How hedges protect water quality

Hedges help protect water quality by acting as barriers to overland flow of water which can contain nutrients and sediment that we don’t want to end up in watercourses. A hedged landscape helps regulate water flow and is good for water quality. Catherine Keena Teagasc & Cathal Somers ASSAP*

*Agricultural Sustainability Support and Advisory Programme

Farmers spend money and effort building up soil fertility to grow grass and crops so it’s a waste to loose these valuable nutrients to watercourses. Currently, water quality in about half of our rivers needs some improvement to meet the required good status. Phosphorus and sediment loss to water need to be tackled to solve this problem. When soil is saturated and rain can’t soak in, these are washed off land through overland flow into open drains and rivers, causing major issues for water quality. 

A well placed hedge acts as a barrier slowing the flow of water over land, reducing the force of overland flow.  It filters sediment and mops up nutrients as it intercepts the flow. Stock-proof hedges along watercourses prevent livestock access, avoiding animal waste and pathogens such as E. coli being deposited in rivers. Hedges along watercourses can stabilise banks, reducing erosion. Some shading of rivers benefits fish and other biodiversity by lowering water temperatures.

Many farms have areas that are more prone to nutrient and sediment losses through overland flow. Targeting these critical source areas or pathways on the farm areas with a well-placed hedge can break the pathway to the watercourse and improve water quality on farms.

In summary, a well-placed hedge can help improve water quality by reducing sediment and nutrient loss; slow down overland flow; prevent livestock and access to water; and reduce watercourse bank erosion.

Further information available in Farming for Water Quality here

Find out more about the value of hedges and Hedgerow Week here