Hydrorock Type D

Durable buffering and infiltration of rainwater

Environmentally friendly buffering and infiltration

Easy and effective buffering and infiltration is made possible with our Hydrorock Type D units.

By placing these infiltration units, a water buffer exists with which the risk of flooding is significantly reduced. With infiltration, the ground water is replenished in a natural manner, also preventing dehydration.

Also applicable for…

  • preventing flooding on overloaded paved areas, in gardens, around buildings and recreational fields;
  • restoring natural water balance by replenishing groundwater;
  • preventing soil dehydration. Trees and plants benefit longer from rainwater.

Calculate INDICATION FOR AMOUNT OF Hydrorock-units

The amount of Hydrorock units you require depends on the situation in which you intend to use them for. In addition to the surfaces that require attachment or infiltration, groundwater and soil type also influences the required amount of units. Our calculator provides you with an indication of how many Hydrorock units you may need in your situation.

Require a calculation for your specific situation? Then kindly contact us.

Type Infiltration capacity Dimensions(LxWxH) Weight Construction depth Max. load per m² Required number Total buffer
D34 34 liter 120x15x20 cm 2,7 kg 35/45 cm 2.500
D45 45 liter 120x20x20 cm 3,6 kg 40/50 cm 2.500
D112 112 liter 120x30x33 cm 9 kg 63/73 cm 2.500
D170 170 liter 120x30x50 cm 13,5 kg 80/90cm 2.500
D220 220 liter 120x40x50 cm 15,5 kg 90/100 cm 2.500
D340 340 liter 120x30x100 cm 9 kg 130/140cm 2.500
D440 440 liter 120x40x100 cm 9 kg 140/150 cm 2.500
The above calculation is based on very heavy rainfall. In the event of ‘normal’ precipitation, 75% of the indicated number of blocks are covered. Please note that with mandatory separation, local authorities may impose either more lenient or more stringent requirements when it comes to the storage capacity per m2.
To ensure the effectiveness of Hydrorock products, we recommend to use our products with a BD type leaf catcher and our unique sand trap (available in different models).

Easy installation Type D

Hydrorock® block are available in slim blocks of different sizes. The enormous buffering capacity and its dimensions limit the necessary digging activities. The blocks are placed either next to each other or behind each other and thus form the desired buffering and infiltration system.
Always fitting for each desired capacity and situation. Only the digging of small trenches is required and the cost for the removal of surplus soil is limited. In other words, flexibility and simplicity.
See the user guide for Hydrorock Type D

The blocks should be positioned vertically, note the ‘this side up’ sticker. This is recommended in regards to the carrying

The blocks should be positioned vertically, note the ‘this side up’ sticker. This is recommended in regards to the carrying capacity of the blocks. Should the carrying capacity be of minor importance, the blocks can also be applied horizontally (for drainage purposes).

Permissible load/carrying capacity in accordance with DIN -EN 1433 (class A15/B125/C250/D400) is applicable to vertically arranged blocks, laid according to the positional instructions stated below and according to the construction depth applicable to the block type and cover on top of the block.

Positioning instructions Type D
Operation and positioning instructions for double placement (2 blocks adjacent to each other):

1.  Dig a trench wide enough for the type of blocks with dimensions described in the table below. The length of the trench is determined by the number of blocks to be placed behind each other (always a multiple of 120 cm). The width of the trench should now be at least 2x the width of the blocks used. Note: the table below is based on construction on and in sandy soil. If this is not the case, be sure to dig an extra 5 cm deeper and 5 cm wider for a 5 cm thick layer of sand. Use masonry or street sand and work this towards the bottom plane.

2. Place the blocks in the trench on the (placed) layer of sand.  For BD blocks, connect the block pipes to each other using the connector pieces.

3. Fill the sides of the trench with masonry or street sand and compact the layer until it is at an even height with the top of the blocks.

4. Fill the trench further with masonry or street sand in layers of 15 cm until you reach ground level. Compact the layer of sand further through vibration or watering.  Materials or machines used for this process should not exceed 1500 kg/m2.

5. The blocks are now placed in the trench and the ground is compacted so the desired finish can now be applied (paving, tiling, grass, gravel, etc.)

Type Max. load per kg/m2 Capacity in liters Dimensions Trench (LxWxH) in cm Construction depth in cm Ground cover in cm Traffic Class
34 / grate 2.500 34 L 120x15x20 20 0 A15/B125
34 2.500 34 L 120x15x35 35/45* 15/25* B125/C250*
45 2.500 45 L 120x20x40 40/50* 20/30* B125/C250*
56 2.500 56 L 120x20x45 45/55* 20/30* B125/C250*
112 2.500 112 L 120x30x63 63/73* 30/40* B125/C250*
170 2.500 170 L 120x30x80 80/90 30/40* B125/C250*
220 2.500 34 L 120x40x90 90/100 40/50* B125/C250*
340 2.500 340 L 120x30x130 130/140* 30/40* B125/C250*
440 2.500 440 L 120x40x140 140/150* 40/50* B125/C250*
43HD 4.500 43 L 120x20x40 40/50* 20/30* C250/D400*
216HD 4.500 216 L 120x40x90 90/100* 40/50* C250/D400*

Operation and positioning instructions for large buffers/infiltration fields wherein several blocks are placed side by side and behind each other (large volume).
For larger constructions, the manufacturer (Hydrorock) will provide tailored advice. The operation and functionality of the blocks align with the specific environment and usage.  Please contact us regarding this.


Why buffering and infiltration with Hydrorock?

The current flooding issues continue to be a source of major problems in urban areas. In many cases, rainwater that reaches the sewer via rain pipes is the cause. During periods of heavy rainfall, sewers overflow causing major issues in the surrounding area. Many local authorities aim to infiltrate as much rainwater into the soil instead of unnecessarily directing it to water treatment plants. It is for this reason that rainwater separation is mandatory for new development sites.

Urbanisation goes hand in hand with a significant increase in paved areas where the existing drainage system has not been calculated. The water is therefore unable to infiltrate. With Hydrorock, the water is separated from the system, buffers under the existing infrastructure and infiltrates into the surrounding soil. The result is a significantly smaller chance of flooding. Simple and effective separation is therefore possible with our Hydrorock Type BD units. Easy and effective buffering and infiltration made possible with our Hydrorock Type D units.


Hydrorock max. storage capacity of total volume

The advantages of Hydrorock

  • Easy installation
  • No pipework necessary
  • Excellent quality and pricing
  • Impact on groundwork is limited
  • 100% durable, 100% natural material
  • Resistant to erosion by plant and tree roots
  • Quickest extraction time; ready for the next downpour
  • VVegetation flourishes better thanks to the unique buffering and infiltration capacity
Productsheet Type D