Low impact development treatment train tool

menu bar of TTT

The Low Impact Development Treatment Train Tool (LID TTT) is designed to help developers, consultants, municipalities and landowners understand and implement more sustainable stormwater management planning and design practices in their watersheds.

The tool focuses on the use of Best Management Practices (BMP)’s and Low Impact Development (LID) techniques, and:

• analyzes annual and event based runoff volumes,
  • including water budget information: surface evapotranspiration, surface runoff, and infiltration to soil
• provides estimates of pollutant load removal.

The tool is built upon the open source EPA SWMM5 model providing a user-friendly interface for novice modelers and cross-compatibility with SWMM5 for further model development.

The LID TTT has been developed in partnership between Lake Simcoe Region Conservation Authority, Credit Valley Conservation, and Toronto and Region Conservation Authority.

Integration with this guide is through suggested 'starting point' values for design parameters for the following BMP types:

• Bioretention
• Vegetated filter strips
• Infiltration trenches
• Permeable paving
• Rainwater harvesting
• Swales

This links to the project page, where you can download your free copy of the TTT

Low impact development is a stormwater management and land development strategy applied at the parcel and subdivision scale that emphasizes conservation and use of on-site natural features integrated with engineered, small scale hydrologic controls to more closely mimic pre-development hydrologic functions.

A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include Source, Conveyance and End-Of-Pipe Controls.

Best management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls.

The portion of water precipitated onto a catchment area, which then flows as surface discharge from the catchment area past a specified point.

Water from rain, snow melt, or irrigation that flows over the land surface.

The mathematical expression of the water balance.

The quantity of water transpired (given off). Retained in plant tissues, and evaporated from plant tissues and surrounding soil surfaces. Quantitatively it is usually expressed in terms of depth of water per unit area during a specified period. e.g. mm/day

The combined loss of water to the atmosphere from land and water surfaces by evaporation and from plants by transpiration.

The total mass of a pollutant entering a waterbody over a defined time period.