Line 8: |
Line 8: |
| *[[Grasses| Resilient turf grass]] | | *[[Grasses| Resilient turf grass]] |
| *[[Check dams]], to facilitate short term ponding | | *[[Check dams]], to facilitate short term ponding |
− |
| |
| '''Additional components may include:''' | | '''Additional components may include:''' |
| *[[Absorbent landscapes| Amended soil]], to increase infiltration to soils below | | *[[Absorbent landscapes| Amended soil]], to increase infiltration to soils below |
| *[[Liner|Impermeable membrane]], to prevent infiltration to soils below | | *[[Liner|Impermeable membrane]], to prevent infiltration to soils below |
| *[[Turf reinforcement]], to prevent scour | | *[[Turf reinforcement]], to prevent scour |
| + | |
| + | ==Design== |
| + | *Minimum residence time of 5 minutes. |
| + | *Maximum flow velocity 0.3 m/s |
| + | *Bottom width between 0.6 - 2.4 m |
| + | *Minimum length 30 m |
| + | |
| + | {|class="wikitable" |
| + | |+ Slope variations |
| + | |- |
| + | |< 2 %||Use underdrain to distribute water for infiltration |
| + | |- |
| + | |2 - 5 %||Design swale for surface flow, consider check dams |
| + | |- |
| + | ||5 %||Check dams required to reduce effective slope to 2 – 3 % |
| + | |} |
| + | |
| + | Maximum depth of flow |
| + | 1/3 height of vegetation for infrequently mown swales. |
| + | ½ height of grass for regularly mown swales, to maximum of 75 mm. |