Watershed Selection for the AESA Stream Water Quality Monitoring Program
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Alberta Environmentally Sustainable Agriculture Resource Monitoring Water Quality Watershed Selection for the AESA Stream Water Quality Monitoring Program Anne-Marie Anderson1, Sandra E. Cooke2, and Neil MacAlpine2 1 Alberta Environment, Water Sciences Branch, Edmonton, Alberta 2 Alberta Agriculture, Food and Rural Development, Edmonton, Alberta Executive Summary A provincial stream survey conducted under the Canada-Alberta Environmentally Sustainable Agriculture (CAESA) agreement described the existence of relationships between agricultural intensity of small agricultural watersheds and stream water quality. A strong commitment was made under the new Alberta Environmentally Sustainable Agriculture (AESA) agreement to continue to monitor water quality in small agricultural watersheds as the industry grows and practices change. The AESA Water Quality Monitoring Committee revisited the watershed selection process under the CAESA program as new technology (e.g GIS) and databases were available to select representative watersheds across Alberta. New databases, such as Agricultural Region of Alberta Soil Inventory Database (AGRASID), PFRA annual unit runoff digital maps and 1996 Canada census data, were used to define overland runoff potential and agricultural intensity. All data were rolled up and mapped according to PFRA gross watersheds of Alberta. Watersheds were ranked according to agricultural intensity. Agricultural intensity indicators included manure production (tonnes/acre), fertilizer expenses ($/acre) and chemical expenses ($/acre) to represent the livestock and cropping sectors. Runoff potential was determined according to landform and soil characteristics that facilitate overland runoff. Twenty-three watersheds were selected to cover the range of agricultural intensity that typifies the province. Most of these watersheds have soil and landscape features that promote runoff. The report describes how representative these watersheds are in a provincial and regional context. Acknowledgements The following individuals contributed expertise and advice in the selection of the watersheds for the AESA Water Quality Monitoring Program: David Neilson, Conny Tomas (AAFRD), and Dave Kiely (PFRA). Members of the AESA Water Quality Monitoring Committee are acknowledged for their support in developing the water quality monitoring program. Review comments from Dave Kiely and Rod Bennett helped improve the report substantially. The Irrigation Branch (AAFRD) supplied some of the initial databases that were assembled in an effort to develop a comprehensive geographic information system. Natasha Carle (AAFRD) and Bridgette Halbig (AENV) provided technical assistance with data organization and presentation. John Kirtz and Ian Johnson conducted the initial data compilation, analysis, and interpretation for the site selection process. Carolyn King’s assistance in reviewing and editing the various versions of this report is gratefully acknowledged. Table of Contents Executive Summary .............................................................................................................i Acknowledgements .............................................................................................................ii Table of Contents ...............................................................................................................iii List of Tables......................................................................................................................iv List of Figures ..................................................................................................................... v 1. Introduction ................................................................................................................... 8 2. Methods......................................................................................................................... 9 2.1 Databases used in the Watershed Selection Process ............................................... 9 2.2. Software, basic GIS and other Data Handling Methods ........................................ 17 2.3 Watershed Selection Criteria................................................................................... 18 2.4. Definition of Runoff Potential................................................................................ 18 2.4.1 Potential for surface runoff based on landform................................................ 18 2.4.2 Potential for Surface Runoff based on Soil Type............................................. 20 2.5. Definition of Agricultural Intensity........................................................................ 22 2.6 Watershed Selection................................................................................................ 29 3. Selected Watersheds...................................................................................................... 30 3.1 Provincial Perspective........................................................................................... 30 3.2 Regional Perspective............................................................................................. 43 4. Conclusions ................................................................................................................. 45 5. Literature Cited ........................................................................................................... 46 Appendix 1: AGRASID criteria to define landscape and soils with different runoff potential.......................................................................................................................49 Appendix 2: Agricultural intensity, runoff potential characteristics for Alberta watersheds ................................................................................................................... 56 Appendix 3: Dominant soil and landform characteristics for the AESA Appendix 4: Distribution of agricultural intensity, manure production, fertilizer expenses and chemical expenses in Alberta watersheds grouped by ecoregion and compared to selected AESA watersheds.............................................................................................. Appendix 5: SAS code and data used to assemble integrated watersheds........................... Appendix 6: SAS Code Used to Import and Parse AGRASID Soil and Landscape Information...................................................................................................................... Appendix 7: SAS Code Used to Classify Soil Polygons by Landscape and Soil Characteristics (Potential for Runoff) ............................................................................. List of Tables 1. Distribution of runoff classes based on landform across the ecoregions. ................... 13 2. Distribution of runoff classes based on soil type across the ecoregions. .................... 17 3. Agricultural intensity indicator values for reference percentiles for the distribution of provincial watersheds.................................................................................................. 22 4. Basic hydrological reference data for AESA watersheds. .......................................... 25 5. Agricultural Intensity data for AESA watersheds....................................................... 29 List of Figures 1. PFRA gross watershed boundaries in Alberta (Cherneski and Ackerman 1998) ......... 3 2. Provincial annual unit runoff yield (dam3/km2), 50% probability of exceedance. ....... 5 3. (a) Provincial annual unit runoff (AUR) zones............................................................ 6 3 (b) Provincial watersheds ranked according to low, moderate and high annual unit runoff............................................................................................................................. 7 4. Ecoregions in Alberta ................................................................................................... 8 5. Agricultural zones in Alberta ........................................................................................ 9 6. Irrigation districts of southern Alberta........................................................................ 10 7. Watersheds that meet size criteria used in the AESA site selection process .............. 12 8. Watershed runoff potential classification based on landforms ................................... 14 9. Watershed runoff potential classification based on soil types and textures................ 16 10. Watersheds ranked according to agricultural intensity based on 1996 census data.... 18 11. Watersheds ranked according to manure production based on 1996 census data....... 19 12. Watersheds ranked according to fertilizer expenses based on 1996 census data........ 20 13. Watersheds ranked according to chemical expenses based on 1996 census data ....... 21 14. Location of the AESA watersheds in Alberta. .......................................................... 24 15. Runoff potential for the AESA watersheds based on landforms ................................ 27 16. Runoff potential for the AESA watersheds based on soil types and textures............. 28 17. Agricultural intensity for AESA watersheds based on 1996 Canada census data ...... 30 18. Manure production for AESA watersheds as compared to provincial intensity values........................................................................................................................... 31 19. Fertilizer expenses for AESA watersheds as compared to provincial intensity