Subsurface drainage design and management practices in irrigated areas of Australia

The final report of a project to investigate best management practices for sub-surface drainage design and management summarises and compares current practices across Australia. The report includes details of practices in eleven irrigation regions around Australia: Burdekin River Irrigation Area Qld, Emerald Irrigation Area Qld, Kerang Irrigation Area Vic, Macalister Irrigation Area Vic, Mid Murray Irrigation Area NSW, Murrumbidgee/Coleambally Irrigation Areas NSW, Ord Irrigation Area WA, Riverland Region SA, Shepparton Irrigation Area Vic, South West Irrigation Area WA, and Sunraysia Irrigation Area Vic. The results demonstrate that saline drainage water disposal is a key issue across all regions and may severely restrict future implementation of subsurface drainage in irrigated agriculture. This may be the greatest constraint to the sustainability of many irrigated areas. New drainage design criteria that provide adequate protection for crops while minimising drain water salinity and volume are required. The results of the investigations will culminate in the development of a best practice manual for subsurface drainage in irrigated areas.