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−|text=<span style="font-size:12%; line-height: 2.1em;">|1=<div class="center" style="width: auto; margin-left: auto; margin-right: auto;">[[#A|A]], [[#B|B]], [[#C|C]], [[#D|D]], [[#E|E]], [[#F|F]], [[#G|G]], [[#H|H]], [[#I|I]], [[#J|J]], [[#K|K]], [[#L|L]], [[#M|M]], [[#N|N]], [[#O|O]], [[#P|P]], [[#Q|Q]], [[#R|R]], [[#S|S]], [[#T|T]], [[#U|U]], [[#V|V]], [[#W|W]], [[#X|X]], [[#Y|Y]], [[#Z|Z]]</div>}}
−
−
−= A =
−=== Aggregate ===
−A broad category of particulate material used in construction, including sand,
−gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates, and available in
−various particulate size gradations.
−
−
−= B =
−=== Berm ===
−A compacted earthen wall that diverts runoff or creates shallow ponding of runoff. In
−some cases, runoff ponds behind the berm and gradually flows through it or is infiltrated.
−
−=== Biofilter ===
−A bioretention stormwater best management practice featuring an impermeable liner
−and underdrain that prevents infiltration of runoff into the underlying native soil; provides
−sedimentation and filtration of urban runoff as it passes through the mulch layer, engineered
−filter media and vegetation root zone.
−
−=== Bioretention ===
−A stormwater filtration and infiltration practice. The practice is a shallow
−excavated surface depression containing a prepared soil mix, mulch, and planted with specially
−selected vegetation. The system is engineered to temporarily store runoff in the depression and
−gradually filters it through the mulch, engineered soil mix, and root zone. They remove
−pollutants from runoff through filtration in the soil and uptake by plant roots and can help to
−reduce runoff volume through evapotranspiration and infiltration.
−
−
−= C =
−=== Check Dam ===
−Structures constructed of a non-erosive material, such as suitably sized
−aggregate, wood, gabions, riprap, or concrete, used to slow runoff water to allow sedimentation,
−filtration, evapotranspiration, and infiltration into the underlying native soil. Can be employed in
−practices such as dry and enhanced grass swales.
−
−=== Cistern ===
−Tank used to store rainwater (typically roof runoff) for later use.
−
−
−= D =
−=== Depression Storage ===
−A technique for incorporating shallow depressed areas into urban
−landscaped areas for storing and infiltrating runoff. Typically, depression storage areas are
−small and have limited capacity and limited duration of retention in order to address property
−owner concerns relating to insects, damage to structures and inconvenience of ponded water on
−their property.
−
−=== Detention ===
−The temporary storage of stormwater to control discharge rates, and allow for
−sedimentation.
−
−=== Drawdown Time ===
−The period between the maximum water level and the minimum level (dryweather
−or antecedent level).
−
−=== Dry Swale ===
−Linear bioretention cells 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.
−
−
−= E=
−=== Evapotranspiration ===
−The combined loss of water to the atmosphere from land and water
−surfaces by evaporation and from plants by transpiration.
−
−=== Enhanced Grass Swale ===
−Vegetated open channels designed to convey, treat and attenuate
−stormwater runoff, also referred to as enhanced vegetated swales. Enhanced grass swales are
−not capable of providing the same water balance and water quality benefits as dry swales, as
−they lack the engineered soil media and storage capacity.
−
−=== Environmental Impact Report (EIR) ===
−The evaluation of the possible effects that may arise from a
−proposed project on the environment, together consisting of the natural, social and economic
−aspects.
−
−=== Exfiltration ===
−Loss of water from a drainage system as a result of percolation or absorption into
−the surrounding medium (e.g., the infiltration of water into the native soil through a perforated
−pipe wall as it is conveyed).
−
−
−= F =
−=== Filter Media ===
−The engineered soil bed component of bioretention cell or dry swale designs,
−typically composed of a sandy soil mixture containing a limited proportion of fine textured
−material, which provides a growing medium for vegetation, maintains a high rate of infiltration
−over the lifespan of the practice, and retains contaminants through filtration and adsorption to
−soil particles.
−
−=== Filtration ===
−The technique of removing pollutants from runoff as it infiltrates through the soil.
−
−=== Fines ===
−Soil materials with less than a 0.050 mm diameter particle size.
−
−=== First Flush ===
−Initial pulse of stormwater runoff which picks up the pollutants that have settled on
−surfaces during the dry period. The first flush contains the highest pollutant concentrations.
−
−=== Forebay ===
−A pretreatment basin at the inlet of a practice that allow settling out of sediment and
−associated contaminants suspended in urban runoff.
−
−=== Flow Path Length ===
−The minimum linear distance of water flow across a surface.
−
−=== Fluvial Geomorphology ===
−The study of the processes responsible for the shape and form, or
−morphology, of watercourses; describes the processes whereby sediment (e.g., silt, sand,
−gravel) and water are transported from the headwaters of a watershed to its mouth.
−
−=== Fused Grid ===
−A hybrid neighbourhood and district layout model that combines the geometries of
−inner city grid road patterns with the loop and cul-de-sac road patterns of conventional suburbs.
−
−
−= G =
−=== Grass Swales ===
−Vegetated, open channels designed to convey, treat and attenuate runoff.
−Design variations range from simple grass channels, which are designed primarily for
−conveyance to more complex treatment and volume reduction designs like enhanced grass
−swales, and dry swales or bioswales.
−
−=== Geotextile ===
−A filter fabric that is installed to separate dissimilar soils and provide runoff filtration
−and contaminant removal benefits while maintaining a suitable rate of flow; may be used to
−prevent fine-textured soil from entering a coarse granular bed, or to prevent coarse granular
−from being compressed into underlying finer-textured soils.
−
−=== Granular ===
−Gravel, or crushed stone of various size gradations (i.e., diameter), used in
−construction; void forming material used as bedding and runoff storage reservoirs and
−underdrains in stormwater infiltration practices.
−
−=== Gravel Diaphragm ===
−Is a level spreading device placed at a runoff discharge location,
−perpendicular to flow, to maintain sheet flow and distribute runoff as evenly as possible across a
−pervious area or stormwater infiltration practice. A gravel diaphragm acts as a pretreatment
−device, settling out suspended sediments before they reach the practice.
−
−=== Green Roof ===
−A thin layer of vegetation and growing medium installed on top of a conventional
−flat or sloped roof, also referred to as living roofs or rooftop gardens.
−
−=== Green Infrastructure ===
−Natural 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.
−
−=== Groundwater Discharge ===
−The outflow of groundwater to a well, spring, wetland or watercourse.
−
−=== Groundwater Recharge ===
−The inflow of surface water to a groundwater reservoir or aquifer.
−
−
−= H =
−=== Hydraulic Conductivity ===
−A parameter that describes the capability of a medium to transmit water.
−
−=== Hydrologic Cycle ===
−The circulation of water from the atmosphere to the earth and back, through
−precipitation, runoff, infiltration, groundwater flow and evapotranspiration.
−
−=== Hydrologic Regime ===
−The characteristic pattern of precipitation, runoff, infiltration and evaporation
−affecting the hydrology of a system.
−
−=== Hydrologic Soil Groups ===
−A soil classification system based on the ability to convey and store
−water; divided into four groups:
−
−A – well drained sands and gravel, high infiltration capacity, high leaching potential and low
−runoff potential;
−
−B – Moderately drained fine to coarse grained soils, moderate infiltration capacity, moderate
−leaching potential and moderate runoff potential;
−
−C – Fine grained, low infiltration capacity, low leaching potential and high runoff potential;
−
−D – Clay soils, very low infiltration capacity, very low leaching potential and very high runoff
−potential.
−
−
−= I =
−=== Impervious ===
−A hard surface area (e.g., road, parking area or rooftop) that prevents or retards
−the infiltration of water into the soil.
−
−=== Infiltration ===
−Penetration of water through the ground surface.
−
−=== Inline ===
−Refers to a system that accepts all of the flow from a drainage area and conveys larger
−event flows through an overflow outlet.
−
−
−= J =
−
−
−= K =
−
−
−= L =
−=== Landform ===
−The natural features of the landscape, dictates flow patterns, runoff velocities and
−discharge rates.
−
−=== Landscape-based Approach ===
−The principle that development form, servicing and stormwater
−management strategies should be defined by the biophysical, hydrological and ecological
−attributes of the landscape.
−
−=== Lot Level ===
−The treatment of urban runoff as close to the source area as possible through
−application of small scale stormwater management practices on individual properties that are
−linked to downstream conveyance and end-of-pipe practices.
−
−=== 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.
−
−
−= M =
−=== Master Environmental Servicing Plan (MESP) ===
−Is a community-scale planning assessment of
−servicing and environmental considerations for a development project.
−
−=== Mulch ===
−Shredded woody material or leaf compost used as a top dressing over vegetation beds
−that provides a source of soil nutrients and helps retain soil moisture; in bioretention cells and
−dry swales the surface mulch layer provides pollutant removal and improves growing conditions
−for the selected plants; shredded hardwood bark has been found to work best as it is less likely
−to float.
−
−
−= N =
−=== Native Soil ===
−The natural ground material characteristic of or existing by virtue of geographic
−origin.
−
−
−= O =
−=== Offline ===
−Refers to a system that when full, stormwater will bypass the practice. Offline systems
−use flow splitters or bypass channels that only allow the water quality volume to enter the
−facility. This may be achieved with a pipe, weir, or curb opening sized for the target flow, but in
−conjunction, create a bypass channel so that higher flows do not pass over the surface of the
−filter bed.
−
−
−= P =
−=== Permeable Pavement ===
−Is an alternative practice to traditional impervious pavement, prevents
−the generation of runoff by allowing precipitation falling on the surface to infiltrate through the
−surface course into an underlying stone reservoir and, where suitable conditions exist, into the
−native soil.
−
−=== Physiography ===
−The physical features of the land, including topography, morphology and
−geologic origin. The physical feature of the land has an influence on the surface water
−movement and the interactions between surface water and groundwater.
−
−=== Pollution Hot Spot ===
−areas where certain land uses or activities have the potential to generate
−highly contaminated runoff (e.g., vehicle fuelling, service or demolition areas, outdoor storage
−and handling areas for hazardous materials and some heavy industry sites).
−
−=== Pollutant Load ===
−The total mass of a pollutant entering a waterbody over a defined time period.
−
−=== Predevelopment ===
−refers to the characteristics and functions of a system prior to urban
−development.
−
−=== Pretreatment ===
−Initial capturing and removal of unwanted contaminants, such as debris,
−sediment, leaves and pollutants, from stormwater before reaching a best management practice;
−Examples include, settling forebays, vegetated filter strips and gravel diaphragms.
−
−
−= Q =
−
−
−= R =
−=== Rain Garden ===
−A lot level bioretention cell designed to receive and detain, infiltrate and filter
−runoff, typically used for discharge from roof leaders.
−
−=== Rainwater Harvesting ===
−Is the practice of intercepting, conveying and storing rainwater for future
−use. The captured rainwater is typically used for outdoor non-potable water uses such as
−irrigation and pressure washing, or in the building to flush toilets or urinals or other uses that do
−not require potable water.
−
−=== Recharge ===
−The infiltration and movement of surface water into the soil, past the vegetation root
−zone, to the zone of saturation or water table.
−
−=== Riparian ===
−A vegetated ecosystem alongside a waterbody, characteristically have a high water
−table and are subject to periodic flooding.
−
−=== Runoff ===
−Water from rain, snow melt, or irrigation that flows over the land surface.
−
−
−= S =
−=== Sedimentation ===
−Settling-out or deposition of particulate matter suspended in runoff.
−
−=== Soakaway ===
−An excavated area lined with geotextile filter cloth and filled with clean granular
−stone or other void forming material, that receives runoff and allow it to infiltrate into the native
−soil; can also be referred to as infiltration galleries, French drains, dry wells or soakaway pits.
−
−=== Soil Amendment ===
−The practice of adding organic material, such as mulch or compost to topsoil
−to improve fertility, and tilling of the native soils to reverse compaction and restore its water
−retaining capacity.
−
−=== Standing Water ===
−Water ponded on the ground surface.
−
−=== Stone Reservoir ===
−An underlying aggregate material bed that temporarily stores stormwater
−before infiltrating into the native soil or being conveyed by an underdrain pipe.
−
−=== Stormwater Planer ===
−A bioretention cell that features an imperveable liner that collects and
−treats stormwater through sedimentation and filtration only (i.e., no infiltration).
−
−=== Stream Channel ===
−A natural waterway, formed by fluvial processes, that conveys running water.
−
−
−= T =
−=== Treatment Train Approach ===
−A combination of lot level, conveyance, and end-of-pipe stormwater
−management practices.
−
−= U =
−=== Underdrain ===
−A perforated pipe used to assist the draining of soils.
−
−=== Urbanization ===
−The changing of land cover and land uses from rural to urban; the growth of
−urban settlements.
−
−
−= V =
−=== Vegetated Filter Strip ===
−Are gently sloping, densely vegetated areas that treat runoff as sheet flow
−from adjacent impervious areas. They function by slowing runoff velocity and filtering out
−suspended sediment and associated pollutants, and by providing some infiltration into
−underlying soils. Also known as buffer strips and grassed filter strips.
−
−
−= W =
−=== Water Balance ===
−The accounting of inflow and outflow of water in a system according to the
−components of the hydrologic cycle.
−
−=== Water Cycle ===
−The continuous movement of water from the oceans to the atmosphere (by
−evaporation), from the atmosphere to the land by condensation and precipitation, and from the land
−back to the sea (via groundwater and stream flow); also referred to as hydrologic cycle.
−
−=== Water Budget ===
−The mathematical expression of the water balance.
−
−=== Water Quality Volume ===
−The amount of stormwater runoff from a given area required to be
−retained by stormwater management practices to reduce pollutant load to an acceptable level.
−
−=== Water Table ===
−Subsurface water level which is defined by the level below which all the spaces in
−the soil are filled with water; The entire region below the water table is called the saturated
−zone.
−
−=== Watershed ===
−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.
−
−
−= X =
−
−
−= Y =
−
−
−= Z =
#REDIRECT[[Terminology]]
−