BMP IMPACTS ON WATERSHED RUNOFF, SEDIMENT, AND NUTRIENT YIELDS¹

Abstract

To quantify the effectiveness of best management practice (BMP) implementation on runoff, sediment, and nutrient yields from a watershed, the Nomini Creek watershed and water quality monitoring project was initiated in 1985, in Westmoreland County, Virginia. The changes in nonpoint source (NPS) loadings resulting from BMPs were evaluated by comparing selected parameters from data series obtained before, during, and after periods of BMP implementation. The results indicated that the watershed‐averaged curve number, sediment, and nutrient (N and P) concentrations were reduced by approximately 5, 20, and 40 percent, respectively, due to BMP implementation. The nutrient yield model developed by Frere et al. (1980) was applied to the water quality parameters from 175 storms, but it failed to adequately describe the observed phenomena. Seasonal changes in nutrient availability factors were not consistent with field conditions, nor were they significantly different in the pm‐ and post‐BMP periods. An extended period of monitoring, with intensive BMP implementation over a larger portion of the watershed, is required to identify BMP effectiveness.

Use of Beryllium‐7 to Document Soil Redistribution following Forest Harvest Operations

“…Several practices, including the construction of cross banks on access roads, skid trails, and landings; the rapid re-establishment of a vegetation cover on disturbed areas; and improved management of streamside zones and logging debris, have been adopted to reduce erosional impacts and to limit the delivery of sediment to watercourses, to maintain water quality standards (Park et al, 1994;Griffin, 1995;Wallbrink et al, 2002). In the Lake Region of Chile, final harvesting in forestry plantations commonly takes place in the drier months of the year, between October and April.…”

Responses of Stream Habitat, Macroinvertebrate, and Fish to Watershed Bmps: Lessons From Wisconsin

“…The central tendency of the regression residuals used to control for natural variability decreased with the implementation of BMPs, and hence the improvement in water quality was likely a result of BMP implementation. In another study evaluating impacts of BMPs in a Virginia stream, Park et al (1994) reported that watershed-scale BMPs reduced runoff curve number, sediment, and nutrient (N and P) concentrations by approximately 5, 20, and 40%, respectively. Edwards et al (1996) also concluded that concentrations of ammonia nitrogen, Kjeldahl nitrogen, and chemical oxygen demand were significantly reduced by watershed BMPs in an Arkansas stream basin.…”

Agricultural Best Management Practice Abundance and Location does not Influence Stream Ecosystem Function or Water Quality in the Summer Season

“…BMPs assessed in past studies have been shown to reduce nutrient levels in agricultural streams (e.g., [21,[57][58][59][60][61][62]). However, results from our study did not suggest that BMPs were enhancing water quality in the studied streams.…”