AN EVALUATION OF APPORTIONMENT MONITORING NETWORKS for the SASKATCHEWAN RIVER at the SASKATCHEWAN-MANITOBA BOUNDARY Prepared by: Prairie Provinces Water Board Committee on Hydrology JANUARY 1997 PPWB REPORT NO. 141 TABLES OF CONTENTS LIST OF FIGURES...........................................................................................................ii LIST OF TABLES............................................................................................................iii CHAPTERS: 1. INTRODUCTION .................................................................................................. 1 2. APPORTIONMENT FLOW................................................................................... 3 3. WATER USE PROJECTS IN SASKATCHEWAN................................................. 7 4. ALTERNATIVE METHODS FOR ESTIMATING FLOW OR WATER LEVEL AT A SITE .............................................................................................. 13 5. SENSITIVITY ANALYSIS .................................................................................. .17 6. CONCLUSIONS ................................................................................................. 27 7. RECOMMENDATIONS ...................................................................................... 29 APPENDIX A SUMMARY OF WATER USE ITEMS IN THE SASKATCHEWAN PORTION OF THE SASKATCHEWAN RIVER BASIN ................................................A-1 LIST OF FIGURES FIGURE 1: SASKATCHEWAN RIVER DRAINAGE BASIN.....................................A-13 FIGURE 2: A COMPARISON OF APPORTIONMENT FLOW (EXISTING NETWORK VERSUS SCENARIO 1 NETWORK).................................... 20 FIGURE 3: A COMPARISON OF APPORTIONMENT FLOW (EXISTING NETWORK VERSUS SCENARIO 2 NETWORK).................................... 21 FIGURE 4: A COMPARISON OF APPORTIONMENT FLOW (EXISTING NETWORK VERSUS SCENARIO 3 NETWORK).................................... 22 FIGURE 5: A COMPARISON OF APPORTIONMENT FLOW (EXISTING NETWORK VERSUS SCENARIO 4 NETWORK).................................... 23 FIGURE 6: A COMPARISON OF APPORTIONMENT FLOW (EXISTING NETWORK VERSUS SCENARIO 5 NETWORK).................................... 24 FIGURE 7: A COMPARISON OF APPORTIONMENT FLOW (EXISTING NETWORK VERSUS SCENARIO 6 NETWORK).................................... 25 LIST OF TABLES TABLE 1: LIST OF STATIONS INVOLVED IN THE COMPUTATION OF MONTHLY APPORTIONMENT FLOW FOR SASKATCHEWAN RIVER AT SASKATCHEWAN-MANITOBA BOUNDARY .......................... 2 TABLE 2: WATER RIGHT PROJECTS IN THE SASKATCHEWAN PORTION OF THE SASKATCHEWAN RIVER BASIN ............................................... 8 TABLE 3: VARIATION OF WATER USE ITEMS IN THE SASKATCHEWAN PORTION OF THE SASKATCHEWAN RIVER BASIN............................ 11 TABLE 4: MEAN FLOW OR WATER LEVEL USED IN THE SENSITIVITY ANALYSIS ............................................................................................... 15 TABLE 5: A COMPARISON OF APPORTIONMENT FLOW VOLUMES FOR SELECTED NETWORK SCENARIOS ........................................... 19 TABLE 6: POSSIBLE EFFECTS OF TERMINATING THE SELECTED GAUGING STATIONS............................................................................. 26 i ii iii iv 1. INTRODUCTION Apportionment balance computation for the Saskatchewan River at the Saskatchewan-Manitoba boundary has been conducted annually since 1973 using a procedure described in a PPWB report entitled “Natural Flow Saskatchewan River at the Saskatchewan-Manitoba Boundary” (PPWB Report No. 45). This procedure requires flow and/or water level records from nine hydrometric gauging stations and two pumping stations. The procedure also requires meteorological data from three meteorological stations. Table 1 shows the gauging stations required for computing apportionment balance at the Saskatchewan-Manitoba boundary. Two of the nine hydrometric gauging stations currently being used for the apportionment of the Saskatchewan River are also needed for other purposes. The Carrot River near Turnberry station (05KH007) is needed for interprovincial water quality monitoring, while the Elbow Diversion Canal at Drop Structure station (05JG006) is needed for the apportionment of the Qu’Appelle River. Saskatchewan River basin (see Figure 1) is one of the major river basins in the prairie provinces where monitoring of apportionment is currently required by the Board. Apportionment balance results for this river at the Saskatchewan-Manitoba boundary have been published in the PPWB annual reports. The results show that Manitoba had received its entitlement every year in the past 22 years (1973 to 1994). In recent years, because of budget restraints, Environment Canada has indicated difficulties in continuing to maintain apportionment monitoring networks at the existing level. The Board, at its March 1994 meeting, approved a COH report entitled “Hydrometric Monitoring Strategy” (PPWB Report No. 127), and directed the COH to review the existing apportionment monitoring networks on interprovincial streams. As part of this review, the Committee on Hydrology at its January 1995 meeting, agreed that the Saskatchewan River’s apportionment monitoring network be evaluated. This report is a summary of that evaluation. v TABLE 1 LIST OF STATIONS INVOLVED IN THE COMPUTATION OF MONTHLY APPORTIONMENT FLOW OF THE SASKATCHEWAN RIVER AT THE SASKATCHEWAN-MANITOBA BOUNDARY Station ID Station Name Operating Agencies 05HF007 Broderick Irrigation Project Sask Water Main Canal below Pumping Station 05KH007 Carrot River near Turnberry Environment Canada 05KH011 Dragline Channel near Squaw Rapids Environment Canada 05JG006 Elbow Diversion Canal at Drop Environment Canada Structure 05HF003 Lake Diefenbaker at Gardiner Dam Environment Canada 05HD033 Reid Lake near Duncairn Environment Canada 05KJ001 Saskatchewan River at The Pas Environment Canada 05HD034 Swift Current Canal at Swift Current Environment Canada 05KD004 Tobin Lake at Squaw Rapids Spillway Environment Canada METEOROLOGICAL DATA REQUIRED 1. Lake Diefenbaker - Monthly gross evaporation and precipitation. 2. Tobin Lake - Monthly gross evaporation and precipitation. 3. Reid Lake - Monthly gross evaporation and precipitation (Gross evaporation for Reid Lake is estimated by multiplying lake Diefenbaker evaporation by 1.10). ADDITIONAL DATA REQUIRED 1. Luck Lake Irrigation Project Annual Pumpage. 2. Riverhurst Irrigation Project Annual Pumpage. vi 2. APPORTIONMENT FLOW Article 3, Schedule B of the Master Agreement On Apportionment defines Manitoba’s share of flow for streams crossing the Saskatchewan-Manitoba boundary as : Natural Flow at the Saskatchewan-Manitoba Boundary minus : a) one-half the water flowing into Saskatchewan in that watercourse from Alberta, b) any water which would form part of the natural flow in that watercourse but does not flow into Saskatchewan because of the implementation of any provision of any subsisting water apportionment agreement made between Alberta and Saskatchewan and approved by Manitoba, and c) one-half the natural flow arising in Saskatchewan. Saskatchewan River is a typical case that applies to the above formula, because it cross both the Alberta-Saskatchewan and the Saskatchewan-Manitoba boundaries. To determine Manitoba’s share of flow, it requires natural flow at the Saskatchewan-Manitoba boundary, recorded flow at the Alberta-Saskatchewan boundary (ie.,Article 3a), consumptive use in Alberta portion of the basin (ie.,Article 3b), and natural flow arising in the Saskatchewan portion of the basin (ie., Article 3c). It is quite clear that Manitoba’s share of flow is not simply one-half of the natural flow at the boundary. To avoid possible confusion, a term”Apportionment Flow” has been used in the Saskatchewan River’s apportionment computation to simplify the procedure of determining whether Manitoba has received its share of flow from Saskatchewan. The term “Apportionment Flow” is defined as flow that is subject to apportionment. In the case of the South Saskatchewan River or the Qu’Appelle River, the apportionment flow is equal to natural flow because natural flow at the boundary is subject to apportionment. While in the case of the Saskatchewan River, natural flow at the boundary is not subject to a 50:50 apportionment between Saskatchewan and Manitoba. The share of flow that Manitoba or Saskatchewan is entitled to is not one-half of the natural flow. Based on the definition stated above, Manitoba’s share of flow on the Saskatchewan River can be interpreted as one-half of the water flow into Saskatchewan from Alberta plus one-half of the natural flow arising in Saskatchewan. Recognizing that the flow is shared on a 50:50 basis between Saskatchewan and Manitoba, therefore, the flow that is subject to apportionment (Apportionment Flow) would be the water received by Saskatchewan from Alberta plus natural flow arising in the Saskatchewan portion of the basin. Apportionment flow at the Saskatchewan-Manitoba boundary and its relationship with natural flow at the boundary may be described mathematically as follows: Determine Manitoba’s share based on Article 3, Schedule B vii SHARE man = NF s/m - (½)RF a/s -USE alta - (½)NF sask ...................(1) Where : SHARE man is Manitoba’s share of flow. NF s/m is natural flow at the Saskatchewan-Manitoba boundary. RF a/s is recorded flow at the Alberta-Saskatchewan boundary. USE alta is consumptive use in Alberta portion of the basin. NF sask is natural flow arising in Saskatchewan portion of the basin. Assuming no channel loss in the