Why stormwater planning should happen early

Roofs, paved areas, driveways and landscaping all change how quickly rainwater moves across a property. Drainage planned before excavation, concrete and landscaping is usually easier to coordinate than pipework added after access becomes restricted.

For renovations and new builds, the plumbing plan should be considered alongside finished surface levels, retaining structures, building footprints and other underground services.

Site fall guides the design

Gravity drainage relies on suitable levels. A site assessment identifies high and low points, likely flow paths and locations where water may collect. The available fall influences pipe depth, pit position and whether alternative design measures need consideration.

Pits and pipework work as a system

Surface inlets collect water at selected points. Underground pipework then carries it toward an approved discharge location. Pipe sizing, gradients, junctions and access points must work together; installing one large pit cannot compensate for poorly coordinated downstream pipework.

Keep clean water and wastewater functions clear

Stormwater and sanitary drainage perform different jobs and require different connections. Property owners should avoid assumptions about existing underground lines. Identification and planning should occur before new connections are made.

Access and maintenance matter

Even a well-designed system benefits from accessible pits and inspection points. Leaves, sediment and landscaping material can enter surface drainage. Access makes inspection and routine cleaning more practical and helps isolate issues if performance changes.

A useful pre-construction checklist

  • Confirm proposed roof, paving and landscape catchments.
  • Review existing and proposed site levels.
  • Identify other underground services and access restrictions.
  • Confirm the approved discharge strategy for the project.
  • Coordinate drainage before slabs, driveways and finished landscaping.

Matrix delivers stormwater, excavation and civil plumbing for residential, commercial and civil sites. Contact the team early when drainage needs to coordinate with a larger construction program.