PERTH AIRPORT Master Plan 2009

P E R T H A I R P O R T M a s t e r P l a n 2 0 0 9
10. Drainage and Hydrology
About this Chapter
This chapter describes the existing drainage system,
identifies current capacity issues and describes the strategy
to develop a system that can support the proposed airport
development described in the Master Plan. The connection
between drainage system development and Perth Airport’s
Environmental Management Strategy is also identified.
10.1 Existing System
Perth Airport is located between the Darling Escarpment to
the east and the Swan River to the west. As a result of its
location a significant amount of storm water runoff from
catchments outside the airport boundary flows through the
airport on route to the Swan River.
The existing drainage system consists of two major drains
that cross the airport and a series of precinct level systems
designed to control storm water in the developed areas on
the site. Precincts 1 and 3 have independent outfalls outside
the airport estate. The balance of the precinct drainage
system flows into one or other of the main drains.
Southern Main Drain
The Perth Airport Southern Main Drain enters the airport site
via two 900 millimetre diameter pipes from the east into an
open unlined drain. It is then piped under Horrie Miller Drive
and Runway 03L/21R with single 1200 millimetre diameter
pipes. Beyond the airfield the drain reverts to an open unlined
drain which follows Tonkin Highway along the south western
boundary of the airport, leaving the airport site near Brearley
Avenue. The drain then continues in a reserve to the discharge
point into the Swan River near Kanowna Avenue in Redcliffe.
Northern Main Drain
The Perth Northern Main Drain is an open unlined drain that
extends from the International Precinct, around the northern
end of Runway 06/24 and the northern end of the General
Aviation Precinct along each side of Taxiway Romeo. The
drain then exits the airport, is piped under the Great Eastern
Highway Bypass and discharges into the Swan River near
Beverley Terrace.
Precinct 1
This system is a combination of open unlined drains
and piped sections which provides drainage for the
developments, runways, taxiway, aprons, terminals, carparks,
and ground transport facilities in the Domestic Precinct.
The drainage system passes through a compensation
basin and silt and hydrocarbon interceptor on the corner
of Fauntleroy Avenue prior to discharging into the reserve
adjacent to the Swan River.
Precinct 3
This drainage system has its outfall via a set of existing
culverts under the Great Eastern Highway Bypass. As
the authority for this road and the associated drainage
infrastructure, Main Roads Western Australia has provided
maximum outfall capacities for the culvert.
10.2 Drainage System Considerations
The considerations for development of the drainage system
at Perth Airport fall into three main categories:
• External system capacity
• Internal system capacity
• Modifications required for development
External System Capacity
There is currently a significant imbalance between the inflows
to the airport estate and the outlet capacity. This results in a
need for significant compensation within the airport to catch
runoff generated in upstream catchments that historically
used the airport land for their compensation.
The development plans on the airport estate identify other
uses for the land used previously as informal compensation,
which reduces this capacity. It is therefore essential that
development of suitably sized compensation in the upstream
catchments occurs to cater for the runoff generated in these
catchments to reduce the flow onto the airport estate.
Alternatively, approval must be obtained to increase outfall
capacity to match inflow from upstream catchments at the very
least, and ideally allow for a reasonable proportion of runoff
generated on the airport site to be disposed of in the main drains.
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