Stability of water supplies is critical to programs of development. Emphasis in water resource management in dryland regions generally is placed on developing or conserving water supplies. The usefulness of water supplies to people also depends largely upon their physical, chemical, and biological characteristics. It is important, therefore, that both quantity and quality be considered in the management of water resources. Developing Water Supplies Numerous methods have been used in developing water supplies in the dryland regions of the world.
Water harvesting is one example of note.
Water harvesting systems were used by people in the Negev Desert over 4,000 years ago, with applications of this technology continuing to the present. Not all of the systems have been successful, although some form of water harvesting has been necessary to sustain livestock and agricultural crop production and forestry, in many instances. Water harvesting methods involve the collection and, in many instances, storage of rainfall until the water can be used beneficially. A storage facility for collected water, unless the water is to be utilized immediately, in which case a water spreading system is necessary. A distribution system when the stored water is to be used later for irrigation purposes.