|Bingner, Ronald - Ron|
Submitted to: Federal Interagency Sedimentation Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/28/2001
Publication Date: N/A
Interpretive Summary: Watershed scale evaluation is an essential step in recommending best management practices and/or setting Total Maximum Daily Load (TMDL) pollutant allocations, with watershed modeling technology available to help in this process. Technology is described in this study that can be used to provide information needed to describe the sediment, nutrient, and pesticide loadings from agricultural fields within a watershed. Comparisons with measured results from a watershed in Mississippi are used to demonstrate the capabilities of this technology. Local, state, and federal watershed management planners can use this technology as a tool to determine the impact non-point source pollution from agricultural watersheds has on the impairment of rivers and streams.
Technical Abstract: Watershed scale evaluation is an essential step in recommending best management practices and/or setting Total Maximum Daily Load (TMDL) pollutant allocations. Allocations established without comprehensive studies will likely require treatment of lands that will contribute little to load reductions and insufficient treatment of higher contributing lands. The Agricultural Nonpoint Source model (AGNPS98) was developed to perform these necessary evaluations. AGNPS98 is a suite of computer models developed to assist the user with quantifying the impacts of agricultural nonpoint source pollution on water quality and the environment. The models in AGNPS98 include: (1) a watershed-scale, continuous-simulation, pollutant loading computer model designed to quantify & identify the source of pollutant loadings anywhere in the watershed for optimization & risk analysis; (2) a set of stream network, corridor, & water quality computer models designed to predict & quantify the effects of bank erosion & failures, bank mass wasting, bed aggradation & degradation; (3) a watershed-scale, stream network, water temperature computer model to predict daily average, minimum & maximum water temperatures; (4) a set of salmonid life-cycle models designed specifically to quantify the impact of pollutant loadings on their spawning & rearing habitats; and (5) an economic model that determines the net economic value of Pacific Northwest salmonids restored to either the commercial or recreational catch. This paper will discuss these components and demonstrate the capabilities of the model using Goodwin Creek Watershed in Mississippi. By applying a watershed management approach, TMDL's can be better defined and practices can be better established in setting these water quality standards.