Original Conditions December 1994

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DRAINAGE

All drainage works as required by the approved Master Drainage Plan are to be
provided by the developer at his own cost. The maintenance of all drainage patlis
and dams shall remain with the development.

The drainage pipe system shall be designed for a Q10 storm frequency. Low flow
pipes catering for Q2 storm frequency may be permitted in areas of the development
provided adequate overland flow paths for the greater rainfall intensities are
provided. Existing drainage paths shall be maintained wherever possible.

Concentration of stormwater run-off shall be prohibited on adjoining lands save with’
the express written permission of the landholder. Details of any approvals given by
adjoining landholders shall be submitted to Council with the Engineering Plans.

The minimum fall for open grassed drains shall be 1%. Drains with slopes less than
1% will require a concrete invert. For open channel flows the minimum velocity of
0.5m/s for a Q5 storm and a maximum velocity of 1.2m/s for a Q1O storm are
required.

On lodgement of the first building application, the Developer shall provide a site
plan indicating the flood height for a Q100 flood.

Grease/oil arrestors are to be provided at all locations within the site where, in the
opinion of the Shire Engineer, stormwater runoff will contain significant proportions
of oil.

A single litter trap is to be provided at a suitable location. The developer shall
implement a system of regular maintenance and cleaning of the litter and oil traps to
the satisfaction of the Shire Engineer.

Special effort is to be made during construction to retain all stormwater on site and
only release water that meets a standard that satisfies the Department of
Environment and Heritage for release into Lake Weyba.