Drainage: choosing your aggregates

In Ireland, there is a broad range of materials available for use in land drainage systems. These materials, predominantly gravels, can vary widely in type and grade, due to local rock types. The performance and working life of land drainage systems depend on the quality and suitability of the materials used in drains well maintained. Cost and practicality usually drive the choice of material used. The relative costs of stone aggregate can direct the farmer towards unsuitable materials in some cases. While some of these are adequate, many more are unsuitable and as a result there are large variations in the performance of drainage systems. Currently there is little guidance on the availability and cost of these materials from around the country. A survey conducted in January 2019 aimed to assess this variability in cost and availability of suitable represented within the survey, in which 93 quarries were assessed for the availability of materials and their related costs.