Introduction of Water distribution block system

A. Case Study Overview

1. Activity/ Project Title:
Introduction of Water distribution block system
2. Themes:
3. Summary:  

Due to the rapid expansion of water supply facilities and water distribution areas in response to population growth during the period of high economic growth, the water pipe network became complicated and difficult to supply water with stable water quality and water pressure.

By introducing a water distribution block system that takes into consideration the terrain and regional characteristics, it has become possible 1) to provide a stable supply of safe drinking water, 2) to respond quickly to sudden accidents, and 3) to distribute water efficiently in terms of energy.

4. Sector:
City : Yokohama Waterworks Bureau
5. Implementation Period:

1971~1979(Approximately 9 years)

6. Project Site :
Yokohama City area
7. Stakeholders&Partners:

B. Objective:

8. Objectives:
Efficient water distribution management by utilizing natural energy and the optimal facility operation

C. Activities

9. /Activities:

Considering the characteristics of each area in the city such as topography and water demand, one water distribution pump station and one water distribution reservoir are placed in each water distribution block. In addition, natural gravity flow utilizing the height difference is prioritized over pump-up flow in the blocks. And installing trunk pipe lines connecting the blocks enables to interchange water between the blocks.

D. Challenges and solutions:

10. Challenges and solutions:

Aiming to optimize the complicated pipe network due to the rapid expansion of water supply system along with high economic growth, Yokohama Water Works Bureau introduced water distribution block system to enhance the efficiency of water distribution.

E. Outcomes and Impacts:

11. Outcomes&Impacts:

There are 4 merits in introducing water distribution block system.

  1. Facilitate water pressure management by levelling water pressure
  2. Distribute water economically and efficiently
  3. Minimize the impact of  large leakage
  4. Interchange water between blocks by main pipes in emergency

As a result of the above merits, distribution pumping stations have been consolidated from 80 to 22, which enabled more energy-efficient facility operation.

F. Budget:

12. Budget:

47billion JPY

13. Source:
Revenue from water tariff, public enterprise bond and national subsidy