Water management in the 21st century

An interesting post from JuraForum reacts to a recent article in Science about water management. Some of the foundations of the way we manage our water supply may be problematic because we can no longer assume that precipitation and stream flow are stable: ... anthropogenic change of Earth's climate is altering the means and extremes of these factors so that this paradigm of stationarity no longer applies, researchers report in the latest issue of "Science". The headline of the article by Christopher Milly, US Geological Survey (USGS), and others reads "Stationarity is dead: Whither Water Management?".

Water professionals around the world have always had to balance water supply and demand and to minimize risks to life and property without knowing what future events nature has in store. Historically, looking back at past observations has been a good way to estimate future conditions. "But climate change magnifies the possibility that the future will bring droughts or floods never seen in old measurements," says Christopher Milly.

...As the authors point out in their article, warming augments atmospheric humidity and water transport. This increases precipitation, and possibly flood risk, where prevailing atmospheric water-vapor fluxes converge. Glacial meltwater temporarily enhances water availability, but glacier and snow-pack losses diminish natural storage of freshwater. In coastal regions the supplies are endangered by rising sea levels. The risk of contamination with seawater is heightened, the authors state.

... A rapid exchange of climate-change information between the scientific realm and water managers will be critical, the authors state. New, higher-resolution models could then represent surface- and ground-water processes more explicitly. These models need to include water infrastructure, and water users, including the agricultural and energy sectors. Modeling should be used to synthesize observations, but it can never replace them, the authors write and suggest to update the analytical strategies used for planning under conditions of non-stationarity. "The assumption that the past is the key to the future has lost much of its value for water management," says [co-author] Kundzewicz.

Photo of Luxapalila Creek in Columbus, Mississipi by Adrien Lamarre, the U.S. Army Corps of Engineers (Wikimedia Commons)