M Agriculture and Agriculture et Agri-Food Canada Agroalimentaire Canada- Research '_ Direction generate Branch - de la recherche iable agriculture Canada in !&. '^i e^ etatdeV THE HEALTH OF OUR Toward sustainable WATER agriculture Canada in D.R. Coote and L.J. Gregorich (editors) Research Branch Agriculture and AgrrFood Canada Publication 2020/E 2000 ©Minister of Public Works and Government Services Canada 2000 Available from Donna Dewan Strategic Promotion Research Planning and Coordination Research Branch Agriculture and Agri-Food Canada 930 Carling Avenue, Room 777 Ottawa, ON K1A 0C5 Tel. 613 759-7787 Fax 613 759-7768 e-mail [email protected] Electronic version available in May 2000 at res2.agr.ca/research-recherche/science/Healthy_Water/toc.html Publication 2020/E Cat. No. A15-2020/2000E Science Writer ISBN 0-662-28489-5 Printed 2000 3M:03/2000 Gregorich L.J. Gregorich Research Designers Ana-Francine Beland Johanne Sylvestre-Drouin Strategic Promotion Agriculture and Agri-Food Canada Production Editors Sharon Rudnitski Strategic Promotion Agriculture and Agri-Food Canada Jane T. Buckley Gilpen Editing Service Cette publication est disponible en francais sous le titre La sante de Veau vers une agriculture : durable au Canada Contents Foreword Vll Preface Vlll Executive Summary XI Chapter Introduction 1 1 Agriculture's dependence on water 1 Agriculture's effects on water 1 Sustainable agriculture 2 The health ofCanada's rural water 2 Objectives ofthis report 2 Reading and using the report 3 Chapter 2 Canada's Rural Water Resources 5 Introduction 5 The hydrologic cycle 5 Canada's water resources 6 Watergains and water losses 7 Surface water 9 Groundwater 12 Diverted water 13 Transboundarywaters 14 Conclusion 14 Chapter 3 Water Use 15 Introduction 15 Agricultural use ofwater 16 Crop production 16 Irrigation 17 Frost protection 20 Livestock production 20 Rural domestic use 21 Other rural water uses 22 Electrical power generation 22 Rural municipal use 23 Manufacturing 23 Mining, oil, and gas 23 Fisheries, aquaculture, and wildlife habitat 23 Recreation 23 Legislation and regulation ofwater use 25 Conclusion 25 Chapter 4 Understanding Water Quality 27 Introduction 27 Risk and water quality 28 Defining and measuring water quality 28 Monitoring water quality 31 National monitoring 32 in Contents Provincial and local monitoring 32 Agricultural effects on water quality 32 Soil condition 34 Sediments 35 Nutrients 35 Pesticides 38 Pathogens and other factors 39 Agriculture's need for good-quality water 41 Irrigation 41 Livestock 41 Domestic use 41 Interprovincial and international issues 41 Conclusion 41 Chapter 5 Surface Water Quality 43 Introduction 43 Suspended sediments 44 Nutrients 49 Pesticides 52 Pathogens 58 Metals 59 Organic matter 60 Conclusion 60 Chapter 6 Groundwater Quality 61 Introduction 61 Nitrate 62 Pesticides 67 Bacteria 70 Other contaminants 72 Conclusion 73 Chapter 7 Ecological Issues 75 Introduction 75 Watercourses 76 Streams and rivers 76 Agricultural drains 79 Floodplains 82 Lakes and ponds 82 Riparian zones 84 Wetlands 85 Benefits ofwetlands 85 Waterfowl habitat 87 Constructed wetlands 88 Integrated ecosystems 88 Water in the landscape 90 Conclusion 90 IV Contents Chapter 8 Protecting Water Quality 91 Introduction 91 The role offarmers 92 Land management 92 Input and waste management 99 Buffer zones and shelterbelts 103 The role ofthe agricultural industry 104 Codes ofpractice 104 Peer advisory programs 105 Environmental farm planning 105 The role ofthe community 106 The role ofgovernment 106 Policy and programs 106 Incentive mechanisms 109 Conclusion 110 Chapter 9 Maintaining Reliable Water Supplies 111 Introduction 111 Drought 111 Surface water management 113 Groundwater recharge 114 Reclaimed water 117 Balancing demand with supply 117 Conclusion 119 Chapter 10 Managing Excess Water 121 Introduction 121 Benefits ofdraining farmland 121 Where drainage is needed 123 Draining organic soils 123 Drainage systems 124 Surface drainage 124 Subsurface drainage 124 Effects ofdrainage on the environment 125 Water quality 125 Riparian zones 126 Hydrology 127 Managing drainage 127 Role ofwetlands 127 Stormwater management 127 Drain maintenance 128 Conclusion 129 Chapter 11 Limits on Rural Growth Related to Water 131 Introduction 131 Sharing the resource 132 Competition for water 132 Conflict with other sectors 132 Water allocation 133 Agricultural concerns 133 Expanding irrigated farmland 133 Expanding livestock industry in western Canada 134 Drought and potential climate change 135 1 Contents Government controls 136 Federal legislation 136 Provincial legislation 138 Municipal bylaws 138 Regulatory constraints 138 Conclusion 139 Chapter 12 Concluding Remarks 141 Introduction 141 What is happening to rural water? 14 Water quantity 141 Water quality 141 Aquatic ecosystems 142 Why are these changes happening? 142 Why are these changes important? 142 What is being done to address these issues? 143 Glossary 145 Bibliography 153 Authors'Affiliations 165 Acknowledgments 171 Citations — D.R. Coote and L.J. Gregorich (eds.) 2000. The health ofour water toward sustainable agriculture in Canada. Research Planning and Coordination Directorate, Research Branch,Agriculture and Agri- Food Canada,Ottawa,Ont. Each chapter can be cited as follows : [Name(s) ofchapter author(s)]. 2000. [Chapter heading]. Pages [...]- [...] in D.R. Coote and — LJ.Gregorich (eds.) The health ofour water toward sustainable agriculture in Canada. Research Planning and Coordination Directorate, Research Branch,Agriculture and Agri-Food Canada, Ottawa, Ont. VI Foreword Many systems in ourworld are dependent on With contributions from almost 100 authors,this — water natural systems,such as biological book draws on the experience and knowledge of — communities, and human systems, including experts from a wide range offields agronomy, towns and cities,industry, and agriculture.All soil science,agricultural engineering, agricultural these users have an effect on the water resource, policy, hydrogeology, meteorology,water and all have an interest in issues ofwater quantity chemistry,aquatic biology, and wildlife and water quality. But because this resource is conservation,among others. This diversity of relatively plentiful in Canada, it may be taken for authorship ensures a balanced treatment ofthe granted and used without adequate care. subject,with fair consideration ofthe manyviews held by various stakeholders. Using a variety of Farmers are sensitive to water issues,because research findings and case studies, TheHealth of their crops and animals need sufficient quantities Our Waterprovides abroad picture ofwater ofgood-quality water. In most areas in Canada, quantity and quality in Canada as they are rainfall supplies crops with needed water. affected by agriculture,and as they affect However,in manyareas water also comes from agriculture itself. It will be useful in identifying surface runoff,watercourses such as streams and issues for immediate action and will also serve as rivers, or groundwater sources.Too much or too a benchmark against which to measure future little water,or water at the wrong time,decreases changes. agricultural production.The extremes,namely droughts or floods, can have disastrous effects. This bookbolsters Canada's international Farmers and other rural residents and industries reputation ofbeing in the vanguard ofresearch must share this resource with fish and wildlife, and reporting on environmental interests. It is a and with those who enjoythe many recreational welcome addition to the pool ofinformation on benefits ofour rural landscape. natural resources and the environment that is available to farmers,the non-farming public, The water resource is affected naturally over time politicians,government agencies,and educational in manyways. Erosion alters the constituents institutions. carried by water. Leachates reachinggroundwater change its chemical composition.Also, climate change causes new runoffpatterns. Many ofthese Harry M. Hill long-term changes can be speeded up or made Senior Policy Fellow, Saskatchewan worse by human activity. For example,the Institute ofPublic Policy quantity ortiming ofsupply may change at Former Director General, Prairie Farm critical times ofthe year; orwater maybe Rehabilitation Administration and contaminated by chemicals or living organisms, Chairman, Canadian National and its usefulness diminished. Such changes may Committee on Irrigation and Drainage be subtle and go unnoticed at first. It is important that the health ofourwaterbe monitored so we can understand the changes taking place.Only then can we take corrective actions as needed. The Health ofOur Wateris an important document that summarizes much useful information on the state ofrural water in Canada.Among other things, it shows that water quality is intimately connected to soil quality, improving where soil conservation practices are used. VI] Preface Water is essential for all living creatures and is an resulting from agricultural production. The important component ofcountless human findings ofthis project, reported in Env—ironmental activities. Canada has an extensive reserve of Sustainability ofCanadian Agriculture Reportof freshwater.Yet water maybe scarce in some places theAgri-Environmental IndicatorProject, provide or ofunsuitable quality for some purposes. much evidence ofa growing stewardship ethic in Growing human demands for water are sure to the agri-food sector and a greater use of add further constraints on this resource.And conservation farming practices than was the case changes in natural forces, such as potential 15 years ago. They also point to geographical climate change,can also affect the supply and areas and farming modes that need further distribution ofwater. It is therefore essential that attention as we work toward a greater we examine the state ofwater quantity and environmental sustainability in Canadian quality in Canada and devise ways to manage our agriculture. water resources sustainably TheHealth ofOur Waterjoins The Health ofOur An interest in issues ofwater quantity and quality Soils and The Health ofOurAirto complete a is a vital component ofthe expanding series ofpublications that show how agriculture environmental agenda ofagriculture in Canada. interacts with our natural resources. However,the This interest was clearly enunciated in the 1990 assurance ofan adequate supply ofclean water is Report to Ministers ofAgricultureby the essential not only for agriculture,but also for Federal-Provincial Agriculture Committee on human health, ecosystem integrity,and the Environmental Sustainability,which emphasized viability ofmany economic activities. the importance ofthese issues for the Consequently,water issues are the focus of sustainability ofthe agri-food sector. Following research and policy making in many other federal this,Agriculture and Agri-Food Canada (AAFC) departments, including Environment Canada and developed its sustainable developmen—t strategy, Health Canada,as well as other levels of Agriculture in Harmony with Nature Strategyfor government.Thus, unlike its companion books, EnvironmentallySustainableAgriculture andAgri- and as a result ofthe nature ofwater research in FoodDevelopment in Canada.This strategy Canada, The Health ofOur Waterdoes not mainly promotes environmental and resource report on AAFC research but instead draws widely stewardship, with an emphasis on water quality, from sources throughout the country both on and offthe farm. The business plan of AAFC's Research Branch also calls for responsible This book carries the State ofthe Environment use ofnatural resources, including the (SOE) reporting symbol,because it satisfies the maintenance ofsurface- and ground-water guidelines for the federal government's SOE quality reporting program. The two key purposes ofSOE reports are to foster the use ofscience in policy- In the past,agricultural production was less and decision-making and to report to Canadians considerate ofthe natural resources on which it on the condition oftheir environment. The Health depends.Today,good stewardship begins with ofOur Watermeets SOE reporting requirements knowing the state ofour resources. It then moves by providing an easily understood overview ofan on to develop ways to maintain or improve this important environmental issue for the non- state. In keeping with this goal,AAFC has now scientist; examining the key trends ofthe water completed a project to develop a set ofagri- issue; discussing links with other issues; and environmental indicators. These indicators are describing the efforts ofgovernment, industry, useful in assessing the current state of and others to address the water issue and make agricultural resources and examining trends in progress toward environmental sustainability. the environmental performance ofagriculture. Two ofthe indicators relate to the risk ofwater We are pleased to present this report and contamination by agriculturally derived anticipate that it will be useful in the hands ofour substances and thus to the threat to water quality many interested partners as we continue to work viu