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[[File:Cover Photo.PNG|thumb|750px|Inspection & Maintenance Guidance of vegetated stormwater best management practices that temporarily store rainwater and snowmelt from roofs, pavement, parking lots, etc. in depressed planting beds, concrete planters or swales. [[Acknowledgements|TRCA, 2016]]<ref> TRCA. 2016. Fact Sheet - Inspection and Maintenance of Stormwater Best Management Practices: Bioretention. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

[[File:Cover Photo.PNG|thumb|750px|link=https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf|Inspection & Maintenance Guidance of vegetated stormwater best management practices that temporarily store rainwater and snowmelt from roofs, pavement, parking lots, etc. in depressed planting beds, concrete planters or swales (TRCA, 2016)<ref> TRCA. 2016. Fact Sheet - Inspection and Maintenance of Stormwater Best Management Practices: Bioretention. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

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==Overview==

==Overview==

[[Bioretention]] treats stormwater by slowing it down, filtering it through soil and plant roots, soaking it into the ground and evaporating it back to the atmosphere. Runoff water is delivered to the practice through [[inlet]]s such as [[curb cuts]], [[Curb cuts: Gallery|spillways]] or other concrete structures, sheet flow from pavement edges, or [[pipes]] connected to [[Pretreatment|catchbasins]] or [[Downspout disconnection|roof downspouts]]. The planting bed and side slopes are typically covered with a mixture of [[plants]], [[mulch]] and [[stone]]. Water in excess of its storage capacity overflows to another BMP or the municipal storm sewer. Filtered water is either infiltrated into the underlying soil to replenish groundwater, or collected by a [[Underdrain|sub-drain]] (i.e., underground perforated pipe) and discharged to the storm sewer system or another BMP. Depending on the permeability of the underlying soil or other constraints, it may be designed with no sub-drain for [[Bioretention: Full infiltration|full infiltration]], with a sub-drain for [[Bioretention: Partial infiltration|partial infiltration]], or with an impermeable liner and sub-drain for a [[Stormwater Tree Trenches|no infiltration practice]]. The sub-drain pipe may feature a flow restrictor (e.g., orifice cap or valve) for gradually releasing detained water and optimizing the amount drained by infiltration. Key components of bioretention practices for inspection and maintenance described further below.

[[Bioretention]] treats stormwater by slowing it down, filtering it through soil and plant roots, soaking it into the ground and evaporating it back to the atmosphere. Runoff water is delivered to the practice through [[inlet]]s such as [[curb cuts]], [[Curb cuts: Gallery|spillways]] or other concrete structures, sheet flow from pavement edges, or [[pipes]] connected to [[Pretreatment|catchbasins]] or [[Downspout disconnection|roof downspouts]]. The planting bed and side slopes are typically covered with a mixture of [[plants]], [[mulch]] and [[stone]]. Water in excess of its storage capacity overflows to another BMP or the municipal storm sewer. Filtered water is either infiltrated into the underlying soil to replenish groundwater, or collected by a [[Underdrain|sub-drain]] (i.e., underground perforated pipe) and discharged to the storm sewer system or another BMP. Depending on the permeability of the underlying soil or other constraints, it may be designed with no sub-drain for [[Bioretention: Full infiltration|full infiltration]], with a sub-drain for [[Bioretention: Partial infiltration|partial infiltration]], or with an impermeable liner and sub-drain for a [[Stormwater planters|no infiltration practice]]. The sub-drain pipe may feature a flow restrictor (e.g., orifice cap or valve) for gradually releasing detained water and optimizing the amount drained by infiltration. Key components of bioretention practices for inspection and maintenance described further below. <br>

 

Trash, debris and sediment builds up at these locations and can prevent water from flowing into or out of the practice.

==Associated Practices==

==Associated Practices==

*'''[[Stormwater planters|Biofilter]]''': Bioretention cell or swale with an impermeable liner or containment structure and sub-drain.

*'''[[Stormwater planters|Biofilter]]''': Bioretention cell or swale with an impermeable liner or containment structure and sub-drain.

*'''[[Bioswale]] / [[Dry swale]] or [[Bioswale|Bioretention swale]]''': A gently sloping, linear oriented bioretention practice designed to be capable of conveying water across an elevation gradient. Also known as a bioswale or dry swale.

*'''[[Bioswale]] / [[Dry swale]] or [[Bioswale|Bioretention swale]]''': A gently sloping, linear oriented bioretention practice designed to be capable of conveying water across an elevation gradient. Also known as a bioswale or dry swale.

==Inspection and Testing Framework==

==Inspection and Testing Framework==

{| class="wikitable" style="width: 1000px;"

|+'''Inspection and Testing Framework - Bioretention/Swales'''

{| class="wikitable" style="width: 900px;"

|+'''Visual Indicators Framework - Bioretention/Swales'''

|-

|-

!<br>'''Component'''

!<br>'''Component'''

!<br>'''Verification Inspection'''

!<br>'''Verification Inspection'''

|-

|-

|rowspan="23"|'''Visual Indicators'''

|rowspan="2"|'''[[Bioretention: Sizing|Contributing Drainage Area]]'''

|-

|-

|CDA condition  

|CDA condition  

|x

|x

|x

|x

|-

|-

|Inlet/Flow Spreader Structural Integrity

|Inlet/Flow Spreader Structural Integrity

|x

|x

|

|

|-

|-

|BMP dimensions

|BMP dimensions

|

|

|x

|x

|-

|-

|Standing water  

|Standing water  

|x

|x

|x

|x

|-

|-

|Vegetation cover

|Vegetation cover

|x

|x

|

|

|-

|-

|Monitoring well condition

|Monitoring well condition

|x

|x

|x

|x

|-

|-

|rowspan="6"|'''Testing Indicators'''

|rowspan="6"|'''Testing Indicators'''

==Construction Inspection Tasks==

==Construction Inspection Tasks==

Construction inspections take place during several points in the construction sequence, specific to the type of LID BMP, but at a minimum should be done '''weekly''' and include the following:

Construction inspections take place during several points in the construction sequence, specific to the type of LID BMP, but at a minimum should be done '''weekly''' and include the following:

# During site preparation, prior to BMP excavation and grading to ensure the CDA is stabilized or that adequate ESCs or flow diversion devices are in place and confirm that construction materials meet design specifications

# During site preparation, prior to BMP excavation and grading to ensure the CDA is stabilized or that adequate ESCs or flow diversion devices are in place and confirm that construction materials meet design specifications

# Prior to hand-off points in the construction sequence when the contractor responsible for the work changes (i.e., hand-offs between the storm sewer servicing, paving, building and landscaping contractors)

# Prior to hand-off points in the construction sequence when the contractor responsible for the work changes (i.e., hand-offs between the storm sewer servicing, paving, building and landscaping contractors)

# After every large storm event (e.g., 15 mm rainfall depth or greater) to ensure [https://sustainabletechnologies.ca/app/uploads/2020/01/ESC-Guide-for-Urban-Construction_FINAL.pdf Erosion Sediment Controls (ESCs)] and pretreatment or flow diversion devices are functioning and adequately maintained. View the table below, which describes critical points during the construction sequence when inspections should be performed prior to proceeding further. You can also download and print the table [https://wikidev.sustainabletechnologies.ca/images/7/7f/Construction_Inspection.pdf '''here''']<br>

# After every large storm event (e.g., 15 mm rainfall depth or greater) to ensure [https://sustainabletechnologies.ca/app/uploads/2020/01/ESC-Guide-for-Urban-Construction_FINAL.pdf Erosion Sediment Controls (ESCs)] and pretreatment or flow diversion devices are functioning and adequately maintained. View the table below, which describes critical points during the construction sequence when inspections should be performed prior to proceeding further. You can also download and print the table [https://wikidev.sustainabletechnologies.ca/images/7/7f/Construction_Inspection.pdf '''here''']<br>

{| class="wikitable" style="width: 1000px;"

{| class="wikitable" style="width: 1000px;"

|+'''Bioretention/Swales: Construction Inspections'''<br>

|+'''Bioretention/Swales: Construction Inspections'''

|-

|-

!<br>'''Construction Sequence Step & Timing'''

!<br>'''Construction Sequence Step & Timing'''

Table below describes routine maintenance tasks for [[bioretention]] practices, organized by BMP component, along with recommended minimum frequencies. It also suggests higher frequencies for certain tasks that may be warranted for BMPs located in highly visible locations or those receiving flow from high traffic areas (vehicle or pedestrian). Tasks involving removal of trash, debris and sediment and weeding/trimming of [[vegetation]] for BMPs in such contexts may need to be done more frequently (i.e., higher standards may be warranted).

Table below describes routine maintenance tasks for [[bioretention]] practices, organized by BMP component, along with recommended minimum frequencies. It also suggests higher frequencies for certain tasks that may be warranted for BMPs located in highly visible locations or those receiving flow from high traffic areas (vehicle or pedestrian). Tasks involving removal of trash, debris and sediment and weeding/trimming of [[vegetation]] for BMPs in such contexts may need to be done more frequently (i.e., higher standards may be warranted).

Individuals conducting [[vegetation]] maintenance and in particular, weeding (i.e., removal of undesirable vegetation), should be familiar with the species of [[Plants lista|plants]] specified in the planting plan and experienced in plant identification and methods of removing/controlling noxious weeds. Key resources on these topics are provided below at the links provided:

Individuals conducting [[vegetation]] maintenance and in particular, weeding (i.e., removal of undesirable vegetation), should be familiar with the species of [[Plant lists|plants]] specified in the planting plan and experienced in plant identification and methods of removing/controlling noxious weeds. Key resources on these topics are provided below at the links provided:

*[http://www.weedinfo.ca/en/ Agriculture and Agri-food Canada’s Weed Info database]

*[http://www.weedinfo.ca/en/ Agriculture and Agri-food Canada’s Weed Info database]

*[http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/weedgal.htm Ontario Ministry of Agriculture, Food and Rural Affairs’ Ontario Weed Gallery]

*[http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/weedgal.htm Ontario Ministry of Agriculture, Food and Rural Affairs’ Ontario Weed Gallery]

*[http://www.agrifs.ir/sites/default/files/Weeds%20of%20North%20America%20%7BRichard%20Dickinson%7D%20%5B9780226076447%5D%20%282014%29_2.pdf Weeds of North America (book), 2014, by Richard Dickinson and France Royer, University of Chicago Press, 656 pgs.]

*[http://www.agrifs.ir/sites/default/files/Weeds%20of%20North%20America%20%7BRichard%20Dickinson%7D%20%5B9780226076447%5D%20%282014%29_2.pdf Weeds of North America (book), 2014, by Richard Dickinson and France Royer, University of Chicago Press, 656 pgs.]

{|class="wikitable" style="width: 1000px;"

{|class="wikitable" style="width: 1280px"

|+'''Bioretention/Swales: Key Components, Descriptions and Routine I&M Requriements'''

|+'''Bioretention/Swales: Key Components, Descriptions and Routine I&M Requirements'''

|-

|-

!Component

!style="width: 500px"|Comnponent

!Description

!style="width: 1500px"|Description  

!Inspection & Maintenance Tasks

!style="width: 1500px"|Inspection & Maintenance Tasks

|-

|-

|'''[[Bioretention: Sizing|Contributing Drainage Area (CDA)]]'''

|'''[[Bioretention: Sizing|Contributing Drainage Area (CDA)]]'''

*Remove trash, debris and sediment from pavements (biannually to quarterly) and eavestroughs (annually);

*Remove trash, debris and sediment from pavements (biannually to quarterly) and eavestroughs (annually);

*Replant or seed bare soil areas as needed.

*Replant or seed bare soil areas as needed.

|-

|-

|'''[[Pretreatment]]'''

|'''[[Pretreatment]]'''

*Remove trash, debris and sediment annually to biannually or when the device sump is half full;

*Remove trash, debris and sediment annually to biannually or when the device sump is half full;

*Measure sediment depth or volume during each cleaning, or annually to estimate accumulation rate and optimize frequency of maintenance

*Measure sediment depth or volume during each cleaning, or annually to estimate accumulation rate and optimize frequency of maintenance

|-

|-

|'''[[Inlets]]'''

|'''[[Inlets]]'''

*Measure sediment depth or volume during each cleaning or annually to estimate accumulation rate and optimize frequency of maintenance;

*Measure sediment depth or volume during each cleaning or annually to estimate accumulation rate and optimize frequency of maintenance;

*Remove woody [[vegetation]] from filter bed at [[inlets]] annually.

*Remove woody [[vegetation]] from filter bed at [[inlets]] annually.

|-

|-

|'''Perimeter'''

|'''Perimeter'''

*Confirm the surface ponding footprint area dimensions are within ±10% of the design and that maximum surface ponding depth meets design specifications;

*Confirm the surface ponding footprint area dimensions are within ±10% of the design and that maximum surface ponding depth meets design specifications;

*Check for side slope erosion or damage that compromises water storage capacity

*Check for side slope erosion or damage that compromises water storage capacity

|-

|-

|'''[[Bioretention: Construction checklist|Filter Bed]]'''

|'''[[Bioretention: Construction checklist|Filter Bed]]'''

*Repair sunken areas when ≥ 10 cm deep and barren/eroded areas when ≥ 30 cm long;

*Repair sunken areas when ≥ 10 cm deep and barren/eroded areas when ≥ 30 cm long;

*Remove sediment when > 5 cm deep or time to drain water ponded on the surface exceeds 48 hours.

*Remove sediment when > 5 cm deep or time to drain water ponded on the surface exceeds 48 hours.

|-

|-

|'''[[Vegetation]]'''

|'''[[Vegetation]]'''

*Replace dead plantings annually to achieve 80% cover by the third growing season;

*Replace dead plantings annually to achieve 80% cover by the third growing season;

*Do not apply chemical fertilizers.  

*Do not apply chemical fertilizers.  

|-

|-

|'''[[Overflow|Overflow Outlet]]'''

|'''[[Overflow|Overflow Outlet]]'''

*Keep free of obstructions;

*Keep free of obstructions;

*Remove trash, debris and sediment biannually to quarterly.

*Remove trash, debris and sediment biannually to quarterly.

|-

|-

|'''[[Underdrain|Sub-drain]]'''

|'''[[Underdrain|Sub-drain]]'''

*Keep pipe and flow restrictor free of obstructions by flushing annually;

*Keep pipe and flow restrictor free of obstructions by flushing annually;

*Inspect flow restrictor frequently (e.g., biannually to quarterly).

*Inspect flow restrictor frequently (e.g., biannually to quarterly).

|-

|-

|'''[[Monitoring well]]'''

|'''[[Monitoring well]]'''

|

|

*[[Wells|Standpipes]] should be securely capped on both ends and remain undamaged.

*[[Wells|Standpipes]] should be securely capped on both ends and remain undamaged.

|}

|}

==How to Preserve Basic BMP Function==

==Tips to Preserve Basic BMP Function==

*Maintain grading of the filter bed (or [[Vegetated filter strips|grass filter strip]] if present) at [[curb cut]] [[inlets]] so at least 5 cm of the back of the curb is visible through regular sediment removal and regrading.

*Maintain grading of the filter bed (or [[Vegetated filter strips|grass filter strip]] if present) at [[curb cut]] [[inlets]] so at least 5 cm of the back of the curb is visible through regular sediment removal and regrading.

*To avoid over-compaction of the [[Bioretention: Filter media|filter media soil]], any maintenance tasks involving vehicle or foot traffic on the filter bed should not be performed during wet weather.

*To avoid over-compaction of the [[Bioretention: Filter media|filter media soil]], any maintenance tasks involving vehicle or foot traffic on the filter bed should not be performed during wet weather.

==Rehabilitation & Repair==

==Rehabilitation & Repair==

Table below provides guidance on rehabilitation and repair work specific to bioretention and dry swales organized according to BMP component.  

Table below provides guidance on rehabilitation and repair work specific to bioretention and dry swales organized according to BMP component.  

{|{| class="wikitable" style="width: 1000px;"

{|{| class="wikitable" style="width: 1000px;"

*Schedule hydro-vac truck or drain-snaking service to clear the obstruction.

*Schedule hydro-vac truck or drain-snaking service to clear the obstruction.

|}

|}

==Inspection Time Commitments and Costs==

==Inspection Time Commitments and Costs==

Estimates are based on a typical partial infiltration bioretention design (i.e., includes a sub-drain); estimates for other designs (i.e., full infiltration and no-infiltration) can be found in the [https://sustainabletechnologies.ca/app/uploads/2016/08/LID-IM-Guide-7.1-Bioretention-and-Dry-Swales.pdf Low Impact Development (LID) Stormwater Management Practice Inspection and Maintenance Guide]

Estimates are based on a typical partial infiltration bioretention design (i.e., includes a sub-drain); estimates for other designs (i.e., full infiltration and no-infiltration) can be found in the [https://sustainabletechnologies.ca/app/uploads/2016/08/LID-IM-Guide-7.1-Bioretention-and-Dry-Swales.pdf Low Impact Development (LID) Stormwater Management Practice Inspection and Maintenance Guide]<br>

[[File:Time commit cost.PNG|thumb|left|450px|General time commitments and costs for inspection of bioretention and dry swale features with partial infiltration (in 2016 $ figures).<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices. Bioretention - Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

[[File:Time commit cost.PNG|thumb|left|400px|General time commitments and costs for inspection of bioretention and dry swale features with partial infiltration (in 2016 $ figures).<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices. Bioretention - Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

[[File:Cost per maintenance task.PNG|thumb|450px|Per-task cost estimates for maintenance and rehabilitation of a partial infiltration bioretention feature (in 2016 $ figures).<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices. Bioretention - Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

[[File:Cost per maintenance task.PNG|thumb|400px|Per-task cost estimates for maintenance and rehabilitation of a partial infiltration bioretention feature (in 2016 $ figures).<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices. Bioretention - Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

[[File:Life cycle costs.PNG|thumb|center|450px|Construction and life cycle cost estimates for bioretention and dry swale features with partial infiltration (in 2016 $ figures).<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices. Bioretention - Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]<br>

[[File:Life cycle costs.PNG|thumb|center|400px|Construction and life cycle cost estimates for bioretention and dry swale features with partial infiltration (in 2016 $ figures).<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices. Bioretention - Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]<br>

</br>

</br>

The 8 page document prompts users to fill out details previously mentioned above on this page in other sections about various zones associated with [[Bioretention]] and [[Dry swale]] features (i.e. inlets, perimeter of the feature, filter bed, outlets, etc.) and describe why each area is a pass or fail, and if remediate action is required and under what timeframe it would be completed by. Furthermore, the forms prompt the reviewer to determine what type of  inspection is being conducted for the feature in question: Construction (C), Routine Operation (RO), Maintenance Verification (MV), or Performance Verification (PV). <br>

The 8 page document prompts users to fill out details previously mentioned above on this page in other sections about various zones associated with [[Bioretention]] and [[Dry swale]] features (i.e. inlets, perimeter of the feature, filter bed, outlets, etc.) and describe why each area is a pass or fail, and if remediate action is required and under what timeframe it would be completed by. Furthermore, the forms prompt the reviewer to determine what type of  inspection is being conducted for the feature in question: Construction (C), Routine Operation (RO), Maintenance Verification (MV), or Performance Verification (PV). <br>

<br>

<br>

[[File:Continuous monitoring.PNG|thumb|500px|Staff conducting monitoring of bioretention's water level with the use of a [[Digital technologies|continuous water level data logger]] located in the feature's[[Wells|monitoring well]]. [https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf Photo Source: TRCA, 2018]<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices - Bioretention. Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

 

[[File:Continuous monitoring.PNG|thumb|300px|Staff conducting monitoring of bioretention's water level with the use of a [[Digital technologies|continuous water level data logger]] located in the feature's[[Wells|monitoring well]]. [https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf Photo Source: TRCA, 2018]<ref>TRCA. 2018. Inspection and Maintenance of Stormwater Best Management Practices - Bioretention. Fact Sheet. https://sustainabletechnologies.ca/app/uploads/2018/02/Bioretention-and-Dry-Swales-Fact-Sheet.pdf</ref>]]

<pdf width="900" height="800">File:Bio Swale Inspection Sheet.pdf</pdf>

<pdf width="900" height="800">File:Bio Swale Inspection Sheet.pdf</pdf>

==References==

==References==