8,255
edits
Changes
Jump to navigation
Jump to search
m
→Design
Line 81:
Line 81:
#Minimum depth: 1 m;+#Sized to ensure non-erosive velocities leaving forebay; +#Maximum area: 20 % of total permanent pool+#Overall: minimum 3:1; +#Forebay: minimum 2:1+#5:1 For 3 m above and below permanent pool; +#Maximum 3:1 elsewhere+#Minimum 450 mm; +#Preferred pipe slope: >1%; +#If submerged, obvert 150 mm below expected maximum ice depth+#Minimum: 450mm outlet pipe; +#Preferred pipe slope: >1%; +#If orifice control used, 75mm diameter minimum; +#Minimum 100mm orifice preferable +#Provided to approval of Municipality; +#Provision of maintenance drawdown pipe preferred+
|Pre-treatment
|Pre-treatment
|style="text-align: left|
|style="text-align: left|
−*Minimum depth: 1 m;
−*Sized to ensure non-erosive velocities leaving forebay;
−*Maximum area: 20 % of total permanent pool
|-
|-
|Length-to-Width Ratio
|Length-to-Width Ratio
|Maximize flow path and minimize short-circuiting potential
|Maximize flow path and minimize short-circuiting potential
|style="text-align: left|
|style="text-align: left|
−*Overall: minimum 3:1;
−*Forebay: minimum 2:1
|-
|-
|Permanent pool depth
|Permanent pool depth
Line 102:
Line 102:
|Safety
|Safety
|style="text-align: left|
|style="text-align: left|
−*5:1 For 3 m above and below permanent pool;
−*Maximum 3:1 elsewhere
|-
|-
|Inlet
|Inlet
|Avoid clogging/freezing
|Avoid clogging/freezing
|style="text-align: left|
|style="text-align: left|
−*Minimum 450 mm;
−*Preferred pipe slope: > 1 %;
−*If submerged, obvert 150 mm below expected maximum ice depth
|-
|-
|Outlet (See also [[flow control]])
|Outlet (See also [[flow control]])
|Avoid clogging/freezing
|Avoid clogging/freezing
|style="text-align: left|
|style="text-align: left|
−*Minimum: 450 mm outlet pipe;
−*Preferred pipe slope: > 1 %;
−*If orifice control used, 75 mm diameter minimum;
−8Minimum 100 mm orifice preferable
|-
|-
|Maintenance access
|Maintenance access
|Access for backhoes or dredging equipment
|Access for backhoes or dredging equipment
|style="text-align: left|
|style="text-align: left|
−*Provided to approval of Municipality;
−*Provision of maintenance drawdown pipe preferred
|-
|-
|Buffer
|Buffer