Attenuation Tanks

What Are Attenuation Tanks & How Do They Work?

Attenuation tanks are an innovative solution for managing surface water in urban areas or on sites with significant impermeable surfaces such as roads and car parks. These tanks temporarily store excess stormwater during heavy rainfall, releasing it gradually into the drainage network or natural watercourses. This controlled release prevents overwhelming the drainage system and minimises flood risk.

Stormwater enters the attenuation tank through road gullies or permeable surfaces. Inside the tank, water is stored and regulated by a flow control device, such as a Hydrobrake, which ensures a steady discharge rate. By controlling the flow, these systems support the environment by reducing erosion and pressure on municipal drainage systems.

Attenuation tanks can be constructed using a variety of materials and configurations, including:

• Geo-cellular crates: Modular and space-efficient, ideal for areas with limited space.
• Large-diameter pipes: Durable and suitable for high-capacity requirements.
• Pre-cast concrete box culverts: A robust solution for heavy-duty applications.
• Steel or plastic tanks: Customisable to meet specific site needs.

Attenuation Tank Design & Installation

At Smart Drainz, we provide complete solutions from initial design to final installation. Whether it’s a bespoke tank or a prefabricated unit, we ensure the system meets your requirements and complies with all regulatory standards.

Our Design Process:

1. Site Assessment: We evaluate the site’s topography, drainage needs and space constraints.
2. Calculating Storage Volume: Working to the Environment Agency’s guidelines, we determine the required storage capacity based on the allowed surface water discharge rate.
3. Solution Design: Our engineers select the most suitable materials and configuration, balancing efficiency, durability and cost.

Installation Process:

1. Excavation: Preparing the site for the tank, ensuring minimal disruption.
2. Tank Assembly: Installing the tank system, whether it’s modular crates, pipes or concrete units.
3. Integration: Connecting the tank to the existing drainage network with precision.
4. Testing & Final Checks: Ensuring the tank operates correctly and adheres to all specifications.

Our installations come with a 10-year guarantee, providing peace of mind and long-term reliability.