The research aims to reach for integrated management economies of small water desalination plants, to achieve sustainable development in the desert lands, by studying how to apply integrated management methods of high-salinity wells desalination plants, also estimate the cost of desalinated water unit produced from reverse osmosis desalination plants powered by solar energy by changing of independent variables that effect on cost finally, a financial analysis of the model of the integrated management project of a desalination plant powered by renewable energy in Al Shalatin area has been done, The main results were as follows:
(1): Increasing the salinity of water from (ppm 2000) to (ppm 48000) led to an increase in the cost of water unit production from $ 0.839 - $ 1.242 / m ³.
(2): Increasing water temperature from (15( to (37) reduced the cost from $ 1.117-1.034 / m3.
(3): Increased salinity concentration in water produced from 50 to 1000 ppm resulted in a lower cost of 1.0935 - 1.0810 $ / m3.
(4): Increasing the production capacity of the desalination plant from 10 m3 / day to 150 m3 / day led to a decrease in desalination cost of cubic meter of desalinated water from 1.551 to 1.033 $.
(5): The financial profitability of the project shows that the payback period was (four years and five months), (NPV) was (46657.21 $), the proportion of (CBA) (1.41), and (IRR) was 22.45%, which indicates the profitability of investment in such projects.