The existence of saline water in some parts of Esfahan province is an issue which has endangered agricultural sustainability. The lack of enough quality water and the existence of saline and alkaline soils annually cause us not to harrest anything on some parts of the lands we have cultivated and thus render our industrious efforts fruitless. This bitter fact can be felt in difference places of cultivated lands. There fore, if agricultural techniques and production efficiency of fields do not logically and appropriately improve, noncompliance between income and the costs of cops production agriculture on these lands. The conservation and survival guarantee of agriculture in saline regions thus entail, on a long term basis, basic investments in agriculture. In this direction, the project of mixing soft and saline waters, especially in saline regions which enjoy the favor of rivers soft water, such as Esfahan, can support agricultural authorities as the most effective strategy. Based on this, in the present study conducted on the farms sampled from saline lands east of Esfahan city, the project of mixing wells water with canals water to supply suitable quality water and its application in sprinkler irrigation using the cost - benefit theory & the budgeting method and considering functional treatments and facilities interest rates were economically tested and assessed. Relevant results showed that in all functional treatments under study, the performance of the above mentioned project enjoys the required economic justification and that the project benefit-cost ratio with an 8% interest-rate loan will be followed by an investment yield return of up to 200%.