programme with IFI to examine the effects of on-going channel maintenance and cleaning. We wanted to see if maintenance could be done in a way that was less damaging and even provide environmental benefits to the channel. This programme carried out scientific studies and identified practical ideas that could be included into everyday work by OPW’s channel maintenance crews. A guidance plan for environmental maintenance procedures was produced, with training provided to OPW staff. Some of these measures are now standard practice in their operations.

In 2008, the EDM was replaced by a new project, the EREP. This work built on the previous programme and implemented more substantial instream and bank-side works to improve the river habitats. Annual audits were undertaken of OPW machine crews to assess their progress, which now form part of the OPW’s standard procedures. In addition, a series of scientific studies were undertaken, covering a range of species and topics in drained river channels. These varied from catchment-wide studies on fish, habitat and barriers; long-term monitoring programme at locations where drainage works have taken place; and opportunistic investigations to explore other new avenues, such as gravel-trap removal, reconnection of cut-off channels and issues with fish passage.

Infographic of the EREP project 2012 to 2022

Current programme

The current Environmental Drainage Maintenance Research Programme (2023-2027) is developing on the datasets built in the EREP. This includes continuing to expand the network of catchments surveyed for baseline metrics across the three OPW regions. Other work packages cover a variety of areas, including barrier mitigation, instream temperature studies and training. Development of tools or methodologies for incorporating a more holistic approach to arterial drainage maintenance to achieve biodiversity goals is a key element of this programme. This new angle for the programme has been informed by targets set out in Ireland’s National Biodiversity Action Plan, as well as the OPW’s own Biodiversity Action Strategy.

Measuring a salmon parr.