Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student Daniel Gilroy makes this connection here…

In the New York Times on May 1, 2013, the article ‘Safe Storage of Water? Go Underground’ was published. This article pertains to elements of hydrology within the field of water resources engineering, focusing primarily on the issues of occurrence, distribution, and magnitude of water in aquifer water storage. In summary, the article brings up some basic facts supportive of the implementation and use of underground reservoirs for water storage. By underground reservoirs, the article is referring to a specific type of underground water storage known as Aquifer Storage & Recovery (ASR). This is a system in which treated water is injected in to a confined aquifer for storage (during periods of ample surface water or low use) and recovered at a later time by pumping it back out (during times of greater demand or water shortage). Such systems have been proven effective in areas of Europe, and have potential as water storage systems in arid landscapes. Countries like Abu Dhabi and areas of the US, like El Paso, are experimenting and implementing these systems due to the nature of increased water security associated with this system. In places like these, more water from above ground reservoirs can evaporate than can be consumed. Underground storage eliminates this problem. Based on my engineering education, the facts presented in this Times article about ASR systems appear to be accurate. According to Wurbs and James, surface water evaporation rates are constantly in flux, and typical evaporation in a given year can exceed the volume of water withdrawn for municipal, industrial, and agricultural uses. To put this in perspective, according to Thakur Falguni, around 40% of water is evaporated from storage reservoirs in India. The Sardar Sarovar Dam has a volume of 9.5 bill m3. Of this, potentially 3.8 bill m3 of water is lost to evaporation. With increased use of underground storage, this water loss can be dramatically cut down. According to studies in Texas, the capture and storage of water when it is available is critical to sustainable water management; this can be achieved through a proven cost effective mean of ASR storage (Assesment of ASR in Texas, 2011). According to this report, the storage of 9mil acre-feet per year is going to be required by the year 2060. Traditional reservoir storage will not fulfill the need for various reasons such as cost and availability of land. The use of Aquifer Storage & Recovery systems could help increase resource security in areas of the world where availability of water is limited.

Our world today is touched in many ways by water resources engineering. On a broader scale, I believe that the issue of mass water storage brought up in the article effects society in the greatest way. The societal context is composed of various elements which are interwoven and affect each other in some way or another. These elements include economy, environment, development, and population structure. According to the article, a main reason for such a push for this Aquifer Storage and Recovery system is the increase in water security. With the increase demand for water throughout regions of the world, and the spatial and legal issues associated with surface reservoirs, the move underground seems to be a logical and effective mean of water storage. According to the Texas Water Development Board, due to environmental challenges associated with the surface water reservoirs the options of ASR have been analyzed. Through research presented in the study, ASR has proven to be an efficient and cost-effective method of storing water when it is available. Through this method of pumping treated water into confined aquifer, not only is clean water stored but an additional benefit of increasing groundwater quality is achieved. Through the system of Aquifer Storage & Recovery, society can be affected for the better with increased in availability of clean water for various consumptive uses. Ground water quality can be increased with the introduction of treated water. More land surface can ultimately be available if above ground reservoirs are not implemented.

cross-section of ARS system

cross-section of ARS system

References:

Texas Water Development Board, (2011). An assessment of aquifer storage and recovery in texas (0904830940). Retrieved from Malcolm Pirnie, Inc website: https://www.twdb.state.tx.us/innovativewater/asr/projects/pirnie/doc/2011_03_asr_final_rpt.pdf

Thakur, F. (2013). Reservoir evaporation forecasting. a case study on sardar sarovar dam. Indian journal of Research, 2(4), Retrieved from http://theglobaljournals.com/paripex/file.php?val=MTA3Mg==

Wurbs, R.A., James, W.P. Water Resources Engineering. Prentice Hall, Upper Saddle River, NJ, 2002.

Ziegler, A. U.S Department of the Interior, U.S. Geological Survey. (n.d.). Equus beds groundwater recharge project. Retrieved from website: http://ks.water.usgs.gov/equus-beds-recharge

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