The Lerma-Chapala Watershed Evaluation and Management The Lerrna-Chapala Watershed Evaluation and Management

Edited by

Anne M. Hansen and Manfred van Afferden Mexican Institute of Water Technology Jiutepec,

Springer Science+Business Media, LLC ISBN 978-1-4613-5125-2 ISBN 978-1-4615-0545-7 (eBook) DOI 10.1007/978-1-4615-0545-7 ©2001 Springer Science+Business Media New York Originally published by Kluwer Academic 1Plenum Publishers, New York in 2001 Softcover reprint of the hardcover I st edition 2001

10987654321 A C.J.P. record for this book is available from the Library of Congress All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher Contributors

Ministry of Urban Development, (SEDEUR) National Water Commission (CNA) Mexican Institute of Water Technology (IMTA) Centrum for International Migration and Development (CIM) Asociacion Mexicana de Limnologia (AML) Aquatic Ecosystem Health and Management Society (AEHMS)

Front cover: Traditional fishing with tumbo in South shore at San Luis Soyatlan county. The tumbo is an extended stationary fishing art for in-water captures. Photography: Pablo Chavez-Hernandez, IMTA

Back cover: Priest of Thiloc (rain god), Rio Blanco-Papaloapan culture, Mexico, 600-900 A.D., terracota, 47 cm, Anthropological Museum, Jalapa, Mexico. The Mesoamerican cultures were aware of groundwater drainage in the mountains. Photography: Carlos Blanco

Hieroglyph: • atl, water in Nlihuatl

Cover design: Xochitl ZUfuga

v Acknowledgements

The editors wish to express their deepest gratitude to the following referees for their critical review and recommendations to improve the quality of the chapters in this book:

1. Javier Alcocer, National University of Mexico 2. Javier Aparicio, Mexican Institute of Water Technology 3. Alfonso Banderas, Mexican Institute of Water Technology 4. Luis Angel Barrera-Morteo, National University of Mexico 5. Arturo Chacon, Michoacan San Nicolas de Hidalgo University 6. Sonia Davila-Poblete, Mexican Institute of Water Technology 7. Benjamin de Leon, Mexican Institute of Water Technology 8. John Dunbar, Baylor University, USA 9. Carlos Escalante, National University of Mexico 10. Mercedes Escamilla, Oficina de Comunicacion del Lago, Mexico 11. Anatoliy Filonov, University, Mexico 12. Tim Ford, Harvard School of Public Health, USA 13. Alberto Guitron, Mexican Institute of Water Technology 14. Carlos Gutierrez-Ojeda, Mexican Institute of Water Technology 15. John R. Jones, University of Missouri, USA 16. Jess Kelly, Baylor University, USA 17. Anna Kurtycz, France 18. Owen Lind, Baylor University, USA 19. Polioptro Martinez-Austria, Mexican Institute of Water Technology 20. Manuel Martinez-Morales, Mexican Institute of Water Technology 21. Jorge Martinez-Ruiz, Mexican Institute of Water Technology 22. Rodrigo Moncayo-Estrada, CIIDIR-IPN-MICH, Mexico 23. Harvey Shear, Environment Canada 24. Joseph White, Baylor University, USA 25. Pedro F. Zarate-del Valle, Guadalajara University, Mexico 26. Nayeli Zuniga, ITESM Campus Monterrey, Mexico

vii Foreword

James O. Leckie Environmental Engineering and Science Program, Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020, USA

Nearly 10 years have passed since the beginning of the systematic studies of the Lerma-Chapala Basin coordinated by the Instituto Mexicano de Tecnologia del Agua. Although many public and private institutions, universities and research centers have conducted studies on the Lerma• Chapala Basin over the last two decades, the need for a comprehensive summary of the findings of those studies has become increasingly obvious and important for this critical water resource. The Lerma-Chapala Basin is located in the central part of Mexico, and partly occupies five states. The watershed comprises the and Lake Chapala. With a length of over 700 km, the tributary watershed covers approximately 54,000 km2. The basin accounts for more than one-third of the country's economic activity, one-fifth of all commerce and one-eighth of the nation's agricultural land. The watershed receives 3% of the country's total rainfall, less than 1 % of the runoff, and accounts for 13% of the total groundwater. Lake Chap ala represents the final destination of most of the pollution discharged to the Lerma river watershed, where surface water and agricultural land are being contaminated by domestic and industrial discharges. The average depth of the Lake Chapala varies between 4 and 7 m, depending on the season and the annual rainfall. Wind mixing helps reduce stratification, and the lake is usually well mixed and oxidized at all depths. Lake Chapala is the largest natural water body in Mexico and, as such is of major importance to both the ecologic and socio-economic systems of the state of Jalisco. The Lerma-Chapala Basin has cultural and historical as well as scientific and economic importance. The presence of many indigenous people's origins within the basin adds archeological and anthropological interest to a complex setting. Although the current book focuses on summarizing the science and water resource management issues, it also set the precedent for the knowledge base of the ecology, social-political and economic aspects of the Lerma-Chapala Basin. Such knowledge bases are

ix x James 0. Leckie necessary for the development of coherent public policy for efficient management and use of this finite resource. Generally speaking, multidisciplinary approaches are obviously required to solve environmental problems. This is at odds with the traditional content of most university training, which requires that students, during the course of their curricula, become ever more specialized. The price of competence in natural, economic and social sciences is linked to this high degree of specialization. Unfortunately, simply putting together teams of specialists cannot attain reconciliation of this requirement with multidisciplinary approaches that are needed to study environmental systems. In order to succeed, scientists must be able to communicate effectively together at the highest possible level, to allow both a constructive exchange of ideas and a clearer realization of the limits of their own specialty. Creating the necessary context to enable effective communication is one of the future challenges facing those responsible for the management and operation of our water resources. The task is complicated by the competing demands on multi-use water resource systems. One of the main purposes of this book is to bring together the wide range of knowledge providing the basis for intelligent management and effective allocation of water as a scarce resource. The authors' and the editors' participation in this endeavor is a valued contribution toward the goal of development of a coordinated comprehensive knowledge base for the Lerma-Chapala Basin water resources. Preface

Alvaro A. Aldama Instituto Mexicano de Tecnologia del Agua, Paseo Cuauhntihuac 8532, Jiutepec, Mor., Mexico

The environmental challenges we face today include many of the same ones that were faced twenty years ago. In spite of the efforts of environmental engineers, scientists, legislators, and the public, our environmental problems remain. Many of our rivers and lakes still suffer the effects of poorly treated sewage and industrial discharges. The Lerma• Chapala basin is no exception to this situation. The Lerma-Chapala basin is of the utmost importance to the development of Mexico, and the control of water use and pollution should be of the highest priority in this region. Urban, agricultural and industrial developments have caused serious conflicts in the use of water and, due to decreased water quality, have limited water availability. The Lerma-Chapala-Santiago Watershed Council was the fIrst river• basin council to be established in Mexico. It also exemplifIes the advances in water management decisions that have been attained through stakeholder participation. Solutions to water management problems are not simple to achieve in such a complex region, given that there is an increasing water demand by industry, agriculture and a growing population. Problems of pollution of surface water, groundwater and soil are also present in the Lerma-Chapala basin. The importance of an accurate water balance cannot be overemphasized. Interrelationships between groundwater and surface water and errors in terms of water budgets have been the focus of studies carried out in the Lerma-Chapala watershed over the past decades. Lake Chapala is Mexico's largest and most important lake. Cyclic decreases in water levels of the lake have alarmed the population not only in the immediate surroundings, but also nationwide and abroad. These fluctuations have caused both ecological and economical problems, including those related to the excessive presence of water hyacinth and blue-green algae. In Lake Chapala, as in other lakes, eutrophication is a natural process taking place over long periods of time and has been greatly accelerated by human activities. With the addition of anthropogenic nutrients, algae growth

Xl xii Alvaro A. Aldama

in the lake is increased. Eventually, a process that would have occurred over geologic time scales is decreased to decades. When not controlled, this process may have some undesirable effects on water quality such as: excessive plant growth (green color, decreased transparency, excessive weeds), hypolimnetic loss of dissolved oxygen (anoxic conditions), loss of species diversity (loss of fishery), and taste and odor problems. Contaminants from human activities in the watershed emanate from both point and non-point sources. Point sources are usually more easily controlled (by wastewater treatment). After point source reductions are accomplished, non-point sources may become the most significant contaminant loading to the water body. Non-point sources are caused by agricultural runoff, storm water runoff or combined-sewer overflows. The control of non-point source pollution is the subject of current research. Both particulate and dissolved forms of contaminant additions are important because even particulate phases become available to the water and biota after desorption or transformation in the natural ecosystem. Bioavailability of contaminants is the subject of much concern and debate as to their relative contribution of particulate and adsorbed pollutants to rivers and lakes. In order to obtain as much information as possible, the distribution and availability of contaminants must be taken into account as new monitoring strategies are designed and implemented. During decades, public and private institutions, research centers and universities have carried out studies on the Lerma-Chapala basin. The results of these studies have received limited exposure and distribution, making recovery of the information difficult. Often studies are repeated, resulting in wasted resources and discontinuity in the historical data that could be used to further work in water use efficiency and ecosystem health assessment. Solutions to environmental problems in general and in particular those that have been found in the Lerma-Chapala basin, must be approached from a multidisciplinary point of view. The present book includes important contributions from several universities and research centers: University of Guadalajara (U de G), Mexican Institute of Water Technology (IMTA) , Autonomous University of Guadalajara (UAG) , Baylor University, and Environment Canada, to name a few. It is meant to serve as a starting point for future research and decision-making based on this knowledge. The editors of this book are privileged to have such a fine group of authors contributing with chapters on the various aspects on watershed managemeht. Many of the authors are experienced professionals in their respective fields. I am convinced that this book gathers the most important technical and scientific information on the Lerma-Chapala basin and will serve as a means to make this information available to the government, research centers and society at large. Introduction

Eduardo Mestre-Rodriguez Independent Senior Consultant on integrated water resources management. Member ofthe World Bank River Basin Water Management Window Team. Queretaro. Qro., MEXICO

Water is either critically scarce or highly abundant in Latin America. Some of the richest countries in per capita water availability in the world are located in this region (Le. Paraguay, Surinam, and Venezuela). However, paradoxically, some of the poorest nations with regards to water availability coexist in this region, with the added stress that their socioeconomic development patterns are rapidly increasing water demands and triggering fierce conflicts. This in turn endangers water governance and has direct negative feedback on water availability, both in quantity and quality. Argentina, Chile, Peru and Mexico, are Latin American countries where in specific sub-regions water is normally scarce or has become scarce either because of natural causes, like cyclical climatic phenomena, or aggravated by human activities and faulty policy that exert increasing pressure on existing supply and reduce it furthermore by pollution. Within Latin America, Mexico is different concerning history and culture. Its cultural archetypes, some of them only slightly understood, and deeply intermixed racial roots, as a result of the marriage of two rich cultures, the Spaniards and the inappropriately called Indians, have produced a unique civilization, located in an attractive natural location in the world, with its potentials, asymmetries and drama - natural and manmade. With a territory of little less than two million square kilometers I , Mexico is the tenth economy in the world with an estimated GNP of 600 billion US dollars for 2000 ($5,980 dollars per capita) and the eleventh country in terms of population with over 95 million inhabitants, 80% of which live in urban

1 Mexico covers 1.97 million km2; it is divided into 31 autonomous states - each with its own elected government - and a federal district, which includes Mexico City.

xiii xiv Eduardo Mestre-Rodriguez settlements. Presently, 60% of the population is either middle or high class, whereas 40% is still poor, among which, 18% live in extreme poverty (however, no famine exists). Mexico's annual exports are above 135 billion dollars2 (eighth, worldwide) as a result of structural economic changes and the benefits of NAFTN, that triggered a positive economic reaction that helped sustain overall annual economic growth rates higher than 5.5% in the period 1996-2000. The Mexican peso has steadily strengthened and is currently the strongest currency in Latin America. Expert fmancial reviews grant the lowest investment risk levels to Mexico together with Chile. Recent favorable negotiations with the European Union and South American economic blocks are expected to reinforce economic activity and exports. In tum, these events will raise water demands, which may unfortunately contribute to aggravate the already critical situation. Water is scarce in Mexico. A complex system of mountain ranges creates 310 hydrological basins, with different degrees of water availability, hydraulic development and water pollution. Although mean rainfall is about 740 mm - roughly the same as in England, its spatial and seasonal distributions make a difference in the ways water is available. Total average surface runoff together with aquifers mean annual recharge is approximately 460 cubic kilometers. Its average annual water availability per inhabitant is below 5,000 cubic meters. In certain areas, like in the Valley of Mexico, the Lerma river basin, La Laguna endorheic system and the Bravo river (Rio Grande), this figure drops below 1,000 m3 per year. Needless to say, Mexico is poor in terms of water supply. Water exists where population density is low, like in the Southeast, where in less than 25% of the territory, two-thirds of all rainfall and surface runoff occur. In dramatic contrast, population and economic activity concentrate in the higher plateaus where climate is temperate but water is either naturally scarce or has become scarce by severe pressure on allocation and by non-optimal water management. In many regions, Mexico currently faces an imbalance between water demand and availability, primarily due to natural water scarcity as well as uneven water quality distribution. Rapid urban and industrial growth, among other economic and social factors, has worsened this scenario. Water needs have raised, water uses are fiercely competing with each other and as a result, conflicts are surging. Water quality has deteriorated as urban and industrial effluents are often discharged with insufficient previous treatment. Furthermore, Mexico's past economic and financial crisis, limited hydraulic infrastructure development and triggered low water services (urban and rural

2 Oil represents less than 20% of overall exports, whereas manufactured goods exports are close to 60%. In lesser extent, agricultural and fisheries are still relevant. 3 Mexico has become US second commercial partner and a strategic ally in political and economic matters. Introduction xv water utilities) in many sectors and locations. Presently, in formal or legal terms, only three countries in the Anlerican Hemisphere allow water markets (either national or regional): The , Chile, and Mexico, each with interesting singularities with regards to underlying concepts, procedures and results. Water markets are rapidly affecting actual water distribution per use and water productivity throughout the country, with extraordinary effects in more developed regions such as Valley of Mexico, Lerma-Chapala and Rio Grande basins. However, water markets, without appropriate regulatory measures might yield unsatisfactory results, as can be seen both in Chile and Mexico. The latter has yet to rule out speculation and monopolization, as well as establish a public participation with regards to sectoral water transfers from one use (irrigated agriculture) to another (industry, urban water utilities). Water markets with insufficient fmancial moderating instruments may go out of kilter. Presently, in Mexico water is gradually reflecting more the overall costs involved in having access to it (capital, operation, management, and opportunity costs), especially in those regions where water is or has become scarce. However, in the past, social factors have led to grant important subsides to certain water uses, mainly irrigated agriculture4• Water productivity is extremely low, and this in turn affect other potential uses that could utilize presently allocated water for higher productivity uses, without affecting agricultural activities, should water efficiencies be improved. Here lies one of the most important possibilities for future water management optimization in Mexico. By Federal Law, water users who are legal tenants of federal - issued water rights titles have to pay for water use by volumeS. These revenues are called derechos de agua (water rights) and were originally conceived as basin tariffs, which would reflect water opportunity costs, that on one hand could render relevant revenues for the water sector, and on the other hand, induce higher water efficiencies.· Periodically water rights rates per cubic meter are published within the Federal Rights Law dispositions - such rates are subject to debate in the House of Representatives that has to approve them before becoming official. Water rights rates are mainly determined according to use and location. Payments should be quarterly made on a self-declaration basis and are thought to find its way back to the water sector, mostly via the National Water Commission (CNA) budget, although revenues only exceptionally return to the specific region where they have been originally produced. In Mexico, revenues are

4 Irrigated agriculture represents more than 75% of all water being used in Mexico. 5 Only the Federal Government, through the CNA is legally entitled to issue water rights, either for surface runoff or groundwater. xvi Eduardo Mestre-Rodriguez close to one billion dollars a year, although the potential is much larget. Basin tariffs are also paid for sewage discharges to national water bodies. Such tariffs are based on the discharged volume on a specific location together with water quality criteria7• Effluent discharge water rights were conceived, similar to water abstraction basin tariffs. The objectives were to raise revenues to support water quality management expenditure throughout the country and foster public and private investment in water treatment facilities and schemes to effectively reduce pollutions. Water discharge tariffs are also periodically published as part of the water rights legislation, and must be previously approved by Congress. All Mexican water resources are national property. However, water allowances - concesiones - may be in the domain of private persons or organizations9• Maximum annual abstraction volumes are indicated in these concesiones as well as their exploitation rate. Water allowances are usually secured for less than 25 years, although no legal recommendations exist. The Lerma-Chapala basin is of paramount importance to Mexico, from the economic, political and social points of view. Consequently, this basin receives priority attention from all three government levels - federal, state and municipal. Public awareneSS on water issues has led to active participating roles played by water users, non-governmental organizations, and social institutions with a plethora of interests directly or indirectly linked to the water sector. The Lerma river - 750 km long - is born in Mexico's central high plateau surpassing 3000 meters above sea level (masl) and ends in Lake Chapala (1510 masl) 10. The Lerma river basin, a subtropical semiarid region with average temperature of 21°C, and an area of 54,421 km2 -less than 3% of Mexico's territory - features an average rainfall of 735 mm per year, mainly concentrated in the summer, from which a mean runoff of 5.76 km3 is derived. The Santiago river flows westward from Lake Chapala to the

6 Potential payers are at least three times as many as those who presently pay. Financial - fiscal- coactive tools have been enforced but mainly dedicated to industrial users who pay for more than 90% of all revenues. Average annual per capita revenues derived from such payments, are presently less than US$lO, whereas in developed countries with similarly based basin tariffs, annual per capita revenues can be over US$60. 7 Only two parameters (total suspended solids and biochemical oxygen demand) were agreed to be accounted for as reasonable proxies for other relevant pollutants. S Originally, water discharge tariffs were purposely higher than equivalent treatment costs (capital investment, operation and management) to improve water treatment. 9 However, water allowances are not real rights in terms of private possession. Furthermore, although such is the case, water allowances are subject to alienation, inheritance and pawning. 10 Lake Chapala is the largest tropical lake in Mexico - 77 km long and 23 Ion wide. Its maximum storage capacity is 8.13 km3 with a global surface around 110,000 ha. The lake is shallow, with an average depth of 7.2 m, and a maximum of 16 m. Introduction xvii

Pacific Oceanll . The Lenna-Chapala river basin comprises portions of the central states of Mexico, Queretaro, , Michoacan, and Jalisco, all of capital importance in Mexico's development. Current basin population is eleven million - one in nine Mexicans - with an annual growth rate slightly less than the national average. The Upper Lenna aquifers supply water to 2 million inhabitants in Mexico City and Lake Chapala supplies water to an additional 2 million inhabitants in Guadalajara. The population in the basin is distributed in 6,224 localities, 18 of which have more than 50,000 inhabitants. Rural population contributes currently with 27% of the basin's total population. Regional socioeconomic development has been triggered by water availability. Industrial and agricultural production per capita has surpassed national levels. Currently, 795,000 hectares (one eighths of Mexico's irrigated land) belong to the Lerma-Chapala basin. National farm goods exports rely heavily on the performance of this tiny region, which is of utmost importance for Mexico's high-value agricultural exports. The region boasts 9,200 industries, which generate one third of the industrial GNP (9% of Mexico's GNP). Furthennore, 20% of all national commerce and service activities occur in this basin. With three highly developed economic sectors and a superior transportation network - partially financed by private investors - this is in fact one of the richest regions in Latin America. All surface runoff in the basin, either natural or effluent, is allocated. Water efficiency in agriculture is low and illegal water abstractions occur in certain seasons. Some 28,000 deep-water wells operate in the basin with very low efficiency rates, high electricity consumption and rather low water yields. Nevertheless, almost 70% of the 38 aquifers in the region are overexploited. Conflicts derived from surface runoff uses (mainly for irrigation and drinking water supplies), combined with generally untreated effluents discharges, have originated serious pollution problems, both locally and regionally. Another frequent conflict over water quality occurs in Lake Chapala, which plays a key role as a main water source for Guadalajara. As efforts from very different sources and interests converge in this region, the Lenna-Chapala basin could become a model in many fields, to guide Mexico as well as some other emerging economies, towards attaining integrated water management.

II The Santiago river basin is less developed in tenns of population and economic activity, except for Guadalajara, the second largest city in Mexico, whose metropolitan area has more than 3.5 million inhabitants. Contents

SECTION I NATURAL RESOURCES AND MANAGEMENT IN THE BASIN 1 Chapter 1 HYDROLOGY OF THE LERMA-CHAPALA WATERSHED 3 JAVIER APARICIO

Chapter 2 GEOLOGY, SEDIMENTS AND SOILS 31 PEDRO F. ZARATE-DEL VALLE, FRAN«;:OIS MICHAUD, CLAUDE PARRON, GABRIEL SOLANA-ESPINOZA, ISABEL ISRADE-ALCANTARA, HERMES U. RAMIREZ-SANCHEZ, AND FRAN«;:OIS FERNEX

Chapter 3 NATURAL RESOURCES MANAGEMENT IN THE LERMA-CHAPALA BASIN 59 BENJAMiN DE LEON-MOJARRO, RAUL MEDINA-MENDOZA, AND ARTURO GONzALEZ-CASILLAS

SECTION II POLLUTION AND HEALTH 93 Chapter 4 TOXIC SUBSTANCES 95 ANNE M. HANSEN AND MANFRED VAN AFFERDEN

xix xx Index

Chapter 5 WATER CONCENTRATIONS, BIOACCUMULATION, AND HUMAN HEALTH IMPLICATIONS OF HEAVY METALS IN LAKE CHAPALA 123 JENNY AYLAJAY AND TIM E. FORD

SECTION III LAKE CHAPALA 137 Chapter 6 AN INTRODUCTION TO THE LIMNOLOGY OF LAKE CHAPALA, JALISCO, MEXICO 139 OWEN T. LIND AND LAURA DAvALOS-LIND

Chapter 7 HYDRO-METEOROLOGY OF LAKE CHAPALA 151 ANATOLIYE. FILONOV, IRINAE. TERESHCHENKO, AND CESAR O. MONZON

Chapter 8 NUTRIENTS AND EUTROPHICATION IN LAKE CHAPALA 183 JOSE DE ANDA AND HARVEY SHEAR

Chapter 9 PHYTOPLANKTON AND BACTERIO-PLANKTON PRODUCTION AND TROPHIC RELATIONS IN LAKE CHAPALA 199 LAURA DAvALOS-LIND AND OWEN T. LIND

Chapter 10 FISH FAUNA OF LAKE CHAPALA 215 RODRIGO MONCA YO-ESTRADA AND HECTOR RENE BUELNA-OSBEN

SECTION IV SOCIAL AND ECONOMICAL ASPECTS 243 Chapter 11 ON THE SHORE: SOCIAL AWARENESS REGARDING LAKE CHAPALA AND ITS ENVIRONMENT 245 PABLO CHAvEZ-HERNANDEZ Index xxi

Chapter 12 SOCIAL CHARACTERIZATION OF THE LERMA- CHAP ALA RIVER BASIN 269 SONIA DA VILA-POBLETE AND ANA HELENA TREVINO- CARRILLO

Chapter 13 COMPETITION FOR WATER IN THE LERMA- CHAP ALA BASIN 291 CHRISTOPHER A. SCOTT, PAULA SILVA-OCHOA, VALENTIN FLORENCIO-CRUZ, AND PHILIPPUS WESTER

Chapter 14 PRoEsTADO-MAUA® 325 JUAN MANUEL HUERTA, MONTSERRAT-SERRA, AND RICARDO SANDOVAL

Chapter 15 INSTITUTIONAL ARRANGEMENTS FOR WATER MANAGEMENT IN THE LERMA-CHAPALA BASIN 343 PHILIPPUS WESTER, ROBERTO MELVILLE, AND SERGIO RAMOS-OSORIO

SECTION V SUMMARY AND CONCLUSIONS 371

SUMMARY AND CONCLUSIONS 373 ANNE M. HANSEN AND MANFRED VAN AFFERDEN

INDEX 379