Bequeathing a Clean Lake Biwa to Future Generations
Lake Biwa Comprehensive Preservation Initiatives
― Seeking Harmonious Coexistence with the Lake's Ecosystem ―
Lake Biwa Comprehensive Preservation Liaison Coordination Council Lake Biwa Comprehensive Preservation Promotion Council Contents
1 Overview of Lake Biwa and the Yodo River Basin ○ Overview of the Yodo River Basin 1 ○ Water Use in Lake Biwa and the Yodo River Basin ○ Land Use in Lake Biwa and the Yodo River Basin
2 Overview of Lake Biwa ○ Lake Biwa, an Ancient Lake 2 ○ Dimensions of Lake Biwa
3 Development of Lake Biwa and the Yodo River Basin ○ Early History 3 ○ 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
4 Background of Lake Biwa Comprehensive ○ Farmland Development and Flooding in the Edo Period (1603 - 1868) 5 Development Program ○ 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 Lake Biwa Comprehensive Development Program ○ Program System 7 ○ Breakdown of the Program Expenses ○ Environmental Preservation ○ Flood Control ○ Promotion Effective Water Use
6 Outcomes of the Lake Biwa ○ Effects of Flood Control Projects 9 Comprehensive Development Program ○ Effects of Projects Promoting Effective Use of Water ○ Effects of Environmental Preservation Projects
7 Current Situation of Lake Biwa ○ Land Use around the Lake 11 ○ Water Quality of Lake Biwa ○ Lake Biwa Water Quality Map ○ Eutrophication of Lake Biwa ○ Reed Colonies ○ Attached Lakes (naikos) ○ Lake's Ecosystems
8 History of Lake Conservation Efforts ○ Freshwater Red Tides 15 ○ 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
9 Survey for Preparing Lake Biwa ○ Background 17 Comprehensive Conservation Plan ○ Guiding Principle and Key Concepts of the Comprehensive Conservation Plan ○ Objectives and Period of the Comprehensive Conservation Plan ○ Promoting Partnerships
10 Comprehensive Environmental Preservation ○ Protecting Water Quality 19 Efforts and Specific Measures ○ 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) 11 Future Progress of Comprehensive ○ Continuous Improvement 30 Lake Preservation Initiatives ○ Coordinating System
12 Chronological Table of Lake Biwa 31 ①The Grandeur of Mt.Shizugatake
②The Granite Cliffs at Kaizuosaki
③Subtle Reflection of Chikubu Island
⑤The White Beach of Omatsuzaki ①
② ③
④The Old Castle in Hikone
④
⑤
⑥
⑦⑦ForestForest on Mt.Hiei ⑦
⑧
⑥A Water District with a Tiny Inlet in Azuchi-Hachiman
⑧The Crystal-clear Water in Seta, Ishiyama
Biwako Hakkei (Eight Scenic Places in Omi) selected in 1949. 1 Overview of Lake Biwa and the Yodo River Basin
1 Overview of Lake Biwa and the Yodo River Basin
Overview of the Yodo River Basin
Fukui The Yodo River, flowing into Osaka Bay, originates in Lake Yogo
mountains in and around Shiga Prefecture. After flowing Ado River out of Lake Biwa, the river travels southward down to the TakatokiAne River River Sonobe Shiga Osaka Plain, combining several branches of various sizes River Lake Biwa
including the Kizu and the Katsura rivers. The Yodo River Okinoshima Island Seri River Hyogo Hitokuraoroji Kyoto Uso River
Echi River changes names during its long travel: the upper and middle River Katsura River Kamo River Kyoto City Gifu Kusatsu Hino River reaches are called the Seta and the Uji rivers, respectively. River
Ina River Otsu City Yasu River The Yodo River basin constitutes an extensive area of Seta River Araizeki Weir Uji River 2 Daito River approximately 8,240 km , covering the six prefectures Mie, Kanzaki River Kizu River Yodo River Yodo River Shiga, Kyoto, Osaka, Hyogo and Nara. Ozeki Weir Osaka Bay Osaka City Old Yodo River
Nabari River Mie Nara Osaka Nunome River
Uda River Shorenji River
Water Use in Lake Biwa and the Yodo River Basin Legend Lake Biwa supplies water for various uses: domestic, Lake Biwa Basin industrial and agricultural uses, and for power generation. Yodo River Basin Water of Lake Biwa and the Yodo River supports social and River economic activities not only in their respective basins, but Urban Area also in extensive areas in the Kinki region. Notably, tap Lake Biwa and Yodo River Basin 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 Shiga 10.1 dams is mainly used in Shiga Prefecture; in the middle Prefecture Kyoto 17.9 reaches, water is taken from Biwako Canals and the Uji Prefecture Osaka 85.3 River primarily for use in Kyoto City; in the lower reaches, Prefecture water from the Yodo River serves the huge population of Hyogo 26.1 Prefecture Osaka and other cities on the Osaka Plain. 020 40 60 80 100 ［million people］
Population Using Tap Water from Lake Biwa/Yodo River (Water service in fiscal 1994) Land Use in Lake Biwa and the Yodo River Basin 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.
1992 1955
1895
0 10 20 30 40km
Legend Municipality Forests Farm Land Urban Areas Unidentified Areas (Source: Lake Biwa Museum) Water Areas Changes in Land Use in Lake Biwa and Yodo River Basin 1 Overview of Lake Biwa 2
2 Overview of Lake Biwa
Lake Biwa, an Ancient 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 Baikal Lake Tanganyika Lake Biwa
Age Approx. 30 million Approx. 20 million Approx. 4 million years old years old years old Lake Baikal Lake Surface 2 2 2 Area 31,500km 32,600km 674km
Maximum Depth 1,637m 1,471m 104m Lake Biwa Lake Tanganyika The Equator Average Depth 740m 572m 41m
Water Storage 3 3 3 Capacity 23,000km 18,880km 27.3km
No. of Species Approx. 2,500 Approx. 1,300 Approx. 600 Lake Malawi Living in Lake
Rate of Endemic Approx. 50% Approx. 50% Approx. 10% Species (Source: "Ancient Lakes" in Lake Biwa Museum) Location and Characteristics of Three Oldest Lakes in the World
Dimensions of Lake Biwa Ground Plan
The surface area of Lake Biwa, Japan's largest lake, is Ibuki Mountains 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 Mt. Kanekuso narrowest point, it is spanned by Biwako Ohashi Bridge. 1,271m The lake's section north of the bridge is called "Hokko" (northern lake) and that south of the bridge is called Ado River Ane River "Nanko" (southern lake); Hokko and Nanko differ in Mt. Ibuki 1,377m character in various aspects. Mt. Buna Amano River Lake Biwa There are approximately 460 rivers of various sizes flowing 1,214m into the lake. There is, however, only one outflow from the Mt. Ryosen Inukami River 1,084m lake (the Seta River), apart from canals constructed during Echi River early modern times. It is estimated that approximately Hira Mountains Suzuka Mountains Mt. Mikuni 815m Mt. Hiei Hino River 19 years are required to change all water in the lake. 848m Yasu River Shiga Prefecture Land Area 4,017km2 Seta River 2 Lake Biwa Catchment Area 3,174km Araizeki Weir Mt. Gozaisho Lake Surface Area 2 674km Daito River 1,210m (Northern Lake:Southern Lake = 11:1) Shoreline 235km 3 Mountain Storage Capacity 27.3km Average Depth 41.2m Hill Maximum Depth 103.6m Flatland Length (North - South) 63.5km Maximum Width 22.8km Minimum Width 1.35km
Seta River Araizeki Weir Cross Section Amagase Dam Biwako Ohashi Bridge
Lake Biwa
Osaka Bay
(Source: The House of Water Benevolence “Aqua-BIWA”)
2 3 Development of Lake Biwa and the Yodo River Basin
Early History 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.
●Dainaka-no-ko lake ruin During 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 Shiga Prefectural Museum of Azuchi Castle and Archaeology) (Courtesy of Lake Biwa Development Integrated Operation Rice Cultivation During the Yayoi Period & Maintenance Office, Water Resources Development) Clay Pot Unearthed from Dainaka-no-ko Lake Ruin
Expanded Farmlands, Increased Rice Production and Subsequent Development of Commerce
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.
A Political Center and Cradle of Culture and Tradition
Since ancient times, the Lake Biwa region played an Sails Returning to Evening Snow Yabase Port essential role in Japan's political scenes, as well as in on Mt. Hira agriculture and commerce. In 667, Japan's capital was Descending Geese relocated to Otsu; in 1579, Azuchi Castle was at Katata
constructed on a hilltop commanding the view of the Evening Snow on Mt. Hira lake. For several subsequent years, Azuchi was Japan's political and economic center.
Along with the development of transport, Lake Biwa Descending Geese became well known for its scenic beauty. Many poems at Katata depicting the lake's landscapes appear in Manyoshu, the Evening Rain at Karasaki Sails Returning to Evening Bell from Miidera Temple Yabase Port earliest extant anthology in Japan, and other collections Clearing Mist at Awazu Sunset Glow of poems. During the Muromachi Period (1333 – 1573), Autumn Moon over Ishiyama Temple over Seta a nobleman named Konoe Masaie selected Omi Hakkei (The Eight Scenic Beauties in Omi) modeled on Sunset Glow Shousyou Hakkei in the Dongting Lake of China. Omi over Seta Hakkei were subsequently depicted by Ando Hiroshige, Evening Rain at a ukiyoe (woodblock print) artist, and his works became Karasaki extremely popular, promoting the scenic beauty of Lake Evening Bell from Biwa throughout Japan. Miidera Temple Clearing Mist at In this way, Lake Biwa has continuously benefited Awazu Autumn Moon over Japanese people spiritually as well as economically, Ishiyama Temple inspiring artists and nurturing various cultures and (Courtesy of Otsu City Museum of History) traditions. Omi Hakkei (eight scenic places in Omi)
3 Development of Lake Biwa and the Yodo River Basin 3
Industrial and Economic Development after the Meiji Restoration 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.
(Courtesy of Otsu City Museum of History) (Courtesy of Yodogawa Construction Office, Kinki Regional Development Bureau, Lake Biwa Steamship Ministry of Land, Infrastructure and Transport) Steamboat on the Yodo River
Changing Lifestyles 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.
4 4 Background of Lake Biwa Comprehensive Development Program
Flood Damage in the Edo Period (1603 - 1868) 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.
Daido River Daido River Koyama River Koyama River
Mt.dainichi Mt.dainichi
Seta River Seta River Current Araizeki Current Araizeki Weir Weir Senjyo River Senjyo River (Courtesy of The House of Water Benevolence “Aqua-BIWA”) Map of the Seta River Map of the Seta River Before Tenpo Dredging After Tenpo Dredging Flood Control During the Meiji Period (1868 - 1912) 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.
(Courtesy of Otsu City Museum of History) Extensive Flooding of September 1896
(Courtesy of Yodogawa Construction Office, Kinki Regional Development Bureau, (Courtesy of The House of Water Benevolence “Aqua-BIWA”) Ministry of Land, Infrastructure and Transport) Nango Araizeki Weir Civil Engineer Johannis de Rijke 5 Background of Lake Biwa Comprehensive Development Program 4
Modern Projects for Using Water of Lake Biwa 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.
(Courtesy of Otsu City Museum of History) Lake Biwa Canal
(Courtesy of the Yomiuri Shimbun) (Courtesy of the Yomiuri Shimbun) Japan’s First Streetcar Keage Power Plan
Increasing Demand for Water in the Showa Period (1926 - 1989) 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.
(million people) 20
15
10
5
0 19551960 1965 1970 1975 1980 1985 1989 1994
(Courtesy of Osaka Municipal Waterworks Bureau) Users of Water Service from the Yodo River System Land Subsidence (Lake Biwa and the Yodo, Katsura and Kizu rivers)
6 5 Lake Biwa Comprehensive Development Program
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.
Project Name
Sewage Systems Program System Night Soil Treatment The major objectives of the Lake Biwa Water Quality ＊ Livestock Waste Treatment Conservation Comprehensive Development Program ＊ Agricultural Community Drainage Facilities were conservation and restoration of the Environmental ＊ Waste Treatment Facilities Preservation ＊ Water Quality Monitoring Stations lake's environment, including water quality; City Parks flood control of Lake Biwa and the Yodo Natural Park Facilities River; and promotion of effective use of Natural Environment Acquisition of Nature Conservation Areas Conservation water. Road Improvement Port Improvement Lake Biwa Rivers Comprehensive Flood Control of Development Inflowing Rivers Dams Program Flood Control Erosion Control Enhancement of Soil's Afforestation and Forestry Roads Recharge Capacity Forest Conservation Breakdown of the Program Expenses Flood Control of Lake Lake Biwa Flood Control and The Program encompassed various Water Resource Development Downstream projects in 22 categories, all contributing Promotion of Water Use to sound development of the Kinki region. Effective Water Use Domestic Water Supply Water Use in The total budget amounted to approx. Industrial Water Supply Shiga Prefecture 1,863 billion yen; when the Program was Land Improvement fully completed, actual expenditures reached 1,905 billion yen. Fisheries Fisheries Fishery Ports *: Projects added at the time of revision of the appropriate law in 1982 Systems of Lake Biwa Comprehensive Development Program
7 Lake Biwa Comprehensive Development Program 5
Special Financial Measures
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 Government The 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 Basin The 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 Fund To 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.
Environmental Preservation Flood Control
To enable continuous To control occasional monitoring of water quality, an flooding of the Yasu River, automatic monitoring station which previously diverged into was constructed inside the lake. two branches at Shinjo, This station is linked with a Moriyama City, a drainage canal central station on land, was constructed that combines equipped with a telemeter the previously diverging water receiver and an information flow and discharges water Water Quality Monitoring Station processing system. Yasu River Drainage Canal directly into Lake Biwa.
The sewage treatment plant To prevent flooding, the was constructed to restore the lake’s shoreline was embanked water quality of Lake Biwa and an administrative road was and improve the regional constructed on the embankment. living environment. The plant At the beach inside the was the first to introduce an embankment, reeds were planted advanced treatment system to restore the reed colony that effective in removing nitrogen once characterized the lake’s and phosphorus from landscape. In addition to wastewater, so as to prevent administrative purposes, the the lake's eutrophication. ［Kusatsu District］ administrative road is used by Konan-chubu Sewage Lakeshore Embankment, Administrative local residents and tourists. Treatment Plant Road and Artificially Planted Reeds Promotion of Effective Water Use
Improvement of the Seta River Araizeki WWeireir (Bypass Canal) Effective Use of Water in Shiga Prefecture:Prefecture: for Promoting WWaterater Use in Lower Basin Mabuchi Purification Plant This bypass canal was Japan's first large-scale facility for controlling For communities around Lake Biwa, an extensive water supply system water flow. A hydroelectric power plant was constructed by the canal, was launched by purifying water from the lake. This new system was for effective water use. effective in supplying water particularly in times of drought, as well as in improving public hygiene and the living environment.
8 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 Houses
incorporated in the Program, 11 concerned environmental 1965 - 1974 conservation, which aimed to improve living and natural 1975 -1984 1965 - 1974 21) 1985 - today environment.
Effects of Flood Control Projects 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. 1975 -1984 For instance, the Program has significantly mitigated damage from flooding in terms of both flooded area and 1985 - today number of houses inundated above and below floor level. (July 1972) Number of Houses Inundated above/below Floor Level (May 1995)
Max. precipitation Precipitation and Number of Houses Inundated above/below Floor Level in Shiga Prefecture
Comparison of Damage from Flooding Factors Flooding in July 1972 Flooding in May 1995 Max. precipitation 424 mm 435 mm Precipitation Location of max. precipitation Yanagase, Yogo Town Tochu, Kutsuki Village Average precipitation in basin 320 mm/5 days 297 mm/13 days Max. water level ＋92cm ＋93cm Area flooded by Lake water 3,377ha 742ha Number of houses inundated above/below floor level (Shiga Prefecture) 755 houses 7 houses
Water Taken from Lake Biwa Effects of Projects Promoting Effective Use of Water Tap Water Industrial Agricultural Other Total Increase by Water Water Development Program
As a result of the Lake Biwa Comprehensive Development 3 m /s Approx. 210 m3/s Program, daily supplied water volume increased significantly, 200
securing a steady water supply for domestic and industrial 180 uses throughout the basin. When dry weather continued from July to September 160 Shiga Prefecture 1994, for instance, the lake's water level fell to -123 cm, 140 the lowest record in the history of the lake's observation. 120 However, the water intake control period was extremely Kyoto 100 Prefecture short compared with the period prior to Program implementation. 80 60 Osaka Prefecture 40
20 Hyogo Prefecture 0 1942 1960 1972 1992 Before Lake Biwa After Lake Biwa Comprehensive Comprehensive Development Program Development Program (Source: data from Lake Biwa Development Integrated Operation & Maintenance Office, Water Resources Development Public Corporation) Effects of Projects to Promote Effective Use of Water
9 Outcomes of the Lake Biwa Comprehensive Development Program 6
Precipitation(mm) 0 20 40 60 Average precipitation in Lake Biwa basin 80 100
Water level(cm) 50 Standard maximum Maximum water level Standard maximum water level between June 16 and water level October 15
1st phase water intake control 0 (Jul. 31, 1973: -36 cm)
2nd phase water intake control (Sept. 4, 1973: -53 cm)
–50
Lifting of 1939 control 1873 (Oct. 4, 1994: -48 cm)
Legend 1994 –100 1st phase water intake control Mitigation of control to (Aug. 22, 1994: -94 cm) 2nd phase level Temporary lifting of control: 3:00 P.M., Sept. 16, 2nd phase water intake control (Sep. 27, 1994: -88 cm) 1994 - 3:00 P.M., Sept 19, 1994 (Sept. 3, 1994: -108 cm) Temporary lifting of control from 5:00 P.M., 3rd phase water intake control Lowest water level Sept. 29, 1994 (Sept. 10, 1994: -116 cm) (Sept. 15, 1994: -123 cm) –150 123456779101112(month) Comparison of Lake Water Level
（％） BOD Sewage service coverage rate （mg/l） Effects of Environmental Preservation Projects 50 Rivers flowing into Southern Lake and Seta River 5.0 45 Rivers flowing into east section of Northern Lake 4.5 Rivers flowing into west section of Northern Lake Despite increase in the population of Lake Biwa's 40 4.0 catchment, its water quality has significantly improved as a 35 3.5 result of water quality conservation projects, including 30 3.0 construction/improvement of sewage treatment plants, 25 2.5 20 2.0 livestock waste treatment facilities, agricultural community 15 1.5 drainage facilities and waste treatment plants. These 10 1.0 Sewage Service Coverage Rate projects were particularly effective in improving water in 5 0.5 0 0.0 rivers into the Southern Lake, thereby mitigating 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 Fiscal year eutrophication.
To enable citizen access to the lake, city parks and （％） T－N Sewage service coverage rate （mg/l） natural parks were constructed along the shoreline. In 50 Rivers flowing into Southern Lake and Seta River 4.0 Rivers flowing into east section of Northern Lake 45 addition, governments of various levels purchased strategic Rivers flowing into west section of Northern Lake 3.5 40 3.0 lakefront areas to preserve outstanding scenic beauty, as 35 well as the lake's indigenous natural environment. 30 2.5 25 2.0 20 1.5 15 1.0 10 2 ha (m /person) Sewage Service Coverage Rate （ ） 695.0 5 0.5 700 6.00 0 0.0 Shiga Prefecture 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 Fiscal 600 573.8 5.51 year Lake Biwa Comprehensive 5.00 Development Program Parks 4.75 500 Sewage service coverage rate Per capita park area 4.00 （％） T－P （ g/l ） Rivers flowing into Southern Lake and Seta River 400 50 450 Rivers flowing into east section of Northern Lake 3.00 45 400 300 273.4 Rivers flowing into west section of Northern Lake 2.58 40 350 2.51 2.00 35 200 173.3 300 30 130.7 250 92 1.00 25 100 200 25 20 0 150 0 0.00 15 Fiscal 1971 Fiscal 1981 Fiscal 1991 Fiscal 1995 10 100
Sewage Service Coverage Rate 5 50 (Note) Per capita park area = city park area / population in urban district 0 0 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 Fiscal year City Park Area in Shiga Prefecture River Water Quality and Sewage Service Coverage Rate
10 7 Current Situation of Lake Biwa
Land Use around the Lake The catchment area of Lake Biwa reaches 3,174 km2, the majority belonging to Shiga Prefecture, the remainder to Kyoto Prefecture. Land use Total land area: 4,017 km2 in the catchment has been changing, driven by increasing population, (About 1% of national total)
ongoing urbanization and changing industrial structures. Residential Today, forests comprise about half the total land area of Shiga Prefecture; and other areas farmlands, mainly comprising paddy fields, comprise less than one-seventh Farmlands 14％ Forests of the total land area. 15％ 51％ Forests and farmlands are helpful for conserving the lake's environment, Lake Biwa, rivers, and other since they recharge ground water, prevent sand/soil erosion and water bodies retain/purify water. The area of forests and farmlands, however, is 20％ 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 in Shiga Prefecture
105 National average 105 National average Shiga Prefecture Shiga Prefecture 100 100 95 95 90 85 90 80 85 75 1972 1975 1978 1981 1984 1987 1990 1993 1996 2000 Fiscal 1972 1975 1978 1981 1984 1987 1990 1993 1996 2000 Fiscal year year 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)
Water Quality of Lake Biwa 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.
（m） Changes in Transparency （mg/L） Changes in T-N Levels 8.0 0.5 Southern Lake 6.0 Northern Lake 0.4 0.3 4.0 Northern Lake 0.2 Southern Lake Environmental Standard 2.0 0.1 0.0 0.0 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)
（mg/L） Changes in COD Levels （mg/L） Changes in T-P Levels 4.0 0.04 Southern Lake 3.0 0.03 Southern Lake 2.0 Northern Lake 0.02 Environmental Standard 1.0 0.01 Environmental Standard Northern Lake 0.0 0.00 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) (Source: "Environmental White Paper" by Shiga Prefecture) Changes in Water Quality of Lake Biwa
11 Current Situation of Lake Biwa 7
Lake Biwa Water Quality Map 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. Transparency COD Total Nitrogen Total Phosphorus (T-N) (T-P)
Below 2 Over 3.5 Over 0.5 Over 0.025 2~3 3.5~3.0 0.5~0.4 0.025~0.020 3~4 3.0~2.8 0.4~0.35 0.020~0.015 4~5 2.8~2.5 0.35~0.3 0.015~0.012 5~6 2.5~2.3 0.3~0.25 0.012~0.008 Over 6 (mg/R) (mg/R) Below 0.008 (m) (mg/R) (Source: "Environmental White Paper" by Shiga Prefecture) Lake Biwa Water Quality Map (Annual Average Values of Fiscal 2001) Eutrophication of Lake Biwa 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.
Freshwater Red Tides From late April to early June, when the water temperature is between 15 - 20ûC, 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. 20
15
10
Number of Days 5
0 1969 1974 1979 1984 1989 1994 2001 Fiscal (Source: "Environmental White Paper" by Shiga Prefecture) year Freshwater Red Tide Occurrence of Freshwater Red Tide (Days)
Blue-green Algae Blooms 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. 35 30 25 20 15 10 Number of Days 5 0 1969 1974 1979 1984 1989 1994 2001 Fiscal (Source: "Environmental White Paper" by Shiga Prefecture) year Blue-green Algae Blooms Occurrence of Blue-green Algae Blooms (Days)
12 Reed Colonies 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. （ha） 300
261ha 200
100 128ha
0 1953 1992 (Source: "Report of the Survey for Lake BiwaComprehensive Development Program in Fiscal 1953" by Shiga Prefecture; Lakeside Reed Colony "Survey of Reed Colonies" by Shiga Prefecture) Reducing Reed Colonies
Natural Attached lake (area) New Attached lake (area) Natural Attached lake (number) Total (number)
4000 40 Attached lakes (naikos) 37 10 10 Attached lakes, directly connected to Lake Biwa by waterways, are unique to the lake; no other lakes in Japan 3000 30 have such attached lakes. 30 29 29 28 27 Although there were dozens of attached lakes around 25 25 25 23 23 23 Lake Biwa, many were reclaimed before and after World 2000 20 Area (ha) War II to create paddy fields for increasing domestic food 2902 supply. In addition to providing wild life with ideal 1000 10 1864 habitats, Attached lakes are believed to retain and purify 111 111 Number of Attached Lakes pollutants and excessive nutrients in the water, lowering the 719 719 703 552 433 433 433 432 425 425 amount of their entry to Lake Biwa. 0 0 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 (Note) Natural: naturally created Attached lakes New: newly created Attached lakes Changes of Attached Lakes in Number and Area
Number Lake Name Area (ha)Number Lake Name Area (ha) 1 Shiozu-naiko 16.8 17 Tsuda-naiko 119 2 Shiozusaba-naiko 16.4 18 Kitazawa-numa 4.9 3 Noda-numa 6.2 19 Suikei-naiko 201.3 4 Hayasaki-naiko 91.9 20 Noda-numa 39.5 5 Daigo-naiko 13.9 21 Hanjo-ike 33.8 6 Hamasuga-numa 2.4 22 Shinanaka-naiko 2.5 7 Irie-naiko 305.4 23 Hira-ko 13.4 8 Matsubara-naiko 73.3 24 Katata-naiko 7.9 9 Noda-numa 15 25 Komatsu-numa 7.8 10 Sone-numa 87 26 Otomegaike 8.9
11 Jinjyo-numa, 27 Shizugawa-naiko 19.9 7.2 Koyaba-numa 28 Gotanda-numa 1.2 12 Iba-naiko 49.0 29 Tonotsubo-numa 2.0 Dainaka-no-ko Suga-numa Entire reclamation 13 1,145 30 2.8 14 Shonaka-no-ko 342.1 31 Imazu-numa — Partial reclamation 15 Nishi-no-ko 221.9 32 Hamabun-numa 5.4 16 Kitanosho-sawa 15.8 33 Nukegawa-naiko 16 (Source:"Studies of Lake Biwa " From Catchment to the Lake-" by Shiga Prefecture Lake Biwa Research Institute, 1988) Map of Attached Lakes
13 Current Situation of Lake Biwa 7
Lake's Ecosystems 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).
(Courtesy of Shiga Prefectural Museum of Lake Biwa) Biwa Trout Nigoro Crucian Carp (onchorhynchus masou rhodrurus) (Carassius grandoculis) (endemic species) (endemic species) (ton) (ton) 600 Trout 7,000 Sweetfish Nigoro crucian carp Shrimp and other animals taken by fishery 500 Willow minnow 6,000 Carp Other shellfish White fish(leucopsarion 5,000 400 Other fish species petersi hilgendorf) Largemouth bass 4,000 Cobiculid clam 300 3,000 200 2,000
100 1,000
0 Fiscal 0 Fiscal 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 year 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 year (Source: "Fishery Production Survey" by Shiga Statistics Office, Kinki Regional Agricultural Administration Office) Changes in Fishery Catches by Fish Species 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. Chinese Little Grebe (Shiga Prefecture bird)
(Number) Swan (Number) Wild goose ４００ ８００
３００ ６００
２００ ４００
１００ ２００
０ ０ 1974 1979 1984 1989 1994 1999 Fiscal 1974 1979 1984 1989 1994 1999 Fiscal year year
(Number) Wild duck (Number) Grebe １００,０００ ３,０００
８０,０００ ２,５００
６０,０００ ２,０００
４０,０００ １,５００
２０,０００ １,０００
０ ０ 1974 1979 1984 1989 1994 1999 Fiscal 1974 1979 1984 1989 1994 1999 Fiscal year year (Changes in Number of Wild Birds) Changes in Number of Wild Birds
14 8 History of Lake Conservation Efforts
Freshwater Red Tides 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.
Phytoplankton (uroglena americana)
Water Quality Conservation Campaigns Initiated by Local Residents 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).
Using both powdered soap and synthetic Using synthetic Using only powdered soap detergent detergent only Don't know April 1979 26.0 28.1 37.5 8.4 （％） 12th survey in Shiga Prefecture (July 1980: Enactment of Eutrophication Prevention Ordinance) Using only powdered soap Other August 1980 70.6 17.9 7.3 4.2 (Survey of Shiga citizens) Using both powdered soap Using synthetic and synthetic detergent detergent not not containing phosphorus containing phosphorus
Campaign Immediately after the Lake Biwa (Source: "Environmental White Paper" by Shiga Prefecture) Eutrophication Prevention Ordinance Took Effect Changes in Use of Powdered Soap
Shiga Prefectural Ordinance Concerning the Prevention of the Eutrophication in Lake Biwa (Eutrophication Prevention Ordinance) 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.
15 History of Lake Conservation Efforts 8
International Conference on the Conservation and Management of Lakes (World Lake Conferences) 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). Sites and Dates of the Past World Lake Conferrences 1st Shiga Prefecture, Japan, 1984 2nd State of Michigan, U.S.A., 1986 3rd Keszthely City, Hungary, 1988 4th Hangzhou, China, 1990 5th Stresa City, Italy, 1993 6th Ibaraki Prefecture, Japan, 1995 7th San Martin City, Argentina, 1997 8th Copenhagen, Denmark, 1999 9th Shiga Prefecture, Japan, 2001 The 1st World Lake Conference * 10th Conference is planned in Chicago, U.S.A. in 2003. Establishment of Lake Biwa - Yodo River Water Quality Preservation Organization 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.
Lake Biwa
Water Intake
⑫ Lakefront Field Experiment Facility
⑪ Multi-Water Channel Experimental Facility ⑩ Lake Biwa Model Experimental Pond
⑥ UF Filter Experimental Facility ⑦ Experimental Facility of Purification Using Soil
Outlet
① Water Channel Type Experimental Purification Facility Visitor's Hall
Water Intake Water To Otsu Intake Administration Office Lakeside Road(Prefectura l Roa d Om ③ Shallow Pond Type Experimental ihac ⑧ Percolation/filtration him ② Deep Pond Type Experimental Purification Facility Purification Facility an Experimental Facility - O tsu ④ Byproduct Treatment Yard L Hayama Agricultural ⑤ Advanced Treatment Experimental Facility River Drainage ⑨ Natural Circulation Method Experimental Purification Facility
Plan of Biyo Center To Moriyama
Reed Water inflow Discharge
Discharge Watercress Elodea nuttallii St. john Water inflow Filtration Water Akadama soil or Andosol inflow Absorption Discharge Absorption Filtration Biological decomposition Pollutant Purification Experiment Using Soil Purification Experiment Using Deep Pond Purification Experiment Using Shallow Pond
Experiments at Biyo Center 16 9 Survey for Preparing Lake Biwa Comprehensive Conservation Plan
Background 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".
Guiding Principle and Key Concepts of the Comprehensive Conservation Plan 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
Bequeathing a clean Lake Biwa to Future Generations ―Seeking Harmonious Coexistence with the Lake's Ecosystem―
Key Concepts Harmonious Coexistence Harmonious Coexistence with the Lake's Ecosystem
Our Common Our Common Our Common Feeling Goals Property
Loving the Lake Seeking Sustainable Bequeathing Lake Biwa to and Nature Development Future Generations
Objectives and Period 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.
17 Survey for Preparing Lake Biwa Comprehensive Conservation Plan 9
Desired state of Lake Biwa
2nd stage objectives 1st stage objectives Comprehensive Conservation Plan
Fiscal 1999 Fiscal 2010 Fiscal 2020 Fiscal 2050 ~ Stage 1st 2nd Future (long-term vision)
From long-term vision Viewpoint From feasibility of initiatives
Promotion of proper land use in consideration of the Ongoing initiatives Preventive measures Focus reflecting new findings lake's environmental changes and progress of environmental surveys, studies and conservation ・Steady implementation ・Implementation and technologies; flexible implementation of the Plan in view and reinforcement of reinforcement of initiatives, of changing public opinion, social and legal systems and ongoing initiatives and based on analysis of their economic conditions their coordination effects ・Introduction of new ・Promotion of new initiatives initiatives and model and model projects to entire Strategies projects region ・Information sharing and ・Information sharing and resident participation resident participation ・Survey and monitoring to ・Survey and monitoring to analyze and identify analyze and identify environmental problems environmental problems Flexible operation in response to constant review and improvement of the Plan
Period and Strategies at Each Stage
Promoting Partnerships
Incorporating Multiple Viewpoints 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.
Promoting Partnerships 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.
Multiple Viewpoints Partnerships Water Quality Complex Conservation Relations
Impacts Enhancement of Soil Recharge Capacity Regional Forest
Challenges Difference Profession Conservation of Natural Environment Scientifically Sufficient and Landscapes Unknown Common Lake Biwa Urban Three Conservation Objectives Factors Coordination Farmland Recognition of Comprehensive Area and Effective Challenges Conservation Initiatives Governments Participation Domicile Generation Lake and Lakeside Citizens Information Sharing Enterprises Stakeholders
Information NPOs Sharing Three Requisites for Partnership Concepts in Policy Making
18 10 Comprehensive Environmental Preservation Efforts and Specific Measures 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】 Protecting Water Quality
① Reducing chemical oxygen demand (COD), total nitrogen and total phosphorus Major Tasks ② Resolving problems of musty odor, freshwater red tides and blue-green algae blooms ③ Reducing influent load from non-point (unspecified) sources ④ Investing and analyzing adequate measures against low biodegradable organics ⑤ Minimizing impact of trace chemicals
First Stage Objectives Second Stage Objectives Reducing influent load to level of latter half of 1960 s Restoring water quality to level of latter half of 1960 s To reduce COD level by approximately 31%, total nitrogen by To restore water quality to the level prior to the emergence of approximately 17%, and total phosphorus by approximately musty odor, freshwater red tides and blue-green algae blooms 36% from 1995 levels (level of latter half of 1960's) Major Initiatives Priorities ○ Measures addressing pollution sources ○ Continual enforcement of wastewater regulations ○ Measures addressing runoff processes ○ Reinforcement of measures to reduce influent load ○ Measures to be taken in the lake itself from non-point (unspecified) sources ○ Regulations on wastewater etc. ○ Reinforcement of measures to enhance the lake’s ○ Research and field studies natural water purification functions ○ Introduction of new initiatives in response to environmental changes ○ Lifestyle reforms to reduce environmental impact
《Specific Measures》 ■Reducing Environmental Impact of Domestic Wastewater (Sewage Systems) 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. （％） 80 National average 69.5 Distribution tank Organic compounds 70 Shiga Prefecture 64.5 Sewage from primary (Methanol, etc.) PAC Final sedimentation 58 60 sedimentation tank 60 54 55 56 64 tank 51 62 47 49 58.8 50 44 45 55 40 42 50.5 37 39 40 36 46.7 32 33 34 43 Anaerobic tank Aerated tank 30 31 39.3 36.1 Sludge return Excess sludge 30 23 33.9 28.230.5 20 16 23.5 Biological treatment (step-feed biological 20.4 17.1 nitrogen removal process + post-denitrification) 10 15.2 3.2 4.6 4.8 11 12.9 1.7 7.8 8.9 0 4550555657585960616263元 2345678910111213 Year end Changes in Sewage Service Coverage Rates Oxygen gas Ozone generator 69 Shiga Prefecture PAC Ozone Granular activated (highest in Japan) carbon
Osaka Prefecture 32 (second highest) Treated Kyoto Prefecture 32 water (second highest) Sand filtration Ozone reaction Bio-activated tower tower carbon filtration tower National average 9.7 Physiochemical treatment (sand filtration + ozonation （%） + bio-activated carbon filtration) 0 10203040506070 Advanced Sewage Treatment Service Ultra-Advanced Sewage Treatment Process Coverage Rate (End of Fiscal 2001) 19 Comprehensive Environmental Preservation Efforts and Specific Measures10
● Sewage treatment facilities for Yogo Town agricultural communities (189 districts)
▲ Comprehensive agricultural effluent (Sewage Treatment Systems treatment model districts (18 districts) Nishiazai for Agricultural Communities) Town Kinomoto Town Azai Town To preserve water quality and improve the living environment Makino Town Takatsuki Town in agricultural districts, various facilities have been Ibuki Imazu Town Kohoku Town Town Torahime Town constructed in agricultural communities, including sewage Biwa Town Nagahama treatment facilities, rainwater treatment facilities and City ShinAsahi town compositing facilities against sludge from sewage Santo Town Kutsuki Village Adogawa Town Omi Town treatment facilities. Maibara Town Takashima Town
Hikone City Shiga (Installation of Domestic Town Toyosato Taga Town Notogawa Town Kora Wastewater Treatment Systems; Johkasou) Town Echigawa Town Town Hatasho Town Azuchi Gokasho In areas where sewage systems have not been constructed, Town Town Koto Town Chuzu Omihachiman Aito Town Town City installation of domestic wastewater treatment systems is Yokaichi City Moriyama City Yasu Eigenji Town currently underway. These systems, called "Johkasou", is Town Ryuo Town Gamo capable of treating both night soil and gray water, and feature Town Ritto City Kusatsu Ishibe Hino Town high performance equivalent to that of sewage treatment City Town Kosei Town plants, as well as ease of installation (requiring only about a Minakuchi Town Tsuchiyama Town week) and relatively small space requirement (about the size Otsu City
Konan Town of a household parking space) Koka Town
Shigaraki Town
Locations of Sewage Treatment Systems for Agricultural Communities Sanitary Sewage Treatment Facilities in Shiga Prefecture End of Fiscal 1998 End of Fiscal 2001
Sewage Service 54.5% 69.5% Sewage Treatment Systems for Agricultural Communities 8.5% 8.8% Domestic Wastewater Treatment Tanks 8.8% 9.5% Sanitary Sewage Treatment Facilities (Total) 71.8% 87.8% Sanitary Sewage Treatment Facilities (national average) Approximately 74%
Purification of Rainwater in Urban Districts
Street surface ■Purification of Rainwater in Urban cleaning Districts Cleaning activities Infiltrating boxes and ducts
Screening To further improve Lake Biwa's water quality, it is Water diverting facilities imperative to reduce influent load from such non-point Swirling water diversion Rainwater reservoir and sedimentation facility (unspecified) sources as urban districts and agricultural Polluted water flows into effluent drainpipe. land. Since the first flush of rainwater contains a Purification with vegetation Sediment and sludge flow particularly high rate of pollutants, measures have been into effluent drainpipe. taken to store and treat the first flush in urban districts. Catalytic oxidation facility
Outlet Purification center Release of treated effluent
Lake Biwa
Reducing Influent Load from Non-point Sources
20 ■Improvement of River Environment (Water Quality of Inflowing Rivers) 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 ■Water Purification Mechanism (Upward flow system) Akanoi Bay, river water is fed to reservoirs (either flooding Conglomerate Effluent duct Soil filtrates impurities, prevention reservoir or ordinary treatment reservoir) and Clean water while iron in the soil adsorbs phosphorus from purified before discharge into the lake. Akadama Flow water. Concurrently, soil direction microorganisms in soil decompose nitrogen and
Conglomerate nfluent duct phosphorus, thereby Contaminated water purifying the water.
Kusatsu River Water Purification Facility
(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.
Dredging of Lake Bottom ■Measures against Low Biodegradable Organics 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).
COD Effluent from roads 100 100
Effluent from roads 80 80 (first flush, post-first flush) Treated water 60 60 40 40 Horizontal treatment Parshall flume equipment 20 20 Slit （g） （%） Excessive water 0 0 Void First time Second time Third time Fourth time reatment chamber Total load Triangle weir Total load in treated water Removal rate (%) Tank Low Biodegradable Organics Treatment System Removal of Low Biodegradable Organics
21 Comprehensive Environmental Preservation Efforts and Specific Measures10
Increasing Soil’s Recharge Capacity
Major Tasks 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
First Stage Objectives Second Stage Objectives Securing sufficient land area for rainfall infiltration Improving soil’s recharge capacity and promoting To secure sufficient land area for rainfall infiltration in forests, adequate water use agricultural land and urban districts by preventing forest erosion To improve and sustain soil's rainfall filtration and holding and through other efforts capacity in forests, farmlands and urban districts To protect forest soil layers on a sustainable basis by To promote adequate water use in artificial water circulation promoting adequate plant growth and management, particularly systems in planted forests
Major Initiatives Priorities
○ Measures to secure sufficient forest and agricultural ○ Proper management of planted forests to stabilize soil land area layers ○ Stabilization of forest soil layers ○ Development of human resources for forest ○ Efficient use of reservoirs and other artificial water maintenance storage facilities ○ Researches to seek various adequate measures for the ○ Construction and improvement of water recycling lake's respective sub-basins in accordance with their facilities water quality and local ecosystems ○ Research and field studies
《Specific Measures》 ■Forest Maintenance Proper 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.
Forest of Long Harvest Cycle
22 ■Afforestation To 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 1 Year Later Restoration of Damaged Forest
■Improving Rainfall Filtration and Holding 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.
Circulatory Irrigation System
■Permeable Pavement and Urban Green Zones To improve rainfall filtration and holding capacity in urban area, increasing numbers of streets have permeable pavements and roadside trees.
Permeable Pavement
23 Comprehensive Environmental Preservation Efforts and Specific Measures10
Preserving the Natural Environment and Scenic Landscapes
Major Tasks ①Preserving wild life habitats ②Preserving biodiversity ③Preserving the lake's indigenous scenic beauty ④Controlling lakeside land use
First Stage Objectives Second Stage Objectives Securing strategic points for the creation of biotope Establishing a framework of biotope networks networks To create a framework of biotope networks and restore natural To preserve biotopes in the transition zone (called "ecotone") ecosystem using it. 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 Major Initiatives Priorities
○ Securing sufficient area of wild life habitats by ○ Monitoring and assessment of wild life habitats creating biotope networks ○ Establishment of a system to involve local residents and ○ Improving habitat environment by creating biotope other users of the lake in environmental conservation networks activities ○ 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
《Specific Measures》 ■Restoration of Rivers and Lakeshore 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. Before Restoration Reproduced Reed Colony (Moriyama District)
■Yasu Riparian Forest Project Without riparian forest An afforestation project is under way along the Yasu High flow velocity = Extensive bank damage River, a major river flowing into Lake Biwa. In addition to Large quantity of floodwater preserving natural ecosystems, riparian forests are effective in augmenting riverbank flood-prevention functions. High flow velocity = deep erosion
Water overflowing the bank is likely to cause extensive damage.
Riparian Forest Zones With riparian forest The revised River Law (1997) introduces the riparian Low flow velocity = Minor bank damage forest zone system, under which river authorities can Small quantity of floodwater create and preserve riparian forest zones as a means of promoting flood prevention and efficient use of river Low flow velocity = minor erosion water. Water overflowing the bank is blocked by trees, eventually minimizing flood damage
24 ■The Ordinance for Conservation of Kohoku Town Reed Colonies In 1992, Shiga Prefecture enacted the Ordinance for Nukegawa-naiko Noda-numa Conservation of Reed Colonies, since such colonies are Imazu Town Onoe - Ebie effective in sustaining the habitats of various birds and fish Hamabun-numa Biwa Town species, protecting the lakeshore from erosion and retaining ShinAsahi Town Nagahama City good water quality. The Shiga prefectural government is Harie promoting the creation and conservation of reed colonies Adogawa Town by designating several areas as reed colony conservation Ado River areas. Takashima Town Hikone City Noda Marsh Inukami River
Biwako Sone-numa ■Conservation of the Lake's Ohashi Bridge Echi River Indigenous Fish Species Iba-naiko To restore the number of indigenous fish species in the Katata Nishi-no-ko lake, local fishers and related parties annually release fries Ogoto Omihachiman City Moriyama City of nigoro crucian carp (carassius auratus grandoculis), willow minnow (gnathopogon caerulescens) and Biwa Reed Protection Areas Karasuma These areas contain reed colonies and trout (onchorhynchus masou rhodrurus). Peninsula ecosystems of particular importance. Kusatsu City Reed Conservation Areas Yabase These areas contain reed colonies of considerable size. Ordinary Reed Areas Other areas within the reed Otsu City conservation areas
Reed Colony Protection and Conservation Areas
Release of Fry
■Elimination of Introduced Fish Species To 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).
Lake Biwa Fishing Regulation: effective in and after April 2003
Do Not Catch-and-release Large-mouth Bass and Bluegill Sunfish.
Shiga Prefecture's Stamp to Promote Lake Biwa Fishing Regulation Fish Species of Foreign Origin Constitute the Majority of a Catch
25 Comprehensive Environmental Preservation Efforts and Specific Measures10
【Three categories of common foundations】 Citizen Participation and Activities
Major Tasks Promoting a wide variety of activities involving citizens
First Stage Objectives Priorities in Second Phase Developing eco-friendly lifestyles and building ○ Involving more people in activities to reduce Lake Biwa conservation networks environmental impacts ○ Soliciting more people in Lake Biwa conservation Major Initiatives campaigns ○ Sustaining conservation plans by coordinating efforts ○ Developing business activities and lifestyles that of related governmental organizations impose less burden on environment ○ Building partnerships with interested parties in and ○ Building Lake Biwa conservation networks outside Japan ○ Sharing eco-consciousness among all generations
《Specific Measures》 Takashima Bloc ■Preparing and Promoting Kohoku Bloc Action Plans of Individual Basin Blocs Koto Bloc To promote comprehensive lake preservation initiatives throughout Shiga Prefecture, all Otsu-Shiga Bloc seven sub-basin blocs in the Prefecture have prepared and are implementing action plans, Higashi-Omi Bloc led by local citizens. Konan Bloc Koga Bloc Residents Committed to Environmental Conservation Activity Sub-Basin Blocs ■Afforestation for Only One Earth Campaign 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. Afforestation Site Planting Seedlings ■Mizusumashi (whirligig beetle) Plan In 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. Agricultural Workshop for Local Residents ■River Improvement Plan To 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. Omi Committee Meeting 26 Information Sharing and Staff Exchange Promotion
Major Tasks Increasing friendly exchange opportunities and establishing easy-to-access networks
First Stage Objectives Priorities in Second Phase
Sharing information and promoting friendly ○ Creating extensive networks for Lake Biwa exchanges environmental preservation, involving individual citizens, enterprises and governmental agencies Major Initiatives
○ Increasing staff exchange opportunities ○ Sharing basic information ○ Establishing easy-to-access networks
《Specific Measures》 ■Omi Network Center Amid 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.
Omi Citizen Activities ■Shiga Environmental Business Exhibition The 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. Shiga Environmental Business Exhibition
■Friendly Exchanges and Information Sharing by the Lake Biwa Museum 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.
Citizens Participating in Dandelion Survey Lake Biwa Museum holds observation and survey workshops on specific themes, recruiting citizens as field reporters.
27 Comprehensive Environmental Preservation Efforts and Specific Measures10
Research and Survey
Major Tasks Promoting systematic monitoring and survey activities
First Stage Objectives Priorities in Second Phase
Promotion of systematic research and survey ○ Promotion of monitoring surveys and establishment of comprehensive water quality control systems Major Initiatives ○ Establishment of survey and research systems ○ Promotion of the "Environmental Information Center" ○ Promotion of monitoring survey plan ○ Establishment of collaboration networks ○ International collaboration on the theme of ancient lakes
《Specific Measures》 ■Survey to Promote Comprehensive Preservation of Lake Biwa In 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. Fiscal Year Program Details
1999 ○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 techniques 2000 were 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 regarding 2001 promotion 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. ■Research and Survey by the Lake Biwa Research Institute 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 quality The 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 environment Using 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 lakes Autonomous Underwater Vehicle “tantan” The 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. ■International Survey and Research by the International Lake Environment Committee (ILEC) 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. Committee Meeting 28 column 9th International Conference on the Conservation and Management of Lakes (World Lake Conferences) 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.
Theme： Partnerships for Sustainable Life in Lake Environments: Making Global Freshwater Mandates Work Organizers： Shiga Prefectural Government, International Lake Environment Committee (ILEC) Co-organizers： Ministry of Health, Labour and Welfare; Ministry of Land, Infrastructure and Transport, Ministry of Environment, J-water Garden, Otsu City Period： November 11 (Sun) - 16 (Fri), 2001 (6 days) Venue： Biwako Hall and other venues in Shiga Prefecture Programs： ●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 enterprises Participants： A total of approximately 55,000 people from 75 countries
Lake Biwa session - Love Letter to Lake Biwa Lake Biwa Discussion session [Think of World Lakes on Lake Biwa Experiences]
Biwako (Lake Biwa) Declaration 2001 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 community 2. Disclose and share information, and promote environmental education, and build a capacity of people 3. Promote scientific research and monitoring 4. 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 Management of Lakes, Biwako2001 November 16, 2001
29 Future Progress of Comprehensive Lake Preservation Initiatives11
11 Future Progress of Comprehensive Lake Preservation Initiatives
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.
Continuous improvement Bequeathing a Clean Lake Biwa ●Flexible Operation of Conservation Plans to Future Generations In response to the progress of conservation projects and changes in the lake's environment, plans must be constantly reviewed and Implementation if necessary revised, together with their targets. (Implementing programs and initiatives) ●Changing Plans to Reflect Results of Observations, Review Surveys, Researches and Technological Development Management (By reflecting views of specialists (Evaluating progress and effects and general public) Research institutions must collaborate to determine the lake's of programs and initiatives) environmental situations and mechanisms in the most effective Evaluation manner. At the same time, results of observations, surveys, (By implementing authorities and third parties) Preservation of natural researches and technological development should be reflected in environment and landscapes conservation plans in a timely manner. Knops Survey and Specialists research Improvement of soil's (Autonomous recharge capacity Lake Biwa catchments Information (Continuous ●Reviews Based on Plan Evaluation implementation) (Key area of continuous improvement) sharing improvement) Improvement of Participation Progress and effects of conservation plans should be constantly Enterprises water quality Governments Collaboration evaluated. If necessary, the plans should be reviewed in terms of Citizens project composition and approaches to specific measures. Lake Biwa - Yodo River basin
●Coordination among Implementing Authorities and Projects (Extensive partnerships) Implementing authorities should share information in advance, to promote mutual understanding and support. Nationwide, worldwide citizens Operation Mechanism
Coordinating System 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) 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)
The Council was established in July 1999, with the Cooperative Structure of Prefectures in the Lake Biwa Catchment
aim of facilitating implementation of Lake Biwa Cooperative Structure of Municipalities preservation programs by coordinating related regional in the Lake Biwa Catchment bureaus of the national government, as well as local Governments Citizens/Enterprises Specialists
governments. Partnerships and The Council's first meeting was held on July 21, Cooperative Structure in the Lake Biwa - Yodo River Watershed respect to autonomy of respective members 1999, to determine Council rules, introduce ongoing (Lake Biwa Comprehensive Preservation Promotion Council) commitments of respective members, and confirm resolutions to strengthen partnerships among members to Cooperative Structure for Ministries and Agencies facilitate the comprehensive preservation of Lake Biwa. (Lake Biwa Comprehensive Preservation Liaison Coordination Council)
Coordination System 30 12 Chronological Table of Lake Biwa
Year Major Incidents in Japan Major Incidents in Lake Biwa Basin Approximately The ice age with several intervals An ancient lake was formed in the Iga Ueno region in Mie Prefecture. 4 million years ago Approximately Lake Katata was formed around Katata. 1 million years ago Approximately Lake Biwa was formed at the present lake site. 400,000 years ago 10,000 - 15,000 years ago The Japanese Archipelago became separated from the Eurasian Continent. Old Stone Age B.C.10000 Stone spear points and tools discovered around Lake Biwa 8000 Jomon 6000 3000 Various Jomon period ruins discovered around Lake Biwa 2000
Yayoi 200 Yayoi Period ruins discovered around Lake Biwa A.D.28 The capital was relocated to Omi. 250 Bronze bell-shaped vessels unearthed from ruins in Yasu
Asuka 646 Taika coup 667 The capital was relocated to Omi (Otsu capital) for a short period. 672 Jinshin civil war Nara 710 The capital was relocated to Nara. 742 A new capital was constructed in Shigaraki (Shigaraki capital). Heian 794 The capital was relocated to Kyoto. A port in Omi was renamed Otsu. 905 Issuance of Engishiki Rice was transported to the capital from northern countries via the lake. 1065 Taira-no-Kiyomori planned to construct a canal between Shiozu and Tsuruga, in vain. Kamakura 1192 Kamakura Shogunate government was established.
Muromachi 1428 Farmers' riots 1455 Shogunate government collected tax from ships sailing on the lake. 1467 Onin civil war 1500 Omi hakkei (eight scenic landscapes of Omi) were selected. Azuchi- 1575 Oda Nobunaga constructed a bridge across the Seta River. Momoyama 1576 Oda Nobunaga began constructing Azuchi castle. 1582 Honnoji incident 1587 Asano Nagayoshi approved free navigation on the lake. 1600 Sekigahara battle Edo 1603 Edo Shogunate government was established. Construction of Hikone castle began. Tokugawa Ieyasu surveyed farmland in Omi. 1672 Westward navigation route opened. Water transport on the lake declined due to development of the westward navigation route. 1802 Extensive flooding of Lake Biwa 1846 Extensive flooding of Lake Biwa 1868 Meiji Restoration Extensive flooding in Shiga Prefecture (+3.3 m) Meiji 1869 A steamship began service on the lake. 1872 Shiga Prefecture was established. 1874 A water gauge was installed at the Torii River. 1878 Disaster prevention project began in the Seta River basin. 1890 The first Lake Biwa Canal incline was completed. 1893 Hikone meteorological observation station opened. 1896 Issuance of the former River Law Extensive flooding of Lake Biwa (+3.76 m) The Yodo River improvement project began. 1905 Nango Araizeki weir was completed. 1912 The second Lake Biwa Canal was completed.
Taisho 1913 Uji River power plant was completed. 1914 Outbreak of World War I Kyoto University opened lakeside observation station in Otsu. 1919 Mt. Ibuki meteorological observation station began operation. 1921 Issuance of Public Waters Reclamation Law 1925 The first public beach opened in Otsu. Showa 1941 Outbreak of World War II (Pacific War) 1944 Shiga Prefecture decided upon reclamation of several inland lakes. 1949 Biwako hakkei (eight scenic landscapes of Lake Biwa) were selected. 31 Chronological Table of Lake Biwa12
Year Major Incidents in Japan Major Incidents in Lake Biwa Basin Showa 1950 Comprehensive National Land Development Act Lake Biwa was designated first quasi-national park in Japan. 1952 Yodo River water control project first-phase completed (water level: -1 m) 1958 Enactment of the Sewage Law, Public Water Quality Preservation Establishment of Liaison Council to Prevent Water Contamination of the Yodo River Law, and Industrial Effluent Water Law 1960 Fish in Lake Biwa were contaminated by PCP from agricultural chemicals. 1961 Enactment of two laws concerning water source development Seta River Araizeki weir completed. 1962 Bio-resource survey began in Lake Biwa. 1964 Enactment of New River Law Biwako Ohashi Bridge and Amagase Dam were completed. Tokyo Olympic Games 1967 Enactment of Basic Law for Environmental Pollution Control Reclamation of Dainaka-no-ko Lake was completed. 1968 Biwako Fair was held. 1969 Shiga Prefecture enacted Anti-pollution Ordinance. Complaints of musty odor in tap water were filed in Kyoto City. 1970 Enactment of Water Pollution Control Law Complaints of odor in tap water were filed by about 400 citizens in Kyoto, Otsu and Osaka. EXPO'70 was held in Osaka. Lake Biwa Comprehensive Development Promotion Council was established. 1971 Entire Lake Biwa region was designated a wildlife sanctuary. 1972 Enactment of Special Law for Developing Lake Biwa Region Environmental standard was introduced to Lake Biwa. 1973 The 1st oil shock Shiga Prefecture enacted Natural Environment Preservation Ordinance. 1974 Omi Ohashi Bridge opened. 1977 Uroglena (vegetable plankton) spread over the lake. 1979 The 2nd oil shock Shiga Prefecture enacted Lake Biwa Eutrophication Prevention Ordinance Yasu River Drainage Canal opened. 1981 Shiga Prefecture adopted environmental impact assessment guidelines. 1982 Partial revision of Special Law for Developing Lake Shiga Prefecture established Lake Biwa Research Institute. Biwa Region (10-year extension) 1983 Shiga Prefecture school ship “Uminoko” began operation. Blue-green algae blooms spread over southern lake for the first time. 1984 Enactment of Special Law for Preserving Lake Water Shiga Prefecture enacted Landscape Preservation Ordinance. Quality Shiga Prefecture held the first World Lake Conference. 1985 Lake Biwa was designated a target of the Special Law for Preserving Lake Water Quality. 1986 International Lake Environment Committee (ILEC) was established. 1987 Lake Biwa Water Quality Conservation Plan was finalized. Heisei 1990 Master Plan for Environmental Management of Yodo River System was finalized. 1992 Partial revision of Special Law for Developing Lake Biwa The 2nd Water Quality Conservation Plan for Lake Biwa was finalized; Region (5-year extension) Shiga Prefecture enacted Reed Colony Conservation Ordinance. The Earth Summit 1993 Enactment of Basic Environmental Law Lake Biwa was registered with the Ramsar Convention on Wetlands. Lake Biwa - Yodo River Water Quality Preservation Organization was established. 1994 Serious water shortage throughout Japan Blue-green algae blooms spread over northern lake for the first time; water level declined to -123 cm on September 15, 1994. 1995 Great Hanshin-Awaji Earthquake UNEP established the International Environmental Technology Center. 1996 Shiga Prefecture enacted the Basic Ordinance Concerning the Environment and the Ordinance to Promote Domestic Wastewater Measures. Lake Biwa Museum opened. 1997 Termination of Special Law for Developing Lake Biwa Region The 3rd Water Quality Conservation Plan for Lake Biwa was established. Revision of River Law 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. 1998 Shiga Prefecture enacted Environmental Impact Assessment Ordinance. 1999 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 2000 G8 Summit of Environmental Ministers was held in Otsu. Shiga Prefecture finalized Mother Lake 21 Plan. 2001 The 9th World Lake Conference was held. 2002 The 4th Water Quality Conservation Plan for Lake Biwa was finalized. Shiga Prefecture enacted Lake Biwa Sport Activities Control Ordinance. 2003 The 3rd World Water Forum was held.
32 Lake Biwa Comprehensive Preservation Initiatives ― Seeking Harmonious Coexistence with the Lake's Ecosystem ―� (March 2003)
Lake Biwa Comprehensive Preservation Liaison Coordination Council Office/ Metropolitan Areas Development Division, City and Regional Development Bureau, Ministry of Land, Infrastructure and Transport
2-1-3 Kasumigaseki, Chiyoda-ku, Tokyo 100-8918 TEL ：03-5253-8111 (ex. 32-323) E-mail ： [email protected] HP ： http://www.mlit.go.jp
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