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→Functional Monitoring
===Functional Monitoring===
===Functional Monitoring===
The purpose of functional monitoring is to verify that stormwater is being conveyed through the stormwater management technology as expected, and that other non-hydrologic objectives of the practice (e.g. [[plants|plant survival]], [[thermal mitigation|temperature mitigation]], aesthetics) are being satisfactorily achieved. It is differentiated from performance monitoring in that the measurements are relatively simple and cost effective. As such, they are not intended to provide precise quantitative values that can be compared to design criteria such as outflow release rates and suspended solids removal. Examples of continuous functional measurements in LID practices during rain events may include:
[[File:Visual indicator bioretention.PNG|thumb|300px|Example of a visual indicator to be used when assessing the condition of a given LID feature. Here we see excessive sediment accumulation at the [[inlet]]/[[curb cut]] of a bioretention cell. Source: (TRCA, 2016).<ref>STEP. 2016. Low Impact Development Stormwater Management Practice Inspection and Maintenance Guide. https://sustainabletechnologies.ca/app/uploads/2016/08/LID-IM-Guide-2016-1.pdf</ref>.]]
{| class="wikitable" style="width: 900px;"
|+'''Visual Indicators Framework - Bioretention/Swales'''
|-
!<br>'''Measurement type'''
!<br>'''Stormwater practice type'''
!<br>'''Purpose of Measurement'''
!<br>'''Required equipment'''
|-
|'''[[Overflow|Surface Ponding]]'''
|[[Bioretention|Bioretention Cells]], [[Rain garden]], [[Bioswale]], [[Enhanced grass swales]]
|Measures duration and depth of surface ponding relative to design objectives. Indicates whether [[filter media|media]] [[Infiltration|infiltration rates]] and ponding durations meet expectations. Indicates size and [[Understanding rainfall statistics|intensity of rain events]] causing [[overflow]] if the overflow pipe is on the surface.
|Water level sensor(s) installed on the soil surface
|-
|'''[[Wells|Subsurface water level fluctuations]]'''
|[[Bioretention|Bioretention Cells]], [[Rain garden]], [[Bioswale]], [[Enhanced grass swales]], [[Permeable pavements]], [[Infiltration chamber]]
|Provides a rough measurement of infiltration rates into native soils for full and partial infiltration systems.
|Water level sensor(s) installed in wells or access manholes
|-
|'''[[Stormwater Tree Trenches#Design|Catch basin water level fluctuations]]'''
|[[Stormwater Tree Trenches]]
|Indicates whether water is flowing freely from the CB through the [[pipes|perforated distribution pipe]]. If an overflow pipe is located in the CB, water fluctuation measurements will indicate frequency of overflows
|Water level sensor in the inlet catch basin
|-
|'''[[Final Certification|Water level fluctuations]]'''
|[[Wet ponds]], [[constructed wetlands]], [[OGS]], [[Filtration MTDs]], [[Rainwater Cisterns]]
|Indicates whether design stage discharge curve is achieved in practice. Larger than expected water level fluctuations (i.e. long [[Drainage time|drawdown times]]) may indicate outlet [[clogging]]. Also, measurements may indicate size/intensity of rain events causing [[overflow]] or bypass.
|Water level sensor(s) installed below permanent pool
|-
|'''[[Stormwater Thermal Mitigation|Temperature]]'''
|All practices for which thermal mitigation may be a concern (e.g. ponds, [[Stormwater Thermal Mitigation#Cooling Trenches|cooling trenches]], etc.)
|Indicates change in water temperature from the [[inlet]] to [[Overflow#Overflow Outlet Options|outlet]], as well as the absolute outflow temperature relative to design targets. In some instances, the difference in temperature from the top to bottom of the practice may also be of interest as this can influence dissolved oxygen levels and chemical stratification and release.
|Water temperature sensor at the inlet and outlet. Sensors at different depths in the facility to determine how different designs may influence thermal stratification.
|}<br>
</br>
===Performance Monitoring===
===Performance Monitoring===
===Environmental Effects Monitoring===
===Environmental Effects Monitoring===