Line 81: |
Line 81: |
| |Pre-treatment | | |Pre-treatment |
| |style="text-align: left| | | |style="text-align: left| |
| #Minimum depth: 1 m;
| | *Minimum depth: 1 m; |
| #Sized to ensure non-erosive velocities leaving forebay;
| | *Sized to ensure non-erosive velocities leaving forebay; |
| #Maximum area: 20 % of total permanent pool
| | *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;
| | *Overall: minimum 3:1; |
| #Forebay: minimum 2:1
| | *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;
| | *5:1 For 3 m above and below permanent pool; |
| #Maximum 3:1 elsewhere
| | *Maximum 3:1 elsewhere |
| |- | | |- |
| |Inlet | | |Inlet |
| |Avoid clogging/freezing | | |Avoid clogging/freezing |
| |style="text-align: left| | | |style="text-align: left| |
| #Minimum 450 mm;
| | *Minimum 450 mm; |
| #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 |
| |- | | |- |
| |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: 450mm outlet pipe;
| | *Minimum: 450 mm outlet pipe; |
| #Preferred pipe slope: >1%;
| | *Preferred pipe slope: > 1 %; |
| #If orifice control used, 75mm diameter minimum;
| | *If orifice control used, 75 mm diameter minimum; |
| #Minimum 100mm orifice preferable
| | 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;
| | *Provided to approval of Municipality; |
| #Provision of maintenance drawdown pipe preferred
| | *Provision of maintenance drawdown pipe preferred |
| |- | | |- |
| |Buffer | | |Buffer |