64BExtraction track drainage

64B Extraction track drainage

64B Extraction track drainage

(1) Harvesting operations must maximise the use of crossfall drainage and slash coverage of extraction tracks, as far as practicable.

(2) Crossbanks, if required, must comply with the following—

(a) a crossbank must be constructed so as to baulk and divert the flow of water away from the track surface,

(b) water must be diverted onto a stable surface capable of handling concentrated water flow which provides for efficient sediment trapping and energy dissipation,

(c) a crossbank must have a minimum effective height of 35 centimetres unconsolidated or 25 centimetres consolidated, and generally should not be greater in height than 50 centimetres,

(d) a crossbank must be constructed within 1 week after the completion of harvesting operations on the track, unless the soil is saturated.

(3) If bare soil areas exist on an extraction track, the areas must be drained to ensure that any surface flow does not exceed the maximum distances for each track grade specified in the Table to this clause.

Table

| Track grade | Maximum distance of surface flow | | Up to and including 5° | 100 metres | | More than 5° and up to and including 10° | 60 metres | | More than 10° and up to and including 15° | 40 metres | | More than 15° and up to and including 20° | 25 metres | | More than 20° and up to and including 25° | 20 metres |