Urban Water in dan Mexico
A perspective from the Academies of Sciences
URBAN WATER
CHALLENGES IN THE AMERICAS
A perspective from the Academies of Sciences
URBAN WATER
CHALLENGES IN THE AMERICAS2 URBAN WATER CHALLENGES IN THE AMERICAS
IANAS The Inter-American Network of Academies of Sciences
IANAS is a regional network of Academies of Sciences created to support cooperation in order to strengthen science and technology as tools for advancing research and development, prosperity and equity in the Americas.
IANAS Translation
Co-Chairs: Michael Clegg (United States) and Juan Asenjo (Chile). Suzanne D. Stephens (Argentina, Chile, Mexico, Canada,
Executive Director: Adriana de la Cruz Molina Honduras, Panama, Costa Rica, Dominican Republic, Peru
and Toronto) and Alejandra Huete (Cuba and El Salvador)Editorial Coordination Katherine Vammen and Adriana de la Cruz Molina
Graphic Design Víctor Daniel Moreno Alanís Francisco Ibraham Meza Blanco
IANAS Water Program Co-Chairs: Katherine Vammen (Nicaragua), Blanca Jiménez (Mexico) and Honorary Co-Chair: Jose Tundisi (Brazil)
Original Cover Design Francisco Ibraham Meza Blanco
Editorial Committee Gabriel Roldán (Colombia), María Luisa Torregrosa (Mexico),
Graphic Design Support Katherine Vammen (Nicaragua), Ernesto J. González (Venezuela), Osiris López Aguilar, Mariana Guerrero del Cueto, Claudia Campuzano (Colombia), Hugo Hidalgo (Costa Rica) and Tania Zaldivar Martínez, and Roberto Flores Angulo Adriana de la Cruz Molina (Mexico)
Administrative Support Verónica Barroso
Proof Reading Ma. Areli Montes Suárez and authors of the chapters
Published by The Inter-American Network of Academies of Sciences (IANAS), Calle Cipreses s/n, Km 23.5 de la Carretera Federal
México-Cuernavaca, 14400 Tlalpan, Distrito Federal, Mexico and the United Nations Educational, Scientific and Cultural
Organization (UNESCO), 7, place de Fontenoy, 75352 Paris 07 SP, France, the UNESCO Office in Montevideo, Edificio Mercosur,
Luis Pereira 1992, 2o piso, casilla de correo 859, 11200 Montevideo, Uruguay © IANAS and UNESCO 2015ISBN: 978-607-8379-12-5 Printed in Mexico
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This publication has been printed on ecological paper (FSC Certification): one part of the fibers is from recycled material and the
URBAN WATER CHALLENGES IN THE AMERICAS
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URBAN WATER
A perspective from the Academies of Sciences
CHALLENGES IN THE AMERICAS
4 URBAN WATER CHALLENGES IN THE AMERICAS
Panamanian Association for the Advancement of Science www.apanac.org.edu.pa
Academy of Medical, Physical and Natural Sciences of Guatemala www.interacademies.net/Academies/ByRegion/
LatinAmericaCarribbean/Guatemala/ Enrique Acevedo, President
Honduras
National Academy of Sciences of Honduras www.guspepper.net/academia.htm Gustavo A. Pérez, President
Mexico
Mexican Academy of Sciences www.amc.unam.mx Jaime Urrutia, President
Nicaragua
Nicaraguan Academy of Sciences www.cienciasdenicaragua.org Manuel Ortega, President
Panama
Jorge Motta, President
Academy of Sciences of Ecuador http://www.academiadecienciasecuador.org Carlos Alberto Soria, President
Peru
National Academy of Sciences of Peru www.ancperu.org Ronald Woodman Pollitt, President
United States of America
US National Academy of Sciences www.nasonline.org Ralph J. Cicerone, President
Uruguay
The National Academy of Sciences of the Oriental Republic of Uruguay www.anciu.org.uy
Rodolfo Gambini, President
Venezuela
Academy of Physical, Mathematical and Natural
Guatemala
Academies of Sciences Members
ArgentinaNational Academy of Exact, Physical and Natural Sciences of Argentina www.ancefn.org.ar
Caribbean Academy of Sciences (Regional Networks) www.caswi.org
Roberto L.O. Cignoli President
Brazil
Brazilian Academy of Sciences www.abc.org.br Jacob Palis, President
Bolivia
National Academy of Sciences of Bolivia www.aciencias.org.bo Gonzalo Taboada López, President
Canada
The Royal Society of Canada: The Academies of Arts, Humanities and Sciences of Canada https://rsc-src.ca/en/
Graham Bell, President
Caribbean
Trevor Alleyne, President
Academy of Sciences of the Dominican Republic
Chile
Chilean Academy of Science www.academia-ciencias.cl Juan Asenjo, President
Colombia
Colombian Academy of Exact, Physical and Natural Sciences www.accefyn.org.co
Enrique Forero, President
Costa Rica
National Academy of Sciences of Costa Rica www.anc.cr Pedro León Azofeita, President
Cuba
Cuban Academy of Science www.academiaciencias.cu Ismael Clark Arxer, President
Dominican Republic
Ecuador
URBAN WATER CHALLENGES IN THE AMERICAS
Peru
Honduras
Dr. Marco Blair National Academy of Sciences of Honduras
Mexico
Dra. María Luisa Torregrosa Latin American Faculty of Social Sciences
Nicaragua
Dra. Katherine Vammen Nicaraguan Research Center for Aquatic Resources
National Autonomus of Nicaragua
Panama
Dr. José R. Fábrega Faculties of Civil and Mechanical Engineering at the Technological University of Panama
Dra. Nicole Bernex Geography Research Center Pontifical Catholic
Guatemala
University of Peru
Uruguay
Dr. Daniel Conde Sciences Faculty
Universidad de la República
USA
Dr. Henry Vaux Univesity of California
Venezuela
Dr. Ernesto J. González Sciences Faculty
Central University of Venezuela
IANAS Water Focal Points
Ing. Manuel Bastarrechea Academy of Medical, Physical and Natural Sciences of Guatemala
5
Argentina
Dr. James McPhee Advanced Mining Technology Center
Dr. Raúl A. Lopardo National Water Institute
Bolivia
Dr.Fernando Urquídi National Academy of Sciences of Bolivia
Brazil
Dr. José Galizia Tundisi International Institute of Ecology
Canada
Dra. Banu Ormeci Carleton University
Grenada
Dr. Martín ST. Clair Forde St. George’s University, Grenada
Chile
University of Chile
El Salvador
Colombia
Dr. Gabriel Roldán Colombian Academy of Exact,
Physical and Natural Sciences
Costa Rica
Dr. Hugo Hidalgo University of Costa Rica
Cuba
Dra. Daniela Mercedes Arellano Acosta National Institute of Hygiene, Epidemiology and Microbiology, Havana, Cuba
Dominican Republic
Ing. Osiris de León Comission of Natural Sciences and
Environment of the Science Academy
Dr. Julio Cesar Quiñones Basagoitia Member of the Global Water Partnership
6 URBAN WATER CHALLENGES IN THE AMERICAS
Coordinators and Authors
Argentina Chile
Raúl Antonio Lopardo James McPhee National Water Institute Advanced Mining Technology Center
University of Chile Jorge Daniel Bacchiega
National Water Institute Jorge Gironás School of Engineering
Luis E. Higa Pontifical Catholic University of Chile National Water Institute
Bonifacio Fernández School of Engineering
Pontifical Catholic University of Chile
Bolivia
Fernando Urquidi-Barrau National Academy of Sciences of Bolivia Pablo Pastén
Department of Hydraulic and Environmental Pontifical Catholic University of Chile
Brazil
José Galizia Tundisi José Vargas International Institute of Technology Chilean Hydraulic Engineering Society
Carlos Eduardo Morelli Tucci Alejandra Vega Universidade Federal do Rio Grande do Sul Pontifical Catholic University of Chile
Fernando Rosado Spilki Sebastián Vicuña Centro Universitário Feevale UC Global Change Center
Ivanildo Hespanhol Universidade de São Paulo
Colombia
Gabriel Roldán José Almir Cirilo Colombian Academy of Exact
Universidade Federal de Pernambuco Physical and Natural Sciences Marcos Cortesão Barnsley Scheuenstuhl Claudia Patricia Campuzano Ochoa
Brazilian Academy of Sciences Antioquia Science and Technology Center Natalia Andricioli Periotto Luis Javier Montoya Jaramillo
Centro de Ciências Biológicas e da Saúde National University of Colombia-Medellin Carlos Daniel Ruiz Carrascal
School of Engineering of Antioquia
Canada
Banu Örmeci Carleton University Andrés Torres
Javeriana Pontifical University-Bogota Michael D’Andrea
Water Infrastructure Management Toronto Jaime Lara-Borrero Javeriana Pontifical University-Bogota
URBAN WATER CHALLENGES IN THE AMERICAS
7
Sandra Lorena Galarza-Molina L.F. Molerio-León MSc. Javeriana Pontifical University-Bogota GRANIK HOLDINGS Ltd
(Dominican Republic) Juan Diego Giraldo Osorio
Javeriana Pontifical University-Bogota Eduardo O. Planos Gutiérrez Cuban Meteorology Institute
Milton Duarte Science and Engineering Research Group
Dominican Republic
Sandra Méndez-Fajardo Osiris de León Javeriana Pontifical University-Bogota Comission of Natural Sciences and
Environment of the Science Academy
Costa Rica
Hugo G. Hidalgo
El Salvador
University of Costa Rica Julio Cesar Quiñones Basagoitia Member of the GWP
Ángel G. Muñoz International Research Institute for Climate and
Society at Columbia University
Grenada
Martin ST. Clair Forde Carolina Herrero St. George’s University, Grenada
Ph-C Ingenieros Consultores Brian P. Neff
Eric J. Alfaro St. George’s University, Grenada University of Costa Rica, School of Physics
Natalie Mora
Guatemala
University of Costa Rica, School of Physics Manuel Basterrechea Academy of Medical
Víctor H. Chacón Physical and Natural Sciences of Guatemala Municipality of Perez Zeledon, C.N.E.
Carlos Roberto Cobos Darner A. Mora Engineering Research Center
National Waters Laboratory Juan Carlos Fuentes
Mary L. Moreno National Electrification Institute International Center for Economic Policy for
Sustainable Development at the National Norma Edith Gil Rodas de Castillo University of Costa Rica Oceans and Aquiculture Studies Center CEMA
University of San Carlos, Guatemala-USAC Jeanette Herrera de Noack
Cuba
Daniela de las Mercedes Arellano Acosta Environmental Law Alliance Worldwide Agency of Environment, Ministry of Science, Technology and Environment, Havana, Cuba Ana Beatriz Suárez Ecological and Chemical Laboratory, S.A.
8 URBAN WATER CHALLENGES IN THE AMERICAS
Honduras
Marco Antonio Blair Chávez Iris Hurtado García National Academy of Sciences of Honduras. Nicaraguan Research Center for Aquatic Resources
(CIRA/UNAN) Manuel Figueroa
National Academy of Sciences of Honduras. Mario Jiménez García Nicaraguan Research Center for Aquatic Resources
(CIRA/UNAN)
Mexico
María Luisa Torregrosa y Armentia Francisco J. Picado Pavón Researcher in the Latin American Faculty of Social Nicaraguan Research Center for Aquatic Resources
Sciences-FLACSO (CIRA/UNAN) Blanca Jiménez-Cisneros Gustavo Sequeira Peña
Water Sciences Division and Secretary of UNESCO Nicaraguan Research Center for Aquatic Resources (CIRA/UNAN)
Jacinta Palerm Graduate Level, Mexico-COLPOS
Panama
Ricardo Sandoval Minero José Rogelio Fábrega Duque Sextante Consulting Services, S.C. Technological University of Panama
Karina Kloster Miroslava Morán Montaño Autonomous University of Mexico City Agua del Trópico Húmedo para América Latina y el
Caribe (CATHALAC) Polioptro F. Martínez Austria
University of the Americas, Puebla Elsa Lilibeth Flores Hernández Technological University of Panama
Jordi Vera Cartas Fondo Golfo de Mexico A.C Icela Ibeth Márquez Solano de Rojas
Technological University of Panama Ismael Aguilar Barajas Fundación Universitaria Iberoamericana
Monterrey Institute of Technology Argentina Ying B
Technological University of Panama
Nicaragua
Katherine Vammen Casilda Saavedra Nicaraguan Research Center for Aquatic Resources Technological University of Panama
(CIRA/UNAN) Berta Alicia Olmedo Vernaza
Yelba Flores Meza Gerencia de Hidrometeorología de ETESA Nicaraguan Research Center for Aquatic Resources
(CIRA/UNAN) Pilar López Palacios Gerencia de Hidrometeorología de ETESA
Selvia Flores Sánchez Nicaraguan Research Center for Aquatic Resources
(CIRA/UNAN)
URBAN WATER CHALLENGES IN THE AMERICAS
School of Architecture University of the Republic
Institute at the Central University of Venezuela
Simón Bolívar University Ramón Montero
Sciences of Venezuela Róger Martínez
Antonio Machado-Allison Academy of Physical, Mathematical and Natural
School of Engineering Andrés Bello Catholic University
Andrés Bello Catholic University José Ochoa-Iturbe
HIDROVEN Plankton Laboratory Eduardo Buroz
Central University of Venezuela María Leny Matos
Ernesto José González School of Sciences
Venezuela
University of the Republic
Federico Quintans Sives School of Sciences
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Peru
Daniel Conde Scalone School of Sciences
Uruguay
Henry J. Vaux University of California
United States of America
Pontifical Catholic University of Peru
University of Maine, France Eduardo Ismodes Cascón
Pontifical Catholic University of Peru Mathieu Durand
National University of San Marcos Fernando Roca
National Health Institute of Peru Ruth Shady Solis
San Antonio National University of Cusco César Cabezas Sánchez
National Engineering University Victor Carlotto Caillaux
University of Peru Julio Kuroiwa Zevallos
Nicole Bernex Weiss Geography Research Center Pontifical Catholic
University of the Republic Adriana Piperno de Santiago
10 URBAN WATER CHALLENGES IN THE AMERICAS
Acknowledgements
The wealth of information presented in this book is thanks to the 120 authors (all listed in page 603 ) who participated in this collection of information on water resources in their respective countries. They use this information to analyze the urban water context and provide suggestions for improving water management along with solutions to problems related to urban water quality and quantity. The authors contributed their vast knowledge and expertise on a voluntary basis in order to advance our understanding of the present status of water resources in the major urban areas of each of their countries. The goal was to provide a collective synthesis describing the principal urban problems and management strategies spanning the wide geographical and economic diversity of the Americas. It is important to acknowledge the coordination work of the IANAS focal points who served as representatives of all 20 countries and who organized groups of specialists in different water topics as a key factor in assuring the high quality of content of each country chapter. This rich collaborative effort is the foundation for the comprehensive coverage presented in every chapter.
The Global Network of Science Academies (IAP) has provided generous support and inspiration for this book and for which we express our sincere gratitude. We are also grateful for the institutional support and encouragement from the United Nations Educational Scientific and Cultural Organization (UNESCO) and especially to the Director of Division of Water Sciences of the Secretary of the International Hydrological Program (IHP). The IHP has been a strong sponsor of the publication of this book which is closely aligned to one of their present priorities, “Water and Human Settlements of the Future” as described above in words from the IHP Director, Dr. Blanca Jimenez. We appreciate and acknowledge the support of UNESCO and IHP in advancing the original idea for this book and for their essential funding and contribution to the project.
The seven members of the editorial committee spent many hours in the coordination of the content of the chapters, in editing each chapter and in assisting with reviews and revisions and finally with proof reading of the English translation. For this we thank Gabriel Roldan (Colombia), Katherine Vammen
URBAN WATER CHALLENGES IN THE AMERICAS
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(Nicaragua), Claudia Campuzano (Colombia), Ernesto González (Venezuela), Hugo Hidalgo (Costa Rica), Maria Luisa Torregrosa (México)and Adriana De la Cruz Molina (Mexico). Henry Vaux (USA) supported in many ways and especially in revisions for some chapters to assure the correct professional English. Their time and efforts are very much appreciated.
We acknowledge the support and encouragement of the IANAS Co-Chairs, Michael Clegg and Juan Asenjo. We are especially grateful to the co-chairs of the IANAS Water Program,
Prof. José Tundisi of Brazil and Dr. Blanca Jiménez Cisneros of Mexico. Their special knowledge, acquired in two countries with mega urban areas, was the stimulus for the original idea that brought about the elaboration of this book. Their confidence in the focal point representatives of the IANAS water program was an important incentive to bring the book to reality.
We highly appreciate the coordination and richness of ideas for content, design and organization of the book from the Executive Director of IANAS, Adriana de la Cruz Molina who spent many 24 hour working sessions to make this publication possible.
The team of translators was essential to bring the content of the chapters into English in order to secure a wider international public for the book. We thank Suzanne D. Stephens and Alejandra Huete for their energy in bringing this highly technical Spanish into an English text.
The many hours and creative energy put into the cover and graphic design of the book by Víctor Daniel Moreno Alanís who was assisted by Francisco Ibraham Meza Blanco and the team of young graphic designers is highly appreciated. Special thanks to Veronica Barroso for her support in all phases of the publication of the book.
We would like to acknowledge the special support of the Global Water Partnership (GWP) of Central America for its contribution with the chapter of El Salvador and their support for the chapter of Honduras.
Katherine Vammen (Nicaragua) Co-Chair of the IANAS Water Program
12 URBAN WATER CHALLENGES IN THE AMERICAS
Index
15
16
19
21
26
52
84
112
128
146
168
202
URBAN WATER CHALLENGES IN THE AMERICAS
13
248
268
308
332
350
382
414
448
474
524
556
14 URBAN WATER CHALLENGES IN THE AMERICAS
URBAN WATER CHALLENGES IN THE AMERICAS
15 Preface
Water is literally the stuff of life. It is absolutely essential for human health, for food production and for sanitation as well as for a host of other uses. A clear un- derstanding of present and future sources of water and of strategies for the ef- fective management of water resources is in the interest of every country. The challenge is urgent because human population demands, as well as climate change, make once secure sources uncertain. Moreover, water projects are of- ten large and expensive and take many years to complete, so future planning is crucial. Accordingly this volume aims to provide a science-based assessment of key water resource issues on a country-by-country basis for 20 countries of the Americas. The goal of IANAS is for this volume to serve as a valuable reference for policy makers, government officials and planners who will have to meet the challenges associated with our water future.
IANAS is the Inter American Network of Academies of Science (www.ianas. org). IANAS includes all the science academies of the Americas and it has access to the best scientific minds of our region. The goal of IANAS is to bring evidence based science to policy makers and to build scientific capacities in our hemi- sphere. IANAS achieves this goal by advancing investments in human resources for science and by focusing on key resource challenges. This volume is the sec- ond in a series on water, published in both Spanish and English, and intended to reach a wide policy audience. The first volume offered a broad assessment of the status of water resources in the Americas. This second volume addresses the fun- damental problem of urban water challenges. The Hemisphere of the Americas is among the most urbanized of regions on the globe and urban water needs are pressing. IANAS intends that this volume make a valuable contribution to a key challenge facing all of our countries.
Michael Clegg Juan Asenjo
Co-Chair IANAS, USA Co-Chair IANAS, Chile
16 URBAN WATER CHALLENGES IN THE AMERICAS
Urban Waters in the Americas Blanca Jiménez Cisneros Director of the Division of Water Sciences and Secretary of the International Hydrological Programme of UNESCO
The UNESCO International Hydrological Programme (IHP) started in 1975 as a continuation of the International Hydrological Decade (1965-1975). IHP is implemented through phases to adapt its activities to the world’s changing needs for the sustainable management of water. The program and its activities are defined through an in-depth consultation coordinated by the IHP Secretariat and the IHP Regional Hydrologists among 169 IHP National Committees, the category 1 UNESCO–IHE Center for Water and Education, the 28 regional and international UNESCO category 2 Water Centers, the 35 UNESCO Water Chairs and other relevant IHP partners and UN water related agencies.
In 2014, the IHP-VIII entered in its 8th Phase, which is dedicated to addressing the global, regional and local challenges to achieve Water Security. Among the six themes of IHP-VIII, the fourth is “Water for Human Settlements of the Future”, covering among other issues Urban Water.
Today, 750 million people lack access to safe water and many millions more have access only to a deficient service. At the same time, urbanization is growing rapidly. In the next 40 years, cities are expected to receive 800,000 additional inhabitants each week. At the global level, since 2011 for the first time in human history the human population lives in majority in cities. This and the absolute or partial lack of services for people already living in cities combined with population and economic growth have been and will continue to be the factors that demand a higher degree of and improved management of urban water. Also, the aging of urban hydraulic infrastructure is evident in many cities and will require significant investments for its renovation. Worldwide rapid urbanization demands new ways to conceive and operate public services, including those for water. New approaches are required to optimize the joint management of water, land use and energy, as well as to decrease the water footprint of cities and to control the transportation of contaminants into water and the transfer of pollutants among water, soil and the urban air. Among the regions with an important urbanization rate, The Americas, and notably Latin America, emerges. This latter region has the highest global rate of urban inhabitants with more than 72% of its population living in cities. No wonder that urban water management in the region is an issue, sometimes well solved, sometimes less so.
URBAN WATER CHALLENGES IN THE AMERICAS
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This book describes the situation of urban water management in 20 countries: all North and South American ones, and a significant number from Central America and the Caribbean region. To produce it a unique network of multidisciplinary scientists was created which in total 120 involved authors. The book is unique not only for this reason, but also because it covers, for the first time, in an integrated but flexible framework aspects never looked at before in urban water management on the American continent. Among those are water quality, water reuse, urban aquifers, rainwater management, urban floods, human and environmental health issues, and, of course, climate change. Through this multi- directional orientation, the book reveals that the challenges for urban water security extend to cities in all countries. Alongside the continuum of economic considerations, inequity of access to services are a concern, investments to renovate the urban water infrastructure need be planned, the problems of urban floods and poor water quality keep growing, and there is the urgent need to create cities resilient to climate change.
In conjunction with IHP’s approach, this book promotes bridging of science and policy by starting a dialog between science and policy makers. The book is a useful tool provided by scientists, inter alia for policy-makers because it was produced using an interdisciplinary approach, by combining the knowledge of scientists with the experience of water utility professionals and by applying it to solve practical problems relevant to society. A particularly noteworthy aspect of this book is the importance given to the role of outreach and creating a knowledgeable, participating public, is transparently informed about problems and involved in solutions. This underlines the requirement for, on one hand, effective communication skills among the specialized water community to convey scientific aspects to the non-scientific community. On the other hand, it highlights the need to provide reliable information for societies on public water problems and create accountable governance systems that engage with the public on the planning and implementation of projects.
Because of its content and scope, this book is fully in line with the purposes of IHP-VIII. In addition, the book has contributed to IHP key tasks, by (a) mobilizing scientific and innovation networks, (b) strengthening the interface between scientists and decision makers, and (c) contributing to the development of institutional and human capacities. No doubt, this publication is an excellent result of the efforts of the Inter-American Network of Academies of Sciences, in collaboration with the National Academies of Sciences and the countries that have contributed to the book. IHP is very proud to have supported this work through its network and to promote its dissemination and use among the Member States.
18 URBAN WATER CHALLENGES IN THE AMERICAS
URBAN WATER CHALLENGES IN THE AMERICAS
19 Water in Urban Regions José Galizia Tundisi
International Institute of Ecology São Carlos, Brazil
Urbanization is a worldwide phenomenon. Most of the human population currently lives in urban regions, with populations ranging from 10.000 to 50.000 inhabitants, to millions of people in metropolitan cities.
The health and quality of life of these urban inhabitants depends on a series of factors and natural phenomena, such as climate, geological features, hydrological cycles, plant cover and biodiversity.
Intensive land use caused by the expansion of the urban area impacts human health and reduces green areas to a few isolated spots. A city’s water resources are a key component in all the complex environmental conditions sustaining the urban population. Water availability, quality and security are all interlinked in urban regions due to the following factors: in many Latin American cities, good-quality drinking water does not reach all communities, especially in periurban areas; pollution and contamination, resulting from intensive land use and the lack of wastewater treatment and eutrophication due to nonpoint and point sources of nutrients. Water security is related to both water availability and pollution.
How then does one transform an urban region or city into a livable environment? First of all, the complexity of a city or large urban region must be understood. This is a task for future generation of scientists, and researchers, who will apply the
1
science of complex systems to urban regions.Second, cities are dependent on resources far away from the urban area: water, food, fibers and timber are usually brought in due to the disruption of ecosystem services in the urban agglomerate.
Third, the network of roads, building and infrastructure disconnects people from nature. It is essential to restore urban ecosystems. Green cities must build up, protect and promote natural parks, riparian forests and wetlands, clean rivers and lakes in order to provide sites for education and water resource conservation, restore urban
2
biodiversity and reconnect people with nature.These actions will guarantee groundwater recharges and the availability of drinking water, and improve the humidity in the air due to the evapotranspiration of vegetation in natural parks and riparian forests.
Restoration of nature in the cities will promote healthy, attractive urban environments, improve the quality of life and provide better opportunities for employment and education. The water cycle in this context is of extreme ecological, economic, and social importance.
1. Reid W. et al 2010. Earth System Science for Global sustainability: grand challenges. Science vol. 330, pp. 916-917.
2. Tundisi J. G. 2005. Green cities. Letter to the Editor. Science. Brazilian Academy of Sciences, Leopoldina Nationale
20 URBAN WATER CHALLENGES IN THE AMERICAS
URBAN WATER CHALLENGES IN THE AMERICAS
21 A Quick Look At
Urban Water Challenges in the Americas
A Perspective from the Academies Katherine VammenCo-Chair of the IANAS Water Program
Can the problems of urban water supply and sanitation be solved with better management?
Can access to safe drinking water be improved?
Can the challenge of improving sanitation and wastewater management be met?
Can water related health problems and water-borne disease be better addressed in urban areas?
What are the water related challenges in adapting to climate change for urban areas and how can they be met?
What are good models and concepts for helping to improve water management in urban areas?
These questions and others are addressed in the present volume which is focused on the urban water problems of the Americas. Urban water problems are especially important since more than 60% of the world population lives in cities and this number is increasing every year. Moreover, according to United Nations statistics the Americas are among the most urbanized regions of the world (> 80%). Urbanization goes hand in hand with intensification in the use of water resources for human needs; in turn, hydrological systems play a role in the development and growth of cities not only as a source of drinking water but also for the deposition of wastes. Urban Water Challenges
in the Americas describes and analyzes the problems of water in urban centers in 20
countries of the Americas: spanning from South America, Central America, Mexico and the Caribbean to the United States and Canada. This unique examination of the countries of the Americas, each with different water resources characteristics, diverse levels of economic and social development, varying problems related to water quality and quantity and different experiences with water management, is a contribution from the Interamerican Network of Academies of Science (IANAS). The goal of the volume is to aid in the search for solutions to the challenges of properly managing water resources in urban areas as described in the 20 chapters of this book. Evidence from both developed and developing countries shows that to be effective the management of water resources must extend beyond the city to include the surrounding watersheds from which the water comes.
This book is organized into country chapters but each one emphasizes the following topics:
Water resources in urban areas and the impacts on water from urbanization. • The adequacy and accessibility of water supply services in urban areas. • The adequacy of wastewater management in urban areas. • The importance of appropriate urban water services for community health. • The potential impacts of climate change on water resources and water services in •
22 URBAN WATER CHALLENGES IN THE AMERICAS
Special themes from many of the countries include:
Urban Systems and Water: Brazil. • Conservation and Water Reuse as Management Tools: Brazil. • Urban Impact due to Rise of Groundwater: Argentina. • Governance and Sanitation Sector Management: Chile. • Sustainable Rainwater Management in Cities: Chile and Grenada. • Aspects of Island Aquifer Management in Wet Tropical Zones: • Cuba. Special problems of water supply on islands: Grenada and Cuba. • Historical Development of Water Supply and Urbanization: Uruguay. • Rainwater Management and Planning in cities: Uruguay. • • Addressing the problems of water scarcity: Managing Water Demand: USA.
Biological Water Quality in Water Treatment Plants: Panama. • Reutilization of Waste Waters: Colombia. • Analysis of Vulnerability to Climate Change of Principle Nicaraguan Cities • Population Growth and the Structuring of Cities: Mexico. • Climate Change and Urban Disaster Risk: Peru. • Extreme Climate Events in the City of Guatemala. • Hydro-Climatic Projections for Central America: Costa Rica. •
Case study on urban water management
An especially instructive Case Study on best practices associated with Urban Water Management in Toronto, Canada is also included.
This unique collection of experiences with urban waters in the Americas rests on a wide geographical representation that includes differences in water resource availability and levels of economic development. The analyses herein offer the opportunity to draw lessons stemming from the commonalities and differences among the countries of the Americas. Also, it highlights the fact that a significant diversity of water management schemes will be required to manage water effectively.
Urbanization and water resources
Urbanization in the Americas ranges from 50% to 94% of the population in Latin-America and North America, respectively, in 2012 according to the WHO and UNICEF report on Drinking Water and Sanitation (2014). Some Caribbean Islands such as Grenada have lower levels (39%), but the degree of urbanization is increasing. This phenomenon has been observed globally and applies across the Americas, ranging from developed countries with large and stabilized urban populations, to developing countries where patterns of urbanization are steadily growing (UN, 2009). Urbanization concentrates competition for the use of water resources into a small space. This allows for efficiencies in water use, but it also imposes special demands associated with water transport, water quality maintenance and the management of excess water from storm events, among other challenges. If the human needs for healthful domestic living conditions are to be met and if economic development is to prosper, more efficient methods
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In general urbanization requires more water per unit area while producing wastes, including wastewaters and solid wastes that tend to degrade water quality and that must be managed. Urbanization also tends to degrade local watersheds and their surrounding areas through deforestation and increases in impervious areas.
Urbanization and impacts on water resources in urban zones
Urbanization has not been accompanied by adequate planning and foresight in most countries. Environmental impacts are accounted for in advance only infrequently with resulting adverse effects on the environment including water resources. Examples include: 1) Inappropriate land use and deforestation in the watershed and surrounding areas of urban centers leading to erosion which then brings heavy sedimentation into the cities and contaminates sources of water; 2) Uncontrolled discharges of domestic and industrial wastewaters into surface waterbodies and coastal areas; 3) Lacking hygienic habits of the population and inappropriate management of solid wastes deposited into sources of water or city drainage systems; 4) Contamination of ground and surface water from different sources: mining, hydrocarbon spills from industry and contamination from storage of fuel tanks at service stations as well as pesticide runoff from agricultural activities from the surrounding watershed; 5) Impairment of recharge to urban aquifers due to reduction of green cover (forests, wetlands, riparian forests) and impermeable infrastructure associated with urbanization and more.
Water supply services and sanitation
In the last decades the access to potable water and treatment of waste water in cities of the Americas has improved. The coverage of water supply systems in the majority of cities has reached levels that fulfill the Millennium Development Goals of the United Nations for improved drinking water sources and it is important to highlight that Latin America and the Caribbean have the highest drinking water coverage of the developing world. However, as observed in the analysis provided in each country´s chapter, there are still serious problems with the coverage for improved sanitation in cities varying from 57 to 100% according to the WHO and UNICEF report on Drinking Water and Sanitation (2014). An exception is Chile where there has been rapid improvement in sanitation coverage in the last decade such that all collected wastewaters are treated. A combination of factors has made this possible, including Chile´s economic stability, institutional restructuring and significant investments in the context of utility privatization. Despite this success, important challenges remain, such as access to sanitation service in peri-urban unincorporated communities.
Adequate water supply services are generally available throughout the developing countries of Latin American and the Caribbean. The problems are centered more on the continuity of services, the need to repair massive leaks in the existing distribution systems and the need to regulate and enforce controls on illegal connections which affect the efficiency in delivery of water and the economic capacity of the water supply companies to make investments in improving services. Faulty distribution systems have also caused problems in Canada and the United States where there is a need to replace old systems and
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undertake new programs of renewal and innovation. The case study of Toronto presents some management steps being undertaken to finance and improve distribution systems.
The lack of adequate monitoring of water quality for contaminants, together with new emerging sources of contamination, is identified as a major problem in both developed and developing countries. It is also important that the microbiological safety of water in most countries is not secure because the detection of viral and protozoan pathogens is not included in standard water monitoring protocols.
It is important to mention that some improved sanitation systems still cause contamination of water sources originating from the same system. Many countries report examples of septic tanks from urban areas and new urban developments that contaminate groundwater sources used for drinking water. Also the majority of developing countries reported massive problems due to the discharge of waste waters into rivers and the ocean without treatment. It has also been reported that 15% of waste waters do not receive even basic primary treatment. Some Central American countries report many cases where Oxidation ponds treating domestic waste waters discharge into surface waterbodies which consequently undergo strong eutrophication and loss of water quality for human consumption and irrigation.
The cities of Latin America and the Caribbean islands are affected by the informal growth of peri-urban areas (usually due to migration from rural areas or consequences of climate change crisis in rural areas) which have little or no water coverage or sanitation. These areas have the highest rate of water-borne disease and a significant incidence of contamination of water sources. These peri- urban areas will require special attention if healthful drinking water supplies and adequate sanitation services are to be provided to the local residents.
For the United States and Canada, urban water issues are focused on the need for improving maintenance and renewal of systems. The deterioration of quality in source waters and of course the water scarcity crisis require innovative financial, technological and “demand management strategies” to reduce loss of the resource and “maintain levels of reliability”.
Urban water and health