| | Why was this study conducted? | Why was Haynes Creek selected? | Where and how was the water tested? | What did we learn? | How can I learn more?
The Haynes Creek study was conducted to determine if runoff from cultivated fields and cattle wintering grounds has a direct influence on surface water quality. The research was conducted as part of the Canada-Alberta Environmentally Sustainable Agriculture (CAESA) Agreement, which monitored surface water quality in agricultural areas across the province. The Haynes Creek watershed was selected for this site-specific study because it was considered representative of an area with very intense agricultural activity, in a landscape sensitive to water erosion. While the project was intended as an impact assessment, not a study of management practices, the results confirm that runoff from some agricultural activities does have an impact on surface water quality. Results from CAESA research and monitoring studies show that Haynes Creek appears to be typical of streams which drain intensively farmed lands. Research in the watershed is continuing.
Why Was This Study Conducted?
As part of a province-wide study to determine if runoff from farm activities could impact surface water quality, researchers monitored the water in 27 streams, located in runoff-prone landscapes across Alberta. One of these streams, Haynes Creek, was selected for a more detailed, site-specific watershed study. The work was conducted to get specific information on the effects on water quality of agricultural practices, runoff, and related natural processes.
Why Was Haynes Creek Selected?
The watershed of Haynes Creek, a small tributary of the Red Deer River, is located east of the Town of Lacombe. The area is home to a large number of mixed agricultural operations, including intensively-farmed cropland and livestock operations.
Background data for the selection process came from a large number of sources, including the 1991 Census of Agriculture, the Soil Landscapes of Canada database, and other information on soils, topography, climate, and agricultural production. The databases identified the Haynes Creek watershed as a suitable study area because:
- Soils in the watershed are erosion-prone, with well-developed natural drainage.
- The area has reliable snowmelt and summer runoff events.
- Agricultural inputs, defined on the basis of fertilizer and pesticide use, and livestock density, are in the top 25% for the province (high intensity area).
- The watershed was readily accessible, had a long record of stream flow data, and had no urban or industrial waste discharges that might skew the findings.
Where and How Was the Water Tested?
Water samples were taken at 18 stations. These sites included:
- A cattle wintering ground on a home quarter section, separated by a grass strip from a tributary of Haynes Creek. (C1)
- A cattle wintering ground on the flood plain. Haynes Creek passes through this site. The animals are bedded in the flood plain, fed in a stubble field on the east bank, and watered on the creek, or on the west bank. (C2)
- Three conventionally-tilled field sites, one with a functioning grassed waterway. (F1-3)
- Seven monitoring sites on the creek. (M1-7)
- A control site west of the creek, on land covered mainly with aspen and dense shrubs. A small number of cattle graze the fringes of the area in the summer. (CX)
Samples were taken during 1995 and 1996. During high flow periods, samples were taken at least once a day. When flows decreased, samples were taken once a month.
Water samples were analysed for nutrient content (total nitrogen [TN] and total phosphorus [TP]), biological characteristics, non-filterable residues [NFR], conductivity and other physical characteristics, some metals and major ions, and a total of 21 commonly used pesticides.
What Did We Learn?
Water quality in Haynes Creek appears to be typical of streams which drain intensively farmed land. Such streams have higher nutrient levels and more frequent pesticide detections than streams which drain land farmed with moderate or low intensity. Frequently, the water in Haynes Creek did not comply with drinking water quality guidelines, nor with guidelines for the protection of aquatic life.
The two years of data from the Haynes Creek project are representative of average (1995) and very high (1996) spring flows. During the sampling period, runoff in the watershed occurred during spring snowmelt only. Although there were rainstorms in both years during the open-water season, they were insufficient to cause runoff.
Key results from the different project locations are described below.
Cattle wintering sites
Water samples downstream of the cattle wintering sites complied less frequently with surface water quality guidelines, than water upstream of the wintering sites. Runoff from cattle wintering grounds contained high levels of nutrients, fecal bacteria, suspended and dissolved solids, and other characteristics. Flooding at site M4 in April 1996 contributed a particularly heavy nutrient and suspended solids load to the stream.
Cultivated field sites
In 1996 nitrogen losses from some fields, mostly in the form of nitrates, represented almost 39% of the nitrogen applied as fertilizer in the previous growing season. Phosphorus losses, mostly in the form of dissolved phosphorus, represented over 16% of the application of that nutrient. These losses are economically significant to the farmer, as well as detrimental to stream water quality.
Nutrient losses from site F1, which does not have a functioning grassed waterway, were far higher than at site F2, which has a well-maintained grassed waterway. Losses of suspended and dissolved solids were also higher at site F1. This helps confirm the effectiveness of grassed waterways in controlling runoff, preventing erosion, and filtering contaminants.
Phosphorus, colour and carbon levels in spring runoff were similar at the field sites and the control site. Nitrogen levels, however, were much higher at the field sites.
Snowmelt on the bare, cultivated fields was rapid. At the control site, where there was substantial vegetative cover, melting was slower and more water seeped into the ground or evaporated. There was no surface runoff at the control site in 1996.
Haynes Creek monitoring sites
None of the samples taken from Haynes Creek itself complied with surface water quality guidelines for the protection of aquatic life for total nitrogen, total phosphorus, or colour.
Levels of suspended solids and turbidity were directly correlated with stream flows and discharge rates. As stream discharge increased, more suspended solids entered the water from overland runoff and disturbance of stream bed materials. Higher spring flows were associated with lower concentrations for most other attributes, due to greater dilution of the water quality contaminants.
Pesticides
The application of 13 different pesticides to the cultivated field sites was reported by local producers. Water samples were analysed for these and for other pesticides in common use across the province. Pesticide residues were detected in 15 of the 22 samples taken in the two year period. Residues of seven herbicides which had been applied the previous spring were detected in field runoff samples. This confirms that pesticides can persist from the spring of one year, to the spring of the following year.
Five pesticides for which there was no local record of application in that area were also detected. This suggests that long-range atmospheric transport and deposition are possible pathways for water contamination.
Water samples from the control site, four sites on Haynes Creek and one site on the Red Deer River were also analysed for pesticides. Of the 67 samples tested, 73% had at least one pesticide detection. Most detections were from the Haynes Creek samples. There were no detections from the control site and only a few from the river.
Eight of the 13 compounds for which the water was tested were detected. Residues of imazamethabenz were found in 61% of the samples. This compound, which is highly mobile in water, was detected more often and at higher concentrations in 1996 than in 1995, possibly as a result of the higher runoff in that year.
None of the samples exceeded existing Canadian Drinking Water Guidelines for pesticide contamination. Only a single detection of trifluralin exceeded guidelines for the protection of aquatic life. However, it should be noted that there is no guideline for imazamethabenz, nor do guidelines exist for six of the eight pesticides which were detected. Consequently, the economic, environmental and health significance of these detections cannot be fully assessed.
How Can I Learn More?
Copies of the technical report for the Haynes Creek study, the summary report for the complete CAESA Water Quality study, and other information on water quality and agriculture are available from your regional AAFRD Conservation Co-ordinator. Or telephone the toll-free Alberta Ag-Info Centre at 1-866-882-7677.
This fact sheet on the Haynes Creek Watershed Study is one of a series of special information bulletins on agriculture and resource management produced by Alberta Agriculture, Food and Rural Development. The other factsheets are: Provincial Stream Surveys and Assessing Alberta's Water Quality
Special thanks are due the agricultural producers in the Haynes Creek area, who so kindly assisted and cooperated in this study. |
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