Design of Major Stormwater Drainage Systems

Major storms can cause flooding, water damage, pollutions, and reduce the aesthetic value of properties. Today we discuss major storm drainage systems, overland flow paths for stormwater runoff, the use of driveways to carry overland flows, and recessed driveways to prevent flooding.

Major storm drainage system

  • Stormwater runoff from major storms is often an overlooked component of residential property design.
  • You don’t get to tell the water where to go during major storms; rather, it usually tells you where to go, and your home needs to get out of its way!
  • The run-off created by major storms can rarely be managed by a piped drainage system; rather, it usually needs to be transported over the land surface as an ‘ overland flood’.

Establishing overland flow paths for stormwater runoff

  • The construction of the major storm drainage system is often ignored since there is no reference within the building codes to such drainage systems.
  • The best way to manage the run-off from major storms is through smart landscaping of the house.
  • Every house should have a well-defined flow path for stormwater run-off that goes through the house and the property.

Use of driveways to carry overland flows

  • In new homes, driveways are often used as ‘ overland flow paths ‘ carrying stormwater run-off either to the street or to underground water storage tanks known as ‘ on-site detention ‘ (OSD) tanks within the stormwater industry.
  • If your home is at risk of stormwater flooding, then having your driveway design checked by a drainage engineer will help you avoid such flood risk.

Recessed driveways

  • If your home is at risk of stormwater flooding, then having your driveway design checked by a drainage engineer will help you avoid such flood risks.
  • In such cases, if a serious storm warning is issued, it is best to park your car in the street, away from the flow path of this stormwater.
  • Major storms are those storms that are less than 10 per cent likely to occur in any given year.

Stormwater Sydney provides Inspection, Cleaning, Maintenance, Repairs, Construction, and Advisory on stormwater systems across Sydney, ensuring compliance with Sydney standards and Council regulations.