Evaluating a multi-level subsurface drainage system for improved drainage water quality

• Published in: Agricultural water management 2007-05, Vol.89 (3), p.208-216
• Main Authors: Hornbuckle, J.W., Christen, E.W., Faulkner, R.D.
• Format: Article
• Language: English
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agronomy. Soil science and plant productions; Australia; Biological and medical sciences; depth; drain depth; Drainage; drainage water; Environmental impacts; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; groundwater; Irrigation; Irrigation. Drainage; Multi-level drainage; Saline ground water; saline water; Salinity; semiarid soils; semiarid zones; soil salinity; soil water regimes; subsurface drainage; water quality; water table
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2007.01.004

This paper describes a multi-level drainage system, designed to improve drainage water quality. Results are presented from a field scale land reclamation experiment implemented in the Murrumbidgee Irrigation Area of New South Wales, Australia. A traditional single level drainage system and a multi-level drainage system were compared in the experiment in an irrigated field setting. The single level drainage system consisted of 1.8 m deep drains at 20 m spacing. This configuration is typical of subsurface drainage system design used in the area. The multi-level drainage system consisted of shallow closely spaced drains (3.3 m spacing at 0.75 m depth) underlain by deeper widely spaced drains (20 m spacing at 1.8 m depth). Data on drainage flows and salinity, water table regime and soil salinity were collected over a 2-year period. Comparisons of water and solute movement between the multi-level drainage system and a single level drainage system are presented. Differences in the performance of the multi-level and single level drainage systems were found in the water table regime, drain water salinity and soil salinity.