Rainwater charges - the current legal situation

For a fair collection of wastewater has been hard-fought for years politically and legally. Zankapfel is above all the proportion of rainwater in the total wastewater. What has finally been legally established and thus become official, this contribution explains.


Together with the wastewater that is generated from the household through the use of water, the collected rainwater is also introduced into the sewage system. This is the case in particular in mixed systems in the sewage system.

There, different types of wastewater are introduced:

  • Rainwater from the property
  • Rainwater from public areas (squares, streets)
  • Dirty water from the households

However, in order to fairly charge the amount of waste water, it has to be taken into account that the proportion of rainwater does not come from the landowner or the landlord. Depending on how large roof areas and other sealed surfaces are, different amounts of rainwater from each plot of land enter the sewage system. In addition, account must be taken of the proportion of precipitation water coming from the site and of public places such as streets or public places.

Duty of the municipalities to eliminate

According to the current legal situation, the duty to sewage disposal in the whole of Germany comes to the communities, and no longer to the countries. The community must therefore ensure that the wastewater is completely eliminated.

Who takes over the costs of rainwater from public roads and squares, may be different - but usually it is the road construction workers.

The cost of disposing of the wastewater from land, however, always comes to the property owners without exception. The fee rate for wastewater disposal always comes from the municipality according to the Waste Water Levy Act.

Just calculation

Some court rulings have found that a single sanitation charge is not fair to landowners. Pure sewage dischargers would therefore pay just as much as those landowners who also introduce a large amount of rainwater into the sewage system.

In separation systems, this problem is basically not, in mixed systems in the sewer but very well.

The so-called freshwater standard should ensure a fair calculation of charges: The extracted water from the water supply (and possibly from other water supply points on the property, such as wells) serves as a standard for the waste water.

According to the current legal situation, this is not allowed.

Current case law

The Federal Administrative Court has only declared the (modified) freshwater standard to be admissible where the amounts of rainwater are very low. According to the findings of the administrative judges, insignificance always occurs when no more than 12% of the waste water to be disposed of is rainwater.

If the proportion of rainwater is higher, there is an obligation to charge separate fees for wastewater and rainwater, the so-called split wastewater charge (GAG). The reason given for this is that the single waste water charge would be in breach of the principle of equality and the equivalence principle.

In order to pay justice to the distribution of rainfall costs, the size of the sealed area is used as a measure of the precipitation water fee. However, the higher administrative burden and the cost of capturing aerial surfaces of sealed areas are criticized by some institutions as they in turn burden taxpayers.

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