Page 392 - Planning and Design of Airports

CHAPTER 9

Airport Drainage

n adequate drainage system for the removal of surface and
subsurface water is vital for the safety of aircraft and for the
Alongevity of the pavements. Improper drainage results in the
formation of puddles on the pavement surface, which can be hazard-
ous to aircraft taking off and landing. Poor drainage can also result in
the early deterioration of pavements. Flat longitudinal and transverse
grades and wide pavement surfaces often pose difficulties in making
provision for adequate drainage at airports.
The material in this chapter is principally concerned with estimating
the amounts of surface and subsurface runoff and not with the hydraulics
of pipes or details of installation. These latter items are adequately covered
in texts on hydraulics and literature provided by pipe manufacturers.
The FAA and the Corps of Engineers have developed most of the
information on airport drainage in the United States and the material
presented in this has been drawn from their work. In 2006, several
agencies worked together to combine existing surface drainage topics
covered in several manuals into one Unified Facilities Criteria (UFC)
document. The resulting manual [1] now serves as the design and
analysis standard for surface drainage for the FAA.

Purpose of Drainage
The functions of an airport drainage system are as follows:
1. Interception and diversion of surface and groundwater flow
originating from lands adjacent to the airport
2. Removal of surface runoff from the airport
3. Removal of subsurface flow from the airport

In very few cases will the natural drainage on a site be sufficient by
itself to satisfy these functions; consequently artificial drainage must
be installed.

Design Storm for Surface Runoff
The selection of the severity of the storm which the drainage system
should accommodate involves economic consideration. An extremely

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