FUTURE WATER USE SCENARIOS IN CAMPO MOURAO BRAZIL DUE TO POPULATION GROWTH AND CLIMATE CHANGE

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1 FUTURE WATER USE SCENARIOS IN CAMPO MOURAO BRAZIL DUE TO POPULATION GROWTH AND CLIMATE CHANGE P. M. Fedri* and L. Fleischfresser* *Environmental Engineering Program/UTFPR, Campo Mourao, Brasil Abstract We present two scenarios to forecast water needs in Campo Mourao until 2014: 1) a population growth scenario and; 2) a climate change scenario. Like many other river basins of the world, the Campo river is almost fully allocated. As such, the use of water management systems becomes an important strategy to plan for future needs. The Water Evaluation and Planning (WEAP) system fulfills this role well. It is designed to perform integrated water supply and demand analysis with a userfriendly interface and intuitive data manipulation. We present a schematic that mimics Campo Mourao s water distribution network with a high degree of fidelity. Data from Companhia de Saneamento do Parana (SANEPAR), Instituto Brasileiro de Geografia e Estatistica (IBGE), and Instituto Nacional de Meteorologia (INMET) were used to calibrate the model and to make forecasts. Both future scenarios resulted in unmet demand. A 10% annual population growth rate resulted in unmet demand for two out of four demand sites beginning in The climate change scenario resulted in unmet demand for the entire city starting in May This scenario is based on a 3% annual population growth rate, and a per capita water use that varies relative to the 2010 reference year. Keywords: water distribution network, sustainable water management, WEAP Introduction Gross domestic product (GDP) is currently perceived as an unreliable measure of a nation s wealth. New metrics are being proposed to account for natural and human resources as fundamental components in promoting quality of life and levels of development [1]. Among natural resources, the recognition of the economical value of freshwater is becoming increasingly important and of strategic relevance in devising this new wealth index. In order to be water sustainable, action plans need to be managed at the city level to promote an active control of current demands and to assess possible future shortfalls. The WEAP system is a valuable tool in this regard [2]. Based on water balances among nodes (demand sites), links (pipelines), and sources (rivers and wells), it provides an integrated view of the current consumption state at a given location. Further, it can be used to forecast scenarios 1/9

2 envisioned by the analyst (e.g., population growth, climate change). The more accurate the representation of the study site, the better one can simulate the future to manage water allocation and mitigation strategies. Materials and Methods Campo Mourao`s water supply and demand situation is not different when compared to other cities of the world. Many WEAP case studies report situations where the main supply to a given region is almost fully allocated ([3], [4], [5] and [6]). Campo river the main source to the city appears to have this kind of stress. It provides around 80% of the water needed for urban consumption. The fact that five (5) wells add to the city s water supply hints that there may be a concern by the authorities that the river s peak limit is being reached (for a discussion of the concept of peak freshwater limit see [7]). The local water distribution network is a typical configuration in Parana. It is based on the concept of influence areas for each accumulation reservoir. There are four (4) such areas in Campo Mourao [8]. In essence, each reservoir supplies water to a particular sector of the city. There is one main water treatment plant (WTP) that treats the river withdrawals for distribution. Moreover, there are two wastewater treatment plants (WWTPs) for the return flow. In this study, only one WWTP is included. Among the data furnished by SANEPAR, 2010 monthly values of total water volumes were inserted in the WEAP configuration. These data are shown in Table 1, where differences reflect losses during WTP processing (Total Treated) and those due to leakages in the distribution network (Treated Measured). Table 1: SANEPAR water volumes in Campo Mourao for Month Total Treated Measured Volume (m 3 ) Volume (m 3 ) Volume (m 3 ) January February March April May June July August September October November December We show the breakdown of the aforementioned water volumes between the 2/9

3 five (5) wells and the Campo river in Figures 1 and 2 respectively. Wells CSB02, CSB03 and CSB05 are shown together since they feed into the same reservoir (RSE04) and they are geographically near each other. Population data were compiled from the 2010 census taken by IBGE. Other data used are annual gross domestic product (also taken from IBGE from 2004 to 2008) and the cost of water from 2010 residential water bills (R$ 2.45/m 3 ). The final map showing the WEAP representation of the water distribution network (demand sites, surface and groundwater sources, reservoirs, transmission links and return flows) is shown in Figure 3. The WTP is configured as a demand site. Only four (4) reservoirs are final destinations for demand sites (REL01, REL02, REL03 and RSE02). All other reservoirs serve as intermediate accumulation scattered throughout the city. RSE01 and RSE03 are exceptions as they accumulate the output from the WTP directly. The 2010 reference scenario was Figure 1: SANEPAR monthly groundwater volumes withdrawn in Blue for CSB01, green for CSB06, and yellow for CSB02 + CSB03 + CSB05. CSB04 was not operational during /9

4 Figure 2 SANEPAR monthly water volumes withdrawn from the Campo river in configured to meet all demand in the system. We adjusted the population breakdownamong the various influence areas (annual activity level) as well as the demand per capita (annual water use rate) for each of the four areas to accomplish this objective. Consumption was set to 80% of the inflow. Two future scenarios population growth and climate change were established at the demand sites level. The population growth scenario follows a 10% annual increase rate in the activity level (above historical trends). The climate change scenario has an increase/decrease in the annual water use rate plus a 3% annual population growth until The reasoning for the former is the consumption increase/decrease that is observed with higher/lower temperatures, a relationship confirmed by others [9]. In order to establish warmer or colder years in relation to 2010, we employ INMET s relative humidity data for the weather station in Campo Mourao. These data are available until April A high relative humidity is associated with an increased amount of water vapor in the atmosphere, which in turn relates to a warm local climate (water vapor is the strongest greenhouse gas). Within this reasoning it is possible to conclude that 2011 was locally colder than 2010 as the annual average of relative humidity was lower. From the data available for 2012, we conclude that it was 4/9

5 Figure 3: Final WEAP distribution map for Campo Mourao. still colder than 2010 (we compare monthly averages from January til April for 2010 and 2012). For 2013 and 2014 we simply assume they will be warmer than We do this by increasing the water use rate at the demand site level. Results After inserting the functional relations for both scenarios as described above, we are able to analyze various behaviors of the system. Here we focus on the unmet demand due to population growth and climate change. These results are presented in Figures 4 and 5 respectively. For the population growth scenario (Figure 4), unmet demand is realized first in the REL03 demand site. During February 2011, approximately 1,000 m 3 is lacking to meet the consumption needs of that area. The peak of unmet demand for REL03 occurs in June 2014, with a volume deficit of 5,600 m 3. Still in the population growth scenario, the RSE02 demand site shows unmet demand beginning in February 2012 (1,300 m 3 ) with 5/9

6 Figure 4: Unmet demand from 2011 to 2014 for the population growth scenario. Green for Demanda REL03, Orange for Demanda RSE02. Figure 5 Unmet demand from 2011 to 2014 for the climate change scenario. Blue for Demanda REL01, Green for Demanda REL03, Orange for Demanda RSE02, Yellow for Demanda REL02 the peak occurring in June 2014 as well (112,500 m 3 ). The other two demand sites (REL01 and REL02) have their demands fully met until Overall, the 6/9

7 accumulated unmet demand for REL03 and RSE02 in the population growth scenario is 1.7 million m 3 from 2011 to On the climate change scenario (Figure 5), unmet demand first appears for REL03 in June 2012 (100 m 3 ), then for REL01 in January 2013 (2,500 m 3 ), for RSE02 in February 2013 (8,600 m 3 ), and finally for REL03 in May 2013 (3,000 m 3 ). In this scenario, all sites have unmet demand from May 2013 onward. The accumulated volume deficit is on the order of 1.1 million m 3. Discussion The population growth scenario had higher unmet demand over a longer period of time when compared with the climate change scenario. However, all influence areas have unmet demand for the climate change scenario, whereas only two areas are in the same situation for the population growth scenario. These results highlight the usefulness of an auxiliary tool like WEAP to manage the water supply to a given city. Here we compare only two distinct outcomes, but it is possible to envision many others. A multiyear dataset could be used to improve the scenario analysis. Conclusion A side benefit of this project that fulfills its outreach purpose is the recognition that the two databases made available by SANEPAR are more useful if merged. One compiles water use by sector (residential, commercial, industrial, public utilities, and public agencies), while the other by influence areas. The inherent difficulty is that the sector data does not account for the influence areas and vice-versa. That is, it is not possible to have a breakdown by sector for each influence area. Our discussions with SANEPAR personnel prompted their action plan to merge the two datasets. It is currently in its implementation phase and it is expected to become available by the end of Acknowledgements We thank the Undergraduate Outreach and Innovation Experience Program at UTFPR for providing an undergraduate assistanship to the first author during the past two years. We are grateful to SANEPAR for making water use data and distribution network information for Campo Mourao readily available to us. In particular, Luciano Ferreira Silva and Rodrigo Becker were instrumental in providing the data from SANEPAR used in this project. Finally, we credit the Stockholm Environment Institute -- 7/9

8 specially Jack Sieber -- for licensing WEAP free of charge and providing support throughout the project s development. References [1] UNU-IHDP and UNEP (2012) Inclusive Wealth Report Measuring progress toward sustainability. Cambridge: Cambridge University Press. [2] Sieber, J., Purkey, D. (2011) WEAP Water Evaluation and Planning System User Guide Stockholm Environment Institute, January [3] Lévite, H., Sally, H., Cour, J. (2002), Water Demand Management Scenarios in a Water-Stressed Basin in South Africa, In: 3 rd WARSFA/Waternet Symposium; Arusha; October [4] Olusheyi, O. Z. (2006), Water Resources Planning and City Sustainable Development. A Case Study Of Heng Shui City, Hebei Province, P.R. China, Master Thesis, Department of Environmental Science, Tianjin University, Tianjin, 144 p. [5] Fonseca, F. (2008), Efeitos do Turismo na Demanda D Água da Bacia do Rio Gramame Estudo de Caso, Dissertação de Mestrado, Curso de Pós- Graduação em Engenharia Civil e Ambiental na Área de Engenharia de Recursos Hídricos, Universidade Federal de Campina Grande, Campina Grande, PB, 143 p. [6] Mugatsia, E. A. (2010), Simulation and Scenario Analysis of Water Resources Management in Perkerra Catchment Using WEAP Model, Master Thesis, Department of Civil and Structural Engineering, Moi University, Eldoret, Kenya, 145 p. [7] Gleick, P.H., Palaniappan, M. (2010) Peak Water Limits to Freshwater Withdrawal and Use, In: Proceedings of the National Academies of Science, June 22, 2010, vol. 107, no. 25. Available at Acessed: 19 June [8] Fedri, P.M., Fleischfresser, L., (2011), Aplicacao do Sistema de Planejamento Hidrico WEAP ao Abastecimento Publico de Campo Mourao - PR, In: Proceedings of the 1 st Outreach and Innovation Seminar of the Federal Technological University of Parana I SEI - UTFPR, Curitiba; September /9

9 [9] Ferreira, C. C., Ferreira, J. H. D.,(2010), Influencia de Fatores Climaticos no Consumo de Agua Residencial da Cidade de Campo Mourao - PR (1999/2004), In: Proceedings of the 1 st Environmental Symposium of the Technological University of Parana - I SIAUT - UTFPR; Campo Mourao; June /9