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Water resource engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student, Christine Smith, makes this connection here….

Kenya’s Giant Aquifer Highlights Groundwater’s Critical Role was an article that was published by National Geographic on October 2, 2013. This article focuses on the WRE issue of the supply of water specifically aquifers and how to find, access them, and the rate at which the water found there can be extracted. Recently there was a relatively large aquifer found in the Turkana region of Kenya which is an extremely arid region where most of the people are forced to lead nomadic lives, following sources of water, just to survive. You can imagine the tremendous impact locating an aquifer of roughly 250 billion cubic meters or 66 trillion gallons of water would have on this region. Nicholas Kulish from The New York Times wrote “malnutrition has been a growing problem among the Turkanan people, and a new supply of water could help head off conflicts”. Naturally people want to start tapping into the aquifer as soon as possible, but as they do so the sustainability of their actions needs to be considered. The issue of sustainability and consequential environmental impacts is a major concern for any aquifer, not only the one found in Kenya. The issue arises from the fact that in a large number of the known aquifers around the world are depleted of their water supply at a faster rate than it was able to be recharged. Walton addresses this sustainability dilemma in his article stating that “The rapid and largely uncontrolled expansion in groundwater exploitation generated major social and economic benefits, but more recently it is also encountering significant problems.” (Walton, 1964). Sustainability of our actions need to be more heavily considered specifically when it comes to aquifer use.

As the demand for water continues to rapidly increase so does the need for new sources of the needed water. This leads to the search for aquifers as one of the methods to try to meet the demand. To find these aquifers people are developing new methods and searching deeper within the earth. However the deeper an aquifer is located generally the longer the recharge time is. The general recharge rates of the world are found in Figure 1. One of the causes of this unsustainability is the fact that the technology has not be developed to accurately find the actual quantity of water is located in the aquifer. My personal opinion is that this is an important aspect and before we simply dip into our aquifer water supplies we need to ensure that we are giving the ground an adequate amount of time to recover and recharge or there will be consequence. This article failed to go into enough detail on what the impacts are environmentally, economically, etc. if we over exert the aquifer’s water supply.

Aquifer recharge rates for the planet

Aquifer recharge rates for the planet

This article and the issue of sustainable aquifers relates to the global issue of water demand and consumption. It effects where and how we meet the growing demand and the consequences that could result if not done suitably. Foster and Chilton write in their article Groundwater: The Processes and Global Significance of Aquifer Degradation that “in some cases current abstraction rate are not physically sustainable in the longer term, and in numerous others there have been varying degrees of aquifer degradation or environmental impact or both” (Foster and Chilton, 2003). This supports the fact that this extraction, when unsustainable, can be damaging to the environment. It is an economics issues as well since the demand of water is increasing which means a greater amount of money will be allocated to finding and treating water.

Work Cited

Basu Tanya. Kenya’s Giant Aquifer Highlights Groundwater’s Critical Role. National Geographic Web site. October 02,2013. Available at: http://news.nationalgeographic.com/news/2013/10/131002-kenya-aquifer-lotikipi-groundwater/. Accessed March 29,2014

Foster S.S.D. and Chilton P.J. Groundwater: the processes and global significance of aquifer degradation. November 05, 2003. Available at: http://www.jstor.org.esf.idm.oclc.org/stable/pdfplus/3558314.pdf?acceptTC=true&jpdConfirm=true. Accessed March 30,2014

Walton William C. Potential Yield of Aquifers and Ground Water Pumpage. February 1964. Available at: http://www.jstor.org.esf.idm.oclc.org/stable/pdfplus/41264136.pdf?acceptTC=true&jpdConfirm=true. Accessed March 30, 2014

 

The Central New York Chapter of the Air & Waste Management Association is pleased to announce that Jordan Gray-DeKraai has been selected to receive a $1,000 scholarship. These competitive scholarships are open to students residing in or attending college in central New York and enrolled in an environmentally-related field of study. Jordan is currently a junior at SUNY ESF, majoring in Environmental Resources Engineering. Jordan’s application documented an impressive range of academic honors and awards, extracurricular activities and community service. Recommendations provided by two of Jordan’s professors attest to her diligence, motivation and eagerness to take on leadership roles and apply the knowledge and skills she has gained. CNY AWMA has also been very lucky to get a chance to know Jordan through her participation as a student liaison with our organization.

AWMA

Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student Kayla Hanczyk makes this connection with the drought crisis that is currently happening in California.

The WRE news article, “Epic California Drought and Groundwater: Where Do We Go From Here? “ from National Geographic on February 4, 2014 reported in the hydrology domain. The issue that was being reported in was the diminishing groundwater in California. In summary this news article discussed how The UC Center for Hydrologic Modeling recently released a report on the California drought. This recent report describes the NASA GRACE satellite mission and how it is able to see the amount of groundwater that is available within the area. It also discusses ways to try and solve this problem. This is a very accurate source as Biology News Net and The New York Times report the same very detailed information about the GRACE mission.

The UC Center for Hydrologic Modeling has been working on this type of research for over 2 decades and the GRACE satellite mission was launched in 2002. The goal of this mission is to quantify the global freshwater availability and to monitor he rate at which it is decreasing. In doing this they hope to be able to restrict use and restore the groundwater levels to a sustainable amount. So far this mission has been very successful, the satellite is able to see how the water supply is changing each month, but not only groundwater is being monitored. The snow, surface water, soil moisture, and groundwater make up seemingly the total water storage and are all able to be monitored by GRACE. It is seen that all of these values are decreasing at a very rapid rate, and with fresh groundwater being a finite resource something needs to be done and fast. One specific event that happened was the major drought between 2006 and 2010. During this time of little to no rain the agricultural business was in great danger. In order for the crops to grow farmers had to majorly tap into groundwater reservoirs resulting in a ground water depletion so great that it was registered at satellite “scale” that orbits about 400km above the Earth’s surface. The big question we now are asking is what we are going to do in attempt to solve this problem.

Figure 1

Figure 1

Reference:

Famiglietti, Jay. Epic California Drought and Groundwater: Where Do We Go From Here?. February 4, 2014. Available at: http://newswatch.nationalgeographic.com/2014/02/04/epic-california-drought-and-groundwater-where-do-we-go-from-here/. Accessed on 13February 2014.

Satellites show “total” California water storage at neardecadelow. brazilc@uci.edu. Biology News Net. February 3, 2014. Avalible at: http://www.biologynews.net/archives/2014/02/03/satellites_show_total_california_water_storage_at_neardecade_low.html. Accessed February 14, 2014

Devenport,Coral. Obama to Announce Aid for Drought-Racked California. The New York Times. February 14,2014.

 

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

The news article, “Grabbing Water From Future Generations: Many of the world’s aquifers are being pumped dry to support unsustainable agriculture” was reported by National Geographic Daily News on December 19, 2012 in an online post. The article relates to the hydrology domain of WRE and specifically speaks about the magnitude that natural aquifers are being drained. Aquifers around the globe are being drained off at a rate that is much higher than that of the natural recharge rate. Specifically in India, which is the main focus of the article, 46 cubic miles (190 cubic kilometers) of water is being drained from underground. The natural recharging rate is estimated to be 29 cubic miles (120 cubic kilometers) a year. Just to put it into perspective, a cubic kilometer is enough water to fill 400,000 Olympic-size swimming pools. This overdrawing is said to be causing water tables to drop 100 feet in the US in places like Texas, Oklahoma, and Kansas. It is estimated that water tables are dropping by as much as a meter per year in the North China Plain. The article goes on to say that farming is a largest instigator for this over pumping and falling water tables because of wasteful watering techniques.

The amounts presented in this article are startling and it caused questions as to whether or not the dated presented was accurate. After a short search, data from a 2000 USGS publication found that the water table had declined more than 200 feet in states like Arizona.

I found that this article was did not include enough solutions to the over-pumping problem. It stated a solution that would lead to further unsustainable agriculture.

This WRE issue further impacts economics and the environment. Economics is impacted, specifically in India, because land owners are using water sources found on their land to live lives of luxury. Although slowing down or halting pumping would be beneficial, it would put individuals income on hold. This pumping is also going directly to agriculture, which impacts the Indian economics because they export rice, as mentioned in the article.

The environment is directly affected because, like the title says, water is being taken away from future generations. The environment would also be directly affected if readers listened to some of the author’s suggestions to use scientifically modified crops that use less water in order to fix the agriculture problem. Genetically Modified Organisms (GMOs) are currently in question within the scientifically community, so offer them as a solution is questioning the author’s true purpose for this article.

A paper from 2001 speaks about the economic value of groundwater through examples from New Zealand. The paper goes on to talk about groundwater management in terms of safe yields for New Zealand.

Figure 1:  Pumping Trunk delivering water taken from an aquifer in India

Figure 1: Pumping Trunk delivering water taken from an aquifer in India

Figure 2:  Ground Water Decline Levels in 2000 in the Southwest of the United States

Figure 2: Ground Water Decline Levels in 2000 in the Southwest of the United States

References:

(n.d.). Retrieved from http://pubs.usgs.gov/fs/fs-103-03/

Pearce, F. (2012, December 19). Grabbing water from future generations: Many of the world’s aquifers are being pumped dry to support unsustainable agriculture. National Geographic, Retrieved from http://news.nationalgeographic.com/news/2012/12/121218-grabbing-water-from-future-generations/

White, P. A. (2001). Groundwaters of new zealand. (pp. 45-75). Wellington North, New Zealand: New Zealand Hydrological Society. Retrieved from http://www.cabdirect.org/abstracts/20033121284.html;jsessionid=8D00DA05B575A59989AB05DD136C8001

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

 

The article, “Precise and Ultrafast Molecular Sieving through Graphene Oxide Membranes”, was posted on the website sciencemag.org on February 14, 2014. The news relates to the WRE domain of hydrology and specifically to the filtration of water. It is basically about a scientific team out of the University of Manchester which has come up with some new filtration applications for graphene oxide, an oxidized crystalline allotrope of carbon. Scientists have been experimenting with how this material can be used as a nanofilter due to its unique interaction with water. Narrow capillaries made from meshing layers of graphene oxide vigorously suck in individual molecules of water allowing its rapid permeation. They permeate through the interconnected nanochannels formed between graphene oxide nanosheets and follow a tortuous path primarily over the hydrophobic nonoxidized surface rather than the hydrophilic oxidized regions. It also blocks all other gases and any solids bigger than the capillaries which scientists have been able to reduce down to 0.45 nanometers. Figure 1 shows an image of the effectiveness the filter.

Figure 1

Figure 1

Based on my engineering education I believe that the data provided in the article is accurate and a great testament to the potential uses of the chemical properties of graphene. The numbers that this article came up with for the size of the capillaries their graphene oxide mesh can have were consistent with data released by another article titled, “Graphene Oxide Membranes for Ionic and Molecular Sieving.” I understand that this is still a relatively new study working with a material for which the cause of its chemical properties and interactions with water are not fully understood, but I believe more information could have been provided about how effective this filter is in a dry vs. aqueous solution. Even the smallest molecules have variance in their diameter depending on whether they are saturated or not and more info could have been provided on how the team is working to overcome this.

 

The end goal of those working on this project is to be able to create a filter that can filter the salt ions themselves out of sea water. This will result in new ways of acquiring fresh water for human use which is a huge global and economic issue we will be facing in the years to come. Water shortages are at all-time highs all over the world and things are beginning to get tense as societies are competing for less available water sources to meet their constantly increasing demand. Some sources have predicted that wars could be started within the next fifty years over this precious resource so any new technology that can add to the collective pool of water resources we all have to work with can prolong such conflicts from arising and also help regions where water shortages are already at dangerous levels.

References

Graphene Oxide Membranes for Ionic and Molecular Sieving. Baoxia Mi Science 14 February 2014: 343 (6172), 740-742. [DOI:10.1126/science.1250247]

Precise and Ultrafast Molecular Sieving Through Graphene Oxide Membranes R. K. Joshi, P. Carbone, F. C. Wang, V. G. Kravets, Y. Su, I. V. Grigorieva, H. A. Wu, A. K. Geim, R. R. Nair Science 14 February 2014: 343 (6172), 752-754. [DOI:10.1126/science.1245711]

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

The article “Egypt and Ethiopia Spar over the Nile” was uploaded to Al Jazeera on February 6, 2014[1]. The article relates to the WRE domain of hydrology in terms of distribution of water along the Nile and the domain of hydraulics in terms of the fluid mechanics that make building a dam desirable. Ethiopia, the main source of the Nile, is currently planning to build a $4.2 billion dam that would produce 6,000 megawatts of electricity, on the Blue Nile River, the main tributary of the Nile. Egypt is concerned that this dam may reduce the flow of water that reaches them1. Since the Nile is the source of 95% of Egypt’s water1, a reduction in flow could result in water shortages, which Egypt is already concerned about even without the dam1. In 1959, Egypt and Sudan, without consulting the other counties of the Nile basin, signed a contract that allocated 66% of the Nile’s water to Egypt, but due to a growing population, Egypt has requested that their allocation be increased to 95%1. Ethiopia claims that not only will the dam not decrease the flow in the river; it will actually increase flow by decreasing evaporation downstream1. The claims of Ethiopia that the dam will not decrease downstream flow in any way are unlikely, especially given that there is no study supporting that claim. While the article states that the dam would decrease evaporation and improve water flow, there is no clear way that the dam would do this. The Nile has a “permanent precipitation deficit in relation to potential evaporation across most of its basin”[2]. The addition of another reservoir would likely increase evaporation. For example, Lake Nasser, a natural lake in Egypt with an area of 6500 km­2 has an annual average evaporation of 3000 mm, which is equivalent to 10% of its overall reservoir storage, 10% of average annual river flow, or 50% of the total discharge by the Nile at low flow1. Additionally, the Nile has very variable flow, 80% of its flow occurs during the wet season months from July to October and only 4% of the flow occurs during the dry season months of February to May[3]. A dam could change the variability of the flow, which would change how it can be used downstream. As Pacini et al. stated “[w]ater storage can be expected to increase water temperature, fuelling yet higher evaporative losses and affecting freshwater species”1. This article did not address the expected size of the reservoir behind the dam or the current plans for the rate of outflow from the dam. Both of these pieces are crucial in calculating the effects on flow of the given dam.

Not only does the issue of the dam effect the hydrology of the area, but it also effects the economics of the region, particularly in Ethiopia, the environment around and downstream of the dam, the society of people living in the region, and the political relationship between Ethiopia and Egypt. The dam will bring a reliable source of energy to the region, which could allow more development to occur. Selling electricity to surrounding countries is expected to provide Ethiopia with a source of income. The dam and reservoir will change the current environment into a different ecosystem and change the flow of the river in that area4. This change in the ecosystem will change the livelihoods of the people who currently live on subsidence farming and agriculture[4]. In addition, the creation of the reservoir will displace approximately 20,000 people3. It will affect Ethiopia and Egypt’s relationship because Ethiopia feels that they need this dam to help alleviate poverty and Egypt feels that the dam must be stopped because the flow of the Nile provides the vast majority of their water and they worry about the dam’s effects on this water1. Furthermore, Ethiopia feel that they have a right to dam the water as they are the source of the Nile, currently claim minimal water from it, and have very few hydrologic developments on it2. Egypt feels that they have a right to the water because of a treaty signed between themselves and Sudan in 19591. As Ethiopia was not consulted on this treaty, they do not feel a compelled to honor it1. The negotiations between the two countries are particularly complicated due to the unrest in the area. Sudan was also opposed to the building of the dam, but since South Sudan recently succeeded, in part due to the support of Ethiopia, Sudan recently withdrew its opposition1. Egypt is also currently in a period of turmoil as its entire government has been overthrown within the timeframe of the dam’s planning. This makes it harder to Egypt to show a united position on the building of the dam.

Map of the Nile and site of proposed dam1

Figure 1. Map of the Nile and site of proposed dam1

Figure 2: Rendering of the proposed dam and reservoir

Figure 2: Rendering of the proposed dam and reservoir

[1] Hussein H. Egypt and Ethiopia spar over the Nile. Al Jazeera. http://america.aljazeera.com/opinions/2014/2/egypt-disputes-ethiopiarenaissancedam.html Published February 6, 2014. Accessed February 21, 2014.

[2] Pacini N, Donabaum K, de Villenueve P, Water-quality management in a vulnerable large river: the Nile in Egypt. International Journal of River Basin Management. 2013; 11: 205-219. doi: 10.1080/15715124.2013.781032

[3] McCartney M, Girma M, Evaluating the downstream implications of planned water resource development in the Ethiopian portion of the Blue Nile River. Water International. 2012; 37: 362-379. doi: 10.1080/02508060.2012.706384

[4]Veilleux JC. The human security dimensions of dam development: The grand Ethiopian Renaissance Dam. Global Dialogue. 2013; 15. http://www.transboundarywaters.orst.edu/publications/publications/Veilleux_GLOBAL%20DIALOGUE_V15_GERD.pdf. Accessed February 6, 2014.

[5]International rivers: The Grand Ethiopian Renaissance Dam fact sheet. http://www.internationalrivers.org/resources/the-grand-ethiopian-renaissance-dam-fact-sheet-8213. Updated 2014. Accessed February/21, 2014.

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

The news entitled, “Current Trends in Pipe Bursting for Renewal of Underground Infrastructure Systems in North America,” was reported in an online journal, Underground Tunneling and Space Technology, in January 2014 in a special issue Underground Infrastructure Research 2012. This article reports on the hydraulics issue of renewing underground pipe infrastructure through pipe bursting by presenting survey data gathered from companies who specialize in pipe bursting. Pipe bursting is a technique for replacing underground pipe infrastructure by breaking the original pipe and replacing it with a new pipe. However, there are many risks and limitations associated with this technique. To burst a pipe, a conical shaped bursting head is pushed through the pipe. This bursting head creates radial expansion in the pipe causing it to crack and split. As the pipe breaks an annulus, or ring shaped opening is formed underground. The pieces of the old pipe break off into the annulus, and new pipe is immediately pushed through the opening to replace the old pipe. Although this seems like a simple concept, there are several risks associated with this procedure and it is expensive. The burst length, host pipe material, upsize diameter of the new pipe, and geological conditions are just a few considerations. The technique is usually only successful in straight pipes between 91-137m or the typical length between manhole covers. From the surveyed companies it was determined that 98% of replacements were done with high-density polyethylene (HDPE) pipe. A common risk associated with pipe bursting is surface heave. Unfortunately, there were no cost estimates presented in the article, and I think this could be an important factor in determining how practical the technique is. The process seems very cost intensive and it is only practical for small, straight sections of pipe. On average, companies interviewed only performed 13 projects a year. It would be interesting to compare this method to other methods of pipe replacement. Overall, the process is broken down into four stages: pre-site planning, on-site planning, bursting, and site restoration.

These stages are time and money intensive, but replacing piping infrastructure is becoming more crucial because many pipe systems in place today are reaching their age of expiration.

Water resources engineering influences societies all over the world since it deals with the hydrology and hydraulics issues associated with water, a substance that sustains all life. WRE issues affect economic, environmental, and social issues across the globe. A broader context area affected by pipe bursting is economics, specifically how cities have to create budgets to maintain and replace underground infrastructure. I included a second article link in this blog to a New York Times article entitled, “A Severe Winter Breaks Budgets as Well as Pipes.” According to the article, Syracuse has reported over 100 main pipe breaks since the beginning of the year, and Detroit has experienced 353 water main ruptures in January alone. A representative from the National League of Cities stated that there have been “many years of disinvestment in things like roads, bridges, water and sewer systems, which makes them more vulnerable when something like this happens,” referring to the severe winter conditions that have been occurring in the North Eastern United States in 2014. Water maintenance has been put on the back burner for too long, and I think we will see an increase in pipe infrastructure problems if cities do not address these issues. Pipe replacement, such as pipe bursting is an expensive process, but it is necessary and it is time states started being proactive regarding replacing pipe infrastructure.

Figure 1. Regions of Pipe Bursting Activity (2007-2010).

Figure 1. Regions of Pipe Bursting Activity (2007-2010).

Figure 2. Technical Envelope Developed to Determine the Risk Associated with Pipe Bursting Based on Upsize Diameter

Figure 2. Technical Envelope Developed to Determine the Risk Associated with Pipe Bursting Based on Upsize Diameter

References:

Ariaratnam, S.T., Lueke, J.S., Michael, J.K. Current trends in pipe bursting for renewal of underground infrastructure systems in North America. Journal of Tunneling and Underground Space Technology. 2014;39:41-49.

McKinley, J., Perez-Pena, R. A Severe Winter Breaks Budgets as Well as Pipes. New York Times. February 15, 2014.

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

The news entitled, “From Rivers to Landslides: Charting the Slopes of Sediment Transport” was reported by the California Institute of Technology on December 29th, 2013 and found on the Science Daily Website. The news related to the WRE domain of hydrology and a reduction of natural disasters with increased knowledge of sedimentation. This article examines the transport of sediments through rivers and streams as they relate to bed failure and possible landslides. Before recent, it was believed that the greater the slope, the more sediment transport that occurred due to an increased gravity, but that is not the case. This research project proved that as slope increases, the sediment actually becomes more stable. (Most stable around 20 degrees). And with the increased slope of flow, there will be a lower water level and higher velocity. The true trouble comes when the amount of water increases above normal amounts, dislodging the sediment causing, at this slope, full bed failure. Further studies must take place to validate the findings of this research, but it is an important step in understanding the deposition and stream bed failure of landslide prone areas.

There are many economic, environmental and societal aspects affected by the research explained in this article. This research talks to the potential of understanding the true mechanisms behind landslides, which, once understood and proven, may act as a precautionary action against damages to property as well as lower deaths caused by these natural disasters. If we have a better understanding who what causes the streambed failure, we can better re-direct water and sediments.   This research also allows us to re-examine the rehabilitation efforts of aquatic animals such as salmon. Due to dams and natural changes, there is a high percentage of areas that are no longer suitable for salmon to nest. While there are efforts to re-build these habitats, not many activists and scientists are fully aware of the reality behind sediment transfer in areas with such extreme slopes and may not be able to properly replenish the environment.

Figure 1: Salmon Habitat in a river

Figure 1: Salmon Habitat in a river

Figure 2: Gradient slope of interest

Figure 2: Gradient slope of interest

References:

California Institute of Technology. (2014, January 29). From rivers to landslides: Charting the slopes of sediment transport. ScienceDaily. Retrieved February 6, 2014 from www.sciencedaily.com/releases/2014/01/140129165419.htm

Egholm, D. L., Knudsen, M. F., & Sanford, M. (2013). Lifespan of Mountain ranges scaled by feedbacks between landsliding and erosion by rivers. Nature , 498 (&455), 475.

Beechie, T., Beamer, E., & Wasserman, L. Estimating Coho Salmon Rearing Habitat and Smolt Production Losses in a Large River Basin, and Implications for Habitat Restoration. North American Journal of Fisheries Management , 14 (4).

 

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

On September 2, 2013, “Restoration Ecology” published an article by Matthew McConnachie, et al., titled “The Challenges of Alleviating Poverty through Ecological Restoration: Insights from South Africa’s ‘Working for Water’ Program.” This article relates to the WRE domain of hydrology and the specific issue of the distribution of water resources being threatened by invasive alien plants in regions of South Africa. Invasive alien plants have grown to become a significant issue for communities in South Africa, decreasing biological diversity and diminishing water resources. To decrease invasive alien plants and increase protection of water resources, the South African government created a program in the 1990’s called “Working for Water” (WFW). This article analyzes the efforts made by WFW to see if the program is meeting their objectives of protecting water resources by diminishing invasive alien plants and alleviating poverty. In this program, people are employed to clear invasive alien plants that interfere with water resources and biological diversity. Methods for ridding of invasive plants include hand pulling, stem injections, and creating catchment areas. Figure 1 shows the relationship between biomass and streamflow reduction (McConnachie et. al, 2013). To analyze the WRE article further, “Ecology and Society” published an article examining WFW’s effects on Table Mountain in Cape Town, SA. The article was in agreement that the implementation of WFW was necessary due to the national issue of invasive alien plants threatening water resources. If catchment areas were not regularly maintained, streamflow would decrease by the equivalent of 30% of the annual water supply to the city of Cape Town (van Wilgen et. al, 2012). A second source stated that these invasive alien plants escalate flooding events, redirect volumes of water from its initial path, and effect agriculture, fisheries, transport, recreation, and water supply (UNEP). What may be missing from this article are the effects some practices WFW uses to eliminate invasive alien plant species could have on the environment, such as stem injections and the use of herbicides.

In a broader economic context, Working for Water was created to give employment to people who were living in underdeveloped rural areas with low to no income. The issue of water resources scarcity in South Africa due to invasive alien plants has negatively affected the economy’s water supply, but positively affected the economy by creating more jobs for low-income communities. The creation of the program has economically and environmentally benefitted South Africa by creating more jobs and securing more water resources. An article published in 2001 in “Land Degradation & Development” commented on the economic effects of WFW. Shown in Table 1 below, the capital and annual costs of managing invasive alien species in South Africa are much higher than not managing the invasive alien species. Although these costs are higher, the management of invasive alien plant species have caused the above ground biomass 15 years after experiencing a fire, reduction in streamflow from biomass, water yield, and the unit cost of water to all be significantly improved (Binns et. al, 2001).

Figure 1 Biomass and Streamflow Reduction

Figure 1 Biomass and Streamflow Reduction

Table 1 Cost Analysis of WFW

With management of alien plants Without management of alien plants
Area (ha) 10000 10000
Mean annual rainfall (mm) 1500 1500
Capital cost of clearing initial infestations ($/ha) 830 0
Capital cost of developing water supply facility (million $) 67.7 0
Total capital cost of water supply facility including initial clearing (million $) 76 67.7
Annual interest on capital cost at 8% 6.1 5.4
Annual cost of continuing alien plant management 8 0
Annual operating cost of water supply facility 1.29 1.29
Total annual costs including operation, alien plant management, and interest 7.47 6.69
Above ground biomass 15 years post fire 3867 10964
Streamflow from rainfall without considering vegetation (mm equivalent) 742 742
Reduction in streamflow from biomass (mm equivalent) 114 256
Water yield (100,000 m3 per year) 62.7 48.6
Unit cost of water ($ per m3) 0.119 0.138

References:

Binns, J. A., Illgner, P. M., and Nel, E. L. Water Shortage, Deforestation, and Development: South Africa’s Working for Water Programme, Land Degradation & Environment, 12: 341-355. May 31, 2001

McConnachie, M. M., Cowling, R. M., Shackleton, C. M. and Knight, A. T. The Challenges of Alleviating Poverty through Ecological Restoration: Insights from South Africa’s “Working for Water” Program, Restoration Ecology, 21: 544–550. 2013

van Wilgen, Brian W. Evidence, Perceptions, and Trade-offs Associated with Invasive Alien Plant Control in the Table Mountain National Park, South Africa, Ecology and Society, 17. 2012

Working for Water: A South African Sustainability Case, United Nations Environment Programme (UNEP). N.D.

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

On September 6, 2013, The Huffington Post published an article by Danica Coto titled “Caribbean Water Supplies Severely Threatened by Climate Change, Scientists Warn.” This article relates to the WRE domain of hydrology and the specific issue of rising sea levels affecting underground aquifers along with the change in climate, affecting annual rain fall. Rising sea levels are a problem that has recently been identified as posing a threat to the source of drinking water in Caribbean countries. Since the majority of the countries are small islands they rely mostly on underground aquifers and rainfall as their source of drinking water. The rising sea levels have caused sea water to being to infiltrate into the aquifers and contaminate the water used for drinking. Over the past century the Global Sea Level (GSL) has be measured as rising 4-8 inches. Recently, the rate of rising has increased with an annual rate of 0.13 inches (Sea Level Rise). With more sea water surrounding the islands, there is a greater pressure put onto the soil by the water, causing more water to infiltrate the underground aquifers, as seen in Figure 1. Weather patterns are also being affected, with the annual mean precipitation levels decreasing steadily. In 2010 the two main reservoirs that supply Jamaica’s drinking water were down 50% of their usual storage. When there is a decrease in rainfall, the aquifers have no way to be replenished. In between droughts, intense rain has been recorded (Jessop, 2010). However, when a sudden large influx of water occurs there isn’t enough time to for the water to be absorbed by the ground, since it turns mainly into runoff, further inhibiting the aquifers to replenish. Based on this information the accuracy of the declining water sources seems to be accurate, however the data showing the aquifers storage volumes, mean annual rainfall and sea level could have been included to introduce some hard data to the article.

Water resources engineering influences the global, economic, and environmental contexts areas because, water is a primary resource which has impacts in all areas of life. The loss of water supplies relates to the global context because rising sea levels and climate change are an issue that affects the entire globe. It is economic, relating to the economy and the flow of money, because with dwindling water resources water will need to be brought in from other sources and the price of water will rise. Lastly, it is an environmental issue because the changing of the aquifers from freshwater to salt water as well as the lack of rain will have an impact on the surrounding ecosystems. The potential threat that rising sea levels pose to freshwater aquifers was also analyzed, in a broader context, by Werner and Simmons (Werner, 2009). In this article Werner and Simmons look at the effects of sea water on aquifers in a broad approach, rather than a single case analysis, in order to understand the process as a whole and develop theories as to why this is occurring and how to stop it. Rising sea levels causing climate change is noted as the largest potential threat to freshwater aquifers. In this case it is clear that rising sea levels are causing a decline in fresh water aquifers and changing the surround environment while also affecting the economy and the availability of resources.

The interface between the ocean and coastal aquifers.

The interface between the ocean and coastal aquifers.

References:

Coto, D. Caribbean Water Supplies Severely Threatened By Climate Change, Scientists Warn . The Huffington Post.September 6, 2013

Jessop, D. The Caribbean Drought . Barabados Gazette . April 13, 2010

Sea Level Rise. National Geographic .

Werner, A. D. Impact of Sea-Level Rise on Sea Water Intrusion in Coastal Aquifers. Ground Water, 2009; 197-204.

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