Cover Photo: Oil Barrel with Blue Water Drop (Oil Barrel Icon made by Freepik, edited by me)
I am currently studying to get a Master's degree and I am taking a course on sustainability at the moment. Every week the professor assigns us readings to do and gives us a question to write a personal response about after the readings. I will be posting these after they are handed back to us to make sure everybody in the class has handed them in. This week, we read:
- Water: Is There a Global Crisis? by Eric H. Oelkers, Janet G. Hering and Chen Zhu (doi: 10.2113/gselements.7.3.157, free)
- Sustaining Freshwater and Its Dependents by S. Postel in Is Sustainability Still Possible? (book only)
- Urban growth, climate change, and freshwater availability by R. I. McDonald, P. Green, D. Balk, B.M. Fekete, C. Revenga, M. Todd, and M. Montgomery (PNAS, free)
- A changing framework for urban water systems by J.G. Hering, T.D. Waite, R.G. Luthy, J.E. Drewes, and D.L. Sedlak (DOI: 10.1021/es4007096, free)
- The Value of Green Infrastructure (Center for Neighborhood Technology, free)
- Reducing nitrogen loading to the Gulf of Mexico from the Mississippi River Basin: Strategies to counter a persistent ecological problem by W.J. Mitsch, J.W. Day, J.W. Gilliam, P.M. Groffman, D.L Hey, G.W. Randall, and N. Wang (DOI: 10.1641/0006-3568, free)
As populations grow across the Earth and the water stress in many regions gets much higher, governments and corporations will have to start treating water as a valuable commodity much like the market sees oil today. For a long time, the growing effects of climate change and water stress were relegated to low-income countries, but events like the drought in California show how the cumulative effects of terrible water management will affect developed nations as well. Realistically though, residential consumer behavior is a relatively small percentage of the water demand and addressing agriculture water use is far more important.
In Water: Is There a Global Crisis?, the authors talk about how dangerous agricultural systems can be to global water reserves. While they correctly point out that the water cycle means it is a renewable resource, they also discuss the danger of consuming water. Often times, farmers "consume" water for agricultural use because they do not employ any methods to recapture it. The fertilizers also contaminate the water which means it no longer supports the ecosystems that it drains into. While 80 percent of the water for agriculture comes from rainfall, there are many places that have to use boreholes or have to transport it from elsewhere to sustain farming.
The biggest issue with water transportation is that it is not even remotely economically feasible in most situations in the current market. This is particularly true for industries with small profits like agriculture. Almost all of Gauteng in South Africa, which includes Johannesburg and Pretoria, purchases its water from Lesotho. This is primarily for human consumption and manufacturing industries since surrounding agriculture relies on the rainfall of about 700 mm. Ideally, proper water treatment systems would mean transportation of water would not be necessary except for the most arid of cities. Furthermore, anything but a pipeline would be tremendously energy intensive and even using a pipeline would require a lot of energy without height differences like between Lesotho and Gauteng.
To me, the most important lesson is once again in Is Sustainability Still Possible?. Farmers in Andhra Pradesh carefully monitor rainfall to ensure that the natural aquifer levels do not deplete. While the implementation is difficult, the project is voluntary which means it would not have such a large implementation if they did not also increase profits over the long run. Thinking back to Jared Diamond's stories of the farmers in Montana who make money doing other jobs and farm because it is their passion, developing water budgets and techniques to manage water usage and environmental damage could be life-changing. If the capital expenditure is worth it in an emerging economy and result in almost double the output, then it can certainly help the struggling American farming industry and reduce its dependency on subsidies.
Water is undergoing a transition that oil went through many years ago. When first discovered, entrepreneurs and designers could not even begin to image that oil would eventually run out or be too harmful to the environment to use. It was not important to minimize oil usage in industrial processes. Even with the relatively cheap oil of the last couple years, engineers work hard with large-scale optimization problems to minimize oil usage. These techniques have yet to really reach the water sector because water seemed like an infinitely available resource, much like oil used to seem. The advantage is that as a society we cannot, and do not need to, eliminate our dependence on water. Once large scale industrial farming companies really start to feel the pressure and hire industrial engineers to run the same large-scale optimization problems for them, but with water.
While agriculture plays the most important role in water management, building green infrastructure that helps recycle water and recharges groundwater is also important for ecosystem preservation and overall urban sustainability. Value of Green Infrastructure provides a quick glance at how urban engineering can assist the water cycle. Green roofs can help a lot with storm surges, but they are very difficult to implement in practice. Adding about 30 lb/ft2 to the design load is very difficult to do when comparing it to the 3 lb/ft2 of a typical photovoltaic array which is often built into the design anyway. It might still fit some situations, but developments like pervious concrete are more important since they allow a minimum of 80 percent of water to infiltrate. These technologies will be very important moving forward, and also display how society will have to be more intelligent about building infrastructure around water management, similar to how it has already built infrastructure for oil.