Technical Abstract: There are increasing demands for limited fresh water for municipal and industrial use. In arid areas water use is already in excess of sustainable quantities. Irrigation as currently practiced with use of high quality waters is not likely to continue. In order to maintain agricultural productivity we need improved water use efficiency such as conversion to drip irrigation as well as alternative water supplies. Most regions have abundant quantities of low quality saline, drainage and sewage waters, most of which could be used for irrigation. This will require new strategies for water management as well as alternative crops or varieties. In many areas the overall water requirements can be met by a combination of rain, fresh water and saline water. In some instances periodic reclamation of the soil or continuous application of amendments will be necessary to control salinity sodicity and toxic element concentrations. These practices must be economically efficient and minimize degradation of waters receiving the subsequent drainage water. Computer models such as UNSATCHEM can be used as tools to analyze the performance of various management practices. Examples are given from a large scale field reclamation study using gypsum as an amendment, a field study with cyclic use of fresh and drainage water and boron leaching studies and model simulations of the impact of irrigation with high B waters.