Bequeathing a Clean Lake Biwa to Future Generations

Lake Biwa ComprehensivePreservation Initiatives

― Seeking Harmonious Coexistence with the Lake's Ecosystem ―

Lake Biwa Comprehensive Preservation Liaison Coordination CouncilLake Biwa Comprehensive Preservation Promotion Council

○ Overview of the Yodo River Basin ○ Water Use in Lake Biwa and the Yodo River Basin ○ Land Use in Lake Biwa and the Yodo River Basin

1

○ Lake Biwa, an Ancient Lake ○ Dimensions of Lake Biwa

2

○ Early History ○ Expanded Farmlands, Increased Rice Production and Subsequent Development of Commerce

○ A Political Center and Cradle of Culture and Tradition ○ Industrial and Economic Development after the Meiji Restoration ○ Changing Lifestyles

3

○ Farmland Development and Flooding in the Edo Period (1603 - 1868) ○ Flood Control During the Meiji Period (1868 - 1912) ○ Modern Projects for Using Water of Lake Biwa ○ Increasing Demand for Water in the Showa Period (1926 - 1989)

5

○ Program System ○ Breakdown of the Program Expenses ○ Environmental Preservation ○ Flood Control ○ Promotion Effective Water Use

7

○ Effects of Flood Control Projects ○ Effects of Projects Promoting Effective Use of Water ○ Effects of Environmental Preservation Projects

9

○ Land Use around the Lake ○ Water Quality of Lake Biwa ○ Lake Biwa Water Quality Map ○ Eutrophication of Lake Biwa ○ Reed Colonies ○ Attached Lakes (naikos) ○ Lake's Ecosystems

11

○ Freshwater Red Tides ○ Water Quality Conservation Campaigns Initiated by Local Residents

○ Shiga Prefectural Ordinance Concerning the Prevention of the Eutrophication in Lake Biwa (Eutrophication Prevention Ordinance)

○ International Conference on the Conservation and Management of Lakes (World Lake Conferences)

○ Establishment of Lake Biwa - Yodo River Water Quality Preservation Organization

15

○ Background ○ Guiding Principle and Key Concepts of the Comprehensive Conservation Plan

○ Objectives and Period of the Comprehensive Conservation Plan ○ Promoting Partnerships

17

○ Protecting Water Quality ○ Increasing Soil's Recharge Capacity ○ Preserving the Natural Environment and Scenic Landscapes ○ Citizen Participation and Activities ○ Information Sharing and Staff Exchange Promotion ○ Research and Survey ○ 9th International Conference on the Conservation and Management of Lake (World Lake Conferences)

19

○ Continuous Improvement ○ Coordinating System

30

31

1 Overview of Lake Biwa and the Yodo River Basin

2 Overview of Lake Biwa

3 Development of Lake Biwa and the Yodo River Basin

4 Background of Lake Biwa ComprehensiveDevelopment Program

5 Lake Biwa Comprehensive Development Program

6 Outcomes of the Lake BiwaComprehensive Development Program

7 Current Situation of Lake Biwa

8 History of Lake Conservation Efforts

9 Survey for Preparing Lake BiwaComprehensive Conservation Plan

10 Comprehensive Environmental PreservationEfforts and Specific Measures

Future Progress of ComprehensiveLake Preservation Initiatives

12 Chronological Table of Lake Biwa

Contents

11

Biwako Hakkei (Eight Scenic Places in Omi) selected in 1949.

①The Grandeur of Mt.Shizugatake

②The Granite Cliffs at Kaizuosaki

③Subtle Reflection of Chikubu Island

④The Old Castle in Hikone

⑤The White Beach of Omatsuzaki

⑥A Water District with a Tiny Inlet in Azuchi-Hachiman

⑧The Crystal-clear Water in Seta, Ishiyama

⑦Forest on Mt.Hiei⑦Forest on Mt.Hiei

①

②

③

④

⑤

⑥

⑦

⑧

ShigaPrefectureKyotoPrefectureOsakaPrefectureHyogo Prefecture

0 100［million people］

80604020

10.1

17.9

85.3

26.1

1 Overview of Lake Biwa and the Yodo River Basin

The Yodo River, flowing into Osaka Bay, originates in mountains in and around Shiga Prefecture. After flowing out of Lake Biwa, the river travels southward down to the Osaka Plain, combining several branches of various sizes including the Kizu and the Katsura rivers. The Yodo River changes names during its long travel: the upper and middle reaches are called the Seta and the Uji rivers, respectively. The Yodo River basin constitutes an extensive area of approximately 8,240 km2, covering the six prefectures Mie, Shiga, Kyoto, Osaka, Hyogo and Nara.

Lake Biwa supplies water for various uses: domestic, industrial and agricultural uses, and for power generation. Water of Lake Biwa and the Yodo River supports social and economic activities not only in their respective basins, but also in extensive areas in the Kinki region. Notably, tap water from the lake/river serves some 14 million people, the largest population in Japan benefiting from a single water source.

The water is taken and used throughout the water source. In the upper reaches, water taken from Lake Biwa and dams is mainly used in Shiga Prefecture; in the middle reaches, water is taken from Biwako Canals and the Uji River primarily for use in Kyoto City; in the lower reaches, water from the Yodo River serves the huge population of Osaka and other cities on the Osaka Plain.

Overview of the Yodo River Basin

Water Use in Lake Biwa and the Yodo River Basin

Land Use in Lake Biwa and the Yodo River Basin

Population Using Tap Water from Lake Biwa/Yodo River (Water service in fiscal 1994)

Since ancient times, many cities have been developed on the flat lands in Lake Biwa and the Yodo River Basin. During Japan's high economic growth period after World War II, industrialization and urbanization progressed remarkably, particularly in Kyoto, Osaka, Kobe and their suburbs; many forests and farmlands around large cities were converted into residential zones during that period. Today, the Lake Biwa Basin and the upper reaches of the Yodo River have a relatively greater proportion of farmland; the lower reaches contain more residential, commercial and industrial districts.

19921955

1895

Changes in Land Use in Lake Biwa and Yodo River Basin

(Source: Lake Biwa Museum)

0 10 20 30 40km

LegendMunicipality

Forests

Farm Land

Urban Areas

Unidentified Areas

Water Areas

1

Overview of Lake Biwa and the Yodo River Basin1

Lake Biwa Basin

Yodo River Basin

River

Urban Area

Lake Yogo

Okinoshima Island

Otsu City

Kyoto City

Osaka Bay

Yodo River

Old Yodo River

Kanzaki River

Uji River

SonobeRiver

HitokuraorojiRiver

Nunom

e Rive

r

Uda River

Taka

toki

Rive

r

Ane River

Ado River

Katsura River

Seri RiverUso River

Echi River

Shorenji RiverNabari River

Ina River

Kizu RiverKam

o River

Hino River

Yasu River

Kusatsu River

Daito River

Shiga

Kyoto

Nara

Hyogo

Mie

Gifu

Fukui

Osaka

Seta River Araizeki Weir

Osaka City

Yodo RiverOzeki Weir

Lake Biwa

Lake Biwa and Yodo River Basin

Legend

2 Overview of Lake Biwa

Overview of Lake Biwa

The surface area of Lake Biwa, Japan's largest lake, is 674 km2, 17,000 times the area of Koshien Ball Park one of the largest baseball fields in Japan and one-sixth the total area of Shiga Prefecture where the lake lies. At the lake's narrowest point, it is spanned by Biwako Ohashi Bridge. The lake's section north of the bridge is called "Hokko" (northern lake) and that south of the bridge is called

"Nanko" (southern lake); Hokko and Nanko differ in character in various aspects.

There are approximately 460 rivers of various sizes flowing into the lake. There is, however, only one outflow from the lake (the Seta River), apart from canals constructed during early modern times. It is estimated that approximately 19 years are required to change all water in the lake.

Lake Biwa is the only ancient lake in Japan. In terms of surface area, despite being the largest lake in Japan, Lake Biwa is ranked 130th among the world's freshwater lakes. In terms of age, however, the lake is the world's third oldest, with a history of some four million years. The term "ancient lake" is generally defined as an extant lake that was created more than 100,000 years ago. Because they have such long histories, ancient lakes feature a great many endemic species that have evolved within the respective lake. Lake Biwa possesses abundant biodiversity, offering habitats to over 1,000 species, including at least 50 endemic species, such as Biwa trout (onchorhynchus masou rhodurus) and Seta corbiculid clam (corbicular sandai).

Lake Biwa, an Ancient Lake

Dimensions of Lake Biwa

(Source: "Ancient Lakes" in Lake Biwa Museum)

Lake Baikal

31,500km2

1,637m

740m

23,000km3

Approx. 2,500

Approx. 50%

32,600km2

1,471m

572m

18,880km3

Approx. 1,300

Approx. 50%

674km2

104m

41m

27.3km3

Approx. 600

Approx. 10%

Lake Tanganyika Lake Biwa

Approx. 30 million years old

Approx. 20 millionyears old

Approx. 4 millionyears old

Age

Lake Surface Area

Maximum Depth

Average Depth

Water Storage Capacity

No. of SpeciesLiving in Lake

Rate of EndemicSpecies

Location and Characteristics of Three Oldest Lakes in the World

The Equator

Lake Baikal

Lake Tanganyika

Lake Malawi

Lake Biwa

Ibuki Mountains

Mt. Kanekuso1,271m

Mt. Ibuki1,377m

Mt. Ryosen1,084m

Mt. Buna1,214m

Ado River

Mt. Mikuni815m

Mt. Gozaisho1,210m

Mt. Hiei848m

Hira

Mou

ntain

s

Suzuka Mountains

Ane River

Amano River

Inukami RiverEchi River

Hino River

Yasu River

Daito River

Seta River Araizeki Weir

Lake Biwa

Mountain

Hill

Flatland

Shiga Prefecture Land Area

Lake Biwa Catchment AreaLake Surface Area

ShorelineStorage CapacityAverage DepthMaximum DepthLength (North - South)Maximum WidthMinimum Width

3,174km2

674km2 (Northern Lake:Southern Lake = 11:1) 235km 27.3km3 41.2m 103.6m 63.5km 22.8km 1.35km

4,017km2

Osaka Bay

Amagase DamSeta River Araizeki Weir

Biwako Ohashi Bridge

Lake Biwa

(Source: The House of Water Benevolence “Aqua-BIWA”)

Ground Plan

Cross Section

2

2

Omi Hakkei (eight scenic places in Omi)

Sails Returning toYabase Port

Sails Returning toYabase Port

Sunset Glowover Seta

Sunset Glowover Seta

Autumn Moon overIshiyama Temple

Autumn Moon over Ishiyama Temple

Clearing Mist atAwazu

Clearing Mist at Awazu

Evening Rain at Karasaki

Evening Rain at Karasaki

Descending Geeseat Katata

Descending Geeseat Katata

Evening Snowon Mt. Hira

Evening Snowon Mt. Hira

Evening Bell fromMiidera Temple

Evening Bell from Miidera Temple

3 Development of Lake Biwa and the Yodo River Basin

It is believed that ancient people began living around Lake Biwa over 20,000 years ago. During the Yayoi Period (ca 300 BC - ca 300 AD), rice cultivation was introduced to the fertile wetland around the lake, where increasing numbers of agricultural communities developed, protected by the natural embankment from seasonal changes in the lake's water levels.

Early History

A Political Center and Cradle of Culture and Tradition

In the course of Japanese history, many new paddy fields were developed on the Omi Plain around Lake Biwa. During the Edo Period (1603-1868), agricultural production on the Omi Plain reached second highest in Japan, first being that of the Kawachi Plain in Osaka.

In addition to rice produced on the Omi Plain, rice and other products from the Hokuriku region were transported by ship to Kyoto and Osaka. Boats called "marukobune" carried products on Lake Biwa and the Uji and the Yodo rivers. Water transportation reached its peak during the mid-Edo Period, when as many as 3,700 boats sailed on the lake. At that time, Lake Biwa served as an essential transportation artery in the Kinki economy, featuring Kyoto, seat of the emperor's court, and Osaka, Japan's commercial center.

Since ancient times, the Lake Biwa region played an essential role in Japan's political scenes, as well as in agriculture and commerce. In 667, Japan's capital was relocated to Otsu; in 1579, Azuchi Castle was constructed on a hilltop commanding the view of the lake. For several subsequent years, Azuchi was Japan's political and economic center.

Along with the development of transport, Lake Biwa became well known for its scenic beauty. Many poems depicting the lake's landscapes appear in Manyoshu, the earliest extant anthology in Japan, and other collections of poems. During the Muromachi Period (1333 – 1573), a nobleman named Konoe Masaie selected Omi Hakkei (The Eight Scenic Beauties in Omi) modeled on Shousyou Hakkei in the Dongting Lake of China. Omi Hakkei were subsequently depicted by Ando Hiroshige, a ukiyoe (woodblock print) artist, and his works became extremely popular, promoting the scenic beauty of Lake Biwa throughout Japan.

In this way, Lake Biwa has continuously benefited Japanese people spiritually as well as economically, inspiring artists and nurturing various cultures and traditions.

Expanded Farmlands, Increased Rice Production and Subsequent Development of Commerce

Clay Pot Unearthed from Dainaka-no-ko Lake Ruin

(Courtesy of Lake Biwa Development Integrated Operation& Maintenance Office, Water Resources Development)Rice Cultivation During the Yayoi Period

(Courtesy of Shiga Prefectural Museum of Azuchi Castle and Archaeology)

●Dainaka-no-ko lake ruinDuring the reclamation of Dainaka-no-ko inland lake, many artifacts produced between the Jomon (ca6,000BC-ca300 BC) and Heian (794AD-1192AD) periods were discovered on the lake bottom. Wooden farm tools and the ruins of paddy fields from the Yayoi period (ca３００ BC-ca３００AD) show that rice was grown around the lake during that period.

(Courtesy of Otsu City Museum of History)

3

Steamboat on the Yodo River

(Courtesy of Otsu City Museum of History) (Courtesy of Yodogawa Construction Office,Kinki Regional Development Bureau,

Ministry of Land, Infrastructure and Transport)Lake Biwa Steamship

After the Meiji Restoration (1868), Lake Biwa and the Yodo River Basin experienced outstanding industrial and economic

development. Osaka in particular prospered as Japan's industrial center. On Lake Biwa, steamship services were used for

transport between Nagahama and Otsu, and for sightseeing tours of the lake. Prior to full-scale introduction of railways,

steamships on rivers played the leading role in transporting both passengers and cargo between Kyoto and Osaka.

During the Meiji Period (1868 - 1912), Osaka citizens bought water-filled barrels from vendors, who drew water from the

Yodo River. In 1905, however, Osaka City commenced tap water supply service, whose source also was the Yodo River.

Industrial and Economic Development after the Meiji Restoration

For centuries, people living in the basin of Lake Biwa and the Yodo River used water from the lake and river in various ways:

they drew water for irrigation, fished on the lake, and washed clothes and vegetables in the lake/river. Thus, the lake and river

were familiar to local residents. During Japan's high economic growth period (1955 - 1974), landscapes in the basin changed

dramatically: farmland disappeared due to rapid urbanization and industrialization. Increasing numbers of people began to live in

cities, where tap water service was available. Instead of going to lakeside/riverside, people began washing rice and vegetables in

their kitchens, even using washing machines for laundry. While such changes made daily life of citizens much more convenient,

permitting them to use more and more water, opportunities to access the lake/river began to decrease.

Changing Lifestyles

Development of Lake Biwa and the Yodo River Basin

4

3

Seta River Seta River

Senjyo River Senjyo River

4 Background of Lake Biwa Comprehensive Development Program

Flood Damage in the Edo Period (1603 - 1868)

Flood Control During the Meiji Period (1868 - 1912)

Extensive Flooding of September 1896(Courtesy of Otsu City Museum of History)

(Courtesy of The House of Water Benevolence “Aqua-BIWA”)

(Courtesy of Yodogawa Construction Office,Kinki Regional Development Bureau,

Ministry of Land, Infrastructure and Transport)

Civil Engineer Johannis de RijkeNango Araizeki Weir(Courtesy of The House of Water Benevolence “Aqua-BIWA”)

Even after the Meiji Restoration, Lake Biwa occasionally flooded, causing extensive damage to farmlands around the lake. The great flood of 1896 caused particularly serious damage, including 111 casualties and 7,885 collapsed houses. Following this disaster, a large-scale disaster prevention program was initiated, targeting the entire Lake Biwa and the Yodo River Basin. The program mainly comprised widening and dredging of the shallow fort of the Seta River, construction of Nango Araizeki Weir, and improvement works of the lower reaches, the Uji River and the Yodo River. As a result, Seta River flow capacity increased four times, and water level of Lake Biwa and flow of the Seta River control became possible by operating weir gates. The gates, however, were manually operated, requiring one full day to open and two days to close.

Land erosion prevention and afforestation projects were also commenced in the beginning of the Meiji Period. Prior to project implementation, Mt. Tanakami by the Seta River had no vegetation; sand and soil eroded from the mountain flowed down with rainwater into the river and were deposited on the riverbed. In the afforestation of this mountain, the Japanese government asked the help of a Dutch civil engineer, Johannis de Rijke, who played a leading role in the project. Subsequently, he committed himself to many river improvement and erosion prevention projects in various parts of Japan, including improvement of the Yodo River and Osaka Bay. For these commitments, he is remembered as the father of flood control in Japan.

Although Lake Biwa generally benefited people living on the Omi Plain, the lake sometimes flooded farmlands, causing great damage to farmers. The major factor of flooding was evident: despite the size of the lake, it had only one outflow, the Seta River, which was shallow and narrow. Well aware of the need to dredge the riverbed, farmers of the Edo Period filed petitions for dredging with the Shogunate government, thereby risking their lives, since such actions were strictly banned under the feudalistic system of that period. The desperate attempts of those brave farmers, however, were seldom rewarded, since villagers on the lower reaches of the river thought that dredging the Seta River would cause flooding in the lower basin. From the militaristic perspective, the Shogunate government regarded the shallow ford of the Seta River as a strategic point for transporting an army across the river, and was naturally reluctant to dredge the riverbed. The Shogunate government allowed dredging only 5 times for 200 years of Edo Period. Accordingly, the farmers around the lake occasionally dredged the riverbed themselves, pretending that they were collecting clams.

Map of the Seta RiverBefore Tenpo Dredging

Map of the Seta RiverAfter Tenpo Dredging

Daido R

iver

Koyama River

Daido R

iver

Koyama River

Mt.dainichi Mt.dainichi

Current AraizekiWeir

Current AraizekiWeir

5

(million people)

20

15

10

5

01955 19891960 1965 1970 1975 1980 1985 1994

Users of Water Service from the Yodo River System(Lake Biwa and the Yodo, Katsura and Kizu rivers)

Keage Power Plan

Land Subsidence

Japan’s First Streetcar

The first modern project for using the water of Lake Biwa was the Lake Biwa Canal Project (the first canal), inaugurated in 1885. This project, aimed at supplying agricultural and domestic water to Kyoto, developing a water transportation route, providing energy through construction of hydroelectric power plants and controlling the water level of Lake Biwa, paved the way for subsequent multi-purpose regional development programs. Also, this was the first large-scale project undertaken solely by the Japanese people without the assistance of foreign engineers. In 1890, along with the canal a power plant was completed, which began supplying electricity to Kyoto City, enabling the City to operate Japan's first street car services. In 1912 a second canal was constructed, which contributed to the further growth of Kyoto City.

Modern Projects for Using Water of Lake Biwa

In the decades after World War II, the Japanese economy began enjoying soaring growth. Under the economic boom, the lower basin of the Yodo River began demanding more and more water from Lake Biwa, urged by increasing population, progress of industrialization, and worsening land subsidence caused by overuse of underground water.

Meanwhile, Shiga Prefecture had its own demands for resolving age-old problems of flooding and drought, as well as for preserving the water quality and ecosystems of Lake Biwa, and using the water for developing local industries.

Given such diverse demands of the various parties concerned, it became essential to prepare a comprehensive program involving all stakeholders. The objectives of such a comprehensive program included promoting effective use of water to develop Shiga and the Kansai economy and controlling flooding, while at the same time conserving the lake's water quality and ecosystems.

Increasing Demand for Water in the Showa Period (1926 - 1989)

Background of Lake Biwa Comprehensive Development Program

6

4

(Courtesy of the Yomiuri Shimbun) (Courtesy of the Yomiuri Shimbun)

(Courtesy of Osaka Municipal Waterworks Bureau)

Lake Biwa Canal(Courtesy of Otsu City Museum of History)

As stated earlier, since ancient times Lake Biwa has continuously benefited people in Shiga Prefecture and the Kinki region, contributing greatly to regional development and prosperity. On the other hand, there have been various challenges related to the lake: residents of the lake area experienced occasional floods and droughts. In addition, progress of urbanization and industrialization aggravated the lake's natural environment and residents' living environment. Ever since the post-World War II high economic growth period, demand for water has increased in the Yodo River basin, imposing a still greater burden on Lake Biwa as an essential water source.

With this backdrop, the Lake Biwa Comprehensive Development Program was initiated in 1972 as a national project in compliance with the Special Law for Developing the Lake Biwa Region. To resolve various problems in a holistic manner and seek economic development of both the upper and lower reaches of the Yodo River, this Program encompasses projects to promote effective use of water, control flooding and drought, and create amenity-rich waterfront areas. At the same time, the Program incorporates measures for addressing environmental challenges, including deterioration of water quality. The Special Law for Developing the Lake Biwa Region was extended twice (for 10 years in 1982 and for additional five years in 1992); in total, the Program was in operation for 25 calendar years from 1972 to 1997.

The major objectives of the Lake Biwa Comprehensive Development Program were conservation and restoration of the lake's environment, including water quality; flood control of Lake Biwa and the Yodo River; and promotion of effective use of water.

5 Lake Biwa Comprehensive Development Program

＊

＊

＊

＊

Lake BiwaComprehensive

DevelopmentProgram

Environmental Preservation

Promotion of Effective Water Use

Flood Control

Water Quality Conservation

Project Name

Sewage Systems

Night Soil Treatment

Waste Treatment Facilities

Water Quality Monitoring Stations

City Parks

Natural Park Facilities

Acquisition of Nature Conservation Areas

Road Improvement

Port Improvement

Rivers

Dams

Erosion Control

Forest Conservation

Lake Biwa Flood Control and Water Resource Development

Domestic Water Supply

Industrial Water Supply

Land Improvement

Fisheries

Fishery Ports

Afforestation and Forestry Roads

Livestock Waste Treatment

Agricultural Community Drainage Facilities

Natural Environment Conservation

Flood Control of Inflowing Rivers

Flood Control of Lake

Downstream Water Use

Water Use in Shiga Prefecture

Fisheries

Enhancement of Soil's Recharge Capacity

Original plan(1972)

Revised plan(1982)

Revised plan(1992)

Actual expenses(1972 - 1996)

2,500

2,000

1,500

1,000

500

0

(Billion yen)

427

1,524

260

325

340

599

1,863

351

333

408

771

1,905

351

321

384

8497287125143

Lake Biwa Flood Control and Water Resource DevelopmentPromotion of Effective Water Use

Flood ControlEnvironmental Preservation

Transition of ExpensesBreakdown of Expenses

Sewage Systems26.6％

Night Soil Treatment 0.6％

Agricultural Community Drainage Facilities 3.5％Livestock Waste Treatment 0.1％Waste Treatment Facilities 1.1％Water Quality Monitoring Stations 0.1％City Parks 0.6％

Natural Park Facilities 0.1％Acquisition of Nature Conservation Areas 0.1％

Roads11.3％

Ports 0.4％

Rivers9％

Dams3.2％

Erosion Control 3.1％

Afforestation and Forestry Roads 2.8％

Forest Conservation 2.1％

Domestic Water Supply4.0％

Industrial Water Supply 0.8％

Land Improvement11.5％

Fishery Ports 0.1％

Fisheries 0.4％

Lake Biwa Flood Control and Water Resource Development 18.5％

<Total expenses:1,905 billion yen>

Program System

44.5％

20.2％

16.8％ Flood Control

Promotion of EffectiveWater Use

*: Projects added at the time of revision of the appropriate law in 1982Systems of Lake Biwa Comprehensive Development Program

7

The Program encompassed various projects in 22 categories, all contributing to sound development of the Kinki region. The total budget amounted to approx. 1,863 billion yen; when the Program was fully completed, actual expenditures reached 1,905 billion yen.

EnvironmentalPreservation

Breakdown of the Program Expenses

This bypass canal was Japan's first large-scale facility for controlling water flow. A hydroelectric power plant was constructed by the canal, for effective water use.

Improvement of the Seta River Araizeki Weir (Bypass Canal) for Promoting Water Use in Lower BasinImprovement of the Seta River Araizeki Weir (Bypass Canal) for Promoting Water Use in Lower Basin

For communities around Lake Biwa, an extensive water supply system was launched by purifying water from the lake. This new system was effective in supplying water particularly in times of drought, as well as in improving public hygiene and the living environment.

Effective Use of Water in Shiga Prefecture: Mabuchi Purification Plant

The Lake Biwa Comprehensive Development Program was implemented in compliance with the Special Law for Developing the Lake Biwa Region, providing legal grounds for allocating special funds from the national government. This legal system paved the way for many subsequent water source development programs throughout Japan.

○Special Funds from National GovernmentThe national government endowed special funds (by raising the share of the national government) to many projects

implemented as part of the Lake Biwa Comprehensive Development Program.

○Share of Municipalities in Lower BasinThe municipalities in the lower basin that would benefit from the lake development projects shared the expenses of the

lake development and conservation projects implemented by Shiga Prefecture and municipalities within the Prefecture. The share ratio was determined in accordance with the water volume to be supplied from the newly developed resources (40 tons in total). The share paid by the municipalities concerned totaled approximately 60.2 billion yen. In addition, Osaka and Hyogo prefectures furnished Shiga Prefecture with funds totaling 5 billion yen.

○Lake Biwa Management FundTo finance construction and operation of various maintenance facilities in Lake Biwa, Shiga Prefecture established the

Lake Biwa Management Fund of approximately 10 billion yen in Fiscal 1996, when the Lake Biwa Comprehensive Development Program was completed.

Lake Biwa Comprehensive Development Program

Environmental Preservation

Promotion of Effective Water Use

The sewage treatment plant was constructed to restore the water quality of Lake Biwa and improve the regional living environment. The plant was the first to introduce an advanced treatment system effective in removing nitrogen and phosphorus from wastewater, so as to prevent the lake's eutrophication.

Konan-chubu SewageTreatment Plant

To control occasional flooding of the Yasu River, which previously diverged into two branches at Shinjo, Moriyama City, a drainage canal was constructed that combines the previously diverging water flow and discharges water directly into Lake Biwa.Yasu River Drainage Canal

To prevent flooding, the lake’s shoreline was embanked and an administrative road was constructed on the embankment. At the beach inside the embankment, reeds were planted to restore the reed colony that once characterized the lake’s landscape. In addition to administrative purposes, the administrative road is used by local residents and tourists.

To enable continuous monitoring of water quality, an automatic monitoring station was constructed inside the lake. This station is linked with a central station on land, equipped with a telemeter receiver and an information processing system.Water Quality Monitoring Station

［Kusatsu District］Lakeshore Embankment, AdministrativeRoad and Artificially Planted Reeds

Special Financial Measures

Effective Use of Water in Shiga Prefecture: Mabuchi Purification Plant

［Kusatsu District］Lakeshore Embankment, AdministrativeRoad and Artificially Planted Reeds

8

5

Flood Control

Flooding in July 1972Factors

PrecipitationMax. precipitationLocation of max. precipitationAverage precipitation in basin

Max. water level

Area flooded by Lake water

Number of houses inundated above/below floor level (Shiga Prefecture)

424 mmYanagase, Yogo Town

320 mm/5 days

＋92cm

3,377ha

755 houses

Flooding in May 1995

435 mmTochu, Kutsuki Village

297 mm/13 days

＋93cm

742ha

7 houses

200

180

160

140

120

100

80

60

40

HyogoPrefecture

OsakaPrefecture

KyotoPrefecture

ShigaPrefecture

20

0

Tap Water IndustrialWater

AgriculturalWater

Other

Approx. 210 m3/s

Total Increase by Development Program

1942 1960 1972Before Lake BiwaComprehensive

Development Program

1992After Lake Biwa Comprehensive

Development Program

Water Taken from Lake Biwa

Houses

Num

ber

of H

ouse

s In

unda

ted

abov

e/be

low

Flo

or L

evel

1965 - 1974

1975 -1984

1985 - today(July 1972)

(May 1995)

1965 - 19741975 -198421) 1985 - today

Effects of Projects to Promote Effective Use of Water

(Source: data from Lake Biwa Development Integrated Operation & Maintenance Office,Water Resources Development Public Corporation)

6 Outcomes of the Lake Biwa Comprehensive Development Program

As a result of projects implemented as part of the Lake Biwa Comprehensive Development Program, Lake Biwa and the Yodo River basin obtained improved infrastructures. Construction of embankments and drainage facilities resolved flood problems; various measures taken against drought enabled a steady supply of water. Of the 22 major projects incorporated in the Program, 11 concerned environmental conservation, which aimed to improve living and natural environment.

As a result of the Lake Biwa Comprehensive Development Program, daily supplied water volume increased significantly, securing a steady water supply for domestic and industrial uses throughout the basin.

When dry weather continued from July to September 1994, for instance, the lake's water level fell to -123 cm, the lowest record in the history of the lake's observation. However, the water intake control period was extremely short compared with the period prior to Program implementation.

Effects of Projects Promoting Effective Use of Water

As a result of the Lake Biwa Comprehensive Development Program, control of the lake's water level has become much easier, in turn enabling flood control.

For instance, the Program has significantly mitigated damage from flooding in terms of both flooded area and number of houses inundated above and below floor level.

Effects of Flood Control Projects

Precipitation and Number of Houses Inundated above/below Floor Level in Shiga Prefecture

Max. precipitation

Comparison of Damage from Flooding

m3/s

9

5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0

50 45 40 35 30 25 20 15 10 5 0

（％） （mg/l）

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996

Sewage service coverage rateRivers flowing into Southern Lake and Seta RiverRivers flowing into east section of Northern Lake Rivers flowing into west section of Northern Lake

Sewage service coverage rateRivers flowing into Southern Lake and Seta RiverRivers flowing into east section of Northern Lake Rivers flowing into west section of Northern Lake

Sewage service coverage rateRivers flowing into Southern Lake and Seta RiverRivers flowing into east section of Northern Lake Rivers flowing into west section of Northern Lake

BOD

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

50 45 40 35 30 25 20 15 10 5 0

（％） （mg/l） T－N

450

400

350

300

250

200

150

100

50

0

50 45 40 35 30 25 20 15 10 5 0

（％） （ g/l ） T－P

700

600

500

400

300

200

100

0

6.00

5.00

4.00

3.00

2.00

1.00

（ha）

Shiga PrefectureLake Biwa Comprehensive Development Program ParksPer capita park area

(m2/person)

0.00

130.7

2.51

0

273.4

Fiscal 1971 Fiscal 1981 Fiscal 1991 Fiscal 1995

2.58

25

573.8

4.75

92

695.0

173.3

5.51

1 2 3 4 5 6 7 7 9 10 11 12

02040

60

80100

50

0

–50

–100

–150

Precipitation(mm)

(month)

Average precipitation in Lake Biwa basin

Standard maximumwater level

Standard maximumwater level

Water level(cm)

Maximum water levelbetween June 16 and

October 15

1st phase water intake control(Jul. 31, 1973: -36 cm)

2nd phase waterintake control

Mitigation of control to2nd phase level(Sep. 27, 1994: -88 cm)

Lowest water level(Sept. 15, 1994: -123 cm)

3rd phase water intake control(Sept. 10, 1994: -116 cm)

2nd phase water intake control(Sept. 3, 1994: -108 cm)

1st phase water intake control(Aug. 22, 1994: -94 cm)

Temporary lifting of control: 3:00 P.M., Sept. 16,1994 - 3:00 P.M., Sept 19, 1994

Lifting ofcontrol(Oct. 4, 1994: -48 cm)

(Sept. 4, 1973: -53 cm)

Temporary lifting of control from 5:00 P.M.,Sept. 29, 1994

Lege

nd 193918731994

Sew

age

Serv

ice

Cove

rage

Rat

eSe

wag

e Se

rvic

e Co

vera

ge R

ate

Sew

age

Serv

ice

Cove

rage

Rat

e

Fiscalyear

Fiscalyear

Fiscalyear

Despite increase in the population of Lake Biwa's catchment, its water quality has significantly improved as a result of water quality conservation projects, including construction/improvement of sewage treatment plants, livestock waste treatment facilities, agricultural community drainage facilities and waste treatment plants. These projects were particularly effective in improving water in rivers into the Southern Lake, thereby mitigating eutrophication.

To enable citizen access to the lake, city parks and natural parks were constructed along the shoreline. In addition, governments of various levels purchased strategic lakefront areas to preserve outstanding scenic beauty, as well as the lake's indigenous natural environment.

Effects of Environmental Preservation Projects

City Park Area in Shiga Prefecture

Comparison of Lake Water Level

River Water Quality and Sewage Service Coverage Rate

(Note) Per capita park area = city park area / population in urban district

Outcomes of the Lake Biwa Comprehensive Development Program

10

6

4.0

3.0

2.0

1.0

0.0

（mg/L）

Environmental Standard

0.04

0.03

0.02

0.01

0.00

（mg/L）

Environmental Standard

Southern Lake

Northern Lake

8.0

6.0

4.0

2.0

0.0

（m）

1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001

1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001

(Fiscal year) (Fiscal year)

(Fiscal year) (Fiscal year)

Northern Lake

Southern Lake

Northern Lake

Southern Lake

0.5 0.4 0.3 0.2 0.1 0.0

（mg/L）

Environmental Standard

Southern Lake

Northern Lake

7 Current Situation of Lake Biwa

The catchment area of Lake Biwa reaches 3,174 km2, the majority belonging to Shiga Prefecture, the remainder to Kyoto Prefecture. Land use in the catchment has been changing, driven by increasing population, ongoing urbanization and changing industrial structures.

Today, forests comprise about half the total land area of Shiga Prefecture; farmlands, mainly comprising paddy fields, comprise less than one-seventh of the total land area.

Forests and farmlands are helpful for conserving the lake's environment, since they recharge ground water, prevent sand/soil erosion and retain/purify water. The area of forests and farmlands, however, is decreasing in Shiga Prefecture even more rapidly than the national average. In coming years, more forests and farmlands are predicted to be converted, though slowly, into roads and housing zones.

Land Use around the Lake

Water quality of Lake Biwa deteriorated during Japan's high economic growth period (1955 - 1974). Following enactments of ordinances such as the Ordinance for Prevention of Eutrophication of lake Biwa in 1979, however, water quality showed steady improvement for most indicators up until about 1985. Subsequently, however, COD and total nitrogen (T-N) levels have been rising gradually, although transparency and total phosphorus (T-P) levels have been held constant. Today, levels of various water quality indices do not meet Japan's environmental standards, except for T-P in the Northern Lake.

Water Quality of Lake Biwa

Land Use in Shiga Prefecture

Changes in Forest Area (% as compared to 1972) Changes in Farmland Area (% as compared to 1972)

(Source: "Land White Paper" by Ministry of Land, Infrastructure and Transport; "Land Use in Shiga Prefecture" by Shiga Prefecture)

Changes in Water Quality of Lake Biwa(Source: "Environmental White Paper" by Shiga Prefecture)

Changes in Transparency Changes in T-N Levels

Changes in COD Levels Changes in T-P Levels

Total land area: 4,017 km2

(About 1% of national total)

Forests51％

Residential and otherareas　 14％Farmlands

15％

Lake Biwa, rivers,and other

water bodies20％

105 National average Shiga Prefecture

National average Shiga Prefecture

100

95

90

85

105

100

95

90

85

7580

1972 1975 1978 1981 1984 1987 1990 1993 1996 2000 1972 1975 1978 1981 1984 1987 1990 1993 1996 2000Fiscalyear

Fiscalyear

11

Transparency COD Total Nitrogen (T-N)

Total Phosphorus (T-P)

Below 22~33~44~55~6Over 6(m)

Over 3.53.5~3.03.0~2.82.8~2.52.5~2.3(mg/R)

Over 0.50.5~0.40.4~0.350.35~0.30.3~0.25(mg/R)

Over 0.0250.025~0.0200.020~0.0150.015~0.0120.012~0.008Below 0.008(mg/R)

The lake's water quality is not uniform. Influenced by differences in populations and industries of lakeside areas, as well as by lake topography, water quality is worse in the Southern Lake than in the Northern Lake, and in the eastern section than in the western section. The eastern section of the Southern Lake has the worst water quality.

Lake Biwa Water Quality Map

Lake Biwa experiences annual occurrences of freshwater red tide and blue-green algae bloom, both caused by eutrophication - the over-enrichment of a body of water due to excess loading of nutrients such as nitrogen and phosphorus, leading to excessive proliferation of plankton and aquatic plants. Eutrophication deteriorates water quality, alters ecosystems and discolors the water surface. Eutrophication sometimes even makes tap water malodorous.

Eutrophication of Lake Biwa

Freshwater Red Tide

Lake Biwa Water Quality Map (Annual Average Values of Fiscal 2001)(Source: "Environmental White Paper" by Shiga Prefecture)

Blue-green Algae Blooms

Freshwater Red Tides

A similar abnormal growth of blue-green algae blooms, including microsystis spp. and anabaena spp. turns the water surface green. In Lake Biwa, outbreaks of blue-green algae bloom have occurred annually from August to September, since the phenomenon was first observed in 1983 in the Southern Lake. Although only the Southern Lake had such blue-green algae blooms up to 1993, subsequent years have seen them in the Northern Lake as well.

From late April to early June, when the water temperature is between 15 - 20˚C, abnormal growth of the phytoplankton uroglena americana turns the water surface reddish-brown and the water malodorous. Since it was first observed in 1977, this phenomenon, called red tide, has occurred annually, excepting 1986, 1997, 1998, and 2001.

Blue-green Algae Blooms

Num

ber o

f Day

sN

umbe

r of D

ays

Current Situation of Lake Biwa

Fiscalyear

Fiscalyear

(Source: "Environmental White Paper" by Shiga Prefecture)

(Source: "Environmental White Paper" by Shiga Prefecture)

20

15

10

5

01969 1974 1979 1984 1989 1994

1969 1974 1979 1984 1989 1994

2001

Occurrence of Freshwater Red Tide (Days)

35

30

25

20

15

10

5

02001

Occurrence of Blue-green Algae Blooms (Days)

12

7

Original landscapes of Lake Biwa featured reed colonies, beaches with pine trees, shoreline forests and inland lakes. These natural scenes, however, have declined due to changes in land use around the lake periphery. The reed bed area in particular decreased from about 261 ha in 1953 to about 128 ha in 1992.

In reed colonies various other plants also grow, including wild rice, river bulrush, willow and alder, providing ideal nesting and resting places for some 100 wild bird species, including the Chinese little grebe. Reed colonies also provide spawning habitats for Nigoro crucian carp (carassius grandoculis), and willow minnow(gnathopogon caerulescens), as well as shelter for juvenile fish to hide from predators. In this way, reed colonies, forming landscapes unique to Lake Biwa, serve wild life as essential habitats.

Reed Colonies

Attached lakes, directly connected to Lake Biwa by waterways, are unique to the lake; no other lakes in Japan have such attached lakes.

Although there were dozens of attached lakes around Lake Biwa, many were reclaimed before and after World War II to create paddy fields for increasing domestic food supply. In addition to providing wild life with ideal habitats, Attached lakes are believed to retain and purify pollutants and excessive nutrients in the water, lowering the amount of their entry to Lake Biwa.

Attached lakes (naikos)

Reducing Reed Colonies

(Source: "Report of the Survey for Lake BiwaComprehensiveDevelopment Program in Fiscal 1953" by Shiga Prefecture;

"Survey of Reed Colonies" by Shiga Prefecture)

Map of Attached Lakes

Lakeside Reed Colony

Changes of Attached Lakes in Number and Area

4000

Are

a (h

a)

Num

ber

of A

ttach

ed L

akes

3000

2000

1000

1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995

111

425425432433433433552703719719

1864

2902

111

0

37

30 29 29 28 2725 25 25 23 23 23

10 10

40

30

20

10

0

Natural Attached lake (area) New Attached lake (area)Natural Attached lake (number) Total (number)

Number1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Shiozu-naikoShiozusaba-naikoNoda-numaHayasaki-naikoDaigo-naikoHamasuga-numaIrie-naikoMatsubara-naikoNoda-numaSone-numaJinjyo-numa,Koyaba-numaIba-naiko Dainaka-no-koShonaka-no-koNishi-no-koKitanosho-sawa

Tsuda-naikoKitazawa-numaSuikei-naikoNoda-numaHanjo-ikeShinanaka-naikoHira-koKatata-naikoKomatsu-numaOtomegaike Shizugawa-naikoGotanda-numaTonotsubo-numaSuga-numaImazu-numaHamabun-numaNukegawa-naiko

16.8 16.4 6.2 91.9 13.9 2.4

305.4 73.3 15 87

7.2

49.0 1,145 342.1 221.9 15.8

119 4.9

201.3 39.5 33.8 2.5 13.4 7.9 7.8 8.9 19.9 1.2 2.0 2.8

5.4 16

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Lake Name Number Lake NameArea (ha) Area (ha)

—Entire reclamation

Partial reclamation

(Note) Natural: naturally created Attached lakesNew: newly created Attached lakes

(Source:"Studies of Lake Biwa " From Catchment to the Lake-" by Shiga Prefecture Lake Biwa Research Institute, 1988)

1953 1992

300

200

100

0

（ha）

13

261ha

128ha

Each winter Lake Biwa is visited by various migratory bird species, including bean goose, whistling swan and large bean goose, the latter designated a protected bird by the national government. Many bird watchers gather around the lake to enjoy first-hand contact with nature and various forms of wild life.

In 1971, the entire Lake Biwa region was designated a wildlife sanctuary; in 1993, Lake Biwa was registered with the Ramsar Convention on Wetlands.

The Chinese little grebe (Shiga Prefecture bird), also known as “nio,” was a familiar bird on the lake, which local residents called “nio-no-umi” (lake of nio). During the first half of the 1980's, the bird population was around 2,000; today, however, it has almost halved.

Changes in Number of Wild Birds(Changes in Number of Wild Birds)

(Courtesy of Shiga Prefectural Museum of Lake Biwa)

Swan Wild goose

Wild duck Grebe

Lake's Ecosystems

Changes in Fishery Catches by Fish Species

Nigoro Crucian Carp (Carassius grandoculis)

(endemic species)

Biwa Trout (onchorhynchus masou rhodrurus)

(endemic species)

Chinese Little Grebe (Shiga Prefecture bird)

(Source: "Fishery Production Survey" by Shiga Statistics Office, Kinki Regional Agricultural Administration Office)

Fishery catches in Lake Biwa show that catches of shellfish, particularly cobiculid clam, have been decreasing sharply since 1955. In addition, catches of endemic fish species are rapidly declining, particularly Nigoro crucian carp (carassius grandoculis), which is used for a local traditional food called Funazushi, as well as willow minnow (gnathopogon caerulescens) and white fish (leucopsarion petersi hilgendorf). The decrease of endemic species is attributable to reduced reed colonies and loss of other habitats for reproduction and spawning, and the invasion of non-native species, such as large-mouth bass (micropterus salmoides) and bluegill sunfish (lepomis macrochirus).

Current Situation of Lake Biwa

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

(ton)

Fiscalyear

Fiscalyear

Fiscalyear

Fiscalyear

Fiscalyear

Fiscalyear

1974 1979 1984 1989 1994 1999 1974 1979 1984 1989 1994 1999

1974 1979 1984 1989 1994 1999 1974 1979 1984 1989 1994 1999

４００

３００

２００

１００

０

(Number)

１００,０００

８０,０００

６０,０００

４０,０００

２０,０００

０

(Number)３,０００

２,５００

２,０００

１,５００

１,０００

０

(Number)

８００

６００

４００

２００

０

(Number)

Sweetfish

Shrimp and other animals taken by fishery

Other shellfish

Other fish species

Cobiculid clam

600

500

400

300

200

100

0

(ton)

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

TroutNigoro crucian carpWillow minnowCarpWhite fish(leucopsarion petersi hilgendorf)Largemouth bass

14

7

8 History of Lake Conservation Efforts

In May 27, 1977, the first occurrence of red tide was confirmed offshore of Otsu City and Shiga and Imazu towns. The lake surface turned the reddish brown associated with the fishy smell hanging in the air. Furthermore, a large quantity of fish died, causing great damage to fishery. The red tides were caused by abnormal growth of phytoplankton resulting from eutrophication - the over-enrichment of water due to excessive loading of nutrients such as nitrogen and phosphorus.

Freshwater Red Tides

The red tides had a significant and lasting impact on the residents of Shiga Prefecture. The outbreak of red tide motivated residents to take action to prevent further eutrophication. Increasing numbers of citizens were involved in the environmental action, resulting in a prefecture-wide campaign to stop using synthetic household detergents containing phosphorus, one of the major causes of eutrophication. Instead of synthetic detergents, the residents began using powdered soap to wash clothing. As a result, use of powdered soap, which accounted for only 26% of use of detergent in 1979, soared to at least 70% in 1980. Driven by the residents' campaign, the Shiga prefectural government, ahead of other prefectures in Japan, decided to enact an ordinance to control wastewater containing nitrogen and phosphorus. This ordinance, enacted in 1979, is titled the Shiga Prefectural Ordinance Concerning the Prevention of the Eutrophication in Lake Biwa (Eutrophication Prevention Ordinance).

Water Quality Conservation Campaigns Initiated by Local Residents

In 1979, Shiga Prefecture enacted the Eutrophication Prevention Ordinance to prevent eutrophication of Lake Biwa by controlling inflow of nitrogen and phosphorus. The Ordinance was the first in Japan to ban the marketing, use, and gifting of phosphorus-containing synthetic detergent, whose use was widespread throughout Japan at that time. The Ordinance also encompassed regulations on industrial wastewater, together with guidelines for reducing nitrogen and phosphorus from domestic and agricultural wastewater.

Shiga Prefectural Ordinance Concerning the Prevention of the Eutrophication in Lake Biwa (Eutrophication Prevention Ordinance)

Phytoplankton (uroglena americana)

Changes in Use of Powdered Soap

(Source: "Environmental White Paper" by Shiga Prefecture)Campaign Immediately after the Lake BiwaEutrophication Prevention Ordinance Took Effect

Using only powdered soap

Using only powdered soap

Using both powdered soap and synthetic detergent

Using both powdered soap and synthetic detergent not containing phosphorus

Using synthetic detergent not containing phosphorus

Other

Using synthetic detergent only

Don't know

（％） April 1979 12th survey in Shiga Prefecture(July 1980: Enactment of Eutrophication Prevention Ordinance)

August 1980(Survey of Shiga citizens)

26.0 28.1 37.5 8.4

70.6 17.9 7.3 4.2

15

As part of Shiga Prefecture's commitment to lakes' comprehensive environmental conservation, the Prefecture planned international conferences on the environmental preservation of lakes worldwide, and hosted the 1st World Lake Conference in 1984.

Following this first conference, World Lake Conferences were held, in principle, biennially in various lakeside cities around the world, with the objectives of gathering scientists, administrators and citizens to discuss various challenges currently confronting the world's lakes, and seeking solutions to such challenges. In 2001, the 9th Conference was held again in Shiga Prefecture, the host city of the first Conference.

To promote the spirit of the World Lake Conferences, a new NGO titled the International Lake Environment Committee (ILEC) was formed with support from Shiga Prefecture and cooperation from the United Nations Environmental Programme (UNEP).

The water resource development project, implemented as part of the Lake Biwa Comprehensive Development Program, promoted collaboration among various stakeholders in preserving the water quality of Lake Biwa and the Yodo River. Fuelled by this trend, the Lake Biwa - Yodo River Water Quality Preservation Organization was established in 1993, financed by the basin's six prefectures and three metropolises, as well as by private enterprises.

The Lake Biwa - Yodo River Water Quality Preservation Organization supports various water purification projects and grassroots riverside cleanup campaigns, in addition to operating the Lake Biwa - Yodo River Water Purification Collaboration Center (Biyo Center), which researches and develops water purification technologies.

Establishment of Lake Biwa - Yodo River Water Quality Preservation Organization

The 1st World Lake Conference

Sites and Dates of the Past World Lake Conferrences

① Water Channel Type Experimental Purification Facility

② Deep Pond Type Experimental Purification Facility ③ Shallow Pond Type Experimental

Purification Facility

④ Byproduct Treatment Yard⑤ Advanced Treatment Experimental Facility

⑧ Percolation/filtrationExperimental Facility

⑨ Natural Circulation Method Experimental Purification Facility

⑥ UF Filter Experimental Facility ⑦ Experimental Facility of Purification Using Soil

⑩ Lake Biwa Model Experimental Pond⑪ Multi-Water Channel Experimental Facility

⑫ Lakefront Field Experiment Facility

Water Intake

Outlet

WaterIntake

WaterIntakeTo Otsu

HayamaRiver

AgriculturalDrainage

Visitor's Hall

AdministrationOffice

Lake Biwa

To Moriyam

a

Plan of Biyo Center

Lakeside Road (Prefectural Road Omihachiman - Otsu L

Experiments at Biyo Center

Purification Experiment Using Shallow Pond

Water inflowWatercressDischarge

Purification Experiment Using Deep Pond

Waterinflow

Reed

Biological decomposition

Absorption Absorption

Elodea nuttallii St. john

Discharge

Filtration

Pollutant

Purification Experiment Using Soil

DischargeAndosolAkadama soil

Filtration

Water inflow

or

History of Lake Conservation Efforts

1st

2nd

3rd

4th

5th

6th

7th

8th

9th

Shiga Prefecture, Japan, 1984

State of Michigan, U.S.A., 1986

Keszthely City, Hungary, 1988

Hangzhou, China, 1990

Stresa City, Italy, 1993

Ibaraki Prefecture, Japan, 1995

San Martin City, Argentina, 1997

Copenhagen, Denmark, 1999

Shiga Prefecture, Japan, 2001* 10th Conference is planned in Chicago, U.S.A. in 2003.

International Conference on the Conservation and Management of Lakes (World Lake Conferences)

16

8

9 Survey for Preparing Lake Biwa Comprehensive Conservation Plan

Lake Biwa is currently confronted with various challenges, including deteriorating water quality and loss of habitats for endemic species, resulting primarily from changes in lifestyles and land use, both driven by recent socioeconomic development. To address these challenges, various ministries and agencies concerned (National Land Agency and Ministry of Construction [now Ministry of Land, Infrastructure and Transport]; Environmental Agency [now Ministry of Environment]; Ministry of Health and Welfare [now Ministry of Health, Labour and Welfare]; Ministry of Agriculture, Forestry and Fisheries; and Forestry Agency) decided to develop a comprehensive lake conservation plan, as a model plan encompassing Lake Biwa and its peripheral regions, by coordinating and integrating various initiatives taken by respective ministries/agencies. To this end, the governmental bodies concerned jointly established a committee comprising specialists from a wide spectrum of academic fields. In the two years from fiscal 1997 to fiscal 1998, the committee conducted a comprehensive survey, studying and discussing diverse aspects, including improvement of water quality and soil recharge capacity, along with preservation of natural environment and landscapes. The survey outcome was compiled in a report titled

"Survey for Preparing Lake Biwa Comprehensive Conservation Plan".

Background

To implement comprehensive preservation initiatives of Lake Biwa by involving all stakeholders, it is essential to establish a common recognition about the lake's situation and to have common goals for all stakeholders.

Based on the view that we should seek harmonious coexistence with the lake's ecosystem, and bequeath a clean Lake Biwa, the special lake of strategic importance, to future generations, the guiding principle was decided as follows:

Guiding Principle and Key Concepts of the Comprehensive Conservation Plan

The Plan period has been set at 20 years, since in 20 years (around 2020), children born at the time of the Plan's initiation will reach adulthood. Furthermore, the Plan encompasses a longer-term vision, envisaging the state of Lake Biwa fifty years from now (around 2050), when the children will become most influential in the future society.

This long-term Plan must enable flexible operation and, if necessary, revisions in response to social changes, since unexpected changes can occur.

The plan has been set for the 1st stage (up to 2010) and 2nd stage (up to 2020). The objective for the 1st stage is to promote environmental conservation through steady yet flexible implementation of ongoing initiatives, based on constant review of their effectiveness; coordination among various initiatives, introduction of new initiatives and model projects, and continuous surveying and monitoring. The 2nd stage objective is to further promote conservation initiatives in response to new findings in the 1st stage, with particular focus on preventive measures.

Objectives and Period of the Comprehensive Conservation Plan

Our CommonGoals

Our CommonProperty

Our CommonFeeling

Seeking SustainableDevelopment

Bequeathing Lake Biwa to Future Generations

Loving the Lake and Nature

Harmonious CoexistenceHarmonious Coexistence with the Lake's Ecosystem

Bequeathing a clean Lake Biwa to Future Generations―Seeking Harmonious Coexistence with the Lake's Ecosystem―

Guiding Principle

Key Concepts

Our CommonGoals

Our CommonProperty

Our CommonFeeling

17

Concepts in Policy Making

Multiple Viewpoints PartnershipsComplexRelations

Water QualityConservation

Enhancementof Soil Recharge

Capacity

Conservation of Natural

Environmentand Landscapes

Participation

InformationSharing

InformationSharing

Impacts

RegionalDifference

ScientificallyUnknownFactors

Governments

Citizens

Enterprises

NPOs

Cha

lleng

es

Thre

e C

onse

rvat

ion

Obj

ectiv

es

SufficientCoordination and Effective

Initiatives

Lake Biwa Comprehensive

Conservation

Common Recognition of

Challenges

Thre

e R

equi

site

s fo

r Par

tner

ship

Sta

keho

lder

s

Domicile Generation

Profession

FarmlandUrbanArea

Lake andLakeside

Forest

Promoting Partnerships

Environmental changes in Lake Biwa and its catchment are the results of many inter-related factors related to forests, farmlands, urban areas, rivers, lakeside and the lake itself. To resolve environmental challenges in the lake, it is therefore essential that a wide variety of stakeholders, regardless of their profession, domicile or generation, develop common recognition, incorporating multiple viewpoints, and work together to fulfill their common goals.

Incorporating Multiple Viewpoints

To promote the Lake Biwa Comprehensive Conservation Plan, it is imperative to build partnerships among related governmental agencies, local residents, enterprises, NPOs and other stakeholders. Both public and private organizations using water from Lake Biwa should establish common recognition of the lake's challenges and develop a wide variety of commitments.

Promoting Partnerships

Survey for Preparing Lake Biwa Comprehensive Conservation Plan

18

9

Period and Strategies at Each Stage

Viewpoint

Focus

Strategies

Flexible operation in response to constant review and improvement of the Plan

Stage

Fiscal 1999 Fiscal 2010 Fiscal 2020 Fiscal 2050 ~

Com

preh

ensi

veCo

nser

vatio

n Pl

an

1st 2nd Future (long-term vision)

From feasibility of initiatives

From long-term vision

Ongoing initiatives reflecting new findings

Preventive measures

・Steady implementation and reinforcement of ongoing initiatives and their coordination

・Introduction of new initiatives and model projects ・Information sharing and

resident participation・Survey and monitoring to

analyze and identify environmental problems

・Implementation and reinforcement of initiatives, based on analysis of their effects

・Promotion of new initiatives and model projects to entire region

・Information sharing and resident participation

・Survey and monitoring to analyze and identify environmental problems

Promotion of proper land use in consideration of the lake's environmental changes and progress of environmental surveys, studies and conservation technologies; flexible implementation of the Plan in view of changing public opinion, social and legal systems and economic conditions

1st stage objectives2nd stage objectives

Desired state of Lake Biwa

Aerated tank

Distribution tank Organic compounds(Methanol, etc.) PAC

PAC

Finalsedimentationtank

Biological treatment (step-feed biological nitrogen removal process + post-denitrification)

Physiochemical treatment (sand filtration + ozonation + bio-activated carbon filtration)

Excess sludgeSludge return

Anaerobic tank

Treatedwater

Sewage from primarysedimentation tank

Oxygen gas

Sand filtrationtower

Ozone reactiontower

Bio-activatedcarbon filtration tower

Ozone generator

Granular activatedcarbon

Ozone

Followings show major tasks, objectives, and measure examples of comprehensive environmental preservation efforts (Protecting Water Quality, Increasing Soil Recharge Capacity, and Preserving the Natural Environment and Scenic Landscape) and common foundations (Citizen Participation and Activities, Information Sharing and Staff Exchange Promotion, Research and Survey).

【Three categories of Comprehensive Environmental Preservation Efforts】

10 Comprehensive Environmental Preservation Efforts and Specific Measures

① Reducing chemical oxygen demand (COD), total nitrogen and total phosphorus② Resolving problems of musty odor, freshwater red tides and blue-green algae blooms③ Reducing influent load from non-point (unspecified) sources④ Investing and analyzing adequate measures against low biodegradable organics⑤ Minimizing impact of trace chemicals

Reducing influent load to level of latter half of 1960 sTo reduce COD level by approximately 31%, total nitrogen by

approximately 17%, and total phosphorus by approximately 36% from 1995 levels

Protecting Water Quality

■Reducing Environmental Impact of Domestic Wastewater(Sewage Systems)

Major Tasks

First Stage Objectives

○ Measures addressing pollution sources○ Measures addressing runoff processes○ Measures to be taken in the lake itself○ Regulations on wastewater etc.○ Research and field studies

Major Initiatives

Restoring water quality to level of latter half of 1960 s To restore water quality to the level prior to the emergence of

musty odor, freshwater red tides and blue-green algae blooms (level of latter half of 1960's)

Second Stage Objectives

○ Continual enforcement of wastewater regulations○ Reinforcement of measures to reduce influent load

from non-point (unspecified) sources ○ Reinforcement of measures to enhance the lake’s

natural water purification functions○ Introduction of new initiatives in response to

environmental changes○ Lifestyle reforms to reduce environmental impact

Priorities

In Shiga Prefecture, the sewage service coverage rate is rising sharply, reaching 69.5% at the end of fiscal 2001, seventh highest among Japan's 47 prefectures. To prevent eutrophication of Lake Biwa (a closed water system), all sewage treatment plants in Shiga Prefecture have already introduced advanced treatment systems, which are effective in removing various substances such as nitrogen or phosphorus from sewage. Moreover, the sewage treatment plants are currently preparing for the introduction of ultra-advanced sewage treatment systems effective in removing still more biodegradable organics.

Ultra-Advanced Sewage Treatment Process

Changes in Sewage Service Coverage Rates

Advanced Sewage Treatment ServiceCoverage Rate (End of Fiscal 2001)

《Specific Measures》

80

70

60

50

40

30

20

10

0

National averageShiga Prefecture

（％）

45 50 55 56 57 58 59 60 61 62 63 元 2 3 4 5 6 7 8 9 10 11 12 13Year end

16

2330 31 32

33 3436 37

39 4042 44 45

47 495154 55 56

58 6064.569.5

1.73.2 4.6 4.8

7.8 8.91112.9

15.217.120.423.528.230.5

33.936.139.34346.750.55558.862 64

69

32

32

9.7

0 10 20 30 40 50 60 70（%）

Shiga Prefecture(highest in Japan)

Osaka Prefecture(second highest)

Kyoto Prefecture(second highest)

National average

19

54.5%

8.5%

8.8%

71.8%

End of Fiscal 1998

69.5%

8.8%

9.5%

87.8%

Approximately 74%

End of Fiscal 2001

Sanitary Sewage Treatment Facilities in Shiga Prefecture

Sanitary Sewage Treatment Facilities (national average)

Sewage Service

Sewage Treatment Systems for Agricultural Communities

Domestic Wastewater Treatment Tanks

Sanitary Sewage Treatment Facilities (Total)

Comprehensive Environmental Preservation Efforts and Specific Measures

In areas where sewage systems have not been constructed, installation of domestic wastewater treatment systems is currently underway. These systems, called "Johkasou", is capable of treating both night soil and gray water, and feature high performance equivalent to that of sewage treatment plants, as well as ease of installation (requiring only about a week) and relatively small space requirement (about the size of a household parking space)

To further improve Lake Biwa's water quality, it is imperative to reduce influent load from such non-point (unspecified) sources as urban districts and agricultural land. Since the first flush of rainwater contains a particularly high rate of pollutants, measures have been taken to store and treat the first flush in urban districts.

To preserve water quality and improve the living environment in agricultural districts, various facilities have been constructed in agricultural communities, including sewage treatment facilities, rainwater treatment facilities and compositing facilities against sludge from sewage treatment facilities.

(Installation of DomesticWastewater Treatment Systems; Johkasou)

■Purification of Rainwater in UrbanDistricts

<Reducing Influent Load from Non-pointSources>

(Sewage Treatment Systems for Agricultural Communities)

Yogo Town

KinomotoTown

Takatsuki TownIbukiTown

TorahimeTown

Kohoku Town

AzaiTown

Biwa TownNagahamaCity

Omi TownSanto Town

Maibara Town

Hikone City

ToyosatoTown Kora

TownTaga Town

EchigawaTown Hatasho Town

Koto Town

Aito Town

NotogawaTown

GokashoTown

AzuchiTown

OmihachimanCity

Yokaichi City

Eigenji Town

ChuzuTown

MoriyamaCity Yasu

Town RyuoTown Gamo

Town

Hino TownKusatsuCity

Ritto CityIshibeTown Kosei

Town MinakuchiTown

Tsuchiyama TownOtsu City

Shigaraki Town

Konan TownKoka Town

ShigaTown

Takashima Town

Kutsuki Village Adogawa Town

ShinAsahi town

Imazu Town

Makino Town

NishiazaiTown

Locations of Sewage Treatment Systemsfor Agricultural Communities

Purification of Rainwaterin Urban Districts

Street surfacecleaning

Cleaning activities

Infiltrating boxes and ducts

Rainwater collection by households

Rainwaterdrainage

ScreeningWater diverting facilities

Swirling water diversion

Polluted water flows intoeffluent drainpipe.

Rainwater reservoir andsedimentation facility

Purification with vegetationSediment and

sludge flowinto effluent

drainpipe.Catalytic oxidation facility

OutletPurification center

Release oftreated effluent

Lake Biwa

Reducing Influent Load from Non-point Sources

Sewage treatment facilities for agricultural communities (189 districts)

Comprehensive agricultural effluenttreatment model districts (18 districts)

▲

●

20

10

Effluent ductClean water

Conglomerate

Conglomerate

Akadamasoil

Flowdirection

nfluent ductContaminated water

Soil filtrates impurities, while iron in the soil adsorbs phosphorus from water. Concurrently, microorganisms in soil decompose nitrogen and phosphorus, thereby purifying the water.

■Water Purification Mechanism (Upward flow system)

■Improvement of River Environment

■Measures against Low Biodegradable Organics

(Water Quality of Inflowing Rivers)

Various studies have been conducted in quest of adequate measures to address low biodegradable organics, which are believed to be responsible for the lake's high COD level. The studies have shown that a system using soil's functions to decompose and adsorb organics is effective in treating high COD level effluent from roads, particularly in the first flush (approximately 2 mm).

Water quality is monitored and analyzed in rivers and inland lakes flowing into Lake Biwa, as well as in sections of Lake Biwa where water contamination is particularly serious. In addition, various measures are taken to improve the lake's water quality, including dredging of the lake bottom and water purification by means of vegetation.

In the Kusatsu River, for instance, a water purification facility has been constructed using soil's water purification function. In this facility, soil removes nitrogen and phosphorus from contaminated river water, thus reducing influent load. In the Moriyama River, which flows into Akanoi Bay, river water is fed to reservoirs (either flooding prevention reservoir or ordinary treatment reservoir) and purified before discharge into the lake.

(Measures against Sediment Contamination)In the areas of advanced eutrophication, dredging and

other measures are taken to address lake bottom contamination and hinder nutrient dissolution into lake water.

0First time Second time Third time Fourth time

20

40

60

80

100

（g）0

20

40

60

80

100

（%）

Total loadTotal load in treated waterRemoval rate (%)

COD

Kusatsu River Water Purification Facility

Dredging of Lake Bottom

Removal of Low Biodegradable OrganicsLow Biodegradable Organics Treatment System

Effluent from roads

Parshall flume

Effluent from roads (first flush, post-first flush)

Horizontal treatmentequipment

Slit

Void

reatment chamber

Tank

Treated water

Excessive water

Triangle weir

21

① Securing sufficient forest area

② Ensuring proper management of planted forests

③ Improving forest maintenance/management systems

④ Securing sufficient agricultural land area

⑤ Increasing soil's rainfall infiltration and holding capacity in urban districts

⑥ Promoting efficient water use

Securing sufficient land area for rainfall infiltrationTo secure sufficient land area for rainfall infiltration in forests,

agricultural land and urban districts by preventing forest erosion and through other efforts

To protect forest soil layers on a sustainable basis by promoting adequate plant growth and management, particularly in planted forests

Major Tasks

First Stage Objectives

○ Measures to secure sufficient forest and agricultural land area

○ Stabilization of forest soil layers○ Efficient use of reservoirs and other artificial water

storage facilities○ Construction and improvement of water recycling

facilities○ Research and field studies

Improving soil’s recharge capacity and promoting adequate water use

To improve and sustain soil's rainfall filtration and holding capacity in forests, farmlands and urban districts

To promote adequate water use in artificial water circulation systems

Second Stage Objectives

○ Proper management of planted forests to stabilize soil layers

○ Development of human resources for forest maintenance

○ Researches to seek various adequate measures for the lake's respective sub-basins in accordance with their water quality and local ecosystems

■Forest MaintenanceProper forest maintenance is essential for sustaining soil's recharge capacity. To promote forest maintenance, various

measures taken include periodic thinning and the creation of mixed forests with multiple canopies and long harvest cycles.

Increasing Soil’s Recharge Capacity

Forest of Long Harvest Cycle

Major Initiatives Priorities

Comprehensive Environmental Preservation Efforts and Specific Measures

《Specific Measures》

22

10

■Permeable Pavement andUrban Green Zones

To improve rainfall filtration and holding capacity in urban area, increasing numbers of streets have permeable pavements and roadside trees.

■Improving Rainfall Filtration andHolding Capacity of Farmlands

To improve rainfall filtration and holding capacity of farmlands, agricultural communities in Shiga Prefecture have introduced agricultural water management systems featuring irrigation water circulation and water recycling systems, together with efficient use of reservoirs.

Permeable Pavement

Circulatory Irrigation System

■AfforestationTo stabilize mountain soil layers and promote ground infiltration of surface water, various measures taken include

restoration of forest areas damaged by a disaster, creation of disaster-prevention forests and improvement of their functions.

Immediately after Disaster Immediately after Restoration

Restoration of Damaged Forest

1 Year Later

23

Withoutriparian forest

Withriparian forest

■Restoration of Rivers and Lakeshore

Preserving the Natural Environment and Scenic Landscapes

①Preserving wild life habitats

②Preserving biodiversity

③Preserving the lake's indigenous scenic beauty

④Controlling lakeside land use

Securing strategic points for the creation of biotope networks

To preserve biotopes in the transition zone (called "ecotone") between water and land

To preserve biotopes along rivers flowing into the lake so as to sustain the functions of those biotopes as ecological corridors linking the lake to the mountains and forests on the edges of the catchment area

○ Securing sufficient area of wild life habitats by creating biotope networks

○ Improving habitat environment by creating biotope networks

○ Cultivating public awareness and establishing rules for the sensible use and protection of the natural environment

○ Involving local residents in conservation activities and field studies

Establishing a framework of biotope networksTo create a framework of biotope networks and restore natural

ecosystem using it.

○ Monitoring and assessment of wild life habitats○ Establishment of a system to involve local residents and

other users of the lake in environmental conservation activities

In the past, Lake Biwa shoreline was mainly comprised of sand beaches and reed colonies. Today, however, many sections of the lakeshore have concrete or sheet pile embankments. Of those sections, those that suffer particular environmental degradation have been selected for restoration of the lake's original landscape, thereby to regain the lakeshore's functions of flood prevention, ecosystem preservation and providing access to the water.

■Yasu Riparian Forest Project

Riparian Forest Zones

An afforestation project is under way along the Yasu River, a major river flowing into Lake Biwa. In addition to preserving natural ecosystems, riparian forests are effective in augmenting riverbank flood-prevention functions.

The revised River Law (1997) introduces the riparian forest zone system, under which river authorities can create and preserve riparian forest zones as a means of promoting flood prevention and efficient use of river water.

Reproduced Reed Colony(Moriyama District)

Before Restoration

Major Tasks

First Stage Objectives

Major Initiatives

Second Stage Objectives

Priorities

Large quantityof floodwater

High flow velocity = Extensive bank damage

High flow velocity = deep erosion

Water overflowing the bank is likely to cause extensive damage.

Water overflowing the bank is blocked by trees, eventuallyminimizing flood damage

Low flow velocity = Minor bank damageSmall quantity of floodwater

Low flow velocity = minor erosion

Comprehensive Environmental Preservation Efforts and Specific Measures

《Specific Measures》

24

10

■The Ordinance for Conservation ofReed Colonies

■Conservation of the Lake'sIndigenous Fish Species

To restore the number of indigenous fish species in the lake, local fishers and related parties annually release fries of nigoro crucian carp (carassius auratus grandoculis), willow minnow (gnathopogon caerulescens) and Biwa trout (onchorhynchus masou rhodrurus).

■Elimination of Introduced Fish SpeciesTo restore and maintain the number of indigenous fish species in the lake, Shiga Prefecture has introduced measures to

eradicate introduced species, or at least control their reproduction. As part of this campaign, in 2002 the Prefecture enacted a fishing regulation for Lake Biwa, which prohibits catch-and-release of large-mouth bass (micropterus salmoides) and bluegill sunfish (lepomis macrochirus).

In 1992, Shiga Prefecture enacted the Ordinance for Conservation of Reed Colonies, since such colonies are effective in sustaining the habitats of various birds and fish species, protecting the lakeshore from erosion and retaining good water quality. The Shiga prefectural government is promoting the creation and conservation of reed colonies by designating several areas as reed colony conservation areas.

Reed Colony Protection and Conservation Areas

Release of Fry

Fish Species of Foreign Origin Constitute the Majority of a Catch

Shiga Prefecture's Stamp to Promote Lake BiwaFishing Regulation

Lake Biwa Fishing Regulation:effective in and after April 2003

Kohoku Town

Noda-numaOnoe - Ebie

Biwa Town

Nagahama City

Hikone CityNoda Marsh

Inukami River

Sone-numaEchi River

Iba-naiko

Nishi-no-ko

Omihachiman CityMoriyama City

KarasumaPeninsulaKusatsu CityYabase

Otsu City

Ogoto

Katata

BiwakoOhashi Bridge

Takashima Town

Ado River

Adogawa TownHarie

ShinAsahi Town

Hamabun-numaImazu Town

Nukegawa-naiko

Reed Protection AreasThese areas contain reed colonies and ecosystems of particular importance.

Reed Conservation AreasThese areas contain reed colonies of considerable size.

Ordinary Reed AreasOther areas within the reed conservation areas

Do Not Catch-and-releaseLarge-mouth Bass and Bluegill Sunfish.

25

■Preparing and PromotingAction Plans of IndividualBasin Blocs

Citizen Participation and Activities

Residents Committed to EnvironmentalConservation Activity Sub-Basin Blocs

Afforestation Site Planting Seedlings

Agricultural Workshop for Local Residents

Omi Committee Meeting

To promote comprehensive lake preservation initiatives throughout Shiga Prefecture, all seven sub-basin blocs in the Prefecture have prepared and are implementing action plans, led by local citizens.

■Afforestation for Only One EarthCampaign

To pass on the precious earth environment to future generations, this campaign, involving citizens and governmental agencies in Shiga Prefecture as well as from other parts of the world, promotes afforestation along the former riverbed of the Yasu River.

■Mizusumashi (whirligig beetle) PlanIn Shiga Prefecture, local people engaged in agriculture and related businesses

have established a council to promote the Mizusumashi (whirligig beetle) Plan, to promote environmental preservation of Lake Biwa and eco-friendly agriculture, while concurrently seeking to retain agricultural productivity. The major objectives of this plan are water circulation and product recycling, eco-conscious lifestyles and citizen participation in policy making.

■River Improvement PlanTo reflect residents' opinions in river improvement plans, the City and

Regional Development Bureau convenes citizen meetings. At the same time, the Bureau holds meetings of a river improvement plan committee (Omi Committee) comprising experts, representatives of the citizen meetings, and of local governments.

Promoting a wide variety of activities involving citizens

Developing eco-friendly lifestyles and building Lake Biwa conservation networks

○ Developing business activities and lifestyles that impose less burden on environment

○ Building Lake Biwa conservation networks○ Sharing eco-consciousness among all generations

○ Involving more people in activities to reduce environmental impacts

○ Soliciting more people in Lake Biwa conservation campaigns

○ Sustaining conservation plans by coordinating efforts of related governmental organizations

○ Building partnerships with interested parties in and outside Japan

Major Tasks

First Stage Objectives

Major Initiatives

Priorities in Second Phase

Takashima Bloc Kohoku Bloc

Koto Bloc

Higashi-Omi Bloc

Koga BlocKonan Bloc

Otsu-Shiga Bloc

Comprehensive Environmental Preservation Efforts and Specific Measures

【Three categories of common foundations】

《Specific Measures》

26

10

《Specific Measures》

Increasing friendly exchange opportunities and establishing easy-to-access networks

Sharing information and promoting friendly exchanges

○ Increasing staff exchange opportunities○ Sharing basic information○ Establishing easy-to-access networks

○ Creating extensive networks for Lake Biwa environmental preservation, involving individual citizens, enterprises and governmental agencies

Information Sharing and Staff Exchange Promotion

Citizens Participating in Dandelion Survey

■Shiga Environmental Business ExhibitionThe Shiga Environmental Business Exhibition, a trade

fair of environmental business, displays eco-friendly products and technologies developed through partnerships between industry, universities and governments so as to develop new industries in the 21st century. The Exhibition is held annually in November. The fifth event, held in 2002, featured over 200 booths of Japanese and overseas enterprises, organizations, universities, and research institutes, all attracting over 40,000 visitors, including the general public.

Omi Citizen Activities

Shiga Environmental Business Exhibition

■Omi Network CenterAmid the worldwide trend of surging citizen activities,

including volunteer activities and NPO projects, citizens of Shiga Prefecture are becoming more and more active in environmental and community development campaigns.

The Omi Network Center, established in 1997, supports such citizen and NPO activities by offering information and opportunities to exchange staff and members, develop leaders and invigorate various activities.

The Lake Biwa Museum, opened in 1996, provides opportunities to exchange and share information. To fulfill its founding mission as a meeting place of people and information, the Museum holds various events, including workshops and field surveys for the general public.

■Friendly Exchanges and InformationSharing by the Lake Biwa Museum

Lake Biwa Museum holds observation and survey workshops on specific themes, recruiting citizens as field reporters.

Major Tasks

First Stage Objectives

Major Initiatives

Priorities in Second Phase

27

Program DetailsFiscal Year

○Problems related to the monitoring of water quality were identified and solutions were sought.

○Indices were selected for evaluating efforts to preserve natural ecosystems and landscapes; studies of monitoring techniqueswere conducted.

○A symposium was held on the theme "Lake Biwa comprehensive conservation program involving all citizens."

○Problems related to the monitoring of soil recharge capacity were identified. Solutions were sought regardingpromotion of comprehensive conservation of the lake, particularly in terms of organizational structures and practical measures.

○The comprehensive lake conservation program was reported at the 9th World Lake Conference.

1999

2000

2001

《Specific Measures》

Research and Survey

Promoting systematic monitoring and survey activities

Promotion of systematic research and survey ○ Promotion of monitoring surveys and establishment of comprehensive water quality control systems

○ Establishment of survey and research systems○ Promotion of the "Environmental Information Center"

plan○ International collaboration on the theme of ancient lakes

■Survey to Promote Comprehensive Preservation of Lake BiwaIn 1997 and 1998, six governmental agencies responsible for Lake Biwa conservation jointly conducted a comprehensive survey

of the lake. Based on the survey result, a further survey program was developed and initiated in fiscal 1999.

■Research and Survey by the Lake Biwa Research Institute

The International Lake Environment Committee (ILEC) established a science committee comprising the world's leading scientists. On the basis of the committee's suggestions the ILEC develops various activities worldwide, including collection and dissemination of lake related information, and environmental education and training. The ILEC is establishing and promoting sound management systems for lakes worldwide, incorporating the outcomes of World Lake Conferences, held nine times to date, including first and ninth meetings in Shiga Prefecture.

■International Survey and Research by theInternational Lake Environment Committee (ILEC)

Committee Meeting

Autonomous Underwater Vehicle “tantan”

○ Promotion of monitoring survey○ Establishment of collaboration networks

The Lake Biwa Research Institute, a center of scientific and managerial research on Lake Biwa established by Shiga Prefecture, is committed to studies of various environmental challenges in Lake Biwa and its catchment. The Institute's activities include:

Estimating the impact of unsteady influent load on lake water qualityThe Institute has prepared a simulation model to estimate the impact of unsteady

(especially at time of rain) influent from the land on the lake's water quality, to seek ideal measures for addressing influent load from non-point sources, thereby to improve water quality.

Long-term estimation of the lake's environmentUsing an autonomous underwater vehicle “tantan”, the Institute is monitoring

environmental changes in the lake’s northern section to prepare a long-term environmental change prediction model.

Studies of biodiversity in Attached lakesThe Institute conducts fieldwork concerning aquatic organisms and vegetations in

Attached lakes, to prepare Attached lake preservation measures with the aim of preserving Lake Biwa's indigenous biodiversity.

Major Tasks

First Stage Objectives

Major Initiatives

Priorities in Second Phase

Comprehensive Environmental Preservation Efforts and Specific Measures

28

10

The 9th Conference was held with the objectives of exchanging views on various challenges currently confronting the world's lakes, seeking solutions to problems of lakes and other freshwater bodies in the 21st century, and building partnerships among researchers, administrators, citizens and businesspersons. On the final day of the Conference, participants adopted Biwako(Lake Biwa) Declaration 2001, which incorporates the spirit of the Conference, as well as its outcomes.

Partnerships for Sustainable Life in Lake Environments: 　　Making Global Freshwater Mandates WorkShiga Prefectural Government, International Lake Environment Committee (ILEC)Ministry of Health, Labour and Welfare; Ministry of Land, Infrastructure and Transport, Ministry of Environment, J-water Garden, Otsu CityNovember 11 (Sun) - 16 (Fri), 2001 (6 days)Biwako Hall and other venues in Shiga Prefecture●Plenary sessions, comprising keynote lectures by leading researchers●Lake Biwa session, featuring discussions on environmental preservation of the lake and

specific action plans●Sub-sessions to discuss content of presentations●Free meetings organized by NGOs and enterprisesA total of approximately 55,000 people from 75 countries

Water is life; lakes are vital for life on earth. Lakes support diverse ecosystems, river systems and cultures.Lake environments are in crisis. The harmonious relationship needed between humans and nature in lake

environments continues to be disrupted and has even deteriorated, despite the Biwako (Lake Biwa) and Kasumigaura Declarations of 1984 and 1995.

We can only protect lakes by looking critically at the developed countries' lifestyles of the 20th century and recognizing the difficult socio-economic situation of developing countries. Since lakes are precious to all life on earth, we must make renewed efforts conserve and restore lake environments.

The essential precondition for improvement and sustainability of lake environments is collaboration among individuals, organizations and communities to restore harmony between people and nature.

As concerned citizens, artists, administrators, politicians, journalists, scientists, students, NGOs, business and community leaders, we stakeholders have come together again on the shores of Lake Biwa to echo and embrace the spirit of the first world lake conference.

New themes have emerged from the new and diverse voices. We have heard a new emphasis on the conservation of lakes based on ecosystem management, and close connection between lake management, culture, and spirituality.

Understanding the fruits and limitations of this conference and reflecting our deep concern, we call for action.

In particular we must:

1. Build and strengthen partnerships among individuals and organizations within the lake community2. Disclose and share information, and promote environmental education, and build a capacity of people3. Promote scientific research and monitoring4. Promote integrated water resource management of lake and river basin systems 5. Promote international cooperation and establish a global lake alliance 6. Explore new and innovative financial arrangements

9th International Conference on the Conservation and Managementof Lakes (World Lake Conferences)

9th International Conference on the Conservationand Management of Lakes, Biwako2001November 16, 2001

Biwako (Lake Biwa) Declaration 2001

column

Theme：

Organizers： Co-organizers：

Period： Venue：

Programs：

Participants：

29

Lake Biwa session - Love Letter to Lake Biwa Lake Biwa Discussion session [Think of World Lakes on Lake Biwa Experiences]

①Lake Biwa Comprehensive Preservation Liaison Coordination Council(Ministry of Health, Labour and Welfare; Ministry of Agriculture, Forestry and Fisheries; Forestry Agency; Fisheries Agency [joined in fiscal 2002]; Ministry of Land, Infrastructure and Transport; and Ministry of Environment)

Coordinating System

Continuous improvement

The Council was established in July 1999, with the aim of facilitating implementation of Lake Biwa preservation programs by coordinating related regional bureaus of the national government, as well as local governments.

The Council's first meeting was held on July 21, 1999, to determine Council rules, introduce ongoing commitments of respective members, and confirm resolutions to strengthen partnerships among members to facilitate the comprehensive preservation of Lake Biwa.

Implementation of comprehensive lake preservation initiatives calls for constant review and improvement in response to social trends, progress in conservation measures, and changes in public opinions. Such a flexible approach is essential since there are many uncertain elements involved in current conservation initiatives. For one thing, the lake's ecological mechanism is not fully understood; for another, citizens' views regarding environmental preservation can change. Accordingly, responsible bodies regarding lake preservation should continue their commitment to making initiatives more effective and rewarding.

Operation Mechanism

Coordination System

Cooperative Structure of Prefectures in the Lake Biwa Catchment

Cooperative Structure of Municipalitiesin the Lake Biwa Catchment

Cooperative Structure in the Lake Biwa - Yodo River Watershed

(Lake Biwa Comprehensive Preservation Promotion Council)

Cooperative Structure for Ministries and Agencies

(Lake Biwa Comprehensive Preservation Liaison Coordination Council)

●Flexible Operation of Conservation Plans

Research institutions must collaborate to determine the lake's environmental situations and mechanisms in the most effective manner. At the same time, results of observations, surveys, researches and technological development should be reflected in conservation plans in a timely manner.

●Changing Plans to Reflect Results of Observations,Surveys, Researches and Technological Development

Progress and effects of conservation plans should be constantly evaluated. If necessary, the plans should be reviewed in terms of project composition and approaches to specific measures.

Implementing authorities should share information in advance, to promote mutual understanding and support.

In response to the progress of conservation projects and changes in the lake's environment, plans must be constantly reviewed and if necessary revised, together with their targets.

●Reviews Based on Plan Evaluation

●Coordination among Implementing Authorities and Projects

11 Future Progress of Comprehensive Lake Preservation Initiatives

Partnerships andrespect to autonomyof respective members

Citizens/Enterprises SpecialistsGovernments Citizens/Enterprises SpecialistsGovernments

The Council was established in June 1999 with the objective of facilitating implementation of Lake Biwa preservation programs by coordinating related governmental bodies.

The Council's first meeting was held on June 28, 1999, to determine the Council's rules and confirm resolutions for strengthening partnerships among members to facilitate the comprehensive preservation of Lake Biwa.

②Lake Biwa Comprehensive Preservation Promotion Council (Kinki Regional Agricultural Administration Office, Ministry of Agriculture, Forestry and Fisheries, Kinki Chugoku Forest Office, Forestry Agency; Kinki Regional Development Bureau, Ministry of Land, Infrastructure and Transport; Osaka Prefecture, Hyogo Prefecture, Kyoto Prefecture, Shiga Prefecture, Osaka City, Kobe City, and Kyoto City)

Bequeathing a Clean Lake Biwato Future Generations

Implementation (Implementing programs and initiatives)

Management (Evaluating progress and effects

of programs and initiatives)

Evaluation (By implementing authorities

and third parties)

Review (By reflecting views of specialists

and general public)

Knops

(Autonomousimplementation)

Enterprises

Citizens

Governments

(Continuousimprovement)

Specialists

Collaboration

Lake Biwa - Yodo River basin

(Extensive partnerships)

Nationwide, worldwide citizens

Lake Biwa catchments(Key area of continuous improvement)

Preservation of naturalenvironment

and landscapes

Improvement of soil'srecharge capacity

Improvement ofwater quality Participation

Survey andresearch

Informationsharing

Future Progress of Comprehensive Lake Preservation Initiatives

30

11

12 Chronological Table of Lake Biwa

B.C.10000

8000

6000

3000

2000

200

A.D.28

250

646

667

672

710

742

794

905

1065

1192

1428

1455

1467

1500

1575

1576

1582

1587

1600

1603

1672

1802

1846

1868

1869

1872

1874

1878

1890

1893

1896

1905

1912

1913

1914

1919

1921

19251941

1944

1949

Year Major Incidents in Japan Major Incidents in Lake Biwa Basin

Old Stone Age

Jomon

Yayoi

Asuka

Nara

Heian

Kamakura

Muromachi

Azuchi-Momoyama

Edo

Meiji

Taisho

An ancient lake was formed in the Iga Ueno region in Mie Prefecture.

Stone spear points and tools discovered around Lake Biwa

Various Jomon period ruins discovered around Lake Biwa

Yayoi Period ruins discovered around Lake Biwa

The capital was relocated to Omi.

Bronze bell-shaped vessels unearthed from ruins in Yasu

The ice age with several intervals

The Japanese Archipelago becameseparated from the Eurasian Continent.

Taika coup

Jinshin civil war

The capital was relocated to Omi (Otsu capital) for a short period.

The capital was relocated to Nara.

A new capital was constructed in Shigaraki (Shigaraki capital).

The capital was relocated to Kyoto.

Issuance of Engishiki

A port in Omi was renamed Otsu.

Rice was transported to the capital from northern countries via the lake.

Taira-no-Kiyomori planned to construct a canal between Shiozu and Tsuruga, in vain.

Kamakura Shogunategovernment was established.

Onin civil war

Farmers' riots

Shogunate government collected tax from ships sailing on the lake.

Omi hakkei (eight scenic landscapes of Omi) were selected.

Honnoji incident

Sekigahara battle

Oda Nobunaga constructed a bridge across the Seta River.

Oda Nobunaga began constructing Azuchi castle.

Asano Nagayoshi approved free navigation on the lake.

Edo Shogunate government was established.

Westward navigation route opened.

Construction of Hikone castle began. Tokugawa Ieyasu surveyed farmland in Omi.

Water transport on the lake declined due to development of the westward navigation route.

Extensive flooding of Lake Biwa

Extensive flooding of Lake Biwa

Meiji Restoration

Issuance of the former River Law

Extensive flooding in Shiga Prefecture (+3.3 m)

A steamship began service on the lake.

Shiga Prefecture was established.

A water gauge was installed at the Torii River.

Disaster prevention project began in the Seta River basin.

The first Lake Biwa Canal incline was completed.

Hikone meteorological observation station opened.

Extensive flooding of Lake Biwa (+3.76 m)

The Yodo River improvement project began.

Nango Araizeki weir was completed.

The second Lake Biwa Canal was completed.

Outbreak of World War I

Issuance of Public Waters Reclamation Law

Outbreak of World War II (Pacific War)

Uji River power plant was completed.

Kyoto University opened lakeside observation station in Otsu.

Mt. Ibuki meteorological observation station began operation.

The first public beach opened in Otsu.

Shiga Prefecture decided upon reclamation of several inland lakes.

Biwako hakkei (eight scenic landscapes of Lake Biwa) were selected.

Approximately4 million years agoApproximately1 million years agoApproximately400,000 years ago10,000 - 15,000 years ago

Showa

Lake Katata was formed around Katata.

Lake Biwa was formed at the present lake site.

31

1950

1952

1958

1960

1961

1962

1964

1967

1968

1969

1970

1971

1972

1973

1974

1977

1979

1981

1982

1983

1984

1985

1986

1987

1990

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Partial revision of Special Law for Developing Lake Biwa

Region (5-year extension)

The Earth Summit

Enactment of Basic Environmental Law

Serious water shortage throughout Japan

Great Hanshin-Awaji Earthquake

Termination of Special Law for Developing Lake Biwa Region

Revision of River Law

Lake Biwa was designated first quasi-national park in Japan.

Yodo River water control project first-phase completed (water level: -1 m)

Establishment of Liaison Council to Prevent Water Contamination of the Yodo River

Fish in Lake Biwa were contaminated by PCP from agricultural chemicals.

Seta River Araizeki weir completed.

Bio-resource survey began in Lake Biwa.

Biwako Ohashi Bridge and Amagase Dam were completed.

Reclamation of Dainaka-no-ko Lake was completed.

Biwako Fair was held.

Shiga Prefecture enacted Anti-pollution Ordinance.

Complaints of musty odor in tap water were filed in Kyoto City.

Complaints of odor in tap water were filed by about 400 citizens in Kyoto, Otsu and Osaka.

Lake Biwa Comprehensive Development Promotion Council was established.

Entire Lake Biwa region was designated a wildlife sanctuary.

Environmental standard was introduced to Lake Biwa.

Shiga Prefecture enacted Natural Environment Preservation Ordinance.

Omi Ohashi Bridge opened.

Uroglena (vegetable plankton) spread over the lake.

Shiga Prefecture enacted Lake Biwa Eutrophication Prevention Ordinance

Yasu River Drainage Canal opened.

Shiga Prefecture adopted environmental impact assessment guidelines.

Shiga Prefecture established Lake Biwa Research Institute.

Shiga Prefecture school ship “Uminoko” began operation.

Blue-green algae blooms spread over southern lake for the first time.

Shiga Prefecture enacted Landscape Preservation Ordinance.

Shiga Prefecture held the first World Lake Conference.

Lake Biwa was designated a target of the Special Law for Preserving Lake Water Quality.

International Lake Environment Committee (ILEC) was established.

Lake Biwa Water Quality Conservation Plan was finalized.

Showa

Heisei

Year

Comprehensive National Land Development Act

Enactment of the Sewage Law, Public Water Quality Preservation

Law, and Industrial Effluent Water Law

Enactment of two laws concerning water source development

Enactment of New River Law

Tokyo Olympic Games

Enactment of Basic Law for Environmental Pollution Control

Enactment of Water Pollution Control Law

EXPO'70 was held in Osaka.

Enactment of Special Law for Developing Lake Biwa Region

The 1st oil shock

The 2nd oil shock

Partial revision of Special Law for Developing Lake

Biwa Region (10-year extension)

Enactment of Special Law for Preserving Lake Water

Quality

Master Plan for Environmental Management of Yodo River System was finalized.

The 2nd Water Quality Conservation Plan for Lake Biwa was finalized;

Shiga Prefecture enacted Reed Colony Conservation Ordinance.

Lake Biwa was registered with the Ramsar Convention on Wetlands.

Lake Biwa - Yodo River Water Quality Preservation Organization was established.

Blue-green algae blooms spread over northern lake for the first time; water

level declined to -123 cm on September 15, 1994.

UNEP established the International Environmental Technology Center.

Shiga Prefecture enacted the Basic Ordinance Concerning the Environment and the

Ordinance to Promote Domestic Wastewater Measures. Lake Biwa Museum opened.

The 3rd Water Quality Conservation Plan for Lake Biwa was established.

Surveys initiated to introduce Lake Biwa Comprehensive Conservation Plan.

World Ancient Lake Conference.

Lake Biwa Comprehensive Development Program was terminated.

Action Plans for Conserving Water Quality of Lake Biwa were finalized.

Shiga Prefecture enacted Environmental Impact Assessment Ordinance.

Surveys to introduce Lake Biwa Comprehensive Conservation Plan were completed.

Establishment of Lake Biwa Comprehensive Preservation Liaison Coordination and

Lake Biwa Comprehensive Preservation Promotion Council

G8 Summit of Environmental Ministers was held in Otsu.

Shiga Prefecture finalized Mother Lake 21 Plan.

The 9th World Lake Conference was held.

The 4th Water Quality Conservation Plan for Lake Biwa was finalized.

Shiga Prefecture enacted Lake Biwa Sport Activities Control Ordinance.

The 3rd World Water Forum was held.

Major Incidents in Japan Major Incidents in Lake Biwa Basin

Chronological Table of Lake Biwa

32

12

Lake Biwa Comprehensive Preservation Initiatives― Seeking Harmonious Coexistence with the Lake's Ecosystem ―�

(March 2003)

2-1-3 Kasumigaseki, Chiyoda-ku, Tokyo 100-8918TEL ：03-5253-8111 (ex. 32-323)E-mail ： daisei@mlit.go.jpHP ： http://www.mlit.go.jp

Lake Biwa Comprehensive Preservation Liaison Coordination Council

Office/ Metropolitan Areas Development Division, City and Regional Development Bureau, Ministry of Land,

Infrastructure and Transport

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