Aiming for a Water Conservation-Conscious City: Fukuoka City Fumihiro KOGA (Head of the Fukuoka City Institution of Professional Engineers)

Introduction Fukuoka City experienced serious droughts in 1978 and 1994, and in response, the city government has been working with citizens to establish the best water conservation-conscious city in Japan. By using water effectively, the population of the city reached about 1.47 million, which was once said to be able to reach 1 million with its own water source. As the world faces water scarcity due to global warming and population growth, we believe it is our responsibility to share the

Fig.1 Fig.1Water-saving Water-savingsymbol symbolmark mark

experience and lessons of water conservation-conscious city with the world. For this reason, the Fukuoka City Institution of Professional Engineers is going to write a series of feature article on our activities. In the first installment, I would like to introduce you the outline of a water conservation-conscious city.

1. Water status in the world 21 st century is described as the “century of water”, and people around the world are making every effort to secure water. World population has recently exceeded 7 billion (4.2 billion are in Asia), and it is estimated to reach 9 billion and urban population in Asian cities will double by 2050. The world will inevitably face water and food shortage. United Nations estimates “3 billion people will not be able to access to clean water by 2025”, and it advocates to “Halve, by 2015, the proportion of people without sustainable access to safe drinking water”.

2. Water status in Japan Japan’s annual precipitation is 1,690mm, about twice the global average of 810mm. If converted into annual rainfall per person, by multiplying Japan’s total land area and dividing by total population, that will become about a third of the world average. Most Japanese rivers are high-gradient and short, therefore the rain flows into the ocean before it is used effectively. Although Japan is far from blessed with abundant water, it has achieved efficient uses of water by water-saving techniques. It has been experiencing challenges that Asian countries are going to face in the future. In Japan, people can drink directly from faucets, and most local governments have directly operated water and sewerage works.

3. Geographical condition in Fukuoka City Fukuoka City has developed as a gateway which connects Japan and Asia, and one of the leading cities in Japan with a population of approximately 1.47 million. (Annual rainfall of Fukuoka City is 1,632 mm) Total area of Fukuoka City is about 339 km 2 and the city is 1

Fig.2 Aerial photograph of Fukuoka

facing the Sea of Genkai in the north and Hakata Bay, which nestles between eastern and western peninsulas. It is located in the center of the semicircular Fukuoka Plain surrounded by mountains (Fig. 2). All the rivers flow into the city are small and medium size, therefore it is not blessed with water resources.

4. The history of Fukuoka City Waterworks Fukuoka City started water service (planned water supplied population: 120,000, maximum facility capacity: 15,000 m 3 /day) by distributing water to 35,000 people in 1923 when the total population of the city was 143,000. Later, municipal mergers and economic growth brought urbanization and more and more people started to live in the urban area. As a result, water demand continues to increase. In order to respond to this situation, Fukuoka City continued expansion project for securing water resources. It especially worked on 8 consecutive dam constructions, water intake from Chikugo River, which flows outside of the city, and construction of sea water desalination center, the largest in Japan. (Fig.3) According to the 2010 year-end performance, administrative population was 1,469,069, water supplied population was 1,458,000, maximum facility capacity per day was 764,500 m 3 , average daily water supply was 403,102 m 3 /day, average daily water supply per person was 276 liters. Average monthly water charge per household was about 2,110 yen for 12.4 m 3 . 3

Facility Capacity (m /day) 900,000 Facility Capacity Population

800,000

Population (people) 1,500,000

1994 drought (August 4, 1994 – May 31, 1995） Supply restriction: 295 days

1,200,000

700,000 600,000 500,000

November 1983 Chikugo River Intake Project started 900,000

1978 drought (May 20, 1978 – March 24, 1979） Supply restriction: 287 days

400,000 600,000

1923 Establishment of waterworks

300,000 200,000

300,000

100,000 0

1923

1928

1933

1938

1943

1948

1953

1958

1963

1968

1973

1978

1983

1988

1993

1998

2003

Fig.3 Transition of the population of Fukuoka City and capacity of its facilities

5. Water Conservation-Conscious City 5.1 1978 drought, one of the worst droughts in Japan Due to low rainfall since previous year, Fukuoka City had to restrict its water supply for 287 days from May 20, 1978 to March 24, 1979. Total hours of supply restriction was 4,054 hours (water supply was suspended an average of 14 hours a day), and a total of 13,433 water trucks were mobilized. Especially in summer, citizens can receive water only 5-6 hours in the evening of the day, and sometimes water supply was completely cut off in about 45,000 households. Citizens were not able to 2

access to water which is indispensable to life, and even there were new words such as “Fukuoka desert” and “drought evacuation”. Civic life was disrupted, and the urban function could be ceased. Families with infants and elementary school children who were on summer vacation evacuated from drought-stricken Fukuoka, and businesses which require plenty of water experienced a drop in income due to menu restriction and reductions of business hours. Households with water cut-off had difficulty carrying buckets of water to their homes; especially people living in

Fig .4 Bottom of a dam during the drought

apartments had to take the stairs. And flush toilets cannot be used without a bucket of water. There were many complaints especially regarding “fair water supply”, especially in using water during no-water period by utilizing water tanks. (Fig.4, 5) 5.2 Water-saving measures A long-term supply restriction reminded both citizens and

Fig.5 Citizens receiving water into buckets

city government the importance and scarcity of water. Having learned valuable lessons from this severe drought, Fukuoka City enacted the “Fukuoka City’s Outline of Measures for Economical Water Use” in 1979. Based on this outline, city government, citizens and business establishments have been working together to promote water resource development, effective usage water usage, and water saving for the stable supply of water. Furthermore, in 2003, 25 years after the establishment of the outline, the city enacted an “Ordinance on the Promotion of Water Conservation” for the first time in Japan, and is further promoting water-saving. (1) Water resource development (as stated above) (2) Promotion of effective use of water •

Leakage prevention Leakage water is wasteful water which hinders the effective water

usage. If the amount of leakage water decreased, the city can save water production costs in intake, conveyance, and purification. The city conducted leakage detection (Fig.6) on distribution pipes throughout the city, and quickly repaired damaged ones. The city is working on systematic leakage preventive project since 1956. The leakage rate in 1955 was 38.4%, but that of in 2010 dropped to 2.6%, the top level in Japan (Fig.7). Fig.6 Leakage detection

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Leakage Rate 40% 38.4% 35% 30% 1994 drought→

25% 20% 15% 10% 5%

10.3% 1978 drought→

2.6%

3.5%

0% 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 Year Fig.7 Transition of leakage rate

•

Water Distribution Control System (Water Distribution Control Center）

Fukuoka City introduced water distribution control system (Fig.8) for the first time in Japan to centrally control flow and pressure in distribution pipes throughout the city by computer for 24 hours a day and the “Water Distribution Control Center” has been operating the system since 1981. This system enables decompression adjustment of water pressure, and it decrease leakage rate from distribution pipes and discharge rate from faucets. In this way, it also makes possible to repair damaged distribution pipes as early as possible, and has greatly contributed to improving efficiency of water distribution. •

Effective use of treated wastewater

As a part of a “water conservation-conscious city”, the city is promoting the installation of water recycling facilities to treat wastewater for flushing toilets and other purposes. There are three types of such facilities: 1)”individual circulation type” using water reclaimed from wastewater that is generated inside of a building (296 cases), 2)”wide-area circulation type” using reclaimed water supplied from two wastewater treatment plants in the city (376 cases), and 3)”non-circulation type” using treated rainwater for flushing

Fig.8 Outline of the system

toilets in 140 facilities including Fukuoka Yahoo! JAPAN Dome (Fig.9). Especially,

wide-area

circulation

type

water

recycling

facilities (sewage works utilizing reclaimed water) started operation for the first time in Japan in 1980. The facilities process treated waste water and distribute reclaimed water for toilets flushing in large buildings in city center and waterfront area (distribution area is 1,414ha) and watering trees in parks and streets. In 2010, Fukuoka City supplied reclaimed water an 4

Fig.9 Fukuoka Yahoo! JAPAN Dome

average of 5,400m 3 /day, to 376 places, the largest number in Japan. (Fig.10 and 11)

Fig.11 Reclaimed Water Distribution Area

Fig.10 Chubu Reclamation Facility

(3) Promotion of water saving measures •

Public Relations to raise awareness of water-saving

The drought in 1978 was a large-scale disaster, but at the same time, it reminds citizens the importance of water. In order not to forget the lessons learned from the droughts, Fukuoka City designated June 1 as “Water Saving Day” and also designed a “water-saving symbol mark”, which described water cycle in 1979 (Fig.1). Starting from “Water Saving Day” on June 1 of every year, from June to August, during people tend to use much more water, the city government undertakes a “water saving campaign”, and conducting public relations campaigns such as distributing information magazines to every household and publishing supplementary reader of social studies for elementary students throughout the year. As a result, according to a survey which Fukuoka City conducts every year, the “rate of citizens who always try to save water” has been around 90%. That exceeds the Japanese average of 72%. •

The spread of water-saving equipments

The city is promoting the installation of a water-saving equipment

to

reduce

water

waste.

By

installing

water-saving plugs (about 90 Japanese Yen per unit) on faucets in kitchens and bathrooms, where water is frequently used, water consumption can be reduced. The city encourages its citizens to use the plug since 1978 drought and more than 95% households have already installed (Fig.12) It also encourages use of water-saving toilet bowls which requires less than 10 liters of water per flush.

Fig.12 Water-saving plug

5.3 The effect of water-saving measures Fukuoka City experienced two serious droughts in the past and especially with a growing sense of water conservation among citizens, the expansion of water recycling facilities, and installation of water-saving equipments, the city has been reducing water supply. The average daily water supply per capita has been gradually decreasing from 363 liters in 1977 to 276 liters in 2010, about 20% less than 5

average water supply in Japanese major cities of 340 liters. With leakage prevention works, maintenance of distribution pipes, and establishment of water distribution system, efficiency ratio of water (proportion of amount of water used efficiently to amount of water annually supplied) has been improving year by year. The rate in 2010 was 97.2%, higher than Japanese major cities average of 94.8%. During the second drought in 1994, despite of inclement weather conditions with the record low annual precipitation, although days of restricted water supply was 295 and exceeded the drought in 1978, the total hours of restricted water supply was less than that of 1978 and no water truck was mobilized. (Table 1)

Table 1 Comparison of conditions during droughts in 1978 and 1994

Year of drought Population supplied Sewage system coverage rate (%) 3

Maximum supply capacity (m /day) Annual precipitation (mm) Days of supply restriction Total hours of supply restriction Average hours of supply restriction per day Number of mobilized valve operators Number of mobilized water trucks Number of complaints and inquiries

1978 1,028,000 37.3 478,000 1,138

1994 1,250,000 96.3 704,800 891

287 4,054 14 32,434 13,433 47,902

295 2,452 8 14,157 0 9,515

Furthermore, there was no restriction on water supply in 2005 when the rainfall was 1020mm, the third lowest ever recorded. These are results of unrelenting efforts in water resources development and toward a water conservation-conscious city. However, I would like to add that these efforts of Fukuoka City were established under inherent geographical conditions and through a long period of time including the serious drought in 1978, and it is not easy for any cities to apply the same efforts immediately.

Conclusion From the next installment, we are going to introduce you to world-class technologies and facilities of Fukuoka City in great detail. We sincerely hope that this article will attract as many technicians in the world as possible to Fukuoka City to see facilities in operation and technologies. ☆ Sewerage works using reclaimed water (Operated since 1980. The city recycles wastewater and supplies reclaimed water for flushing toilets of buildings 5,300 m 3 /day.It supplies to 376 facilities, the largest number in Japan.） ☆ Water Distribution Control System (Operated since 1981.The city monitors flow and pressure in distribution pipes throughout the city by centrally-controlled system and prevents water leakage. Its leakage rate of 2.6% is the top level in Japan.）

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☆Ordinance on the Promotion of Water Conservation (The

ordinance

regarding

water

conservation

measures which enacted in 2003 for the first time in Japan. Average daily water supply of 276 liters per person is about 20% lower than the average of major cities in Japan.） ☆Seawater Desalination （Operated by Fukuoka District Waterworks Agency since 2005. The largest in Japan 50,000 m 3 Fig.13) Fig .13 Uminonakamichi Desalination Plant

Nata

Seawater

*(Reference) The Fukuoka City Institution of Professional Engineers It is an organization consists of both active and retired officials of Fukuoka City Government who hold the Japanese national qualification stipulated by the Professional Engineer Law. It was established to contribute to technical administration of Fukuoka City in 1978 when the first serious drought occurred. It has 82 members (55 active officials and 27 retired officials) and half of them are professional engineers in the area of water and sewerage. As a part of the organization, it is currently disseminating information on experiences and lessons of “Water Conservation-Conscious Fukuoka City” to the world.

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