Stormwater Management Plans

The design team here at Leamac Hydraulic Consultants has had extensive exposure and experience in the design of stormwater management systems to cater for all regions. We consider all soil conditions and site variables.

The design team here at Leamac Hydraulic Consultants has had extensive exposure and experience in the design of stormwater management systems to cater for all regions. We consider all soil conditions and site variables.

Storm water is water that originates during rainfalls. In developed areas, where the ground surface does not readily absorb water, this storm water becomes surface runoff. If there is a substantial build-up in surface runoff, flooding may occur, which in turn could cause damage to surrounding properties, including the foundations of buildings. Excess surface runoff may also carry contaminated materials, such as oil and chemical elements.

Leamac Hydraulic Consultants prides itself on having extensive experience in engineering roof water drainage systems in accordance with the BCA and the Australian Standards. Our design team has experienced the challenges of designing to such extremes in rainfall activity in the Northern Territory and other remote areas in the north.

Correct sizing of gutter, gutter types, quantity, size and placement of downpipes and the provision of appropriate overflow devices is essential to the efficiency of the design. In the design and detailing of a roof drainage system, consideration is always given to a range of factors such as:

  • rainfall intensity (ARI)
  • roof catchment area
  • gutter size/capacity
  • gutter fall
  • gutter outlets (sumps, rain heads, nozzles)
  • downpipe size, quantity and placement
  • overflow consideration
  • material selection

On Site Detention Systems  (OSD) collect rainfall that falls on a building or the site, which would normally flow directly into the local storm water infrastructure/network. The OSD stores the storm water temporarily and then releases it slowly, thereby reducing the impact from the roofs, driveways and paths hitting the storm water system all at the same time. Otherwise, this can cause localised flooding downstream during heavy rainfall events. Integral to our design process, we always adhere to the local council requirements in regard to location on site and type (above or below ground).