MIDS calculator sample exercises

For each Best Management Practice (BMP) in the Manual a page was created explaining how to apply that BMP in the Minimal Impact Design Standards (MIDS) calculator. Each page provides a discussion of the requirements, recommendations and information for using that BMP in the calculator. Each page contains an example application for the BMP. Links to those pages are shown below.

• Bioretention with no underdrain
• Bioretention with an underdrain
• Swale with no underain
• Swale with an underdrain
• Swale side slope
• Wet swale
• Sand filter
• Tree trench/tree box with no underdrain
• Tree trench/tree box with an underdrain
• Green roof
• Permeable pavement
• Constructed stormwater pond
• Stormwater wetland
• Other BMP
• Infiltration basin/underground infiltration
• Harvest and re-use

• BMPs in series

• The MIDS calculator was developed as a site tool. Thus, BMPs are typically entered as individual entities rather than lumped together. For example, if a site has three bioretention BMPs, each BMP would be entered individually in the calculator. However, BMPs can be lumped in the calculator. In this example, the three bioretention BMPs could be combined and treated as a single BMP. Lumping BMPs has the advantage of simplifying complex site and may be useful when using the calculator for larger areas where several BMPs are implemented. Lumping BMPs can introduce errors in the calculations if the BMPs are not properly sized, since lumping smoothes out these sizing differences. The following document provides an example comparing calculator results for a site where BMPs are treated individually and lumped.

File:16 - Individual vs Clumping example.docx

During the winter of 2013-2014, Minimal Impact Design Standards (MIDS) calculator training workshops were held. Example exercises and answers from those workshops are contained in the following pdf document: File:Calculator exercises and answers.pdf