Net annual costs for disposal by pumping to the Murray River, an on-farm evaporation basin, conjunctive use with surface water to irrigate dairy pasture, and undiluted irrigation of a salt tolerant grass were estimated and compared. Total conjunctive use (TCU) is the cheapest option below 10dS/m groundwater salinity. TCU becomes more expensive than river disposal above 10 dS/m and than total evaporation above 15 dS/m. Above 10 dS/m, partial conjunctive use with disposal of some groundwater by irrigating salt tolerant forage is similar in cost to river disposal and less expensive than total on-farm evaporation. Farm and regional perspectives for optimising sustainable salt management are discussed.