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Stormwater infiltration and attenuation

Efficient - safe - digital, with us your project will be a success.

The direct effects of increasing land sealing are noticeable everywhere. Most noticeable are rising costs for stormwater drainage as well as flood damage. Over the last few years, a process of rethinking has taken place. The old goals of drainage and centralized treatment of stormwater are being revised. The idea of decentralized infiltration, i.e. the infiltration of excess rainwater as far as possible where it occurs, is becoming more and more prevalent and is becoming an essential component of sustainable stormwater management - for the benefit of citizens and the environment.

Increasingly, decentralized infiltration and attenuation on site is also being demanded by the authorities. More and more cities and municipalities are promoting these measures, in part through more favorable wastewater charges, exemption from the levy for rainwater or a subsidy for unsealing and infiltration measures. With our complete range of products, we provide you with a unique all-round service for the success of your project.



In Germany and some other countries, decentralized infiltration and retention on site is increasingly being called for by the authorities. More and more cities and municipalities are promoting these measures, in part through lower wastewater charges, by exempting rainwater from charges or through subsidies for unsealing and infiltration measures. With our complete range, we provide you with a unique all-round service for the success of your project.


Stormwater infiltration

Store heavy rain and simply feed it to the groundwater where it occurs. There are various options for the infiltration of stormwater from sealed surfaces. INTEWA offers you complete solutions for infiltration by infiltration trenches and trough infiltration trenches.


Commercial projects          Domestic projects


Stormwater attenuation

Store heavy rainfall and discharge it into the drainage system in a throttled manner. Stormwater attenuation is required when a discharge restriction into the public drainage system is specified. The discharge restriction results in a necessary retention volume to temporarily store heavy rain events on the property. The necessary buffer volume can be represented above ground - usually as a basin - or below ground.

Commercial projects          Domestic projects

Capillary underground irrigation system for cities & municipalities

A completely new and integrative approach to stormwater management is offered by the innovative underground irrigation system with capillary rise. Similar to the natural water cycle, this system combines infiltration, retention, evaporation and thus cooling, purification and irrigation in a new, unique way.

Learn more about DRAINMAX

Infiltration trenches become digital

With the innovative INTEWA CONNECT technology, these systems can now be monitored remotely for the first time worldwide. Plant operators are informed about sludge level, filter flow and discharge capacity at any time via the INTEWA cloud server. This new remote monitoring guarantees the flawless operation of the system and pays for itself in just a few years. 

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DRAINMAX tunnel trench

Our core stormwater management product consists of 1.6 m³ capacity, plastic trays that create a hollow volume of any size in the soil. It can be used for infiltration, attenuation or storage of water.

  • Truck loading capacity and DIBt® approval
  • Best price per m³
  • Easy installation
  • Only system with flushable bottom

More information about the DRAINMAX tunnel trench

Maintenance at any time

The entire system around our DRAINMAX tunnel drain offers a reliable and easy-to-use maintenance concept. Starting with the easily flushable tunnel elements, up to the digital monitoring, which can be realised with only a few sensors.

Learn more about the maintenance of DRAINMAX

Prefiltration according to DWA and DIBt

Depending on the dirt input of the connected areas, different cleaning measures are required before infiltration or discharge into the sewer or receiving water. In addition to cost-effective sedimentation and filtration chambers, we also offer systems for the treatment of heavily polluted road runoff.

More about the prefiltration according to DWA

Project support from A to Z

There are many aspects to consider when planning and implementing a construction project. In a short time you have to make many decisions that affect the entire construction phase. With regard to your rainwater or greywater solution, we will guide you through all phases, from the planning to the execution of your project.

  • Concept development and price calculation for the preliminary planning
  • Dimensioning with Rainplaner Software
  • Compilation of tender texts
  • Creation of CAD system drawings
  • Support of the executing companies
  • Commissioning Service
  • Monitoring of the systems


Realized projects for decentralized stormwater infiltration and attenuation

Do you have questions or are you interested in a non-binding offer?

We look forward to hearing from you.

Here you will find brochures, instructions, certificates, technical drawings and much more.

Dimensioning of INTEWA products

Planning sheets for various applications

Rainplaner software

With our knowledge portal we offer you information about stormwater management, water reuse and more.