One of the basic steps in developing a watershed plan or a municipal pollution reduction plan (to meet TMDL or MS4 requirements) is to estimate the current pollutant load for the area of interest and the projected load with future development and implementation of best management practices (BMPs). Two key evaluation factors in the section of BMPs to meet pollutant reduction goals are cost and pollutant removal effectiveness. The Center has developed two tools that assist with this work: the Watershed Treatment Model and the Clean Water Optimization Tool. These two spreadsheets allow customization by users and are free and downloadable from the Online Watershed Library.
The Watershed Treatment Model (WTM) 2013 is a spreadsheet-based model that helps users calculate annual pollutant loads and runoff volumes and estimate benefits from a wide range of stormwater runoff and pollutant removal practices. There are two versions: an “off-the-shelf” version that comes as-is and has a simple user interface, and a customizable version. Links to download the WTM and associated resources are provided below
WTM 2020 Update for 64 Bit Machines
To provide feedback, ask questions or report problems with the WTM, contact Deb Caraco at dsc@cwp.org.
The Clean Water Optimization Tool is a planning tool for Maryland communities to develop more cost-effective strategies for reducing stormwater pollution to meet nutrient and sediment reduction goals. Although the impetus for the Tool was the Chesapeake Bay TMDL, it can also be used to address local impairments for nutrients and sediment. The Tool was developed by the Center for Watershed Protection with funding from the Town Creek Foundation and it allows the user to optimize BMP selection based on cost-effectiveness for a particular pollutant, determine the practical limits of implementation, and evaluate progress towards water quality goals. The Tool also includes the most up-to-date crediting procedures approved by the Chesapeake Bay Program and allows the user to evaluate the impact of practices that have not yet been approved. Links to download the Tool and associated resources are provided below:
Clean Water Optimization Tool v 1.01
BMP Implementation Tracking Spreadsheet
This spreadsheet can be used for tracking BMP implementation and reporting to the Maryland Department of the Environment, and the compiled data can be entered into the Tool to track progress towards TMDL targets.
Clean Water Optimization Tool User Manual
Clean Water Optimization Tool Eastern Shore Case Studies
The Center tested out the Tool with four Eastern Shore counties, and showed a reduction in costs of 25%- 67% over the original Watershed Implementation Plan strategies.
Both the Watershed Treatment Model and the Clean Water Optimization Tool are owned by the Center for Watershed Protection and were developed for educational, research, and non-profit purposes. Use of these tools, their components or derivations for profit is strictly prohibited.
