Changes

The guidance found on this page is not intended be prohibitive of LID options, but rather to help reduce the number of LID options in the preliminary phases of design and alert the designer to LID opportunities unique to the site being assessed. When going through the process of screening LID options, it is important to have a larger contextual understanding of [[Integrated water management]], [[Site design strategies]], [[Siting and layout of development]], and [[Link title]].  

The guidance found on this page is not intended be prohibitive of LID options, but rather to help reduce the number of LID options in the preliminary phases of design and alert the designer to LID opportunities unique to the site being assessed. When going through the process of screening LID options, it is important to have a larger contextual understanding of [[Integrated water management]], [[Site design strategies]], [[Siting and layout of development]], and [[Link title]].  

=== Site Conditions ===

== Site Conditions ==

Complete definition of pre-development site conditions is essential prior to screening of

Complete definition of pre-development site conditions is essential prior to screening of potential stormwater BMPs. The designer should prepare maps describing site

conditions to ensure that all environmental features and functions that need

development regulations are identified. This includes watercourses and small drainage features, floodplains, important recharge areas, steep slopes, wetlands, natural heritage

conservation areas and significant wildlife habitats. In addition, information regarding native soil types, infiltration capacity and depth to water table must be determined.

 

 

 

conservation areas and significant wildlife habitats. In addition, information regarding

 

native soil types, infiltration capacity and depth to water table must be determined.

* residential, see [[Site Conditions Residential]]

* residential, see [[Site Conditions Residential]]

=== Define Design Criteria ===

== Define Design Criteria ==

 

respective CVC and TRCA Stormwater Management Criteria documents. If outside jurisdictional  

A detailed description of the design criteria that need to be defined is provided in the respective CVC and TRCA Stormwater Management Criteria documents. If outside jurisdictional  

boundaries, criteria developed should have requirements to:

boundaries, criteria developed should have requirements to:

* maintain an appropriate diversity of aquatic life and opportunities for human uses

* maintain an appropriate diversity of aquatic life and opportunities for human uses

The design criteria required to protect, enhance or restore the environmental resources

The design criteria required to protect, enhance or restore the environmental resources can be grouped under the following five categories.

 

can be grouped under the following five categories.

* Flood Protection;

* Flood Protection;

=== Screen Potential LID Options ===

== Screen Potential LID Options ==

 

 

 

 

information regarding constraints to the design of various end-of-pipe BMPs can be

A number of factors need to be considered when screening the suitability of a given location within a development site for application of stormwater BMPs. Table 3.4.1

found in the Ontario Ministry of the Environment Stormwater Management Planning and

summarizes site constraints associated with some general types of structural LID practices for stormwater management that should be considered. Further

Design Manual (2003). The use of LID BMPs should be considered first to meet the

information regarding constraints to the design of various end-of-pipe BMPs can be found in the Ontario Ministry of the Environment Stormwater Management Planning and

design criteria before the use of end-of-pipe BMPs.

Design Manual (2003). The use of LID BMPs should be considered first to meet the design criteria before the use of end-of-pipe BMPs.

==== Structural Requirements or Site Constraints ====

=== Structural Requirements or Site Constraints ===

[[LID Site Criteria and Constraints]]

[[LID Site Criteria and Constraints]]

==== Performance Requirements ====

=== Performance Requirements ===

For additional resources on LID performance studies, please click on [http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/ LID Performance Reports]

For additional resources on LID performance studies, please click on [http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/ LID Performance Reports]

==== Operations and Maintenance Requirements ====

=== Operations and Maintenance Requirements ===

[http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/low-impact-development-stormwater-practice-inspection-and-maintenance-guide/ LID Inspection and Maintenance Guide]

[http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/low-impact-development-stormwater-practice-inspection-and-maintenance-guide/ LID Inspection and Maintenance Guide]

==== Life Cycle Costing Requirements ====

=== Life Cycle Costing Requirements ===

[http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/low-impact-development-life-cycle-costs/ LID Life Cycle Costing Tool]

[http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/low-impact-development-life-cycle-costs/ LID Life Cycle Costing Tool]

=== Select LIDs (Conceptual Design) ===

== Select LIDs (Conceptual Design) ==

In order to assess if the selected suite of BMPs effectively meet the design criteria

In order to assess if the selected suite of BMPs effectively meet the design criteria either computer models or simple spreadsheet models should be used. Model selection

either computer models or simple spreadsheet models should be used. Model selection

will be based on the size and type of development. A wide range of simple to complex computer models such as Visual OTTHYMO, SWMM, SWMMHYNO, HSP-F andQUALHYMO are available.

will be based on the size and type of development. A wide range of simple to complex

The Low Impact Development Treatment Train Tool (LID TTT) has been developed by Lake Simcoe Region Conservation Authority (LSRCA), Credit Valley Conservation (CVC) and Toronto and Region Conservation Authority (TRCA) as a

computer models such as Visual OTTHYMO, SWMM, SWMMHYNO, HSP-F and

tool to help developers, consultants, municipalities and landowners understand and implement more sustainable stormwater management planning and design practices in their watersheds. The purpose of the tool is to analyze

QUALHYMO are available.

annual and event based runoff volumes and pollutant load removal by the use of Best Management Practices (BMP)’s and Low Impact Development (LID) techniques. The LID TTT provides preliminary water budget analysis (i.e.  

Once the suite of best management practices have been selected and the models have

novice modelers and cross-compatibility with SWMM5 for further model development. To download the beta version, please click [http://www.sustainabletechnologies.ca/wp/low-impact-development-treatment-train-tool/ LID

should be used until the environmental design criteria are met. The project can then

Once the suite of best management practices have been selected and the models have been run, a comparison of the results and the environmental design criteria can be made. An iterative approach, which involves adjusting the

proceed to the detailed design stage.

size or adding/deleting BMPs should be used until the environmental design criteria are met. The project can then proceed to the detailed design stage.