Our attenuation tanks and soakaway solutions are key components in modern stormwater designs that help developers meet planning development requirements, prevent flooding, and protect natural watercourses across residential, commercial and infrastructure projects.

Tailored Water Management Solutions

We provide engineered systems to suit all site conditions:

• Below-ground attenuation tanks (plastic crate or concrete chamber systems)

• Modular soakaways with geotextile-wrapped granular fill

• Infiltration basins incorporating reed beds for natural filtration

• Combined systems linking attenuation with rainwater harvesting

Technical Design Process

Our approach combines hydrological expertise with practical installation knowledge:

1. Site Assessment

• Percolation testing to BS EN 12946 standards

• Groundwater level monitoring

• Runoff calculations using WinDes software

2. System Specification

• Storage volumes calculated for 1:100 year storm events

• Flow control chambers with vortex or orifice plates

• Oil interceptors where required by environmental regulations

3. Compliance Management

• Section 104 adoption agreements

• SuDS compliance for local planning

• CIRIA C753 best practice guidance

Installation Excellence

Our construction teams deliver:

• Excavation with laser-guided levelling for precise falls

• Structural backfill compaction to 95% Proctor density

• Hydrobrake flow controls calibrated to 2 l/s/ha rates

• CCTV surveyed pipework prior to handover

Materials & Innovation

We utilise:

• Recycled polypropylene crate systems (95% post-consumer content)

• Permeable geocomposite layers enhancing infiltration

• Smart monitoring systems with remote water level sensors

Maintenance & Adoption

We provide:

• As-built drawings and operation manuals

• Annual inspection programmes

• Sediment removal and chamber cleaning services

MAC Group Ltd’s systems combine engineering precision with environmental responsibility, managing water where it falls to create climate-resilient developments. Contact our drainage team to discuss your project’s requirements.