Cost of a cistern between purchase and savings

The cost of a cistern varies considerably in both purchase and maintenance. "Inner" factors are the purchase price and the type of water use, as "external" influences are the local water price and the wastewater costs added. The technical entertainment causes negligible costs.

Build yourself from 500 euros

If you want to buy a cistern, you have to carry out a comprehensive calculation in order to be able to answer to what extent the cistern is worthwhile. The construction and material costs can be minimized by building yourself.

The cheapest variants are a concrete cistern made of manhole rings or a plastic cistern, which is installed by itself. Depending on the size of the cisterns are from about 500 euros to realize, a large proportion of own contribution provided.

Advanced connections

If it is a pure water reservoir for watering the plants, there are no additional installation costs. However, the capacity needs to be adapted to local conditions, such as average rainfall and perimeter area, to avoid over-cistern overflow.

If the cistern also supply useful water, the connection options must be checked. If a connection to a domestic water system, for example, the toilet flushing and the washing machine feeds, appropriate installation knowledge must be present.

Possible additional costs

A rainwater cistern with industrial water production must also comply with some water regulations, which are given by the responsible lower water authority when viewing and any necessary approval. The structural implementation generates additional costs, which can make up to 200 euros for self-construction.

If you choose a two-part or monolithic concrete cistern among the cistern types, you should calculate with acquisition costs starting at one thousand euros. This usually includes the insertion into a prepared pit, provided that the installation time is limited to usually thirty minutes. If the installation takes longer, the suppliers charge high surcharges.

Drinking and sewage fees

When deciding whether or not to buy a cistern, a levy on the future water savings is the decisive factor in the calculation. On the one hand, the consumption of drinking water lowers, on the other hand also by rainwater sewage, for which fees are due.

In order to calculate the wastewater charges, the different collection procedures in each municipality must be taken into account. In Germany, the model of the split wastewater fee is becoming increasingly prevalent. Here, not only the actual amount of wastewater is considered, but also the degree of sealing of the property.

In order to determine the actually running costs or savings for a cistern, a computer designed for the municipal calculation model must be used for the split sewage charge. Most cistern manufacturers offer online calculators on their websites.

Cost factors for external assembly

For a supplied and assembled cistern installation, costs starting from 2000 Euro have to be calculated, which consist of the following components:

  • cistern tank
  • Coarse and small animal filters
  • fine filter
  • cistern pump
  • Element for calmed water intake
  • Connecting pieces and lips
  • piping
  • delivery
  • Assembly with or without existing excavation
  • Optionally device for floating water withdrawal
  • If necessary, drinking water supply
  • If necessary, level indicator

Calculation basis

On average, an adult household member consumes about 120 liters of water a day. Half of this is attributable to types of use, which are also covered by rainwater from the cistern. On the side of pure water savings through reduced drinking water use can be saved up to half of the annual fees, which can make up 200 to 400 euros. When combined with wastewater charges, the savings potential varies between thirty and fifty percent.

Tips & Tricks

Do not lose sight of the saving potential when calculating the cistern. The plant should pay for itself in the period between five and ten years.

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