Environmental and Economic Evaluation of Cow-Calf Wintering Site Runoff Control as a Beneficial Management Practice to Improve Surface Water Quality

Abstract

Abstract A runoff diversion-collection system was evaluated as a beneficial management practice (BMP) for minimizing the impact of wintering site runoff on the water quality of an adjacent reach in the headwaters sub-basin of the Haynes Creek Watershed in central Alberta. Significant (α = 0.05) post-BMP mean annual load reductions of 13, 47, and 17% for dissolved, particulate, and total phosphorus, respectively, were realized. Mean annual loads of nitrate nitrogen and total Kjeldahl nitrogen were also reduced by 83 and 22%, respectively. The sum of total loads of Kjeldahl nitrogen and nitrate-plus-nitrite nitrogen, a surrogate measure of total nitrogen, also showed a reduction of 29%. However, mean annual load of total residue increased by 15%. Despite significance at the wintering site, these water quality changes were not statistically detected at the outlet of the subbasin. In spite of the measureable improvement in downstream water quality, adoption of the studied BMP represented a net economic cost to the producer under the current management conditions at the site. Furthermore, there appeared a need for concurrent implementation of BMPs in the headwaters sub-basin to be able to register any detectable changes in water quality at its outlet.