The Rainwater Refund Calculator
DA
Free and no obligation

Is it worth disconnecting your rainwater?

Check in 30 seconds whether you could get a refund from your water utility by disconnecting your rainwater from the sewer – and get an estimate of the infiltration trench and cost.

About 30 secondsIndicative estimateLocal drain-layer

Prefilled from the building register (BBR) if we can find your property.

Driveway, patio and similar. Optional.

Which scenario fits you?

We've built a calculator for the most common situations – each with relevant default values and answers to the scenario's questions.

See all scenarios →
House & single-family home

Single-family home on a combined sewer with roof and surface water. The classic situation where there is typically a refund to be had.

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Separate sewers

If your rainwater is already on a separate sewer, there is usually no refund – but an infiltration trench can still pay off for climate-proofing.

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Commercial property

Large roof and paved areas. Refund and sizing are calculated the same way, just on a bigger scale.

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Condominium & shared roof

Roofs and driveways are typically common areas – the decision lies with the homeowners' association, not the individual owner.

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Frequently asked questions

What does a calculation cost?

It is free and no-obligation. You immediately get an estimate of the refund, infiltration trench size and cost.

Who can get a refund for disconnecting rainwater?

It depends on your property type and your utility company. Typically it applies to properties where roof and surface water can be disconnected from the sewer, and where the utility offers a refund for it.

Does the refund apply in all municipalities?

No. The refund depends on which utility covers your address and on the local rules. The calculator currently covers a selection of utilities. If your municipality is not covered, you still get an estimate of the infiltration trench and the cost.

Does all rainwater have to be disconnected to get a refund?

It depends on the utility. Some require full disconnection of all rainwater, while others give a refund for partial disconnection. The calculator takes the utility's requirements into account.

Is the infiltration trench size decisive for my project?

The infiltration trench size in the calculator is an estimate based on your paved area. You get the final sizing and an exact quote from a local drain-layer.

What happens after I submit my contact details?

We match you with a partner drain-layer in your area, who contacts you with a no-obligation quote. We only share your details if you have given consent.

We are not the drain-layer. We are an independent calculator that matches you with a local drain-layer if the project pays off.

  • Free and no-obligation calculation
  • Indicative figures – your drain-layer gives the final quote
  • We only share your details with a partner drain-layer if you say yes