Frequently Asked Questions and Answers

Questions in Regard to Water Charges

Q; How are water charges calculated?

A; Your water charges are calculated according to the volume of water used and the size of your water meter. The rates used to calculate the charges are determined by the costs of providing the water supply. Your water charges will vary in accordance with the increase or decrease in your individual water usage.
Also, customers such as general households who use pipes with a diameter smaller than 25 millimeters, have up to 5m3 of water usage per month included in their service charge and do not have to pay commodity charges for water usage up to that amount.

By Type Definition Costs to be covered
Charge billed to the customer dependent on the water meter size regardless of the amount of water used Installation of the water meter
Collection of charges, etc.
Charge billed to the customer dependent upon the amount of water used Cost of power / chemicals
Maintenance and upkeep of the facilities, etc.

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Q; What are the criteria by which the Service Charge and Commodity Charge are determined?

A; Costs of water supply are fixed costs involved in providing a supply of safe and delicious water, and variable costs depending on the amount of water supplied.
The criteria for service charges is, out of this, set at a level at which the fixed costs can be covered. As an example of the fixed costs, the costs required for reading the meter and collecting charges, costs of setting up the meter, costs of maintaining the water supply infrastructure, and so on.
Also, the commodity charges are set so that they cover the cost of chemicals and power costs and other variable costs involved with water supply.

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Q; Is it true that if I use a lot of water the unit rate will get much higher?

A; The Bureau of Waterworks works on a system where the more water you use, the higher the charges. We supply the water necessary for your daily life at a cheap rate, as well as getting you, the customer, to try and save water.
Water commodity charges in Tokyo are determined by the size of the meter. The charges are divided into seven ranks according to the amount of water used, and each of those ranks has a charge determined in respect of each 1 cubic meter equivalent of water usage.

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Q; I previously lived in Saitama. Are the water charges here different from there?

A; Water charges are different between different water supply entities. That is because of the distance from the water source, the quality of the source water, and the date of construction of the water infrastructure will vary, so the costs to operate waterworks differ.
In Tokyo, the same charges apply to water usage anywhere in the 23 Wards of Tokyo and the 26 towns and cities of the Tama District that is part of the same water Metropolitan water supply network.

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Q; How much do water charges cost per cubic meter?

A; Water charges are composed of a service charge, which is determined by the size of the service pipe, and a commodity charge, which is determined by the amount of usage.
The commodity charge is calculated on a cumulative basis, where the unit rate per cubic meter increases in stages  in proportion to the quantity of water used.
Accordingly, different charges per cubic meter apply, depending on the size of the service pipes used and the amount of water used.
Also, when calculating the charges for usage of 24 cubic meters in a month for a 20 mm pipe, the charge for water usage per 1 cubic meter is 140.5 yen, including tax.

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Q; The volume of water I use is getting larger, what is happening?

A; An increased volume of water usage could have various causes.

  • Have the conditions of your water usage changed recently?
  • Is there an increase in the number of people in your household using water (for example, having a baby or relatives returning home temporarily)?
  • Have you increased the number of baths you take or the number of times you do the washing?
  • Have water leaks occurred?
  • Have you had to repair water leaks in the water supply pipes or the toilet, etc. in the time since the previous meter reading (usually once every 2 months)?

●What happens if there are no changes in my water usage?
→In that case, please contact one of our service stations.
We will arrange an inspection of your house to determine whether there are any leaks and whether the meter is operating correctly.

For details of which service stations to contact see here.

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