“Stationarity—the idea that natural systems fluctuate within an unchanging envelope of variability—is a foundational concept that permeates training and practice in water resource engineering.”1 However, as Peter Milly has observed, stationarity with respect to water resources is dead, as volatility in climate, precipitation and temperatures are causing wider fluctuations in available water resources. Water managers must now consider how to deliver and maintain water resources in this new order.
With the demise of the notion of stationarity within our industry, our reality is one of uncertainty and unpredictability. As such, we must be more innovative in our approach to water management, look beyond the traditional infrastructure-based projects and implement solutions that can handle the instability.
We can probably safely say that humans have never lived without impacting their local environment. This is particularly true as it relates to water resources. Some of the first large scale engineering works were dedicated to finding and delivering water to sustain human activity. Water projects were central to the Egyptians, the Minoans, the Romans, the Mayan, the Hohokam as well as a myriad of other civilizations. The fact that water is not always where we need it, when we need is a driving force in the supply-side driven, engineering-based water management philosophies that continue to be utilized today.2
Consumption is taking place on a canvas of an increasingly volatile natural supply of water. While for the first time in 50 years, water withdrawals for United States public supply actually declined, worldwide water consumption continues to increase, particularly as it relates to domestic and industrial water use. Over the coming century, these withdrawals are expected to rival the consumptive use associated with agriculture:
“A large increase in domestic and industrial water use is…obvious in the global trends…. Domestic water consumption is projected to more than double from ~280 to ~600 cubic kilometers per year (km3/yr) by the end of this century, while the increase in industrial water consumption is expected to be slightly milder from ~300 to ~550 km3/yr. Future irrigation water consumption…shows a much lower increase from ~1,400 to ~1,600 (±~200) km3/yr over the same period.”3
With our ever-increasing ability to quantify the influence of climate volatility on water resources on both a global and human scale, we can see the impact of changing environmental conditions — and the news is not good. These conditions will result in significant water deficits for certain areas. The old real estate adage is true for water resources — location matters.