Changes

|Avoid clogging/freezing  

|Avoid clogging/freezing  

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|style="text-align: left|

*Minimum 450 mm;  

*Minimum 450 mm diameter inlet pipe;  

*Preferred pipe slope: > 1 %;  

*Preferred pipe slope: > 1 %;  

*If submerged, obvert 150 mm below expected maximum ice depth

*If submerged, obvert 150 mm below expected maximum ice depth

|Avoid clogging/freezing  

|Avoid clogging/freezing  

|style="text-align: left|

|style="text-align: left|

*Minimum: 450 mm outlet pipe;  

*Minimum: 450 mm diameter outlet pipe;  

*Preferred pipe slope: > 1 %;  

*Preferred pipe slope: > 1 %;  

*If orifice control used, 75 mm diameter minimum;  

*If orifice control used, 75 mm diameter minimum;