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==Planning considerations==
==Planning considerations==
==Design==
==Design==
+{| class="wikitable"
+!Element
+!Design Objective
+!Criteria
+|-
+|Drainage Area
+|Sustaining vegetation, volumetric turnover
+|5 Ha (≥10 Ha preferred)
+|-
+|Treatment Volume
+|Provision of appropriate level of protection (Table 3.2)
+|See Table 3.2
+|-
+|Active Storage
+|Detention
+|Suspended solids settling 24 hrs (12 hrs if in conflict with min. orifice size)
+|-
+|Forebay
+|Pre-treatment
+|Minimum depth: 1 m; ii) Sized to ensure non-erosive velocities leaving forebay; iii) Maximum area: 20 % of total permanent pool
+|-
+|Length-to-Width Ratio
+|Maximize flow path and minimize short-circuiting potential
+|i) Overall: minimum 3:1; ii) Forebay: minimum 2:1
+|-
+|Permanent Pool Depth
+|Vegetation requirements, rapid settling
+|The average permanent pool depth should range from 150 mm to 300 mm
+|-
+|Active Storage Depth
+|Storage/flow control, sustaining vegetation
+|Maximum 1.0m for storms < 10 year event
+|-
+|Side Slopes
+|Safety
+|i) 5:1 For 3 m above and below permanent pool (ii) Maximum 3:1 elsewhere
+|-
+|Inlet
+|Avoid clogging/freezing
+|i) Minimum 450 mm; ii) Preferred pipe slope: >1%; iii) If submerged, obvert 150 mm below expected maximum ice depth
+|-
+|Outlet
+|Avoid clogging/freezing
+|i) Minimum: 450mm outlet pipe; ii) Preferred pipe slope: >1%; iii) If orifice control used, 75mm diameter minimum; (iv) Minimum 100mm orifice preferable
+|-
+|Maintenance Access
+|Access for backhoes or dredging equipment
+|(i) Provided to approval of Municipality; (ii) Provision of maintenance drawdown pipe preferred
+|-
+|Buffer
+|Safety
+|Minimum 7.5 m above maximum water quality/erosion control water level
+|}
+
==Performance==
==Performance==
STEP (under previous name SWAMP) conducted their own research into the performance of stormwater wetlands, the project page and report can be viewed [https://sustainabletechnologies.ca/home/urban-runoff-green-infrastructure/conventional-stormwater-management/constructed-wetlands/performance-assessment-of-an-open-and-covered-stormwater-wetland-system-aurora-ontario/ here].
STEP (under previous name SWAMP) conducted their own research into the performance of stormwater wetlands, the project page and report can be viewed [https://sustainabletechnologies.ca/home/urban-runoff-green-infrastructure/conventional-stormwater-management/constructed-wetlands/performance-assessment-of-an-open-and-covered-stormwater-wetland-system-aurora-ontario/ here].