GRAF Professional Solutions – Use, Treatment, Retention, and Infiltration of Stormwater
From rainwater tanks, infiltration and retention systems, to wastewater technology and treatment plants, all the way to cisterns for firefighting water: GRAF offers quality made in Germany.
Why GRAF – Your benefits at a glance
✓ High-quality materials: Durable plastic, recyclable, tested for long service life
✓ Focus on sustainability: Products made from recycled raw materials, manufactured in our own raw material centers in Germany
✓ Significant cost savings: Rainwater harvesting reduces drinking water consumption and wastewater fees
✓ We offer a wide variety of solutions: For collecting, using, retaining, or infiltrating rainwater—from rainwater treatment to wastewater technology and treatment plants
Find the right product quickly & easily
Start your journey toward sustainable water use today: Discover the ideal rainwater solution with the right product advisor
Products from our GARANTIA brand
Support from A to Z
GRAF - sustainability & innovation in plastics
FAQs – GRAF Rainwater Systems
Here you'll find frequently asked questions and answers about rainwater harvesting.
-
What is GRAF, and what does the company stand for?
GRAF is a leading manufacturer of solutions for underground rainwater harvesting, aboveground rainwater harvesting (GARANTIA), infiltration, retention, and wastewater treatment.
The company develops tanks, filters, systems, and accessories for private households, businesses, and municipalities.
-
Why should you use rainwater?
Rainwater harvesting helps conserve resources and save drinking water. Rainwater is ideal for watering gardens, flushing toilets, running washing machines, or cleaning.
-
What products does GRAF offer?
GRAF manufactures above-ground and underground tanks, filtration systems, infiltration modules, retention systems, pumping equipment, and complete rainwater harvesting systems—all tailored to various applications.
-
What tank size do I need?
The appropriate tank size depends on the roof area, the amount of precipitation, and the intended use. For a single-family home, 2,000–6,500 liters is usually recommended. GRAF offers consulting services and tools to help with sizing.
-
What types of GRAF tanks are available?
- Underground tanks: Space-saving, out of sight, ideal for new construction.
- Above-ground tanks (GARANTIA): Flexible, easy to retrofit.
- Modular tanks: Expandable as needed.
- Small rain barrels (GARANTIA): Suitable for gardens and balconies.
-
Do I need maintenance?
GRAF rainwater systems require little maintenance. Filters should be checked and cleaned regularly. Underground tanks must be inspected at longer intervals, depending on usage.
-
Are GRAF products frost-resistant?
Above-ground tanks should be emptied in the winter or positioned so they are protected from frost. Underground tanks are generally installed in a way that protects them from frost. Details can be found in the technical data sheets for each product.
-
Can an existing house be retrofitted?
Yes, GRAF rainwater systems can be easily installed in both new and existing buildings. Our team of experts will work with you to find the best solution for your specific needs.
-
How sustainable are GRAF products?
Our tanks are made from recycled plastic and are themselves recyclable.