New guidelines on the operation of hydroelectric schemes may mean "retrospective" inspection and amendments to existing schemes, as well as stricter conditions for all future small schemes.
The draft guidelines are in a discussion document drawn up by the South Western Regional Fisheries Board with consultation with other boards and are now being considered by the Central Fisheries Board.
Evaluations of existing small hydroelectric schemes in Northern Ireland and elsewhere have identified shortcomings in fish passes and weirs for smolts and for adult salmon and a similar survey should now be undertaken in the Republic, the report recommends.
Modifications to benefit migrating fish and river channels would require around 5 per cent of the original capital costs, and developers of future schemes should make this kind of allowance, according to the recommendations.
The numbers of applications for hydroelectric schemes has increased in recent years. Many of the proposed hydro-schemes have been successfully over-turned by anglers and have also led to conflict with canoeists.
The consultation document "written from a fishery's perspective" highlights concerns with regard to small schemes particularly. The term "small" can be misleading, the guidelines warn. Smaller schemes have no water storage and the volume of water diverted from the main channel may be high, even during dry spells.
It highlights shortcomings in the current legislation relating to fish passes. There is no legislation governing water abstraction or requirement to assess the performance of screens.