Changes

;aquifers  

;aquifers  

:Layer of rock or soil that holds or transmits water.  

:Layer of rock or soil that holds or transmits water.  

;Asphalt  

;Asphalt  

;Base flow  

;Base flow  

;base flow

;base flow

:The sustained flow in a channel due to groundwater interaction.  

:The sustained flow in a channel not from storm runoff, instead arising from groundwater interaction.  

;Basin  

;Basin  

;dry swales

;dry swales

:Linear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil.

:Linear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil.

;Catchment  

;Catchment  

;conveyance

;conveyance

:Movement of water from one location to another.  

:Movement of water from one location to another.  

;Cultivar  

;Cultivar  

;cultivar

;cultivar

;Drainage time  

;Drainage time  

;drainage time

;drainage time

:The period between the maximum water level and the minimum level (dry weather or antecedent level).

:The period between the maximum water level and the minimum level (dry weather or antecedent level).

:An area of land that drains into a river or a lake. The boundary of a watershed is based on the elevation (natural contours) of a landscape.

:An area of land that drains into a river or a lake. The boundary of a watershed is based on the elevation (natural contours) of a landscape.

   

   

Clay (SOILS)  

Clay (SOILS)  

1. A mineral soil separate consisting of particles less than 0.002 millimeter in equivalent diameter. 2. A soil texture class. 3. (Engineering) A fine-grained soil (more than 50 percent passing the No. 200 Sieve) that has a high plasticity index in relation to the liquid limit. (Unified Soil Classification System).  

1. A mineral soil separate consisting of particles less than 0.002 millimeter in equivalent diameter. 2. A soil texture class. 3. (Engineering) A fine-grained soil (more than 50 percent passing the No. 200 Sieve) that has a high plasticity index in relation to the liquid limit. (Unified Soil Classification System).  

Collector Road

 

A road on which traffic movement and access to property have similar importance.  

;Collector road

Combined Sewer  

A wastewater collection system, which conveys sanitary wastewater (domestic, commercial and industrial wastewaters) and Stormwater runoff through a single-pipe system to a treatment works.  

:A road on which traffic movement and access to property have similar importance.  

CSO or Combined Sewer Overflow

 

A discharge to the environment from a Combined Sewer system that occurs because of a precipitation event when the capacity of the interceptor sewer or treatment plant is exceeded. It consists of a mixture of sanitary wastewater and Stormwater runoff.  

;Combined Sewer  

Conveyance Control

:A wastewater collection system, which conveys sanitary wastewater (domestic, commercial and industrial wastewaters) and Stormwater runoff through a single-pipe system to a treatment works.  

A structural best management practice thatis located within the drainage system where flows are concentrated and are being conveyed along corridor. Conveyance controls include but are not limited to pervious pipes, roadside ditches, and other similar systems.  

 

Ditch  

;CSO  

A long narrow trench or furrow dug in the ground, as for irrigation, drainage, or a boundary line.  

;Combined sewer overflow

Drainage  

Natural or artificial means of intercepting and removing surface or subsurface water (usually by gravity).  

:A discharge to the environment from a Combined Sewer system that occurs because of a precipitation event when the capacity of the interceptor sewer or treatment plant is exceeded. It consists of a mixture of sanitary wastewater and Stormwater runoff.  

Drainage Area

 

The total surface area upstream of a point on a stream that drains toward that point. Not to be confused with watershed. The drainage area may include one or more watersheds.  

;Conveyance  

Drainage System

A structural BMP that is located within the drainage system where flows are concentrated and are being conveyed along corridor. Include but are not limited to pervious pipes, swales, and other similar systems.  

A system flow of gully inlets, pipes, overland flow paths, open channels, culverts and detention basins used to convey runoff to its receiving waters. City of Toronto 45 Wet Weather Flow Management November 2006  

 

;Ditch  

:A long narrow trench or furrow dug in the ground, as for irrigation, drainage, or a boundary line.  

 

;Drainage

:Natural or artificial means of intercepting and removing surface or subsurface water (usually by gravity).  

 

;Drainage area

:The total surface area upstream of a point on a stream that drains toward that point. Not to be confused with watershed. The drainage area may include one or more watersheds.  

 

;Drainage system

:A system flow of gully inlets, pipes, overland flow paths, open channels, culverts and detention basins used to convey runoff to its receiving waters. City of Toronto 45 Wet Weather Flow Management November 2006  

   

   

Sewage flow resulting from both sanitary wastewater (combined input of industrial, domestic and commercial flows); and infiltration and inflows from foundation drains or other drains occurring during periods with an absence of rainfall or snowmelt.

;ecosystem

:A biological community, including humans and their natural environment.  

 

;End-of-pipe control

A biological community, including humans and their natural environment.  

End-of-pipe Control

:A structural best management practice that is located at the end of a flow conveyance route. End-of-Pipe Controls on surface and below ground but are not limited to wet ponds, constructed wetlands and other similar systems.  

A structural best management practice that is located at the end of a flow conveyance route. End-of-Pipe Controls on surface and below ground but are not limited to wet ponds, constructed wetlands and other similar systems.  

 

Enhancement  

;Enhancement

Emphasis on improving the value of particular aspects of water and related land resources.  

Environment  

:Emphasis on improving the value of particular aspects of water and related land resources.  

Refers to the conditions in which an organism lives and survives or the conditions in which an organism resides. These conditions can be described as aspects of a “physical”, “social” or an “economic” environment, depending on the perspective perceived by the observer.  

 

Erosion  

;Environment  

:Refers to the conditions in which an organism lives and survives or the conditions in which an organism resides. These conditions can be described as aspects of a “physical”, “social” or an “economic” environment, depending on the perspective perceived by the observer.  

 

;Erosion  

(1) The wearing away of the land surface by moving water, wind, ice or other geological agents, including such processes as gravitation creep; (2) Detachment and movement of soil or rock fragments by water, wind, ice or gravity (i.e. Accelerated, geological, gully, natural, rill, sheet, splash, or impact, etc).  

(1) The wearing away of the land surface by moving water, wind, ice or other geological agents, including such processes as gravitation creep; (2) Detachment and movement of soil or rock fragments by water, wind, ice or gravity (i.e. Accelerated, geological, gully, natural, rill, sheet, splash, or impact, etc).  

Erosion Control

 

Includes the protection of soil from dislocation by water, wind or other agents.  

;Erosion control

Evapotranspiration (ET)  

The quantity of water transpired (given off). Retained in plant tissues, and evaporated from plant tissues and surrounding soil surfaces. Quantitatively it is s

:Includes the protection of soil from dislocation by water, wind or other agents.  

usually expressed in terms of depth of water per unit area during a specified period.  

 

Exfiltration  

;Evapotranspiration (ET)  

The downward movement of water through the soil, the downward flow of runoff from the bottom of an infiltration BMP into the soil.  

: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

Extended Detention

 

A stormwater design features that provides for the gradual release of a volume of water in order to increase settling of pollutants and protect downstream channels from frequent storm events.  

;Exfiltration  

First Flush

The delivery of a disproportionately large load of pollutants during the early part of storms due to the rapid runoff of accumulated pollutants. The first flush of runoff has been defined several ways (e.g., one half inch per impervious City of Toronto Wet Weather Flow Management November 2006 46

:The downward movement of water through the soil, the downward flow of runoff from the bottom of an infiltration BMP into the soil.  

 

area).  

;Extended detention

Floodplain (100-year)  

The area adjacent to a stream that is on average inundated once a century  

:A stormwater design features that provides for the gradual release of a volume of water in order to increase settling of pollutants and protect downstream channels from frequent storm events.  

 

;First flush

Geomorphology  

A branch of both physiography and geology that deals with the form of the earth, the general configuration of its surface, and the changes that take place due to erosion of the primary elements and the buildup of erosional debris.  

:The delivery of a disproportionately large load of pollutants during the early part of storms due to the rapid runoff of accumulated pollutants. The first flush of runoff has been defined several ways (e.g., 10 mm per impervious area).  

Groundwater  

 

The water below the surface, and typically below the groundwater table.  

;Floodplain (100-year)  

Groundwater Recharge

:The area adjacent to a stream that is, on average, inundated once a century  

Increases in groundwater storage by natural conditions or by human activity. See also artificial recharge  

 

Groundwater Table

;Geomorphology  

:A branch of both physiography and geology that deals with the form of the earth, the general configuration of its surface, and the changes that take place due to erosion of the primary elements and the buildup of sediment.  

 

;Groundwater  

:The water below the surface, and typically below the groundwater table.  

 

;Groundwater recharge

:Increases in groundwater storage by natural conditions or by human activity. See also artificial recharge  

 

;Groundwater table

The upper surface of the zone of saturation, except where the surface is formed by an impermeable body.  

The upper surface of the zone of saturation, except where the surface is formed by an impermeable body.  

Headwater  

 

;Headwater  

Referring to the source of a stream or river.  

Referring to the source of a stream or river.  

 

Implementation of Wet Weather Flow measures following hierarchical approach in the following order:  

Source Control measures, Conveyance Control measure and End of Pipe treatment to achieve the water quality and water balance target for lot level development of the preferred strategy. In some guidance documents for Stormwater quality management, this is also known as the treatment train approach.

Hydrologic Cycle

Stormwater management following the hierarchical approach: Source Control measures, Conveyance Control measure and End of Pipe treatment to achieve the water quality and water balance target for lot level development of the preferred strategy.  

Also called the water cycle, this is the process of water evaporating condensing, falling to the ground as precipitation and returning to the ocean as run-off.  

 

Hydrological  

;Hydrologic cycle

Relating to the properties, distribution and effects of water on and below the earth’s surface, and in the atmosphere.  

:Also called the water cycle, this is the process of water evaporating condensing, falling to the ground as precipitation and returning to the ocean as run-off.  

Infiltration  

 

The slow movement of water into or through a soil or drainage system.  

;Hydrological

Infiltration Rate

The rate at which stormwater percolates into the subsoil measured in inches per hour.  

:Relating to the properties, distribution and effects of water on and below the earth’s surface, and in the atmosphere.  

I/I (Infiltration/Inflow  

 

Inflow and/or infiltration of water into a sewer.  

;Infiltration

Irrigation  

Human application of water to agricultural or recreational land for watering purposes. City of Toronto Wet Weather Flow Management November 2006 47  

:The slow movement of water into or through a soil or drainage system.  

 

;Infiltration rate

:The rate at which stormwater percolates into the subsoil measured in inches per hour.  

 

;I/I  

;Infiltration/Inflow  

:Inflow and/or infiltration of water into a sewer.  

 

;Irrigation

:Human application of water to agricultural or recreational land for watering purposes. City of Toronto Wet Weather Flow Management November 2006 47  

   

   

Local Road

;Local road

A road primarily for access to property.  

Low  

:A road primarily for access to property.  

Impact Development  

 

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.  

;Low Impact Development  

Major Drainage System

: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.  

That storm drainage system which carries the total runoff of the drainage system less the runoff carried by the minor system (storm sewer). The major system will function whether or not it has been planned and designed, and whether or not developments are situated wisely with respect to it. The Major Drainage System usually includes many features such as streets, gullies, and major drainage channels.  

 

Minor Drainage System

;Major drainage system

That storm drainage system which is frequently used for collecting, transporting, and disposing of snowmelt, miscellaneous minor flows, and storm runoff up to the capacity of the system. The capacity should be equal to the maximum rate of runoff to be expected from the minor design storm which may have a frequency of occurrence of one in 2, or 5 years. The minor system may include many features ranging from curbs and gutters to storm sewer pipes and open drainage ways.  

:That storm drainage system which carries the total runoff of the drainage system less the runoff carried by the minor system (storm sewer). The major system will function whether or not it has been planned and designed, and whether or not developments are situated wisely with respect to it. The Major Drainage System usually includes many features such as streets, gullies, and major drainage channels.  

 

;Minor drainage system

:That storm drainage system which is frequently used for collecting, transporting, and disposing of snowmelt, miscellaneous minor flows, and storm runoff up to the capacity of the system. The capacity should be equal to the maximum rate of runoff to be expected from the minor design storm which may have a frequency of occurrence of one in 2, or 5 years. The minor system may include many features ranging from curbs and gutters to storm sewer pipes and open drainage ways.  

;Natural Systems Solutions

;Natural systems solutions

:Projects following the philosophy in which terrestrial and aquatic vegetation provides the ability to cleanse water of its contaminants.  

:Projects following the philosophy in which terrestrial and aquatic vegetation provides the ability to cleanse water of its contaminants.  

;Permeable  

;Permeable  

;permeable

;permeable

:Soil or other material that allows the infiltration or passage of water or other liquids.  

:The property of a material that allows the infiltration or passage of water (or other liquids).  

;Pollutant  

;Pollutant  

:The rate of rainfall in millimeters per hour.  

:The rate of rainfall in millimeters per hour.  

Recharge  

;Recharge

The addition of water to ground water by natural or artificial processes.  

:The addition of water to ground water by natural or artificial processes.  

Receiving Waters

;Receiving waters

Watercourses and Lake Ontario, to which Stormwater and Combined Sewer Overflows discharge.  

:Watercourses and Lake Ontario, to which Stormwater and Combined Sewer Overflows discharge.  

Riparian Areas

;Riparian areas

Areas adjacent to a watercourse that are saturated by groundwater or intermittently inundated by surface water at a frequency and duration sufficient to support the growth of vegetation typically adapted for life in saturated soil.  

:Areas adjacent to a watercourse that are saturated by groundwater or intermittently inundated by surface water at a frequency and duration sufficient to support the growth of vegetation typically adapted for life in saturated soil.  

Runoff  

;Runoff

That potion of the water precipitated onto a catchment area, which flows as  

surface discharge from the catchment area past a specified point.  

:That potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.  

;Sand  

;Sand  

:Mineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm.  

:Mineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm.  

Sediments  

;Sediments  

Soil, 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.  

Sedimentation  

Deposition of material of varying size, both mineral and organic away from its site of origin by the action of water, wind, gravity or ice.  

:Soil, 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.  

The liquid waste from domestic, commercial and industrial establishments. City of Toronto Wet Weather Flow Management Guidelines November 2006 49  

 

;Sedimentation  

:Deposition of material of varying size, both mineral and organic away from its site of origin by the action of water, wind, gravity or ice.  

 

:The liquid waste from domestic, commercial and industrial establishments. City of Toronto Wet Weather Flow Management Guidelines November 2006 49  

   

   

Silt  

;Silt

Substrate particles smaller than sand and larger than clay (3 to 60 m)  

Soakaway Pit

:Soil or media particles smaller than sand and larger than clay (3 to 60 m)  

A pit into which liquids may flow and then percolate slowly into the subsoil.  

 

Source Control

;Soakaway

A practice or structural measure that is usually implemented at the beginning of a drainage system or at the lot level, to reduce the volume of runoff and minimize the concentration of pollution in overland flow from private property and prevent pollutants from entering Stormwater runoff or other environmental media, as described by the Ministry of Environment.  

Stakeholder  

:A pit into which liquids may flow and then percolate slowly into the subsoil.  

Any person, agency or group who has a direct interest in the purpose of a proposed undertaking.  

 

Stormwater  

;Source control

Surface runoff resulting from rain or snowmelt events.  

:A practice or structural measure that is usually implemented at the beginning of a drainage system or at the lot level, to reduce the volume of runoff and minimize the concentration of pollution in overland flow from private property and prevent pollutants from entering Stormwater runoff or other environmental media, as described by the Ministry of Environment.  

Stormwater Wetlands

 

;Stakeholder  

:Any person, agency or group who has a direct interest in the purpose of a proposed undertaking.  

 

;Stormwater  

:Surface runoff from at-grade surfaces, resulting from rain or snowmelt events.  

 

;Stormwater wetlands

Shallow, constructed pools that capture stormwater and allow for the growth of  

Shallow, constructed pools that capture stormwater and allow for the growth of  

characteristic wetland vegetation.  

characteristic wetland vegetation.