AS-KRECHT

The AS-KRECHT is a tunnel-shaped accumulation and drainage system consisting of a light, plastic semicircular box (boxes) closed at both ends with plastic fronts. It is a high-capacity underground system that is suitable for the accumulation and gradual infiltration of rainwater from consolidated areas and surfaces into soil…

The AS-KRECHT is a tunnel-shaped accumulation and drainage system consisting of a light, plastic semicircular box (boxes) closed at both ends with plastic fronts. It is a high-capacity underground system that is suitable for the accumulation and gradual infiltration of rainwater from consolidated areas and surfaces into soil.

Rainwater accumulation systems

Growing cities are more and more frequently facing the problem of draining rainwater from consolidated surfaces at their peripheries. The small diameters of sewerage pipelines or insufficient capacity of the channels of local recipients make it impossible to drain the required quantities of fallen rainwater with sufficient speed. A refurbishment of the sewerage system or adaptation of recipient channels is very costly and sometimes infeasible from the technical point of view.

Original green area suitable for rainwater infiltration
- excess water safely drained by the water course
Industrial landscape - consolidated, impermeable surfaces = large, sudden quantities of rainwater cannot be absorbed by the sewerage system or the water course

This problem can be solved by the construction of infiltration systems or deceleration retention areas. This problem generally represents an obstacle for the further development of the area.

  • Conventional solution: accumulation in an open polder
    accumulation in a concrete tank or sump
    gravel underground space
  • New progressive systems: plastic blocks and reservoirs

For several years, plastic structures of various designs have been used abroad for both ways of dealing with rainwater, as accumulation spaces for the retention of excess water. As compared to traditional gravel, these systems have immense benefits, mainly in their high accumulation capability, of 95% to 100% of the useful volume, with a very low material weight.

AS-KRECHT Rainwater Accumulation Systems

The AS-KRECHT is a tunnel-shaped accumulation and drainage system consisting of a light, plastic semicircular box (boxes) closed at both ends with plastic fronts. It is a high-capacity underground system that is suitable for the accumulation and gradual infiltration of rainwater from consolidated areas and surfaces into soil.

The AS-KRECHT semicircular tunnel boxes have a 100% storage capacity, and as compared to gravel this system represents a saving of more than 2/3 of the excavation volume. Rainwater may freely penetrate to the soil through the bottom and side openings in the plastic tunnel-shaped box.

Both the fronts of the tunnel-shaped box are equipped with an inlet opening and are adapted for the connection of a pipeline up to the DN300 diameter. With only three particular components (a semicircular tunnel section, and an initial and end front of the section) a stable and widespread system can be built with minimal construction costs. The system is very compact and lightweight, which keeps transport costs to a minimum.

Advantages of the AS-KRECHT system:

  • Efficient construction, excellent economical benefit
  • Minimal installation costs
  • Minimal transport costs (compact system)
  • Good strength and carrying capacity under carriageways
  • 100% utilization of the accumulation space
  • Simple and quick assembly by connecting the tunnels together
  • Long service life thanks to the use of recyclable polyethylene (HDPE)
  • Exceptionally light and portable
Technical data

Material: Polyethylene (HDPE)

AS KRECHT - T 1600 central tunnel
Dimensions: 2.3 x 0.81 x 1.3 m (L x H x W)
Effective length: 2.25 m
Weight: 32 kg
Volume (net): 1,600 litres

AS KRECHT - T 100 SE/ 100 E initial and end fronts

Dimensions: 0.48 x 0.78 x 1.3 m (L x H x W)
Effective length: 0.44 m
Weight: 5 kg

Mechanical characteristics Carrying capacity at the min. covering layer thickness
for a car = 5 kN/m 2 coverage at least 0.5 m
for a lorry = 16.7 kN/m 2 coverage at least 0.8 m

Loading complying with DIN1072 in different installation depths. Other loading values available on request.

Dealing with the issue of rainwater accumulation

Conventional solution
  • Concrete sumps
    Expensive ceiling structure, therefore the required volume
    is rather achieved by means of narrow and deep sumps
  • Underground space filled with gravel
    weight: 2,000 kg/m 3
    spatial capacity (free space for water):
    20% - 25% of the volume
Modern solution
  • Plastic systems
    • Advantage of creating shallow underground structures with large ground plan dimensions
    • Underground space arranged with the use of a plastic system
      weight: 40 - 42 kg/m3 = 50x lighter
      spatial capacity: 95% - 100% of the volume = 4x more than gravel


1. Original open retention tank, ugly appearance, possible source of problems (including hygienic)


2. Insertion of plastic accumulation systems


3. Resulting effect! Underground accumulation space. Beautiful spot within the site.