LID Treatment Train Tool
With beta testing now complete, version 1.0 of the Low Impact Development Treatment Train Tool (LID TTT) has been officially released!
**UPDATE**
A new Version 1.2.1 of the LID TTT has been updated with revised default land cover Event Mean Concentrations (EMCs), to sync better with local and regional data associated with these various land cover options and associated Total Suspended Solids (TSS) and Total Phosphorus (TP) loadings generated from the Tool.
Access Version 1.2.1 on the Sustainable Technologies Evaluation Program (STEP) website for all the latest updates, including release notes for v1.2.1. Case study examples are scheduled for release soon! Access the downloads from the menu bar on the right side of the page.

Developed by the Lake Simcoe Region, Credit Valley and Toronto and Region Conservation Authorities, the LID TTT is an exciting new open-source tool created to help developers, consultants, municipalities and landowners better understand, plan and implement sustainable stormwater practices.

Using results from the US Environmental Protection Agency's Storm Water Management Model (EPA SWMM5) engine, the tool assesses runoff volume control targets (retention and captured/treated), along with total suspended solids (TSS) and total phosphorus (TP) reductions for both annual and event-based scenarios, throughout the design process. It also provides preliminary water balance analysis (i.e. surface evapotranspiration, surface runoff, infiltration to soil).
The tool is built using the open source EPA SWMM5 model as the engine, to provide a user-friendly interface for novice modelers and can be exported to provide a SWMM5 input file for further model development during detailed design.