Draining external pavements in commercial properties

Along Australia’s east coast, recent storms have made us acutely aware of the importance of surface water management directly outside of buildings. The stark reality is if you do not deal with water in the exposed areas adjacent to buildings, then you may be forced to deal with water at the building line where it is more difficult to manage.  Amongst other things, failure to deal with runoff at the building line may result to damage to foundations, entranceways and floors, not to mention mould and costly repairs.

Despite whether or not stormwater runoff effects the building line, bad drainage in exposed areas has its own problems.

• Inconvenience and hazards to people
• Short pavement longevity
• Unplanned construction and maintenance costs

The latter consequence affects architects and building owners who constantly face the threat of litigation and their budgets running over. It is therefore important to select the best design approach for surface water management to provide a safe, aesthetically pleasing, hydraulically efficient and cost effective drainage layout where:

• E arthworks & pipework are minimized
• E xisting levels and drainag e infrastructure utilised (where possible)
• Other client or council requirements are adhered to e.g. Stormwater detention

Rider Levett Bucknall, an independent quantity surveyor, compared the installation costs of 3 alternative surface drainage designs for the same project. As well as comparing the costs of the options, there is a strong design argument , which focuses on installation, hydraulics, maintenance, safety and walkability.