Problem Tree
For my Development Project Management Institute Plus (DMPI +) internship, I researched and analyzed the current status of freshwater in Lima, Peru. Through my research, I discovered that there is not enough freshwater to supply the current population of the Lima Metropolitan area (current population = 9.5 million people), and with future projections for steady population growth in the area and a decrease in the amount of water in the three basins that feed into Lima’s supply, there will be an even greater shortage of freshwater to service Lima’s human population. As such, I decided to identify a lack of water to supply the human population of Lima as a direct threat, and thus I created a problem tree to examine the threat’s contributing factors.
The first thing one might notice from this problem tree is that there are many contributing factors to Lima’s lack of water; not only does Lima exist in the middle of a desert, but also there are many pressures on the three water basins that feed into Lima’s water supply. The right side of the problem tree primarily depicts those water issues that are quantitative direct threats, while the left side illustrates the water quality issues that are direct threats.
Quantitative Water Threats
Lima, Peru is located in the Sechura Desert. As such, it receives very little rainfall each year. Little rain means a long period of time is necessary for the water bodies and aquifers in Lima’s watershed to recharge. Hence, there is a natural lack of freshwater to service Lima’s human population. With increasing threats due to climate change regarding the quantity of water that exists in Lima’s three water basins (the Rímac, Chillón, and Lurín river basins), it is increasingly likely there will be less water to service Lima’s human population as time continues.
As stated above, the Lima Metropolitan Area (Lima) currently has an estimated 9.5 million residents. It is estimated that Lima’s current growth rate of 1.56% per year (INEI, 2012) will continue for the foreseeable future. I calculated the human population of Lima for the next 10 years assuming a continuous population growth rate of 1.56%, and according to these calculations, by 2022 the human population of Lima will reach over 11 million inhabitants, placing an even greater demand on Lima’s freshwater resources.
As of 2010, Sedapal (Lima’s drinking water company) reported that it produced 270 liters of water per person per day for domestic use. This figure was calculated for the people hooked up to Sedapal’s network, and thus did not include the water used by one million people in the Lima Metropolitan area who received water for domestic use from other sources. It is difficult to estimate the per capita quantity of water used by the 14% of Lima’s population that is not hooked up to Sedapal’s network, since this population gets their water from various sources, including digging personal wells, buying water from trucks, and purchasing bottled water. Water is disproportionately more expensive for the communities that are not hooked up to the official system. People not connected to SEDEPAL’s network pay up to 20 times more for their water than those who have official connections. The communities without official connections are also the most impoverished communities, making it likely that people in these areas are using significantly less water than those with connections to the formal water network.
Although Sedapal claims it produces 270 L/p/d, this does not signify that every person in Lima receives 270 liters of water every day of the year. "According to a 2005 survey carried out in 1,628 municipalities, access to water services is not continuous in about half of them. In 7.7 percent of the municipalities continuity of water services was less than 11 hours per day. Large urban centers in Latin America have an average of 24 hours per day of water supply, while Lima has only 21 (World Bank, 2011)." During the dry season Sedapal depends on water stored in lagoons to meet the water demand for Lima. This has led to shortages and even rationing in the past, with less affluent districts suffering greater water shortages.
Another issue facing Lima’s water supply is leakage. In the water world, “leakage” can refer to either the wasteful physical removal of water from a system, such as when water pipes crack and leak. Leakage can also refer to poor management behaviors that lead to the improper management of water, such as when a person leaves a faucet running while not actively using the water. Lima’s water supply suffers from both forms of leakage.
Lastly for quantitative problems, the natural systems involved in the water cycle can no longer maintain clean water. While the system is being overdrawn in order to supply Lima’s large population with water for all its perceived needs, people are adding greater amounts of contamination to the system. With time, the ecosystems involved could purify the water again, but Lima does not function on the time schedule of nature. Instead, the water is saturated with high concentrations of pollutants, making the water unsuitable for Lima’s needs. Moreover, people are changing Lima’s landscape by adding impermeable surfaces such as parking lots and large apartment complexes. This further decreases the ability of the natural systems to maintain clean water, and as such, there is less available potable water.
Qualitative Water Threats
Not only does contamination affect how much water is available in the system, it also has an impact on the water itself. From the left side of the problem tree one can understand the different threats that contribute to the contamination of the water in the Rímac, Chillón, and Lurín river basins. Deforestation leads to a decrease in the retention of contaminants by tree roots and by the soil. Without the plants holding the contaminants in place until such time as the system could naturally detoxify them, the pollutants then runoff into the surface and ground water supplies, resulting in higher concentrations of toxins in the water. The heavy metals released into the water supply from mining activities are extremely hazardous to the health of humans and other biota living within the watersheds.
People throughout the watersheds do not dispose of their solid waste, or trash, properly. This trash finds its way directly into the waterways where it sits in the system, slowly degrading. Even when it has degraded into smaller forms, it still affects the water and the biota living within the water. For example, plastics over time will turn into microplastics. These microplastics are consumed by freshwater species, such as fish, which are then consumed by humans. Microplastics from freshwater resources travel downstream and end on beaches and in the ocean. Lima’s beaches and oceans are filled with solid waste and microplastics (Weissinger, 2011).
Lastly, the human population within the three watersheds is flooding the system with wastewater, much of it filled with fecal matter. There are only a few weak treatment plants before the water reaches Lima’s boundaries, meaning the water sitting in the riverbeds has high concentrations of fecal matter. Once the water reaches Lima, much of it is treated, but the system still does not have the capacity to treat all the water. Wastewater is then allowed to flow directly into the ocean. People not officially linked to Sedapal’s system use the excess contaminated water for their everyday needs.
Overall, the issue of Lima’s lack of water supply for its human population is complex with many direct threats. WWF has the opportunity to address some of Lima’s water issues in the near future.
The first thing one might notice from this problem tree is that there are many contributing factors to Lima’s lack of water; not only does Lima exist in the middle of a desert, but also there are many pressures on the three water basins that feed into Lima’s water supply. The right side of the problem tree primarily depicts those water issues that are quantitative direct threats, while the left side illustrates the water quality issues that are direct threats.
Quantitative Water Threats
Lima, Peru is located in the Sechura Desert. As such, it receives very little rainfall each year. Little rain means a long period of time is necessary for the water bodies and aquifers in Lima’s watershed to recharge. Hence, there is a natural lack of freshwater to service Lima’s human population. With increasing threats due to climate change regarding the quantity of water that exists in Lima’s three water basins (the Rímac, Chillón, and Lurín river basins), it is increasingly likely there will be less water to service Lima’s human population as time continues.
As stated above, the Lima Metropolitan Area (Lima) currently has an estimated 9.5 million residents. It is estimated that Lima’s current growth rate of 1.56% per year (INEI, 2012) will continue for the foreseeable future. I calculated the human population of Lima for the next 10 years assuming a continuous population growth rate of 1.56%, and according to these calculations, by 2022 the human population of Lima will reach over 11 million inhabitants, placing an even greater demand on Lima’s freshwater resources.
As of 2010, Sedapal (Lima’s drinking water company) reported that it produced 270 liters of water per person per day for domestic use. This figure was calculated for the people hooked up to Sedapal’s network, and thus did not include the water used by one million people in the Lima Metropolitan area who received water for domestic use from other sources. It is difficult to estimate the per capita quantity of water used by the 14% of Lima’s population that is not hooked up to Sedapal’s network, since this population gets their water from various sources, including digging personal wells, buying water from trucks, and purchasing bottled water. Water is disproportionately more expensive for the communities that are not hooked up to the official system. People not connected to SEDEPAL’s network pay up to 20 times more for their water than those who have official connections. The communities without official connections are also the most impoverished communities, making it likely that people in these areas are using significantly less water than those with connections to the formal water network.
Although Sedapal claims it produces 270 L/p/d, this does not signify that every person in Lima receives 270 liters of water every day of the year. "According to a 2005 survey carried out in 1,628 municipalities, access to water services is not continuous in about half of them. In 7.7 percent of the municipalities continuity of water services was less than 11 hours per day. Large urban centers in Latin America have an average of 24 hours per day of water supply, while Lima has only 21 (World Bank, 2011)." During the dry season Sedapal depends on water stored in lagoons to meet the water demand for Lima. This has led to shortages and even rationing in the past, with less affluent districts suffering greater water shortages.
Another issue facing Lima’s water supply is leakage. In the water world, “leakage” can refer to either the wasteful physical removal of water from a system, such as when water pipes crack and leak. Leakage can also refer to poor management behaviors that lead to the improper management of water, such as when a person leaves a faucet running while not actively using the water. Lima’s water supply suffers from both forms of leakage.
Lastly for quantitative problems, the natural systems involved in the water cycle can no longer maintain clean water. While the system is being overdrawn in order to supply Lima’s large population with water for all its perceived needs, people are adding greater amounts of contamination to the system. With time, the ecosystems involved could purify the water again, but Lima does not function on the time schedule of nature. Instead, the water is saturated with high concentrations of pollutants, making the water unsuitable for Lima’s needs. Moreover, people are changing Lima’s landscape by adding impermeable surfaces such as parking lots and large apartment complexes. This further decreases the ability of the natural systems to maintain clean water, and as such, there is less available potable water.
Qualitative Water Threats
Not only does contamination affect how much water is available in the system, it also has an impact on the water itself. From the left side of the problem tree one can understand the different threats that contribute to the contamination of the water in the Rímac, Chillón, and Lurín river basins. Deforestation leads to a decrease in the retention of contaminants by tree roots and by the soil. Without the plants holding the contaminants in place until such time as the system could naturally detoxify them, the pollutants then runoff into the surface and ground water supplies, resulting in higher concentrations of toxins in the water. The heavy metals released into the water supply from mining activities are extremely hazardous to the health of humans and other biota living within the watersheds.
People throughout the watersheds do not dispose of their solid waste, or trash, properly. This trash finds its way directly into the waterways where it sits in the system, slowly degrading. Even when it has degraded into smaller forms, it still affects the water and the biota living within the water. For example, plastics over time will turn into microplastics. These microplastics are consumed by freshwater species, such as fish, which are then consumed by humans. Microplastics from freshwater resources travel downstream and end on beaches and in the ocean. Lima’s beaches and oceans are filled with solid waste and microplastics (Weissinger, 2011).
Lastly, the human population within the three watersheds is flooding the system with wastewater, much of it filled with fecal matter. There are only a few weak treatment plants before the water reaches Lima’s boundaries, meaning the water sitting in the riverbeds has high concentrations of fecal matter. Once the water reaches Lima, much of it is treated, but the system still does not have the capacity to treat all the water. Wastewater is then allowed to flow directly into the ocean. People not officially linked to Sedapal’s system use the excess contaminated water for their everyday needs.
Overall, the issue of Lima’s lack of water supply for its human population is complex with many direct threats. WWF has the opportunity to address some of Lima’s water issues in the near future.
Works Cited
"Adaptation to Climate Change in the Rímac River Basin." KfW Entwicklungsbank, 2010. Web. 9 Sept. 2012. <http://www.idrc.ca/Documents/Lima-engl.pdf>.
Brown, Amber and Matlock, Marty D.“A Review of Water Scarcity Indices and Methodologies.“ 2011. University of Arkansas. The Sustainability Consortium. White Paper #106.
DIGESA. "Dirección De Ecología Y Protección Del Ambiente | DIGESA." Dirección De Ecología Y Protección Del Ambiente | DIGESA. Web. 3 Sept. 2012. <http://www.digesa.sld.pe/DEPA/DEPA.asp>.
"Disponen Limpieza De Ríos Rímac Y Chillón Para Revertir Contaminación Por Plomo." Disponen Limpieza De Ríos Rímac Y Chillón Para Revertir Contaminación Por Plomo. 28 Dec. 2007. Web. 19 Oct. 2012.
INEI. Perú Compendio Estadístico. Edición De Bolsillo ed. Vol. 2012. Lima: Instituto Nacional De Estadistica E Informatica, 2012. 5 - 72. Print.
Sedapal. “Servicio De Agua Potable Y Alcantarillado De Lima.” Web. 10 Aug. 2012. <http://www.Sedapal.com.pe/>.
"Vigilancia Y Monitoreo De Los Recursos Hídricos | DIGESA." Vigilancia Y Monitoreo De Los Recursos Hídricos | DIGESA. Web. 3 Sept. 2012. <http://www.digesa.minsa.gob.pe>.
World Bank. "Projects & Operations." Projects: PE Optimization of Lima Water and Sewerage Systems | The World Bank. 2011. Web. 11 Aug. 2012.