Since environmental impacts of desalination processes are intrinsically related to system efficiency, per water-unit produced loads have constantly decreased over the past decades. However, some significant fouls remain. The example of Spain is punctually used throughout this paper, to illustrate the main environmental impacts of the desalination technology. One major concern is the potential environmental impacts caused by extensive brine discharge; unavoidable desalination sub-product that may heavily affect marine biota. Recommendations are outlined to reduce environmental degradation related to hypersalinity. A further drawback is the production of greenhouse gases associated with the required power generation. Environmental loads of any process can be considerably reduced when integrated with renewable energy production systems. After these two 'direct' environmental impacts are addressed, some socially-induced factors leading to unsustainable water management are identified.