A sustainable environment requires sustainable water—a review of some water issues to learn from

Water sustainability has become one of the most severe issues in the 21st century due to urban population growth and climate change. This paper reviews some of the critical key water issues that need to be considered in the quest for water sustainability for the upcoming decades. The purpose is to recognize the critical circumstances for maintaining water sustainability and send warning signals for regions that have passed the “tipping point” of balancing their water sustainability, while failing to realize restoring sustainability will be extremely difficult. Examples are used to demonstrate situations which, in hindsight, have been initially shown to be effective but highly problematic in the long term. This review considers, amongst others, the example of 1960s India, which shows that an agricultural “success” that started in the 1960s has subsequently become an environmental disaster. Additional issues, including the impacts of dietary adjustments, upstream diversions raising downstream shortfalls, and water transfers from agriculture to urban areas, are used as examples. They demonstrate that lessons must be learned from the past to achieve water sustainability, and adaptive measures must be adopted to help humanity avoid irreversible environmental tragedies. This paper highlights the urgent need for policymakers and stakeholders to proactively promote better water resource management strategies, domestic/international collaborations, and strict water use practice regulations, all of which will contribute to water sustainability and management plans.