Technical note Cost-estimating procedures for drip-, micro- and furrow-irrigation systems

The total annual fixed and operating costs of a drip-, micro- and furrow-irrigation system were estimated, as well as the marginal factor cost of water applied. An existing centre-pivot irrigation cost-estimating procedure was used. The type of irrigation system data needed are specified. The assumptions about the salvage value and expected lifespan of the system components are given. The total investment cost of the drip-, micro- and furrow-irrigation system is R200 000, R277 586 and R132 012 respectively. The total annual fixed and operating costs of the drip-, micro- and furrow-irrigation system are R28 509, R39 817 and R17 763 (fixed) and R36 957, R38 980 and R106 375 (operating) respectively. The marginal factor cost of water applied for the drip-, micro- and furrow-irrigation systems is R2.00/mm·ha, R1.90/mm·ha and R2.20/mm·ha. The proper estimation of irrigation costs is critical for irrigators to be able to evaluate efficient water use techniques. Water SA Vol.31 (3) 2005: pp.403-40