ASABE Technical Library - Abstract
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An Innovative Model for Watershed Management and the Development of Narrative TMDLs
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org
Citation: Pp. 496-503 in Total Maximum Daily Load (TMDL) Environmental Regulations: Proceedings of the March 11-13, 2002 Conference, (Fort Worth, Texas, USA) 701P0102.(doi:10.13031/2013.7602)Authors: Avinash S. Patwardhan, Farhan Shaikh
Keywords: TMDLS, Watershed Protection, Sustainable Development, Compliance, WISE Model
The State of Georgia s water quality standards are intended to provide protection for designated uses.
TMDL (Total Maximum Daily Load) targets are based on these water quality standards. In cases where
numeric water quality standards are not available, narrative standards are used for developing TMDLs.
These narrative standards cannot be allocated, hence, there is a need to link the narrative standards to
pollutant loads generated from the watershed.
The WISE (Watershed Improvements through Statistical Evaluations) Model was designed to link the
watershed pollutant loads to narrative standards, i.e., biological indices. Specific biological standards
based on biological indices such as Index of Biological Integrity (IBI), Fish Score, and Invertebrate
Community Index (ICI) are used as measurement tools and are linked to various pollutant loads from the
watershed. The WISE model allows users to view various scenarios based on desired goals in order to
make technically sound decisions for developing narrative TMDLs. The what-if scenarios allow users
to screen various combinations of best management practices (BMPs) and present a reality check by way
of cost-benefit analyses. The model also allows local governments to track new developments and control
the amount of pollutants carried by runoff from the site by using BMPs.