13 narrow “fire corridors” each 77m long, running between the gardens of rows of houses were subject to serious regular flooding due to the existing impermeable paving, often making the paths impassable. There was a requirement to buffer 3,700 litres of water in 1 hour, and infiltrate half of this volume in 12 hours. The images on the right show the first of 13 installations commissioned.
Due to the existing sewage system unable to cope with the rain events of 20mm per hour, the local authority insisted the water to be managed onsite. However, as the paths are narrow other drainage systems aren’t suitable and there was also limited access for large machines.
The Hydrorock Natural Aquifer SuDS System
Hydrorock Solutions were approached to implement a cost-effective green SuDS system which dealt with the water within the confines of the site. Previously the only solution was to drain the path and take the water offsite, which is now forbidden. It was important to the local authority that the selected drainage system was completely green and that the use of plastics in the ground was avoided wherever possible.
Because the area was not subject to vehicular traffic, standard-density blocks were suitable which have a lower cost per litre than the high-density blocks. 13 D170 blocks were used in conjunction with 13 SL300 slimline drainage grates, as shown by the block on the right.
As the blocks are lightweight and the installation process is simply ‘plug and play’, the project only required two men and a mini digger to be completed. The narrow grates and blocks could be installed with minimal lifting of the current paving, which could be reused around the entry grills. These blocks were spaced evenly along the path. Due to the modular design, the works were completed by the two men in one day with minimal disruption.
The infiltration rates were exceptional, meaning that 3,700 litres of water can be buffered in an hour for a system that has a static capacity of 2,210 litres. The unique infiltration ability of the Hydrorock Natural Aquifer system means that far less capacity is required compared to other solutions. The required system capacity of 3,700 litres will be infiltrated in 2.74 hours, so the system will have 100% capacity in this time.
This was the cheapest solution proposed, not to mention that the system is also maintenance free. For more information on the total cost download our datasheet.
By selecting Hydrorock, the drainage engineers were able to design a SuDS solution for the project that:
Prevents rainwater flooding
Retains all infiltrated all rainwater on site, using a dispersed aquifer system
Is 100% green, using a natural substrate
Minimal maintenance and lasts a lifetime
Modular design meant that installation caused minimised disruption
Only required two men to install
The installation could work around existing underground infrastructure
Buffers 3,700 litres of water in 1 hour
If you have any questions regarding this case study, any projects that you wish to discuss or any other questions about the Hydrorock Natural Aquifer SuDS System, please get in touch from the details below.
To provide a fully integrated green SuDS solution that harvests and buffers rainwater and runoff, before infiltrating all site water within the confines of the site, our Hydrorock Aquifer Water Infiltration System was integrated.
Aquifer Water Infiltration System
Our range of Hydrorock Aquifer Blocks are configured for each specific site allowing for far faster infiltration of rainwater. Our HD range of Hydrorock Aquifer Blocks gives a new, cost effective infiltration system that has many advantages over current solutions.