SUDS Attenuation solutions

Sustainable natural aquifer block solutions for attenuation and infiltration

SUDS Attenuation solutions

Sustainable natural aquifer block solutions for attenuation and infiltration

Fully dispersed system

Giving greater volume to area and faster infiltration

Maximises land usage

Dispersed modules permit optimised land use

Extremely configurable

Easily able to cope with unknown in-ground problems such as hidden services and utilities

Solid in-ground solution

Blocks form solid modules. No voids, no root penetration, no possibility of collapse

Smaller excavations

No large scale, centralised excavation required

Filters while buffering

Pre-wrapped geotextile effectively filter run off while system absorbs rainfall

Can be installed in phases

This means more installation flexibility, less disruption and lower costs

Integrated solutions

Hydrorock attenuation systems can be integrated with other Hydrorock infiltration, ClaySolve and irrigation systems to provide flexible area-wide solutions

Hydrorock natural aquifer blocks offer a range of flexible and sustainable solutions for the buffering, attenuation and control of storm-event rainfall.

Varying degrees of water management are achievable, from full attenuation and discharge to adopted or other sewer systems off site, to connection to other Hydrorock elements further buffering or infiltrating over a wider site area.

Design Detailing

A totally green and effective SuDS attenuation solution

Hydrorock natural aquifer blocks are – unsurprisingly – natural aquifers. Manufactured from stone wool, they soak up water like sponges and hold it as a reservoir before releasing it in a controlled manner.

The Hydrorock natural aquifer block attenuation system uses the natural absorption performance of Hydrorock blocks, but an outer impermeable membrane allows the system to retain water within the module and release to the nominated outlet system.

Equally, Hydrorock natural aquifer attenuation systems can also be combined with other Hydrorock SuDS systems such as infiltration, ClaySolve, rainwater harvesting and irrigation, to suit site criteria and local soil conditions.

By maximising the retention and utilisation of precious rainwater onsite, local soil quality and stability improves, while minimising wasteful and environmentally costly offsite discharges.

Maintenance free lifetime system integrity

  • Plastic crated solutions create a near void in the ground, whereas Hydrorock is a solid solution, with up to 4,000 kg per m2 loading strength.
  • Hydrorock natural aquifer blocks cannot collapse, and a geotextile membrane prevents penetration by roots and influx of soil particles.
  • This ensures routine maintenance free, lifetime integrity of the whole system, with operational performance always remaining at design specification.

Ideal for use on difficult sites and in limited spaces

Separate Hydrorock modules can be easily installed retrospectively alongside existing installations and other underground obstacles.The blocks can even be positioned next to the existing walls of buildings. This versatility and flexibility in installation means there is nearly always an ideal solution for green or brown field new builds, or retrofitting within the existing built environment.

Maximising land use for cost-effective construction

As the Hydrorock is pre-wrapped, the size of the excavation required need only be as large as the volume required.

Hydrorock blocks are solid, so the attenuation system can be positioned closer to buildings, maximising  site potential. Dispersing smaller modules across a site avoids the creation of an extensive construction exclusion zone, normally required around a centralised underground crated water sump in a large void. This increases the potential number of properties that can be built, maximising value from land and construction.




Click here to use our calculator and quickly calculate the number and volume of Hydrorock natural aquifer blocks needed for your application.


Hydrorock natural aquifer blocks are available to provide 100% sustainable, 100% recyclable water management solutions.

D Block
D Block
BD Block
BD Block
DHD Block
DHD Block
BDHD Block
BDHD Block
BD Block
IR Block
LG Block
LG and SL Blocks
IP Range
IP Range
Filter units
Filter units
Hydrorock fixings and connectors
Hydrorock fixings and connectors


Hydrorock is pre-wrapped greatly speeding up handling. In most projects, the size of the required excavation needed and the actual volume of the blocks required is also considerably less than that required, by other alternatives, enabling simple and rapid installation.

  • Installation is very simple and quick with minimal disruption.
  • The excavation needs to be only as large as the system, as no access is required to fit the membrane.
  • No specialist installation engineering or equipment is needed, with simple snap-together fittings which require no special skills or tools.
  • Hydrorock natural aquifer blocks are used in a single layer, on a 100 mm layer of sand. This increases the surface area of the bottom of the system.
  • Hydrorock natural aquifer blocks are normally installed in a module three blocks wide. This allows for the system to self-vent, and if by human error the filters are compromised, the whole system can be flushed.
  • Integrated perforated pipe allows rapid inflow and storage water in each Hydrorock Aquifer Block underground.
  • The system can be placed around existing infrastructure, such as pipes and cables unlike crated sumps. This flexibility allows for optimisation of the site.
  • Placing the system on a 100mm layer of sand will permit infiltration from the module into the surrounding soil and facilitate the discharge of water from the Hydrorock Aquifer Blocks.