DRAINMAX – a new system series that can be used in a variety of ways.

 

New system series for rainwater management, water storage and underground irrigation - a contribution to climate-resilient urban development.

Eine grafische Darstellung eines Gebäudes mit einem Regenwassermanagement-System. Links sind Parkplatz und Regenwasserversickerung dargestellt, rechts das Gebäude mit kapillarer unterirdischer Bewässerung und Regenwassernutzung. Der Text betont die vielseitigen Anwendungen des Systems.
Image 01: INTEWA DRAINMAX Rainwater management in residential construction

Introduction

The direct effects of increasing surface sealing are noticeable everywhere. Most noticeable are the rising costs of rainwater drainage and flood damage. In recent years, however, a process of rethinking has taken place. The old goals of centralised treatment of rainwater are being revised. The idea of decentralised infiltration at the point of origin is gaining ground and is becoming an essential component of sustainable rainwater management - for the benefit of citizens and the environment.

Increasingly, decentralised infiltration and on-site retention are also being demanded by the authorities. More and more cities and municipalities are demanding and promoting these measures, in part through more favourable wastewater charges, by exempting rainwater from charges or through subsidies for unsealing and infiltration measures, so-called "rainwater management".

The combination of rainwater management with water storage for later use in the building or for irrigation or cooling of the surrounding area are components of sustainable water management that have hardly been used to date. However, such a combination of rainwater management with utilisation and storage options can significantly increase the efficiency of these sustainable technologies. In this context, this article highlights a new, innovative, modular system series with tunnel elements made of plastic, which should now enable cost-effective and easy-to-implement solutions for combining rainwater management, water storage and underground irrigation.

One component as a basic building block

Ein schwarzes, gewölbtes Kunststoffteil mit gerillter Oberfläche. Es hat eine Öffnung an der Oberseite und könnte als Abdeckung oder Schutz verwendet werden. Die Struktur ist robust und weist ein modernes, funktionales Design auf.
Image 02: INTEWA DRAINMAX tunnel element with 1.6 m³ storage volume

 

The individual tunnels are characterised by their low weight of 38 kg, which enables them to be installed quickly by two people. Thanks to the optimised injection moulding production process, stackability and therefore minimal transport and storage costs, the technology is very cost-effective with a price of less than €190.00 per cubic metre of storage volume. The elements are laid overlapping in rows, protected with geotextile fleece and geotextile fabric, and compacted at the sides and on top with suitable filling material. In combination with EPDM sheeting and sheet protection with fleece and fabric, a water reservoir is created. The base of these systems can be cleaned using a high-pressure flushing nozzle. This also guarantees the infiltration capacity in the long term.

One system - numerous applications - ready-to-use packages

Ein schematisches Diagramm zeigt das DRAINMAX-System zur Regenwasserbewirtschaftung. In der Mitte befinden sich drei Tunnel, umgeben von verschiedenen Anwendungen wie Wasserlagerung, Trinkwasser und Bewässerung. Verschiedene Abschnitte verdeutlichen die Funktionen wie Infiltration, Rückhaltung und Nutzung für die Landwirtschaft.
Image 03: INTEWA DRAINMAX modular rainwater management applications

 

 

The individual tunnels can be used to construct various modular applications, such as rainwater infiltration and retention: Rainwater infiltration and retention, storage of rainwater or extinguishing water, infiltration of run-off water from sewage treatment plants or underground irrigation.

Grafik zeigt verschiedene Modelle des DRAINMAX Tunnels in unterschiedlichen Größen für Regenwassermanagement. Die Größen reichen von 10 m³ bis 120 m³. Die Tunnel sind modular und können je nach Bedarf kombiniert werden.
Image 04: INTEWA DRAINMAX rainwater management packages

 

 

Ready-made packages on pallets are available for system sizes up to 120 m³. This makes planning, delivery and installation much quicker. Larger storage tanks are coupled.

Underfloor irrigation with capillary rise application

Illustration eines Wasserspeichers, der Regenwasser von der Oberfläche auffängt und unterirdisch speichert. Oben sind Wolken mit Regen und die Sonne abgebildet, während das Gras darüber gedeiht. Nach unten gerichtete Pfeile symbolisieren den Wasserfluss.
Image 05: INTEWA DRAINMAX underfloor irrigation

 

The "subsurface irrigation" application combines retention, infiltration, evaporation, cleaning and irrigation in a single, underground system. Precipitation water is stored over a large area and then rises upwards due to the capillary effect without pump energy - for watering green areas and cooling the surroundings through evaporation. The system is interesting for greened municipal, commercial or agricultural areas and contributes to a climate-resilient sponge city.

Advantages

  • Irrigation through capillary rise

  • Up to 100 % higher crop yields and 50 % water savings in agriculture

  • Cooling & microclimate stabilisation through evaporation up to 7°C

  • Rainwater retention & protection against flooding

  • Purification of polluted rainwater

Infiltration application

Das Bild zeigt ein Regenwassersystem. Oben ist ein Auto unter einem Regenbogen, während Wasser von einem Dachrinne in einen unterirdischen Tank fließt. Der Tank speichert das Regenwasser, das durch Pfeile nach unten angezeigt wird.
Image 06: INTEWA DRAINMAX infiltration

 

In the "infiltration of rainwater and wastewater from sewage treatment plants" application, the water first passes through the integrated sedimentation, filter and separation area, is then buffered in the large-volume tunnels and then infiltrated into the ground. Once the monitoring system has been installed, the operator of the system receives information about the sludge level and infiltration performance of his infiltration trench via a browser platform. Maintenance can be carried out via the integrated inspection and cleaning shaft.

Rainwater retention application

Diagramm zeigt ein Regenwassersystem. Regenwasser sammelt sich in einem unterirdischen Behälter, während ein Auto und ein Haus darüber abgebildet sind. Wasser fließt durch einen Kanal in den Behälter, um die Entwässerung zu zeigen.
Image 07: INTEWA DRAINMAX retention of rainwater

 

In the "retention application", the integrated sedimentation, filter and separation area also ensures cleaning performance directly in the system - without additional sumps. The systems are installed in a basin, which is sealed with an EPDM film. In the finished packages, these foils are supplied in one piece ex works. This eliminates the need for gluing or welding on site. This guarantees watertightness.

Water reservoir application

Das Bild zeigt ein Feuerwehrfahrzeug mit Leiter neben einem unterirdischen Löschwasserbehälter. Dieser enthält eine Löschwasser-Anschlusseinrichtung und EPDM-Auskleidung. Ein Text im Bild beschreibt die technischen Spezifikationen des Behälters.
Image 08: INTEWA DRAINMAX rainwater or extinguishing water storage tank

 

In the "water storage" application, the tunnels are also installed in a basin, which is sealed with a one-piece EPDM film without gluing or welding. In addition to storing rainwater, the systems can also be used to store extinguishing water. The extinguishing water systems are designed in accordance with DIN 14230. The innovative water storage tanks are delivered on pallets and can therefore be installed almost anywhere. Transport and storage costs are minimised.

Integrated pre-cleaning and throttle drain

Die Abbildung zeigt ein technisches Gerät mit einem schlauchförmigen Element und einer Metallverbindung. Das Gerät scheint Teil eines Systems zur Fluidübertragung zu sein. Der Fokus liegt auf der Verbindung zwischen den Komponenten.
Image 09: INTEWA DRAINMAX sedimentation filter and separator insert

Pre-cleaning in rainwater management is important in order to remove pollutants and impurities from roof or road runoff water. This protects the environment and bodies of water, prevents blockages in infiltration systems and protects technical systems. In many areas, pre-treatment measures are now mandatory.

In Germany, the following regulations, among others, must be observed:

  1. Code of practice DWA-M153
  2. Since December 2020: DWA-A102
  3. Since October 2024: DWA-A138

Stormwater treatment DWA-A102 vs. DWA-M153 vs. DWA-A138-1

A fundamental change in DWA-A102 is the categorisation of connection areas into only three categories with different levels of pollution. A further subdivision is made according to the type of utilisation of the areas. For the retention of pollutants, the following parameters can be tested in the test according to DIBt: "DIBt ZG_Niederschlagswasserbehandlungsanlagen_Teil_1_Mai_2023":

  • Particle retention (AFS)
  • Hydrocarbon retention (MKW)
  • Heavy metal retention, zinc and copper
  • Redissolution behaviour of heavy metals when exposed to de-icing salts
Die Abbildung zeigt ein technisches Modell eines Rohresystems. Es beinhaltet eine runde Struktur mit Wellenmuster und mehrere grüne Rohre, die daran angeschlossen sind. Ein Mechanismus zur Steuerung oder Anpassung ist ebenfalls sichtbar, hervorgehoben durch eine vertikale Ausrichtung.
Image 10: INTEWA DRAINMAX outlet restrictor for rainwater retention

 

For the retention application, the system already includes a discharge throttle with a throttle volume of up to 20 l/s in the standard package. A separate shaft is therefore no longer required.

I-Connect remote monitoring

Auf dem Bildschirm ist eine technische Darstellung eines Infiltrationssystems zu sehen. Die Grafik zeigt zwei Wasserbecken, Rohre und Symbole zur Darstellung des Wasserflusses. Oben sind Optionen und Steuerungen zur Anpassung des Systems. Es handelt sich um eine grafische Benutzeroberfläche für die Überwachung.
Image 11: INTEWA I-Connect Monitoring for rainwater management

Each rainwater management and storage system must be monitored every six months without monitoring and includes the following measures:

  • Check the sedimentation and filter area for sludge content using a dipstick
  • Check the sedimentation and filter area for leaks
  • Check pre-filter for flow rate and contamination
  • Check throttle outlet for free movement, soiling or blockage
  • For storage tanks: Check water level and tightness

As a rule, this check must be carried out by two employees. To solve this problem and save costs for the operator, remote monitoring is available for the DRAINMAX systems. In order to be able to monitor and maintain the systems remotely, they are equipped with sensors that supply the data to a central control unit. Using a web application, system operators can now view all the data, such as the infiltration rate, throttle capacity, sludge level and fill level of their system online and are informed of any maintenance requirements. This can amortise within approx. 5 years and also increases system reliability.

Summary and outlook

The new system series presented marks significant progress for the modern sponge city. The system offers an innovative modular solution with just a few components that is unique for various applications. This offers planning security for operators, planners and contractors. The systems integrate pre-cleaning, control, flushing and throttling directly into the storage system. This eliminates the need for additional shaft elements, resulting in cost savings of around 30 %. The new system series is also characterised by simplified installation, resulting in significant time savings. By standardising package sizes (10 to 120 m³ and multiples thereof) as stock items, logistical processes are optimised, resulting in faster delivery readiness. The new IoT solution enables remote monitoring, saving costs for maintenance and operation.

Author: Oliver Ringelstein, INTEWA GmbH

Characters: 11,535 incl. spaces

Status: 17.10.25

Further information:

Note:

Changes to the technical article are only permitted with the express authorisation of the author!

Eine grafische Darstellung eines Gebäudes mit einem Regenwassermanagement-System. Links sind Parkplatz und Regenwasserversickerung dargestellt, rechts das Gebäude mit kapillarer unterirdischer Bewässerung und Regenwassernutzung. Der Text betont die vielseitigen Anwendungen des Systems.
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