Car park drainage for public spaces, multi-storeys & undergrounds

Car park drainage needs to consider the following factors:

Load and forces

Vehicles exert significant loads, dynamic forces and stress on surfaces when braking, turning, reversing and accelerating. The car park drainage channel must be robust to withstand a variety of loads and forces, including vertical and lateral ones over a long period of time.

Pedestrian safety

A safe environment for pedestrians requires secure systems with anti-slip surfaces and heelsafe gratings. Incorporating these features within the overall project will provide safety and design flexibility.

Climate changes

Drainage systems must be resistant to frost, de-icing salts and UV radiation to ensure longevity and low-maintenance costs.

Extensive surfaces

For larger catchment areas, it’s often more cost-effective to choose a car park drainage solution with a higher drainage and retention capacity. Precise and accurate hydraulic calculations will help determine the correct channel sizing and drainage system for the project under design.

Contamination

Tyre wear, brake dust, fuel hydrocarbons, as well as other contaminants like petrol, oil, zinc and copper can be found on parking surfaces. These pollutants can enter local sewer systems or natural watercourses. A rainwater treatment channel can collect and treat surface water at the source before being released.

Theft and vandalism

Having a parking drainage system with multiple bolt connections or anti-vandal locking handles can protect the gratings from vandalism and theft.

Additional challenges for underground parking:

Loads and forces:

Turning tightly around columns, ramps and small parking spaces imposes significant loads, stress and forces on the system and adjacent surface. Linear drainage across ramps is subject to high impact loads when trafficked.

Corrosive environments:

Parking surfaces and channel gratings are subject to continual attack by corrosive substances including oil, petrol, brake fluid, cleaning detergents and de-icing salts. Therefore, the drainage solution must be durable and corrosion-resistant.

Installation depth restrictions:

Floor structures within underground car parks, often have limited depth available for installation of surface drainage above damp-proof membranes. If there are depth restrictions, linear drainage systems will need to have shallow inverts.

High surface water run-off:

Due to the steep incline of underground ramps, surface water flows more quickly. The channel system gratings should be selected for an efficient interception to avoid surface water crossing over drainage channels.