Establishing a Soakaway in the Garden

Purpose

• Rainwater should not burden the sewer system, basements, or treatment plants.
• Rainwater should infiltrate and become a new groundwater resource.

What is a Soakaway?

• A solution for managing rainwater.
• Consists of a large box under the lawn where rainwater is collected.
• The water slowly seeps down and becomes groundwater.

Practical Application

• The lawn can be used normally (playing, trampoline, grilling).
• Only visible part: sediment trap, typically a well in front of the soakaway, where sand collects.

Advantages

• Prevents flooding and burden on treatment plants.
• Energy savings and reduced use of chemicals in purification.

Important Considerations

• Sizing is crucial for the soakaway's efficiency.
• You cannot reconnect to the sewer system after disconnection, so correct sizing is important from the start.

Sizing Example

• 8 m³ soakaway per 100 m² roof area is sufficient even in areas with clayey soil, such as in Copenhagen.

Practical Advice

• Municipalities and local sewer service companies are helpful.
• Sewer contractors have experience with establishing soakaways.
• Also consider installing a backflow preventer for additional protection against flooding.