Measurements of losses from on farm channels and drains (2001)
This CRC funded project had two main aims including to determine the magnitude of percolation losses attributable to on-farm channels and drains. The second major aim was to consider approaches and for need to identify problem were and to consider likely remediation techniques.
The project was undertaken within selected farms in Coleambally and Murrumbidgee Irrigation Areas in southern NSW during the irrigation seasons of 1997/98, 1998/99 and 1999/00. To undertake the points of infiltration the Idaho Seepage Meter was used as a result of being rapid, direct and cheap. The study investigation were undertaken on farm trials using EM31, Peizometer measurements, soil texture and salinity measurements, channel distribution on farm, channel seepage metres, inflow and out flow and depth of flow channel width. The conclusion of the project indicated that EM31 reading were strongly related to change in seepage rate. It was stated that area’s of low conductivity compared to surrounding areas inferred that the leakage rate was high. It was also stated soil types and water depth in the centre of channels or drains are the most important channel factors with respect to seepage in the on-farm channels and drains. It was indicated that seepage magnitude is affected considerably by the width of the channel. The EM31 measurements provide very good results for the identification and quantification of seepage. Additionally the combination of the Idaho seepage meter and EM31 measurement provided a good technique for the identification and quantification of seepage from sections of the on-farm channels and drains.