Performance Evaluation of the Tanoso Irrigation Scheme in the Brong -Ahafo Region of Ghana

The purpose of the study was to assess the performance of the Tanoso irrigation scheme in terms of distribution uniformity, coefficient of uniformity, water application rate/efficiency, infiltration rate and storage efficiency of the soil. The study was done in Tanoso irrigation scheme where data was obtained through primary and secondary sources between March and April, 2016. Primary data was obtained from interviews, field measurements and field tests while secondary data were obtained through literature review. The data obtained were analysed using efficiency equations and Microsoft Excel. The scheme had an average infiltration rate of 10.32mm/h and an average application rate of 10.13mm/h which indicated that, there is rapid drainage of water in the soil and deep percolation. The distribution uniformity values calculated for both lateral 1 and lateral 2 were 74.04% and 79.7% respectively which indicated that they were all performing according to recommended value of 70% or higher for rotor sprinkler irrigation system. The estimated coefficient of uniformity values for lateral 1 and lateral 2 were 68.08% and 81.8% respectively indicating that they were both performing below recommended value of 85% for vegetable crops and shallow rooted crops. The storage efficiency was calculated to be 40.10% and 55.8% for lateral 1 and lateral 2 respectively, this indicated that the maximum storage efficiency of 100% was not reached for both laterals and that the soil was not capable of holding enough water for crop utilization. Leakages from pipes, main lines, broken weir, dam gates blockage by weeds and malfunctioning riser were some of the problems which affected the efficient performance of the scheme.