- S2.2.5
- Surface crowning is where the reinstatement lies above the mean level of the adjacent surfaces; see Figure S2.4. Intervention is required where the surface crowning spanning more than 100 mm in any plan dimension exceeds the intervention limit Z shown in Table S2.2.
- S2.2.6
- Earlier intervention is required if crowning alone results in standing water wider than 500 mm or exceeding 1 m2 in area, at 2 hours after the cessation of rainfall.
Table S2.2 Intervention limits for surface crowning Reinstatement width W (mm)
Intervention limit Z (mm)
Combined defect intervention limit (mm)
Up to 400 10 10 Over 400 to 500 12 10 Over 500 to 600 14 12 Over 600 to 700 17 14 Over 700 to 800 19 16 Over 800 to 900 22 18 Over 900 25 20
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