Transboundary Implications of the Garrison Diversion Unit INTERNATIONAL JOINT COMMISSION Transboundary Implications of the Garrison Diversion Unit INTERNATIONAL JOINT COMMISSION CANADA AND UNITED STATES 1977 INTERNATIONALJOINT COMMISSION CANADA AND UNITED STATES COMMISSIONERS MAXWELL COHEN, Chaitrmafi HENRY P. SMITH 111, Chaihmun BERNARDBEAUPRE CHARLESR. ROSS KEITHA. HENRY VICTOR L. SMITH SECRETARIES DAVID G. CHANCE WILLIAMBULIARD A. Ottawa Washington FOREWORD The International Joint Commissionwishes to acknowledgewith gratitude the valuable contribution of the members of theInternational Garrison Diversion Study Boardand of the members of the five Committees which assistedthe Board in its endeavours.Without their indi- vidualzeal and collective effort, completion of the Commission's inquiry in such a short time would nothave been possible. TheCommission appreciates the large amount of data providedby the United States Bureau of Reclamation. While it was suggested during theinquiry that all datahad notbeen made available, the Commissionand its Board are satisfied with and commend the Bureau of Reclamation for its cooperation. The Commission also wishes to acknowledge the supportand cooperation of the seventeen federal, state andprovincial agencies that actively participated in the investigation. i i i TABLE OF CONTENTS Chapter Page SUMMARY 1 I INTRODUCTION Nature ofthe Problem Scope of theInquiry Chronology of Events I1 THE STUDY AREA 11 The Garrison Diversion Unit 11 The Areas Affected by the Garrison Diversion Unit 15 Climate 16 Demography 17 I11 EXISTINGCONDITIONS IN THE STUDY AREA IN CANADA 19 Present Water Quantities 19 Present Water Quality 21 Present State of the 24 Biological Resources Present and Anticipated Water Use 27 IV THE BOARD'SINVESTIGATION 31 Method of Determining Existing Conditions 34 Method of Determiningthe 35 Possible Impacts ofthe Project Measures to Minimize Adverse Effects of GDU 39 v IMPACTS ON CANADA OF THE GARRISONDIVERSION 41 UNIT ASENVISAGED Water Quality Parameters 42 Impact on Water Quantity 45 Impact on Water Quality 48 Impact on Biological Resources 54 Impacts on Uses 58 Possible Benefits to Canada 60 iii TABLE OF CONTENTS (contI d) Chapter Page VI MODIFICATIONS TO THE GARRISON DIVERSION UNIT AND REMAINING IMPACTS 63 Reduction of Highly-Saline Soils 64 Wetland Restoration 65 Modifications to McClusky Canal Fish Screen 66 The Closed System 66 Lining of the Velva Canal 70 Cost of Modifications 71 Effectiveness of Modifications 71 Remaining Impacts 76 Mitigating Measuresin Canada 77 VI I PUBLIC HEARINGS 79 Initial Hearings 80 Public Briefingby the United States Bureau of Reclamation 86 The 1977 Hearings 86 VI11 CONSIDERATIONS AND CONCLUSIONS 95 Transboundary Implications 96 Existing Conditions 98 Impact in Canada of GDU as Envisaged 99 Measures to Alleviate Potential Adverse Impacts 106 Delay of Further Construction 113 Verification and Research 114 Water Quality Agreement 116 IX RECOM”DATI0NS 121 SEPARATE OPINION OF COMMISSIONER BEAUPRB 125 iv TABLE OF CONTENTS (cont 'd) Page Appendices A Text of Reference 129 B Directive to the Board 133 C Membership of the Board 139 D Membership of theTechnical Committees 141 E Participating Agencies 145 F Persons Presenting Briefs or Testimony ' 147 at the Hearings List of Figures Figure 1 SchematicRepresentation of the GarrisonDiversion Unit 12 2 Return Flows to Souris River from GDU as Envisaged 47 3 Concentrations of TotalDissolved Solids on Sourisand Red Rivers 49 4 Sketch of a Typical Irrigation and DrainageSystem 69 5 Study Area 155 List of Tables Table 1 Historic and Projected Water Quality for the Souris River nearWesthope 74 2 Historic and Projected Water Quality for the Red River at Emerson 75 V SUMMARY This report of the International Joint Commission is in response to a Reference fromthe Governments of Canada and the United States. It brieflydescribes the Garrison DiversionUnit, the area in Canada affected by it, theadverse effectson Canadian waters and their uses,and measures to avoid or relievethese adverse effects. The reportdescribes the technical investigation carried out for the Commission by its InternationalGarrison Diversion Study Board during 1976 and summarizes thetestimony given at thepublic hearings conductedby the Commission. Finally, the report outlines thesubstance of the Commission's deliberations based on the investigationand hearings and presents its conclusionsand recommendations. Constructionof the GarrisonDiversion Unit was authorized by theUnited States Congress in 1965. The purpose ofthe Project was to irrigate some 250,000 acres toprovide municipaland industrial water supply to 14 communities,and to furnish recreational, fish andwildlife opportunities in North Dakota using water diverted from the Missouri River. Since many ofthe features of the Garrison Diversion Unit (GDU) are in the Hudson Bay DrainageBasin, most of the drainageand wastewaters from the irrigated areas would flow into trans- boundary streams andcould have an adverse impact on Canada. Article IV ofthe Boundary Waters Treaty of 1909 reads in part as follows: "It is further agreed that the waters herein defined as boundary waters andwaters flowing across the boundary shall not be polluted on either side to the injury of health or property on the other." Manitobaofficially expressed its alarm that leaching of the irrigated soils of'GDU woulddegrade the water quality 1 2 of theSouris, Assiniboine and Red Rivers as well as Lakes Manitobaand Winnipeg, and that the return flows would increasethe amountand frequency of flooding.There was also concern that the water conveyancesystems of the Garrison Diversion Unit.would provide a direct connection between the Missouri River and the Hudson Bay Drainage Basinthereby enabling the possible introduction of foreign fish, fish eggs, fish parasites, fish diseases andother biota intoManitoba waters. This couldhave an irreversible adverseimpact on existing aquatic systems and on commercial and recreational fishing in Manitoba. The Canadianconcerns, crystallized in an aide-msmoire, prompteddiscussion between the Governments of Canada and theUnited States in 1970. Fiveyears later the twoGovernments referred the matter ofthe transboundary implicationsof the Garrison Diversion Unit to the Inter- national Joint Commission. The Commission was requested to report on the existing conditions of water quality, waterquantity, biological resources, and present and anticipated water uses;the impact of GDU as envisaged at the time of the Referenceon them; to make recommendations as tosuch measures as might be taken to assist Governments in ensuring that the provisions of Article IV of the Boundary Waters Treaty of 1909 are honoured,and to estimate the costs of suchmeasures. All this was tobe completed within the severe time constraint of one year. The Commissionimmediately established the International Garrison Diversion Study Board tounder- take the technicalinvestigation. The limited time frame precluded field studies to obtain new data. Therefore, existing data were 'used to assess the impact of GDU on Canadian waters. The Boardduring their intensive year- long investigation adhered to a rigorousschedule so as to 3 Concurrentlydetermine existing conditions in Manitobaand estimate thequantity, quality and impact of return flows resulting from theGarrison Diversion Unit. It also examined proposals to minimizethe adverse effects of GDU and to miti- gate the remaining impacts. The eight public hearings conducted by the Inter- national Joint Commission were an integral part of the inquiry intothe transboundary implications of the GarrisonDiversion Unit. Three initialhearings were held in November 1975 to obtain opinions on the possible effects of GDU andguidance in planningthe investigation. Two months after theBoard's report was distributed,five public hearings were held,in March 1977, to receive commentson thereport and further views ofconcerned individuals, citizen groups, elected represen- tativesand governmental officials. At eachpublic hearing all those interested were given the opportunity to express theirviews orally or presentdocumentary evidence. In addition to these formal publichearings, the Board, pursuant to a Commission Directive,held open meetings to answer questionson its investigation. The Commission in its deliberationsconsidered testimonygiven at the publichearings, the Board's report and writtensubmissions. On the basis of this evidence the Commissionhas concluded that the construction and operation of the GarrisonDiversion Unit as envisagedwould cause injury to health and property in Canada as a result ofadverse impacts on the water quality and biological resourcesin Manitoba. Modifications to GDU as envisaged such as the elimination of direct connections between the MissouriRiver and the Hudson Bay DrainageBasin, replace- ment of highly-saline soils with a similar acreage of soils less saline, lining the Velva Canal,and wetland habitatrestoration, would reduce, but not eliminate, all 4 of theadverse impacts in Canada. Most ofthe remaining impacts,other than those from possible biota transfers, can bemitigated to a significant extent. The Commissionhas concluded that it would be prudent to verify the predicted quantity and quality of returnflows from GDU. Research to determinethe ultimate fate of nitrogen inthe Souris River is essential before there is development of irrigation in that area. The International Joint Commissionrecommends that the portion of the Garrison Diversion Unit which affects waters flowing