Difference between revisions of "Definition of Low Impact Development"

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This article is about definitions. The regional context for LID is presented in [[Urbanization]] and [[Climate change]].  
 
This article is about definitions. The regional context for LID is presented in [[Urbanization]] and [[Climate change]].  
  
This guide has been developed as a tool to help developers, consultants, municipalities and landowners understand and implement more sustainable stormwater management planning and design practices in their watersheds. Many jurisdictions have defined the term low impact development. For this document, the following definition, adapted from the [https://www.epa.gov/nps/urban-runoff-low-impact-development United States Environmental Protection Agency] will be used:
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This guide has been developed as a tool to help developers, consultants, municipalities and landowners understand and implement more sustainable stormwater management planning and design practices in their watersheds. Many jurisdictions have defined the term low impact development. The Sustainable Technologies Evaluation Program uses the following definition:  
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systems and practices that use or mimic natural processes that result in the [[infiltration]], [[evapotranspiration]] or [[Rainwater harvesting|reuse]] of stormwater in order to protect water quality and associated aquatic habitat.}}
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:::Low impact development (LID) is a stormwater management strategy that seeks to mitigate the impacts of increased runoff and stormwater pollution by managing runoff as close to its  source as possible. To accomplish this, it uses practices that help to preserve or to restore predevelopment hydrological and ecological functions. For preservation, it uses site design strategies to minimize runoff and to protect natural drainage patterns. For restoration, it uses distributed structural practices that filter, detain, infiltrate, evapotranspire and harvest stormwater. LID practices can effectively remove sediment, nutrients, pathogens and metals from runoff, and they reduce the volume and intensity of stormwater flows.
  
 
The field of stormwater management has undergone considerable evolution in the last 40 - 50 years, from underground drainage systems for rapid water disposal, to stormwater management ponds, to today’s myriad of near-to-nature practices and technologies<ref name ="Fletcher" />. This paradigm shift could be explained by a change of perception about water from a waste to a resource. With this evolution comes the evolution of terminology to describe the latest visions, practices and technologies.
 
The field of stormwater management has undergone considerable evolution in the last 40 - 50 years, from underground drainage systems for rapid water disposal, to stormwater management ponds, to today’s myriad of near-to-nature practices and technologies<ref name ="Fletcher" />. This paradigm shift could be explained by a change of perception about water from a waste to a resource. With this evolution comes the evolution of terminology to describe the latest visions, practices and technologies.
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==Green infrastructure==
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==LID and Green infrastructure==
 
In many cases, the terms LID and GI are used interchangeably to describe an alternate management approach from the conventional ‘grey’ infrastructure approach. The inconsistent use of these two terms by different agencies and scholars across North America and other parts of the world contributes to the confusion already associated with these relatively new approaches to stormwater management.
 
In many cases, the terms LID and GI are used interchangeably to describe an alternate management approach from the conventional ‘grey’ infrastructure approach. The inconsistent use of these two terms by different agencies and scholars across North America and other parts of the world contributes to the confusion already associated with these relatively new approaches to stormwater management.
 
In this guide we make a distinction between LID and GI on the grounds of geographic and structural (engineered) scales of classification and implementation.  
 
In this guide we make a distinction between LID and GI on the grounds of geographic and structural (engineered) scales of classification and implementation.  
Traditionally, the term infrastructure connotes a requirement that is necessary to keep an urban center functional, while green space connotes a want, putting it at the bottom of priority lists.  
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Traditionally, the term "infrastructure" connotes a requirement that is necessary to keep an urban center functional, while green space connotes a want, putting it at the bottom of priority lists.  
 
The term GI emerged to put more emphasis on green space as a need rather than a want and elevate it within budget priority lists. As such, in addition to traditional water-related infrastructure, GI encompasses non-traditional infrastructure, such as:
 
The term GI emerged to put more emphasis on green space as a need rather than a want and elevate it within budget priority lists. As such, in addition to traditional water-related infrastructure, GI encompasses non-traditional infrastructure, such as:
 
*heritage features,
 
*heritage features,

Revision as of 13:47, 13 September 2019

This article is about definitions. The regional context for LIDLow 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. is presented in Urbanization and Climate change.

This guide has been developed as a tool to help developers, consultants, municipalities and landowners understand and implement more sustainable stormwater management planning and design practices in their watersheds. Many jurisdictions have defined the term low impact developmentA 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.. The Sustainable Technologies Evaluation Program uses the following definition:

Low impact developmentA 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. (LIDLow 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.) is a stormwater management strategy that seeks to mitigate the impacts of increased runoffThat potion of the water precipitated onto a catchment area, which 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. and stormwater pollution by managing runoffThat potion of the water precipitated onto a catchment area, which 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. as close to its source as possible. To accomplish this, it uses practices that help to preserve or to restore predevelopment hydrologicalRelating to the properties, distribution and effects of water on and below the earth’s surface, and in the atmosphere. and ecological functions. For preservation, it uses site design strategies to minimize runoffThat potion of the water precipitated onto a catchment area, which 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. and to protect natural drainage patterns. For restoration, it uses distributed structural practices that filter, detain, infiltrate, evapotranspire and harvest stormwaterSurface runoff from at-grade surfaces, resulting from rain or snowmelt events.. LIDLow 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. practices can effectively remove sedimentSoil, sand and minerals washed from land into water, usually after rain. They pile up in reservoirs, rivers and harbors, destroying fish-nesting areas and holes of water animals and cloud the water so that needed sunlight might not reach aquatic plans. Careless farming, mining and building activities will expose sediment materials, allowing them to be washed off the land after rainfalls., nutrients, pathogens and metals from runoffThat potion of the water precipitated onto a catchment area, which 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., and they reduce the volume and intensity of stormwater flows.

The field of stormwater management has undergone considerable evolution in the last 40 - 50 years, from underground drainage systems for rapid water disposal, to stormwater management ponds, to today’s myriad of near-to-nature practices and technologies[1]. This paradigm shift could be explained by a change of perception about water from a waste to a resource. With this evolution comes the evolution of terminology to describe the latest visions, practices and technologies. There are various terms used in stormwater management related literature across the globe. Some terms differ only in their geography while others differ in their connotation.

Regional terminology use[1]
Terminology North America New Zealand Australia United Kingdom Europe
Green Infrastructure (GIGreen infrastructure) x
Low Impact DevelopmentLow 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. (LIDLow 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.) x x
Water Sensitive Urban Design (WSUD) x x x
Integrated Urban Water Management (IUWM) x
Best Management PracticesState 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. (BMPs) x
Stormwater Control Measures (SCMs) x
Alternative Measures x
Source Control x

LIDLow 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. and Green infrastructureNatural vegetation and vegetative technologies in urban settings such as: urban forests; green roofs; green walls; green spaces; rain gardens; bioswales; community gardens; natural and engineered wetlands and stormwater management ponds; and porous pavement systems. These systems are designed to provide multiple benefits, such as moderate temperatures, clean air and water, and improve aesthetics.

In many cases, the terms LIDLow 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. and GIGreen infrastructure are used interchangeably to describe an alternate management approach from the conventional ‘grey’ infrastructure approach. The inconsistent use of these two terms by different agencies and scholars across North America and other parts of the world contributes to the confusion already associated with these relatively new approaches to stormwater management. In this guide we make a distinction between LIDLow 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. and GIGreen infrastructure on the grounds of geographic and structural (engineered) scales of classification and implementation. Traditionally, the term "infrastructure" connotes a requirement that is necessary to keep an urban center functional, while green space connotes a want, putting it at the bottom of priority lists. The term GIGreen infrastructure emerged to put more emphasis on green space as a need rather than a want and elevate it within budget priority lists. As such, in addition to traditional water-related infrastructure, GIGreen infrastructure encompasses non-traditional infrastructure, such as:

  • heritage features,
  • parklands,
  • street trees,
  • natural channels, or

in other words any natural(ized) green space.

GIGreen infrastructure describes a strategically planned and delivered network of natural and semi-natural elements that collectively deliver a wide range of ecosystemA biological community, including humans and their natural environment., social and economic services to help reduce dependence on grey infrastructure and to address environmental resilience and climate change. The LIDLow 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. approach to stormwater management falls under the overarching umbrella of GIGreen infrastructure as a semi-natural element. LIDLow 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. comprises comprehensive, engineered site-design strategies and techniques that seek to mitigate the impacts of increased runoffThat potion of the water precipitated onto a catchment area, which 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. and stormwater pollution by replicating or maintaining the site’s pre-developmentrefers to the characteristics and functions of a system prior to urban development. hydrologicalRelating to the properties, distribution and effects of water on and below the earth’s surface, and in the atmosphere. and ecological functions. This is achieved as close to the runoffThat potion of the water precipitated onto a catchment area, which 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. source as possible through the processes of retention, filtrationThe technique of removing pollutants from runoff as it infiltrates through the soil., infiltration and evapotranspirationThe 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/dayThe combined loss of water to the atmosphere from land and water surfaces by evaporation and from plants by transpiration.. These practices can effectively remove nutrients, pathogens and heavy metals from runoffThat potion of the water precipitated onto a catchment area, which 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., and they reduce the volume and intensity of stormwater flows.


  1. 1.0 1.1 Fletcher TD, Shuster W, Hunt WF, et al. SUDS, LID, BMPs, WSUD and more – The evolution and application of terminology surrounding urban drainage. Urban Water J. 2015;12(7):525-542. doi:10.1080/1573062X.2014.916314.