6 Evolving Issues Toward Improvementof the Lake Biwa–Yodo River Basin
Governance
Masahisa Nakamura, Keiko Wada, Kentaro Taki, and Naoko Hirayama

Abstract This chapter presents the historically evolved basingovernance challenges facing the Lake Biwa–Yodo River Basin,
specifically focusing on (1) the basin-wide water quality improvement achieved and the remaining challenges, with particularfocus on the reduction of nonpoint source pollution; (2) a newly
introduced program on Integrated Flood Risk Management andits potential basin-wide adoption; and (3) the historically evolved
people–community–government relationships in the Shiga
Prefecture. For the above purposes, an overview of the Basin withrespect to its geography, geohydrology, and socio-­demography is
first presented. It also attempts to address the historic transformations of land–water linkage structures and the resulting
appearance or disappearance of lentic (static, impounded) andlotic (moving, flowing) flow regimes. In the concluding section,
the earlier sections will be reflected within on the concept of the“Ecosystem Service Framework” as a tying thread theme foraddressing the future basin governance challenges.
Keywords Basin governance • Nonpoint source pollution •Flood risk management • Participation • Ecosystem services

M. Nakamura (*)
Research Center for Sustainability and Environment,
Shiga University, Shiga, Japan
International Lake Environment Committee Foundation,
Kusatsu, Shiga, Japane-mail: m-nakamu@ilec.or.jp
K. WadaInstitute of Lake Biwa–Yodo River Water Environmental
Research, Lake Biwa – Yodo River Water Quality Preservation
Organization, Osaka, Japane-mail: wada@byq.or.jp
K. Taki · N. Hirayama
School of Environmental Science, The University of Shiga
Prefecture, Hikone, Shiga, Japane-mail: taki.k@ses.usp.ac.jp; hirayama.n@ses.usp.ac.jp

Introduction
In this chapter, “basin governance” is described for a basin system with a given set of spatial (basin and its interaction linkages),
temporal (past, present, and future to work toward sustainability), and perceptional (who are involved in what way and how)spheres, as continuous interactions of rules, institutions, and processes with the basin society exercise powers and responsibilities
to make and implement decisions on the basin resources. The
governance of basin resources involves societal decisions, a decision-making system, and implementation of decisions to deal
with congestion, competition, and conflicts in their use. The concept of “basin governance” is important for sustainable resourceuse, because the basin management is neither a project nor a program. It is a governance challenge that evolves over time.
An overview of the spatial sphere of Lake Biwa–Yodo River
Basin (hereafter referred to also as “Biwa–Yodo Basin” whereconvenient) is given in section “The Biwa–Yodo Basin in brief ”
in terms of geographical, demographical, and socioeconomic
implications. An overview of the temporal sphere of the Biwa–
Yodo Basin Section is given in section “Historic transformationsof the Biwa–Yodo Basin” in terms of the land–water linkage
structure with historical transformational features about its flow
regime with natural as well as anthropogenic forces. The perceptional sphere is formed collectively by the communities within
and outside of the basin, gaining over historical time the technological and managerial capacities to interact with the nature, i.e.,aquatic ecosystem and environment in particular, which are also
spatially and temporarily transforming.
With the above in mind, section “Evolving governance inmanaging point and nonpoint source pollution” presents thepast trend of water quality, particularly with regard to theincreasing proportion of nonpoint source pollution as contrasted to point source pollution, with associated governancechallenges, focusing on the work of the Lake Biwa–Yodo River
Water Quality Preservation Organization (BYQ), an organization playing the role of a trans-basin knowledge hub on water
quality. Section “Evolving Basin governance for Integrated
Flood Risk Management” presents the prospective adoption
across the basin of an Integrated Flood Risk Management© The Author(s) 2020
H. Kawanabe et al. (eds.), Lake Biwa: Interactions between Nature and People, https://doi.org/10.1007/978-3-030-16969-5_6

486

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance﻿(IFRM) based on the site-specific probability assessment, withassociated governance challenges. The presentation will bebased on the study of the Shiga Prefectural Government on thesite-specific flooding probabilities for developing the area-wide
hazard risk maps for the Lake Biwa region, to be replicated inother Yodo River Basin prefectures via the Union of Kansai
Governments (UKG). Section “Evolving Basin governance ofparticipation: Communities and citizens” presents the historicalcontext of paddy water governance under extreme conditions,the historically pervaded conflicts and contentions in the management of the Lake Biwa–Yodo River Basin, and the pursuits
toward meeting the current and future challenges facing Lake
Biwa environmental and ecosystem concerns by participatory
governance. The presentation here is based mainly on the studies undertaken in relation to the Shiga Prefecture’s citizen andcommunity participation programs on environmental and ecosystem concerns about Lake Biwa.
Lastly, section “Basin governance improvement for ecosystem restoration” will conclude this chapter by focusing on theconcept of “Ecosystem Service Framework” as a tying thread
while taking note also of the concept of the concept of “Principleof Subsidiarity” as a crosscutting concept. Collectively they shedsome light to the perceptional feature of the Biwa–Yodo Basingovernance that has evolved over time to meet the challenges
facing the Basin today and in the future.
The development of sections “The Biwa–Yodo Basin in
brief ”, “Historic transformations of the Biwa–Yodo Basin”, and“Basin governance improvement for ecosystem restoration” ismainly coordinated by Nakamura, with all, section “Evolving
governance in managing point and nonpoint source pollution”
mainly contributed by Wada, section “Evolving Basin governance for Integrated Flood Risk Management” mainly contributed by Taki, and section “Evolving Basin governance ofparticipation: Communities and citizens” mainly contributed by
Hirayama and Nakamura.

The Biwa–Yodo Basin in Brief
The Lake Biwa Basin system with its tributary rivers and theirwatershed lands constitutes a sub-basin system of the entire
Lake Biwa–Yodo River Basin system with the remaining tributary rivers and their watershed lands, connected to the Osaka
Bay system through the discharging Yodo River. Management of
the former (Biwa–Yodo Basin) is an inclusive part of management of the latter (Biwa–Yodo–Osaka Bay Basin), and some
aspects of the above inclusive relationship have been presented
earlier (Nakamura et al. 2012), and other basic information isavailable from various sources, e.g., from the Shiga Prefecture(Shiga Prefectural Government 2014).
The Lake Biwa–Yodo River Basin covers 8240 km2, includingthat of Lake Biwa of 3848 m2, with a channel length extending
75.1 km. The Basin encompasses the western part of the Mie

Prefecture, the southern half of Kyoto Prefecture, the northernhalf of Osaka, the southwest of Hyogo, and the northwest of the
Nara Prefecture in addition to the Shiga Prefecture within whichlies Lake Biwa itself. The configurational feature of the Basin issuch that Lake Biwa lies in the uppermost part, and the semiclosed Osaka Bay portion of the Seto Inland Sea lies in the lowermost part, sandwiching the mainstream Yodo River and its
tributaries in the middle. The three tributaries of Yodo River are
the Uji River connecting to Lake Biwa in the north, the Katsura
River dendritically spanning toward the west, and the Kizu River
spanning toward the east. The mainstream stem part of the Yodo
River is only a short stretch of some 20 km or so, from the confluent point of the three rivers to the river mouth at the Osaka
Bay. The outflowing river from Lake Biwa down toward the
Yodo River is called the Seta River within the Shiga Prefecture
but is also called the Uji River within the Kyoto Prefecture before
it joins the mainstream stem part of the Yodo River. In terms ofbasin land area, the Uji River and Lake Biwa sub-basins constitute approximately half of the total, and the other half is contributed by the Kizu, the Katsura, and the Yodo River sub-basins
toward the Osaka Bay river mouth. The flow contribution to the
Yodo River of the Uji, Kizu, and Katsura Rivers are, respectively,
64%, 18%, and 17% (see >Fig. 1). The approximate annual average flow, high flow, and low flow are, respectively, 180 m3/s,
230 m3/s, and 120 m3/s.
Lake Biwa is Japan’s largest freshwater lake and one of theworld’s leading ancient lakes, tectonically formed more than
4 million years ago. It lies within the Ohmi Basin surrounded by
the Ibuki and Suzuka mountain ranges in the east with theirelevations ranging in the order of 1200–1300 m and by the Hiraand Hiei mountain ranges in the west with their elevations in theorder from 800 to 1200 m. In the south, there are the Shigaraki
and Tanakami mountains with their elevations ranging in elevation from about 600 to 700 m. The Kohoku mountains in thenorth divide the Lake Biwa region and the Japan Sea coastal
region feature by the city of Tsuruga. The lake measures 63.5 km
in a north–south direction and is divided into two sub-basins at
the constriction point approximately 16 km from the southern
end. It has a total surface area of 674 km2, a volume of 27.5 billion m3, and a shoreline length of 235 km. The water surface
elevation is 85 m above sea level, and the deepest point is 104 m.
The mean depth of Southern Lake is about 4 m, and that ofNorth Basin is about 40 m. Its catchment area is 4.7 times thearea of the lake itself, and its boundary more or less coincides
with that of the prefecture, constituting 96% of prefectural land.
In terms of the Shiga Prefecture land area of 4017 km2, forestland accounts for approximately 51%, agricultural land covers
approximately 13%, and the rest is occupied by lake water surface
together with rivers and artificial channels (20%), housing (7%),
roads (4%), and others (6%). Relatively large extents of cultivatedland lies in the area surrounding Lake Biwa and in the upstream
region, while housing, commercial, and industrial lands arelocated in the downstream region. Since the Lake Biwa watershedEvolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 1
Jurisdictional boundaries of the Biwa–Yodo–Osaka Bay region

area occupies 93% of the Shiga Prefecture jurisdictional area, thepolicies and programs implemented across the prefectural land
directly or indirectly reflect on the lake’s water quality. It isreported that the agricultural lands have been reduced by 27%,
roads increased by 69%, and residential areas increased by 10% in
45 years since the early 1970s. The trend in land use in the Shiga
Prefecture continues reflect a decline in forests and agriculturallands and an increase in impervious land surfaces covered byroads, residential areas, and commercial districts. The proportion of residential land has significantly increased from some
12.5% in 1975 to 21.3% in 2010 (see >Fig. 2).
Some 460 rivers and streams flow into the lake, although
only the Seta River flows out of the lake. In addition, the two
canals constructed in 1890 and 1912, respectively, transportlake water to the city of Kyoto. Apart from municipal water supplies, the Lake Biwa water also serves for paddy irrigation andhydropower generation in the downstream Seta River. In addition, the fishery and navigational values have historically fostered a sense of special attachment to the lake for the Shiga
residents.

The Biwa–Yodo–Osaka Bay hydrological system is the lifeline of the metropolitan regions of Kyoto, Osaka, and Kobe. The
natural setting of this region differs widely between the north,which faces the Sea of Japan, and the south, which faces the
Pacific Ocean. The weather is generally much warmer and drierin the south than in the north. The mountain ranges around
Lake Biwa and the tributaries of the Yodo River are generally
covered with dense forest that function as a natural reservoir aswell as a gigantic filter producing high-quality raw water toreplenish Lake Biwa and the Yodo River. There are, however,some 20 or so dams (including irrigation dams) in the watershed
for the integrated management of water resources to compensate for fluctuations in precipitation.
The Biwa–Yodo–Osaka Bay Basin has a temperate climate, withmarked variations among seasons and, especially in winter, between
north and south. The mean annual atmospheric temperature in thelowland part of the watershed ranges from 14.8 °C in Otsu, 16 °C in
Kyoto, and 17 °C in Osaka. The mean temperature in January is
1–3 °C, while that in August is 24–27 °C. As in most of Honshu, themain island of Japan, its weather is dominated by the Sea of Japan

487

488

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 2
Land use classifications in the
Biwa–Yodo–Osaka Bay Basin as
in 2009 (BYQ 2017). GIS Data
Source: The National Land
Numerical Information Service,Japan

and the vast Asian Continent to the north and northwest and by thenorthern Pacific to the south and southeast. In the winter(November through March), the cold air mass from Siberia dominates, sweeping across the Sea of Japan and bringing much snow to
the region north of Lake Biwa, while the southern areas remain relatively warm and dry. In spring and autumn, there are periodic rainspells caused by the movement of low (cyclones) and high pressure(anticyclones) from the East China Sea. In early summer from early
June to mid-July, a stationary front dominates and gives this region
a continuous rain called baiu (plum rain) and tsuyu (consistentrain). In August and September, a tropical south easterly maritime
air mass from the Pacific prevails over Japan, giving it warm weather
with periodic thunderstorms. From early September through late
October, the Lake Biwa region is at risk of experiencing occasional
typhoons that can cause floods around lakeshore.

The annual precipitation in the Lake Biwa region is high,varying from about 1600 mm around the southern lake up to3000 mm in the northern mountains, some of which tower
over 1000 m. The north receives significantly more precipitation in the winter in the form of snows brought from the Japan
Sea by northwest monsoons that weaken as they move southward. The snow cover in the northern mountains can be several meters deep. Summer precipitation is more concentrated
in the mountains whose height ranges in the hundreds ofmeters. The year-­to-­year variations in precipitation in the Lake
Biwa area are large. The maximum annual precipitation inmodern times during the last century was 3096 mm in 1896,
three times the ­minimum of 1101 mm recorded in 1939. The
recorded variations during the “baiu” period has been considerably greater, with a 13 times difference between maximum

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceand minimum. There has been a notable trend of decreasing
precipitation from the early 1960s through the mid-1990s, but
not since then. The mean temperature rise over the past
100 years was approximately 0.78 °C, while the rate of increasein temperature over the same period was 1.84 °C in terms of
the yearly lowest temperature in Hikone (Shiga Prefectural
Government 2016).
In terms of population (see >Fig. 3), the cities of Otsu andKyoto and the surrounding municipalities form the Kyoto metropolitan region which has a combined population of 2.68 million. The Osaka metropolitan region, including Osaka andsome ten or so neighboring cities, including those along thecoastal industrial belt zone toward Sakai in the south, boasts a
population of approximately 12 million. The city of Kobe,
together with the surrounding municipalities lying along theSeto Inland Sea coastal region toward west, forms the Kobe
metropolitan region with a population of some 2.5 million.
Although the population in the main cities like Kyoto andOsaka is declining, those in the surrounding municipalities are6

increasing, making the combined total number more or less thesame over the past decades. The population in the Kyoto–
Osaka–Kobe metropolitan regions (hereafter referred to as the
Keihanshin Region) constitute close to 10% of the total population in Japan.

Historic Transformationsof the Biwa–Yodo Basin
This section consists of three subsections to tie together the previously discussed historic transformations. The first subsection(section “Transformation of the land–water linkage structure”)
introduces the historic transformation of the land–water linkage
structure. The second subsection (section “Transformation of
the flow regimes”) discusses the implications of flow regimechanges to the Basin. The third subsection (section“Technological and managerial implications”) discusses the ecosystem transformation in the Basin.

⊡⊡ Fig. 3
The Biwa–Yodo–Osaka Bay Basin, population distribution, GIS data source: The National Land Numerical Information Service, Japan

489

490

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance ransformation of the Land–Water Linkage
T
Structure
The land–water linkage structure of the Biwa–Yodo Basin has
been transformed in a number of different ways over the courseof basin history. Geo-historically, for example, the sea level during Japan’s Jomon Period (6500–5000 years ago) was a few
meters higher, and the Osaka Bay coastline was also much further inland than it is today. As the sea level gradually recededover the next millennia, the inflowing rivers into the Osaka Bay
began forming the alluvial plains. The inflowing freshwater
began to replace the seawater in the embayment formations, creating a freshwater lake. The alluvial formation persisted, and by
the latter part of the Jomon Period (from about the thirteenth
century BC to about the fourth century BC) through the Yayoi
Period (from about the tenth century BC to about the third century AD), the current Osaka City area began to appear as marshland formations separated by milliards of meandering water
courses. Subsequently, the marshlands began to be increasingly
drained by the settlers, gradually transforming them to dryer
lands more suitable for larger-scale human settlements surrounded by paddy fields that were connected by navigationalroutes and constructed irrigation ponds, collectively contributing to the emergence of various commodity trade transactions.
Even the two oldest written documents of Japan’s history, Kojiki(written during 711–712) and Nihon Shoki (completed in 720),
refer to the development of flood control and paddy irrigation
facilities as early as the Nintoku Emperor Era around 320 AD. In
more general terms, because of the limitation of inhabitable andcultivatable land space in the mountainous Japanese archipelago, land development for paddy agriculture had to be rigorously pursued throughout history. In the western part of Japan,
development of the available land for paddy agriculture wasmore or less completed by the mid-medieval time of around thefifteenth century, leaving only a limited land space for development thereafter. On the other hand, conversion of wetlands andwastelands to paddy agricultural lands was rigorously pursued
even toward the northeastern part of Honshu Island, particularly during the Edo Era (1603–1868). It is reported that the estimated national population during the middle to the latter periodof Edo Era was some 30 million, or one quarter of what is today,
being consistently supported with rice as a staple food.
In the riparian regions along the Yodo River, the water
course modifications and channel improvement works were
important responsibilities of the feudal loads. For example,
Hideyoshi Toyotomi (1537–1598), the first Shogun to unite thenation (1586), dedicated himself to improve the navigationaland flood control structures in and around Osaka Castle as well
as along the Yodo River and its tributaries. The trend continued
throughout the following centuries to include, for example,
Zuiken Kawamura, a civil engineer assigned by the shogunate toimprove the hydraulics of the downstream Yodo River by exca-vating an island blocking the flow, launched the project in 1684and completed it in 1687. Similarly, the construction of a floodway leading to the Osaka Bay from the Yamato River, with a distance of 14.5 km, was completed in 1704, changing sparing the
Kawachi plain (the current Osaka region) from being a to be
flood-prone land to an arable land for paddy and cotton agriculture. More recently, Lake Ogura (Ogura-ike), originally existingas part of the Uji River system at the confluence point of the Uji,
Katsura, and Kizu rivers to form the main stem of the Yodo
River, was embanked and partially isolated from the Uji Riverduring the above Hideyoshi Period for the construction of
Fushimi Castle. As an aside, the lake was totally cut off in 1906
as part of the Uji River Improvement project, later to be completely drained to be subjected to a large-scale paddy land development project undertaken as recently as the 1933–1941 period.
A detailed historic account of the Yodo River Basin with respect
to flood control, water resource development, and environmental and ecosystem concerns is given in Nakamura et al. (2012).
Various accounts of the management intervention history of the
Yodo River are also provided in the popular literature (e.g.,
Yodogawa gaidobukku henshuiinkai 2007; Fujioka 1983;
Nishino 2009) (see >Fig. 4 for a schematic image of the geo-­
historical transformations of the Osaka Bay configuration).
The pursuit for urban water metabolism also involved someland–water transformations, particularly in relation to the construction of sewerage systems in the current city of Osaka, or the
Yodo River Delta formation where much of the land was originally interspersed with expansive wetlands. The earliest kind ofhousehold drainage systems in Japan are found in the remains ofhuman settlements of the Yayoi Period. By the Nara Period(710–794), the archeological sites of Heijo-kyo, the oldest capitolof Japan in the current city of Nara, located some distancetoward the south of Osaka, a well-laid-out sewer drainage network is found in its archeological sites. More recently, the castle
town of Osaka was historically in need of sewerage to preventthe spread of waterborne diseases. A stone culvert system called
the Taiko Sewerage constructed in the Azuchi–Momoyama
Period (1573–1603) was found still intact today in the previous
castle town area surrounding the Osaka Castle, where rich merchants and higher-class solders used to reside. The historicalextension of the above stories are the modern day Osaka sewerage and stormwater drainage systems. The city launched construction of a combined sewer system (a sewerage system tocollect and treat the wastewater under the dry weather condition
but to collect and discharge it directly to the Osaka Bay together
with the collected urban stormwater under wet weather conditions when the combined flow exceeded a certain limit) in 1894
after major cholera outbreak incidents. Upgrading of the extensively developed Osaka sewerage system continued, providing
the city with one of the most extensively developed seweragesystems in Japan as early as the 1970s. The system progressively
improved, including the completion of an extensive ­undergroundsewage network, as well as stormwater retention and discharge

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 4
Geo-historical transformations of the Osaka Bay Configuration: a) up to some 9400 years ago, b) up to some 8000 years ago, c) up tosome 5500 years ago, d) up to some 4500 years ago, and e) as of today (Ransetu no Sayama Sa-an, no date)

systems. In the meantime, the municipal water supply system inOsaka also was developed in about the same time period. The
first modern water supply system was constructed in 1895, also
for combatting outbreaks of waterborne diseases. This watersupply system was soon expanded to serve for the rapidly developing surrounding municipalities and also to meet the growing
industrial water demand as well.

Transformation of the Flow Regimes
The transformation from the lentic–lotic flow regime to ahydrostatic–hydrodynamic regime (see >Box 1) can take placein many different shapes and forms of artificial interventions
over the course of its history. For example, the geohydrologicalalteration of the Osaka Bay Delta region, being much more
toward the inland direction, with the receding sea water level
creating a deep embayment formation that was subsequently

transformed to Kawachi Lake, illustrates a transformation of
one form of lentic–lotic flow regime to another, without any
human interventions. During the late Jomon and early Yayoi
periods, the former Lake Ogura was an important componentof the Lake Biwa–Yodo River lentic–lotic flow regime, together
with many other natural lake- and pond-like formations of various sizes, some temporary and others semipermanent. In themeantime, the paddy farmers construct drainage channels andcanals for paddy irrigation purposes, resulting in many otherhydrostatic–hydrodynamic systems. Typical structures existed
in the Yamato, Kawachi, and Settsu plains, where water was
drained out via manually constructed canals, transforming wetlands to dry fields suitable for paddy agriculture. The humansettlements were developed on higher grounds in the form ofmounds surrounded by deep moat formations, later named“Wajyu” systems. With an increased population and food production need, the conversion of wetlands to dry fields continued through the medieval Edo Period (between 1603 and 1868,

491

492

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin GovernanceBox 1 The Flow Regime Transformations: Lentic–Lotic vs. Hydrostatic–Hydrodynamic
Lakes and reservoirs are broadly considered as “standing” or “static” water systems, or, using a hydrologic term, they are designated “hydrostatic” systems. In contrast, “moving” waters, such as rivers, can be regarded as “hydrodynamic” systems. In
general, the terms hydrostatic and hydrodynamic are also more commonly associated with human ingenuity to control andutilize the physical properties of water through application of technologies. Similar expressions exist in the ecology literature
as well. The descriptive terms are “lentic” and “lotic” systems. The meaning of “lentic” is basically the same as for hydrostatic,
and the meaning of “lotic” is the same as for hydrodynamic. However, the lentic and lotic expressions have the additional
connotation of their imbedded ecological functions. That is, the term “lentic” also connotes the ecological properties uniqueto a standing body of water, while the term “lotic” also connotes the ecological properties unique to a moving water system.
In other words, the terms lentic and lotic imply the geo-historically formed ecosystem significance associated with standing
and moving waters, even to connote the anthropogenic state of water with evolutional and historic memories of human–nature interactions. Thus, the basin water systems as they exist naturally, such as lake–river systems, pond–stream systems,
and wetland–spring systems are lentic–lotic systems because of their historically fostered ecosystem functions. Even if thebasin water systems have been modified by human interventions, the greater the time that has passed after such interventions
that allow more time for “naturalization” to occur, the greater are their lentic–lotic implications. On the other hand, a watersupply storage tank of treated water, with inflowing and outflowing conveyance pipelines, constructed with artificially manufactured materials, such as steels and concretes, would be regarded only as hydrostatic–hydrodynamic systems. Those water
systems constructed by man when such technologies and materials were not available may have acquired lentic–lotic properties through many decades and centuries of naturalization.
The transformation of basin flow regime, i.e., from the “more lentic–lotic state” to “more hydrostatic–hydrodynamic
state,” occurs as a result of historical human interventions to alter the land–water linkage structure that has occurred becauseof the basin population and their intervention capability and capacity, as shown in Box >Fig. 1a. In essence, the dynamics ofbasin water are founded on the natural hydrological phenomena (forming the basis of natural water circulation system) andthe artificially instituted hydrological mechanisms (forming the basis of artificially created water metabolism) and are sup-Strongly Lentic – Lotic
Examples:More
Lentic-Lotic• natural lake-river systems,• pond-stream systems,• wetland-feeder spring systems

Less HumanIntervened

Moderately Lentic – Lotic
Examples:• pond-channel systems constructed inold days, becoming naturalized

More
HydrostaticHydrodynamic

Weakly Lentic – Lotic
Examples:• storage tanks and pipelines• detention ponds and discharge
channels⊡⊡ Box Fig. 1a
Lentic–lotic basin systems in the hydrostatic–hydrodynamic context

More HumanIntervened

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6

Hydrostatic Hydrodynamic
Systems
Lentic - Lotic
Systems⊡⊡ Box Fig. 1b
A basin with overlapping lentic–lotic and hydrostatic–hydrodynamic flow regime

ported by the overall framework of their management or the basin governance. Over some thousands of years of humaninterventions, the scale and magnitude of human interventions have dramatically increased with the acquired technologicaland managerial skills, particularly in the last few centuries. Many lake–river embayment basins today exhibit a configuration
feature consisting of a complex combination of lentic–lotic and hydrostatic–hydrodynamic flow regimes, in an often multiply
nested manner, as shown in Box >Fig. 1b.

for 265 years)until the mid-twentieth century. The extent of
conversions was constrained by the configurational feature of
the Biwa–Yodo Basin terrain. After most of the easily conversional land was transformed to arable land, the increased foodproduction depended more on an increased productivity perunit land space and an increasing variety of crops other than
paddy rice.
>Figure 5a is a map of wetland areas identified to haveexisted in early Meiji Period (mid-nineteenth century), and>Fig. 5b is a map of what is called the wetland potential calculated using a GIS computational tool (SAGA GIS 2018) that
supposedly simulates the geo-historically existed lowland
areas. The two closely resemble each other. >Figure 6 is a mapof the depressions artificially created by using GIS (the size ofdepressed land formations is exaggerated for ease of visible
identification). The distribution of thin lines represents tributaries of the main rivers, while that of dots are the depressions
where water would have easily been impounded. As it turned
out, the Biwa–Yodo Basin and the surrounding region are
known for numerous irrigation ponds having been constructed
over the course of history and exist to the present time. They
are another form of lentic waters interlinked with lotic waters,i.e., the hand-dug canals and dendritically spanning tributary
rivers.

Technological and Managerial Implications
The transformation of a basin flow regime from the “more lentic–lotic state” to a “more hydrostatic–hydrodynamic state”
takes place as a result of historical human interventions. Broadly
speaking, it often involves some thousands of years of humaninterventions during which the scale and the magnitude ofhuman interventions have dramatically increased, particularlyin the last few centuries with the acquired technological andmanagerial skills. The concept of “water management,” therefore, has also evolved to encompass “water control” in the latenineteenth century after a series of government interventions
and then “water metabolism” of the urbanizing regions, particularly in the latter half of the twentieth century in multiple sub-­basins of the Biwa–Yodo Basin. Here the term “management” ofa basin is quite an encompassing concept in that it pertains tomanagement of such constituent mattes as water, soil, sediments, etc., management of the bounded land space, or thephysical expanse of such constituent basin areas as urban area,
forest area, agricultural area, etc., and it further pertains to various resource values such as water (quantity and quality), thestate of their existence (surface and subsurface flows and theirtransient behaviors), as well as the activities taking place within
the spatial existence of land and the associated productive func-

493

494

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 5
Actual wetland in the mid-nineteenth century (a), calculated wetland potential (b), and river inundation hazard area (c)Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 5(continued)

tions such as urban and industrial activities. In addition, water
management also entails accommodation as much as possible
for specific ecosystem characteristics of the basin terrain, fromthe uppermost reaches of dendritically shaped feeder river systems and their surrounding forestlands that provide for theirretention capacity, among others, all the way down to the delta
formations at the river mouths and the tidal estuaries that possess the geo-historically formed physical, chemical, and biological properties and functions.
Among “water management” elements is “control of flowing
water” such as flood control to reduce inundation and structuraldestruction and damages and drought control to reduce shortages of water for household, urban, industrial, and agriculturaluses. The reduction of flooding risks may be achieved by structural intervention measures such as construction of dams andlevees and by nonstructural measures such as preparation inadvance of the risk aversion, risk avoidance, and other meansand procedures for preparatory and precautionary actions. The
reduction of water shortage risks may be achieved by structuralintervention measures such as construction of reservoirs andrainwater holding facilities and by nonstructural measures suchas preparation in advance for implementing water-saving prac-

tices. These water control policies and programs generally fallunder the jurisdiction of water resources management and rivermanagement agencies.
The concept of water metabolism has emerged to describe
the material balance and transformation within the systems
humans have developed and their support mechanisms. For
example, in the case of urban water metabolism, the quality ofwater suitable for drinking is produced through water treatment
processes that provide for physicochemical and biological water
quality transformation processes such as mixing, flocculation,
filtration, adsorption, and settling. The transformed quality
water will be provided to the consumers through the distribution system by taking advantage of water’s transportability bygravity. If the quality of raw water is sufficiently good, the cost ofwater quality transformation would be lower than otherwise.
The similar situation applies to waters used for industries and for
agriculture or irrigation, the quantity of which is generally muchgreater in most cases. Because the intake, transport, and distribution systems, respectively, of drinking, agricultural, andindustrial purpose waters are generally independently constructed, their collection and disposal systems (i.e., sewerage,
effluent discharge, and irrigation return flows) exist independently.

495

496

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 6
Image of the original Lake Biwa–Yodo River lentic–lotic systems (credit: Thomas Ballatore, Lake Basin Network)

Depending on the size of such systems determined on the basisof human convenience, these artificially created systems of water
metabolism may straddle more than one basin, resulting in artificial inter-basin water transfers.
In essence, the dynamics of basin water are founded on thenatural hydrological phenomena (forming the basis of natural
water circulation system) and the artificially instituted hydrological mechanisms (forming the basis of artificially createdwater metabolism), and have become complexly intertwinedwith multiple frameworks of their management, or the basingovernance. With regard to flood control, the countermeasures
have been gradually improved over the past several decades,
although there are many pending issues of concern such as theincreasing frequency of extreme weather events. With regard to
the water metabolism infrastructures such as water supply andsewerage facilities, the population provided with piped water
exceeds 17 million or nearly all of the population within theBasin, and the sewerage coverage is quite high in the densely
populated areas within the Basin (>Fig. 7), although the facility
renewal needs have emerged as a growing concern. As a whole,
therefore, the lentic–lotic and hydrostatic–hydrodynamic balance within the Biwa–Yodo Basin has shifted significantly
toward the latter, highlighting the need to address the ecosystem
sustainability of the Basin system.

 quatic Ecosystem Features and Their
A
Transformations
There is a number of reasons that aquatic ecosystem areadversely affected. For example, according to Nishino (2009,
p 41–48), the threat factors to native fish species in the Lake
Biwa–Yodo River system include introduction of carnivorous
alien species of fish, channelization and other river improvement works, water pollution, agricultural land improvement
works, water level control for flood control and drought management, lakeshore levee construction, a decline in the numberof host bivalve shellfish, and overfishing, where each threatened
fish species is found to have been subjected to more than one
factor. Among the above factors, channelization and other river
improvement works, agricultural land improvement works, andlakeshore levee construction are physical alterations of fish habitats or, in relation to the expressions used in this chapter, transformation from a lentic–lotic flow regime to ahydrostatic–hydrodynamic flow regime. These physical alterations, together with water pollution and water level controls, areman-induced (non-biological) factors, while alien species offish and decline in bivalve shellfish are biological factors. Of the
42 threatened fish examined, 35 of them are ascribed to thethreats category of physical alteration of fish habitats (Nishino

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 7(a) Sewage treatment facilities in 2010, (b) Sewerage coverage rate by population served (%) in 2010 (BYQ 2017)2009, p 42). More specifically, Lake Biwa has undergone rather
dramatic changes of concern with respect to the aquatic ecosystem features attributable to land–water transformations and tothe human–nature interaction features implicitly ascribable tothe flow regime transformation as follows:
The aquatic ecosystem features include:•• Disappearance of attached lakes, i.e., the reduction in fish
diversity is attributable in part to the landfilling of satellite
lakes attached to Lake Biwa. Recent studies on satellite lakes
have proven to have amplifying effects on biodiversity.
•• Artificially constructed shorelines, i.e., the dominance of
only a few carnivorous species capable of surviving in theartificially constructed shorelines is found to be contributing
greatly to the diminishment of fish species diversity.
•• Levee cum ring road, i.e., the shoreline along the lakeshore
has been extensively transformed to levee cum ring roads
that have been found to suppress the growth of wetland species of plants.
The human–nature interaction features include:•• Traditional water culture lifestyles, i.e., some of the ruralcommunities are favorably located to maintain the tradi-tional water culture, such as using the spring water for nonpolluting household purposes and the discharge of its
wastewater free of contamination (keeping the lentic–lotic
water environment).
•• Discharge of paddy irrigation return flow, i.e., the paddy
farmers, now provided with irrigation water from large-scalelake water irrigation by pumping (a hydrostatic–hydrodynamic system), are also being guided to reduce the amountof contaminated return flows being discharged into the lake,
possibly by recirculation and reduction of water use. The traditional low-­impact cascading irrigation systems (lentic–lotic system) are now experimentally tested for its advantage,i.e., to appeal for the environmentally conscious consumers.
•• Man-made rivers, i.e., the ayu fish (Plecoglossus altivelis)
fisheries are using the man-made rivers with pumped water
mimicking the natural river flows for the fish to spawn on
the artificial spawning ground (a simulated lotic–lentic regime using a hydrostatic–hydrodynamic technology). Such
artificial rivers were created as the newly introduced operation rule of the Setagawa Weir being operated for flood control and drought management which defy the naturally fluctuating lake water level, leading to drying up of natural
spawning grounds during the spawning season.

497

498

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin GovernanceIn all, the bountifulness of Lake Biwa ecosystem has beensignificantly compromised by the transformations of linkage
structure and of flow regime.
The bountifulness of ecosystems in the Yodo River portion
has also been declining during the course of flow regime transformation from lentic–lotic to hydrostatic–hydrodynamic innature, except that the lotic/hydrodynamic features, typicallyexhibited by the water systems of flowing nature such as rivers
and channels, are much more dictating than the lentic/hydrostatic features typically exhibited by the water systems ofimpounded forms such as lakes and reservoirs.
Rivers have morphological features and associated ecosystem functions as reflected in (1) domains of flowing water, (2)interactions among water media interfaces, and (3) transientand transitional features of the landscape. As for item (1), there
are three domains, i.e., surface flow domain, subsurface flow
domain, and geosphere domain such as wetted perimeters andembankment formations. As for item (2), a milieu of intricate
interactions is taking place in the hydrosphere (water), geosphere (soil), and their interface environments. As for item (3),the topography (e.g., soil types and elevations) and hydrography(e.g., depth, velocity, surface area, and water quality) change
gradually and continuously toward the downstream direction,
as well as toward the shoreline direction, to form the landscapefeatures. The morphological features and associated ecosystem
functions change over multiple temporal and spatial scales in
response to the water quantity and water level fluctuations, as
typically represented by the recurrence cycles, e.g., on the orderof years, scores of years, and centuries. The recurrence of seasonal changes less than 1 year in duration, such as occasional
small-scale flooding and rainy and dry seasons, is the driver for
perpetuation of annual landscape features (Osaka kougyo
daigaku yodogawa kankyo kyouiku sentah (2008).
The physical alteration impacts to the aquatic ecosystem in
the Yodo River, therefore, should be considered to be undermuch greater stress than that Lake Biwa, not only because of thedramatic transformation of the flow regime from more lentic–
lotic than hydrostatic–hydrodynamic but also because of thenear-total disconnect of river flows due to the installation ofvarious in-stream flow control structures for flood control,
drought management, and navigation purposes. For example,
the mainstream Yodo River and Lake Biwa was virtually disconnected from downstream upward by the installation of the
Nango Weir in 1905 and the Amagase Dam in 1970. Such downstream–upstream disconnects have virtually prevented the
upstream migration from the Yodo river mouth connected to
Osaka Bay of such species as Oncorhynchus masou masou,
Plecoglossus altivelis, Anguilla japonica, and Eriocheir japonica,
known locally as “Satsukimasu,” “Umiayu,” “Unagi,” and“Mokudugani.” On the other hand, Nishino (2009, p 28) also
notes that because of the upstream–downstream disconnect, of
the 61 indigenous species of fauna (mostly shellfish and fish),

only 21 species are recorded as being identified in the aquatic
environments downstream of Lake Biwa, despite the fact thatthe species are being constantly supplied through the Seta Riverand Lake Biwa Canal. It is inferred that the species may reachdownstream, but they simply cannot multiply due to the lack ofsuitable food and environment for a lasting habitat.
As a showcase movement for aquatic ecosystem restoration, afish species identified as Acheilognathus longipinnis, commonly
known as Itasenpara, has been drawing much attention. The fish
was thought to have become extinct in the Lake Biwa water by themid-1940s and in the Yodo River water by the early 1960s.
However, it was reidentified in 1971 by a group of high school
students studying the river at one of the water pools in the midstream Yodo River and later at a few dozen other locations along
the river. The fish then acquired the natural monument status in
Japan in 1974, and ever since it has become a symbol of the Yodo
River ecosystem restoration, with many groups of citizens and scientists volunteering to protect their habitats. The habitat spots
identified were actually called the “Wando (fluvial lagoon),” being
constructed as part of the river improvement work starting in
1878, headed by a Dutch Engineer. These “Wando” structures are
sided with partitioning stone piers protruding out toward the
deep to create a deeper channel within the river course even during drier periods with little water. However, the role of these“Wando” structures was thought to have been already fulfilled indeveloping the new river improvement plan of 1971. The plan was
to increase the throughput of the Yodo River flow by large-scale
dredging of the river bottom together with installation of a flow
control structure at Kema, only several kilometers from the rivermouth entering Osaka Bay. The “Wando” structures got graduallyphased out over the course of time, except for a couple of dozen ofthem having survived, still to forming water pools here and there.
Those “Wando” remains found their own purpose of different
kinds, i.e., for aquatic ecosystem restoration of Itasenpara.

 volving Governance in Managing
E
Point and Nonpoint Source Pollution
This section consists of three subsections. The first subsection
deals with the Lake Biwa–Yodo River water quality trends overthe past 20 years, as expressed in GIS map displays, with reference to the point source–nonpoint source relationship. During
the period, there was land use changes with associated flow
regime transformation from more lentic–lotic to more hydrostatic–hydrodynamic, contributing to the trend toward increasing nonpoint source pollution (section “Basin water quality:
Shifting emphasis from point source to nonpoint sources”). The
second subsection presents an overview of the road drainage
nonpoint source pollution, one of the most challenging nonpoint pollution issues yet to be addressed adequately (section““Road drainage”: An overlooked issue”). The last subsection

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governancedeals with key governance challenges facing the Lake Biwa–
Yodo River nonpoint source pollution issues in whole and theneed for conceptual realignment needed about the future
courses of action in dealing with the challenge (section “Beyond
the conventional approach”).

 asin Water Quality: Shifting Emphasis
Bfrom Point Source to Nonpoint Sources
The water pollution loads entering into lakes and rivers originate
either from specifically identifiable discharge points or from notso-easily identifiable discharge points. Typical point sources ofpollution include municipal wastewater treatment plants, industrial wastewater treatment plants, stocking and disposal facilities
of livestock manure and aquaculture wastes, as well as the discharge outlets of combined sewer overflows. Typical rural nonpoint pollutants include excess fertilizers, pesticides and otheragricultural chemicals from such sources as paddy fields, croplands and forestlands. Typical urban nonpoint pollutants include
atmospheric depositions, chemical and biological contaminants
as well as debris particles on the paved surfaces, rooftops, roads
and highways in the urban areas. The quantities of nonpoint
sources of pollution discharged to the receiving waterbodies
depends much on the intensity and frequency of precipitation.
The overall state of water quality in the Biwa–Yodo Basin
attributable to point sources of pollution has been significantly
improved over the past decades, thanks to the increased coverage of wastewater treatment systems by area and population
served. The state of sewerage service coverage by population
served (in percent) in 2010 of the Biwa–Yodo Basin is shown in>Fig. 7, which may be compared with >Fig. 3 (population distribution), indicating that most of the Lake Biwa population
centers and the downstream Kyoto and Osaka metropolitan
areas are already well served by their respective sewerage systems. The major wastewater treatment plants located around
Lake Biwa are provided with tertiary treatment process forphosphorus and nitrogen removal. The stringent implementation of regulatory measures, advancement of monitoring techniques, and research and applied study capabilities at the
government institutions and universities also contributed to thedevelopment of control policies and programs for point andnonpoint source pollution.
The GIS graphics shown in >Figs. 8 and 9 are the changes
in biochemical oxygen demand (BOD) and chemical oxygen
demand (COD, measured using potassium permanganate asan oxidizing agent, or CODMn, hereafter referred to simply as
COD) over the 20-year period between 1990 and 2009 for thewhole Biwa–Yodo Basin. The areas with little or no improvement in river water quality (red and orange) correspond to thearea provided with insufficient sewerage coverage, as shown in

6>Fig. 7. Overall, significant improvement has been achieved

with respect to BOD, but less with respect to COD.
While the reduction in the river COD concentration is
attributable to increased sewerage coverage, the increase in the
COD concentration is due to the increasing inflow of wastewaterfrom areas where the sewerage systems were still inadequate totake care of the rapidly increasing population and industrial
activities. The poor improvement of lake water COD concentration is due mainly to the growing quantity of COD generated
in-lake, well as by the growing inflow of land-based COD materials contained in the river water.
>Figure 10a–d illustrates four pairwise comparisons of thepotential nonpoint pollution magnitudes computed using thevalues for the GIS 500-m grid size data (computed as the combined mean of 25 100-m grid size data), >Fig 10a as illustrated in>Table 1 based on the values provided by the Japan Sewage Works
Association (2009) and Nishizawa and Tachi (2009), and >Fig
10b–d using the unit pollution load for the respective land use
categories of the COD, TN, and TP shown in >Table 2, based on
the values provided by Shiga Prefecture and Kyoto Prefecture
Background Document for the Preparation of Fifth Lake Biwa
Water Quality Conservation Plan (2006 through 2010).
The following are interpretations of GIS figures, >Fig. 10a–d,
for the assessed parameters of the runoff coefficient, COD, TN,
and TP.
A pair of GIS images is shown for each of the above fourparameters, i.e., the status assessment for 2009 shown on the left
side and the status assessment for the incremental change during the period between 1991 and 2009 shown on the right side.
The interpretation of the left side image (i.e., the 2009 statusassessment) should be straightforward. The grid color represents the assessed magnitudes of the runoff coefficient and of thepollution load discharge values of COD, TN, and TP in 2009,
based on the assumed values shown in >Tables 1 and 2. Theinterpretation of the right side image (i.e., the status assessment
for the incremental change during the period between 1991 and2009) will require knowledge regarding land use changes during
the period. The figure indicates a significant reduction in domestic and industrial loads attributable to the extensive coverage ofsewerage system for the reduction of respective point sourceloads, with the resulting decrease in the sewerage effluent load
after their treatment. On the other hand, there are increases inurban nonpoint source loads, despite the fact agricultural loads
have been reduced. The increased rainwater load is attributablein part to climate change impacts during the period. The
increased urban nonpoint source load is attributable both to theslow progress in urban nonpoint source control and to thechange in land use from agricultural land to urban land forwhich the unit pollution load is higher for the latter. The following are specific observations for each of the eight cases:<Runoff coefficient for 2009, >Fig. 10a)-left>

499

500

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 8
Improvement in BOD values
between 1990 and 2009 (the1990 and 2009 values are themean values of 1988, 1989,
and 1990 and the mean valuesof 2007, 2008, and 2009,
respectively). (BYQ 2017)•• The intensity is high in the urban areas (reddish, 0.8–1.0),
particularly in the highly populated municipal areas on bothsides of the downstream Yodo River region. It is also high inthe highly populated urban centers in the eastern plain partof Lake Biwa watershed, although they are immediately surrounded by the agricultural areas exhibiting slightly lower
coefficient values (green/yellow, 0.4–0.7). The intensity is
generally quite low for the forestland (blue).
<Runoff coefficient, differential increment during the 1991–
2009 period, >Fig. 10a)-right>•• The reddish grids on both sides of the downstream Yodo
River region, in the upstream Kizu River (toward the easternwatershed boundary), and on the eastern side of the South
Basin of Lake Biwa correspond to the areas where land use

has changed from suburban agricultural land to housing or
to other urban built-environment land, resulting in increased runoff coefficient values. The reddish grids scatteredinto the forestland areas are locations where forest clearing
took place for land development purposes.
<COD pollution load potential for 2009, >Fig. 10b)-left>•• The values are quite high (mostly reddish, more than 140 g/ha/day) in the urban areas on both sides of the midstream
Yodo River and in the entire metropolitan Osaka region
downstream of the river. The values are also quite high in theeastern plain part of the South Basin of Lake Biwa.
<COD pollution load potential, differential increment during the 1991–2009 period, >Fig. 10b)-right>

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 9
Improvement in COD values
between 1990 and 2009 (the1990 and 2009 values are themean values of 1988, 1989,
and 1990 and the mean valuesof 2007, 2008, and 2009,
respectively). (BYQ 2017)•• In general, there are close overlaps between the reddish gridclusters in >Fig. 10a)-right and those in this figure, meaning
the regions with increasing trends in runoff coefficients tend
to match closely to the regions with increasing trends in
COD pollution load potential.
•• The reddish grids in the Lake Biwa watershed area and in the
Yodo River region represent the areas where paddy land parcels were converted to suburban housing land parcels, andthe suburban sprawl land parcels interspersed with patchesof agricultural land were converted to the densely urbanized
land parcels, etc.
•• One of the major reasons for the decreased COD in the upper Kizu River region (toward the eastern watershed boundary) is because a significant number of farmer population
have given up paddy agriculture, leaving much of their pad-dy land to become idle grassland and golf links. Similar reasoning applied to the agricultural areas in the mountainous
region exhibiting similar decreasing trends in COD over the
20-year period.
•• The land use changes from paddy land to urban and suburban lands increase the COD load, but not significantly (from118 to 144), while those from forestland and idle grassland
to urban and suburban lands increase the COD load quite
significantly (from 46.2 to 144). These two “increasing” factors contribute to the overall reddish appearance of gridclusters, compared to TN and TP cases discussed below.
•• The blue grid clusters spread across the upstream land bordering the watershed boundaries because many paddy landparcels have been converted to croplands, reducing the COD
load to half (from 118 to 62).

501

502

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 10a(a): Runoff coefficient values for 2009 (left), and the difference between the 1991 values and the 2009 values at the respectively
corresponding locations (right). (b), (c) and (d): The COD, TN and TP pollution load distributions each for 2009 (left), and the difference
between the 1991 values and the 2009 values at the respectively corresponding locations (right).
The GIS displays were developed using the data obtained from the National Land Numerical Information Service, Japan

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 10b(continued)

6

503

504

6

⊡⊡ Fig. 10c(continued)

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin GovernanceEvolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 10d(continued)⊡⊡ Table 1
Runoff coefficient values for respective land use categories
Land use types
Paddy field
Other farmlands
ForestIdle grassland
Building use
Highways and transportation
Other urban field
Rivers, lakes, and reservoir
Golf links

Runoff coefficient value
0.4
0.2
0.3
0.2
0.9
0.85
0.2
1.0
0.2

Source: The Japan Sewage Works Association (2009) and Nishizawa andTachi (2009)

6

505

506

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Table 2
Unit pollution load values for respective land use categories
Unit pollution load (g/ha/day)Land use types

COD

TN

TP

Paddy field
Other farmlands

118.0

39.2

2.68

62.0

261.0

0.54

Forest

46.2

18.0

0.35

Idle grassland

46.2

18.0

0.35

Building use

144.0

38.6

2.00

Highways and transportation

144.0

38.6

2.00

Other urban fields

144.0

38.6

2.00

Rivers, lakes, and reservoirs

–

–

–

Golf links

62.0

261.0

0.54

Source: Background Document for the Preparation of Fifth Lake Biwa Water Quality Conservation Plan (Shiga Prefecture and Kyoto Prefecture 2006
through 2010)<TN pollution load potential for 2009, >Fig. 10c)-left>•• The values (orange and red colors) are particularly high inthe tea plantations and golf links (261 g/ha/day) in the deep
suburban and hill areas.
•• The yellow, orange, and red grids near the urban areas correspond mostly to vegetable and other croplands.
<TN pollution load potential, differential increment during
the 1991–2009 period, >Fig. 10c)-right>•• The land use changes from paddy land to urban and suburban lands does not greatly affect the TN load (from 39.2 to38.6), although those from forestland and idle grassland tourban and suburban lands affect TN load somewhat significantly (from 18.0 to 38.6).
•• There are many bluish grid clusters appearing in the entire
Lake Biwa–Yodo River over the 20-year period, indicatingareas with conspicuously cumulative TN reductions over the
20-year period in areas where paddy land parcels were converted to housing land parcels.
•• As discussed with respect to COD, a significant number ofthe farmer population have given up paddy agriculture, leaving much of their paddy land to become idle grassland, resulting in a significant number of bluish grid clusters implying a significant TN decrease over the 20-year period.

coefficient is highest because of a high density of roads (0.85)
and an extensively built-up environment (0.90).
<TP pollution load potential, differential increment during
the 1991–2009 period, >Fig. 10d)-right>•• The land use changes from paddy land to urban and suburban lands reduce the TP load somewhat significantly (from2.68 to 2.00). The bluish grid clusters in the urban and suburban areas in the Lake Biwa watershed close to the lakeshore attest to this fact.
•• The land use changes from forestland and idle grassland tourban and suburban lands increase the TP load quite significantly (from 0.35 to 2.00), as indicated by the reddish color.
Such lands are scattered around in the upstream region in
the southeastern part as well as northwestern and northeastern coastal regions of the Lake Biwa and in the midstream
suburban regions of Yodo River.
•• As shown in >Table 2, the TP and TN profile are similar. In
other words, there are areas with decreased TP due in part tothe paddy land converted to housing land and also due to theincrease in idle grassland and golf links resulting from abandonment of paddy agriculture in certain higher altitude regions. On the other hand, the TN would increase by the transformation of cropland to housing land and to idle grassland, as
shown by the distribution of grid clusters with reddish color.

<TP pollution load potential for 2009, >Fig. 10d)-left>•• The distribution of red grids corresponds to the paddy agricultural land in the Lake Biwa watershed and in the upstream of Katsura River toward the southwestern mountainregion. The brownish grids on both sides of downstream
Yodo River region correspond to the highly populated urban
areas on both sides of Yodo River, where the value of runoff

“Road Drainage”: An Overlooked Issue
Among the most challenging nonpoint pollution issues is that of“road drainage,” consisting of gaseous and particulate exhausts
and fuels, worn and torn tire debris of various sizes, asphalt andEvolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6

concrete chips and powders, shredded plastic parts and torn vidual drivers, automobile and tire manufacturers, etc., althoughmetal pieces, roadside vegetation litters, etc. They contain haz- their individual and collective responsibilities have not yet beenardous inorganic and organic chemicals, including polycyclic clearly delineated, partly because the legal and policy framearomatic hydrocarbons (PAHs), as well as eutrophication-­ works have not yet been established. While implementation of acausing nutrients such as nitrogen oxides and phosphorus. These totally dedicated policy to reduce the road drainage pollution
noxious substances get accumulated in dry weather and washed may face complicated legal, institutional, and administrative
off at times of storm events (e.g., Wada et al. 2006, 2011, 2015).
challenges, the reduction may be achievable by taking advantage
Some initial studies to estimate their magnitudes for the of the purification capacity of natural and constructed wetlands
Lake Biwa watershed have been undertaken (Wada and Fujii available for meeting other objectives such as flood risk reduc2007, 2010). The studies focused on the “first flush” (the initial tion, environmental amenity enhancement, and aesthetic
wash-off of the accumulated pollutants on the road surface at a improvement.
rain event after a period of dry weather) of the Lake Biwa Basinroad drainage. The precipitation measurements for an intervalof 10 min with a scale range of 0.5 mm recorded at the Beyond the Conventional ApproachOmihachiman District Meteorological Observatory was
obtained from the Japan Meteorological Agency (2000). Data for As discussed in the previous two subsections, sections “Basin
all dry weather periods and all rainfall amounts were substituted water quality: Shifting emphasis from point source to nonpoint
into the model, and the pollutant loads were calculated as aver- sources” and ““Road drainage”: An overlooked issue”, the quanage values for 10 years for the 1998–2007 period. A summary of tity of nonpoint sources of pollution to be reduced in the Biwa–
Yodo Basin is still far from satisfactory. Some of the major
the study findings are as follows:difficulties associated with introducing effective control mea•• The pollutant loads of road drainage in the Lake Biwa watersures for nonpoint source pollution include:2
shed were 29.9, 3.50, and 0.18 kg/(km ·d) for COD, TN, andTP, respectively.
•• The spatial extent of nonpoint source pollution is generally•• These values are used as unit loads for estimating the refar too expansive for the introduction of cost-efficient
spective pollutant loads. The unit loads are expressed asmeasures.
mass per area per time, typically kg/(km2·d). The unit loads •• It is generally infeasible to direct appropriate sets of manageof road drainage in the Lake Biwa Water Quality Protection
ment policy, institutional framework, as well as the financing
Program (LBWQPP, Shiga & Kyoto Prefectures 2007) were
scheme, for prevention, control, and treatment of all types of
14.4, 3.86, and 0.20 kg/(km2·d) for COD, TN, and TP,
nonpoint source pollution from numerous individual source
respectively.
types.
•• The COD value obtained in this study was twice as much as •• Development of legal and regulatory frameworks for nonthat of the LBWQPP, and the values of TN and TP were alpoint source control generally requires considerations formost the same as those of the LBWQPP (>Fig. 9). Thesebalancing the competing policy objectives. For example, efvalues were multiplied by the total area of roadways in thefective control of agricultural nonpoint source pollution repwatershed (98.8 km2) obtained from the Roadways Traffic
resents a subtle balance between agricultural and environCensus (Ministry of Land, Infrastructure, Transport andmental policy objectives, which may bring about half-hearted
Tourism and Shiga Prefecture 2002), and the road drainage
and ineffective implementation results.
amounts in the Lake Biwa watershed were determined to be •• In general, the management programs of nonpoint source
2950 COD kg/d, 350 TN kg/d, and 18 TP kg/d,
pollution encompass multiple policies and programs berespectively.
longing to different sector agencies, and their collective im•• This estimated COD load was equivalent to 7.7% of the total
plementation may be hampered by the ambiguity in legal
COD inflowing load to Lake Biwa in 2005 (38,400 COD kg/
delineations and by the incompatibilities of technical andday). Considering the extremely hazardous nature of the
managerial practices.
first flush road drainage discharged directly to the water •• Introduction of countermeasures would generally requirecourses, the need for effective control measures isinstallation of extensive and expensive physical facilities that
imminent.
are far beyond the responsibility and capability of a particular sector. For example, the control of forestland nonpoint
The foremost of many possible reasons for the challenges
source pollution, e.g., dissolved and suspended pollutants
facing road drainage is that there are so many factors affecting it,
being washed off together with soil particles at times ofbut none being significantly prominent. Thus, it is difficult tostorm events, may require installation of extensive facilities
develop a viable institutional framework to deal with this issue
far beyond the forest sector’s financial capability.
unlike the cases with other sources of nonpoint pollution. As for •• The physical, chemical, and biological response characteristhe managerial complexities, the parties to be held responsible
tics of nonpoint source pollution are spatially nonuniform
could include the road authorities, road transport industry, indiand temporary irregular, making it quite challenging to

507

508

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governancemake precise and accurate assessment for the developmentof effective programs.
•• The land–water interactions, including those related to subsurface water flows, are too complex to make accurate
measurements.
•• The recent changes in climatic conditions are affecting theirtemporal and spatial behaviors beyond the prediction basedon the past historical records.
Further, together with their special features of integrating
nature, long retention time, and complex response dynamics,
the nonpoint source pollution problems will continue to linger
for such enclosed bodies of water as lakes, wetlands, and coastal
embayment formations.
In the meantime, there are some promising developments
both in Japan and in other countries. In the case of Japan, theonly legislation that specifically provides a legal framework for
managing nonpoint source pollution is the Law Concerning theSpecial Measures for the Prevention of Lake Water Quality,
enacted in 1984 and amended in 2005. The law stipulates that
“The areas which require some measures to treat contaminatedeffluent water from the farmlands and urban areas are designatedas ‘target areas’ for the treatment of effluent water, and the actions
plans should be formulated and promoted. The peripheral areasof lakes and marshes which requires special protection for preserving the water quality is designated as environmental preservation areas around the lakes, and the notification is obliged intaking some plants from these areas” (WEPA 2018). The numberof cases pertaining to this amended stipulation is increasing overtime. As expected, many of the projects and programs implemented under the above legal provisions do not necessarily pertain exclusively to the management of nonpoint source pollution.
For example, many of them are implemented as part of the policy
to reduce urban flooding risks. Similarly, many agricultural nonpoint source control projects and programs are actually for promotion of environmentally friendly agriculture aiming to reduce
the use of unnecessary amounts of fertilizers and pesticides.
Specifically, there are Ministry of Agriculture policy provisions
that pertain to promotion of environmentally friendly agricultural practices, as well as promotion of agricultural products forhealthy food habits, discouraging the release of harmful agricultural chemicals beyond the level considered appropriate.
Similar ideas have also been promoted elsewhere. In the caseof the USA and Europe, in addition to the use of the such contemporary approaches as retention pond, wetland, soil conservation, and infiltration beds, collectively called Best Management
Practices (BMPs), there is a growing interest and emphasis on
the use of SUDS (sustainable urban drainage systems) (e.g.,
USEPA 2007) and LID (low-impact development) (e.g., Schueler
1987; CIRIA 2015; Prince George’s County Department ofEnvironmental Resources 1999). SUDS alternatives intend tomeet both the technical requirements of runoff discharge andthe quality requirements such as public amenity and ecosystem
functions, and LID alternatives focus on integration of nature aspart of land use planning (e.g., USEPA 2000). Together with theGreen Infrastructure concept (e.g., green buffers, rooftop greeneries, application of ecosystem service concept), the applicationof SUDS and LID is drawing growing interest as a means of pursuing multiple policy objectives, including the reduction of nonpoint source pollution, rather than ways that bring about
incidentally acquired results that happen to be more than the
reduction of nonpoint source pollution. There are many factors
associated with successfully devising SUDS and LID approaches,
including those hydro-geometric features as geography, topography, hydrography, and hydrology that have evolved over thecourse of development history of land and water systems, as discussed in sections “The Biwa–Yodo Basin in brief ” and “Historictransformations of the Biwa–Yodo Basin”. Regardless, they entail
many disciplinary and sectoral fields for the governance of“basin metabolism” with flexible institution, progressive policies
and programs, hybrid of technologies to fulfill multiple policy
objectives, and the duly designed applied studies involving not
only natural science fields but also social science fields, all to bebroadly supported by sustainable funding.
In >Fig. 11, the principle author of this section, Wada, proposes a schematic representation of the holistic framework ofmutually interlinked policies interfacing with the subject of
nonpoint source pollution control and management. Each individual thematic fields has direct, as well as indirect, implications
regarding nonpoint source issues, and therefore, their individual
pursuits for meeting own objectives will naturally accompany
policies, plans, and programs interfacing with nonpoint source
issues, likely to bring forth multilayered contributions to thegovernance of nonpoint source pollution issues. It is also important to point out that the range of governance challenges pertaining to nonpoint source issues of hybrid nature as shown in>Fig. 11 entails the concept of a participatory environmental
governance approach, to be discussed in section “Evolving Basingovernance of participation: Communities and citizens”, and theconcept of ecosystem services to be discussed in section “Basingovernance improvement for ecosystem restoration”.

 volving Basin Governance for Integrated
E
Flood Risk Management
This section deals with the Shiga Prefecture’s efforts on the basin
flood management policy and the efforts by the Union of Kansai
Governments, to realize what is called Integrated Flood Risk
Management (IFRM). First, a historic account of the Japaneseriver management policy with respect to flood control is briefly
described (section “Government responsibilities in flood control and management”). In the case of the Lake Biwa–Yodo River
Basin, a number of compounded historical issues culminated in
the Shiga Prefectural Government (SPG) taking an exceptional
step to expand the scope of flood control from one focusing
exclusively on the traditional structural approach to one that

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 11
Multi-policy solution approaches for nonpoint source issues, a conceptual framework (prepared by K. Wada)

integrates the risk-based floodplain management (section “Fromflood control to flood risk management: A Shiga Prefecture initiative”) A section responsible for floodplain management in
SPG took the lead and brought this exceptional attempt to successful initial steps for institutionalization. The Union of Kansai
Governments (hereafter referred to as UKG), a regional legal
government entity established in 2010 for dealing with hitherto
unattended cross-jurisdictional basin management issues in theBasin region, is now attempting to adopt the scheme and also
intending to expand the scope of this framework to environmental management and ecosystem restoration issues (section“The Kansai Initiatives in Integrated Rivers/Lake BasinManagement”).

 overnment Responsibilities in Flood Control
Gand Management
The responsible ministry in Japan for flood control and management is the Ministry of Land, Infrastructure, Transport andTourism (MLITT). MLITT pursues its responsibilities under theRiver Law (being enacted and promulgated in 1896 as old River
Law and then being replaced with the present River Law promulgated in 1964 and amended in 1997), and, under this Law,
the Japanese rivers are classified into three categories. The first-­
class rivers are those rivers designated by Ministry ofConstruction (the current MLITT) as water systems especially
important from the view of land conservation and/or national
economy. The second-class rivers are those which do not belong-

509

510

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 12
Administrative classification ofrivers in the Lake Biwa–Yodo
River Basin, GIS data source:
The National Land Numerical
Information Service, Japaning to the first-class river systems but are designated as important by the prefectural governors. The rivers that do not belong
to the first- and second-class rivers may be designated as important by the municipal mayors, being classified as locally designated rivers. The number of first-class rivers is 109 in Japan, of
which the Yodo River system is also one, basically being administered by MLITT. In the Yodo River system, the downstream
part of the Seta River Weir is under direct control of the MLITT,
but Lake Biwa and the inflowing rivers are basically managed by
the Governor of Shiga Prefecture. >Fig. 12 shows the division of
the direct and designated section of the Yodo river system.
Within the flood protection plan of the Yodo river system, thetarget level of river improvement is determined according to therelative importance. Against the downstream part, where there areconcentrations of assets that would potentially be adversely affected,
the protection level for the middle upstream and the tributaries
command lower levels of flood protection. This relationship isstrictly observed even in the interim stages of implementing theriver improvement plan. If improvement of the middle upstream
and branch precedes, the downstream region will suffer from frequent flooding. The flooding risk is simply passed to the downstream region, which is not humanely tolerable. This is why the
implementation level of flood protection in the downstream section
is considered a high priority. It will be possible to implement flood
protection in the middle upstream part and in the tributaries only
after the protection plan is implemented for the downstream part toaccept floods originating from the middle upstream part and thetributaries. Based on these principles, the allocation of the river
improvement project budget is determined, balancing those for 109
water systems and for the upstream–downstream tributaries.
Shown in >Table 3 is the history of the modern flood control policy in Japan (Hori et al. 2008).

⊡⊡ Table 3
History of modern flood control policies in JapanThe 1ststage

Control the largest record flood of the subject river
without any overflow by channel improvement and byconstruction of levees and reservoirs

The 2ndstage

Control the design floods by channel improvement andby construction of levees and reservoirs without any
overflow. A given probable flood such as decade–year
flood is considered as the design flood of the river.
The flood level is defined for each river by using such
indicators as basin size, population, and floodplain
properties

The 3rdstage

Consider the measures to reduce discharge into rivers
from the catchment area as one alternative, in addition
to the measures to control the flood water in rivers

The 4thstage

Consider the overflow, caused by excessive floods, fromthe rivers, and take into account not only the basin–
river system but also the floodplain in preparation forpossible property damages

In considering the recent trends in climate change and thedecreasing population in Japan, Hori et al. (2008) recommendthat the flood control policy stage be advanced to the fourthstage in >Table 3.

 rom Flood Control to Flood Risk Management:F
A Shiga Prefecture Initiative
The Lake Biwa–Yodo River Basin has had a long history of
upstream–downstream conflicts with regard to the control of
the Lake Biwa water level (Nakamura et al. 2012). While theupstream–downstream conflict seemed to have been mostlyEvolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceresolved after completion of Lake Biwa Comprehensive
Development Project (hereafter referred to as LBCDP, thename has subsequently been changed to Lake Biwa
Comprehensive Preservation and Improvement Project. or
LBCPIP, also dubbed as Mother Lake 21), the specific plansand programs transpiring out of the LBCDP framework overthe next decades were yet to be developed at the time of its
completion. The specifics of the necessary plans and programs
to follow through the LBCDP outcome had to be developedand implemented over the following decades. In particular,
those to be included in the Yodo River Basin Management
Plan with deep involvement of the Yodo River Basin
Committee (referred to as Committee) established by the
Yodo River Basin Management Bureau of MLITT were of critical importance. During the period of heated interactions
between the Bureau and the Committee, many contentious
issues resurfaced, not so much as the upstream–downstream
conflict but more as mixtures of contentious relationships
between the central government and the prefectural governments, between the soft alternative proponents (citizens,
NGOs, progressive academicians including ecologically conscious natural scientists and social scientists, etc.) and thehard alternative proponents (conservative academicians
including dam-­proponent experts in water security and flood
management disciplines), and even between the expert viewpoints and the lay citizen viewpoints, including those of vocal
local politicians. These contentious issues could be regarded
as having reflected the rather unsettling sociopolitical climate
at the time in the whole Japan, with serious economic slowdown and the breakdown of traditional top-down hierarchicalrelationship between the national government ministries andthe prefectural government. In a nutshell, the first decade after
the completion of LBCDP was also a politically turbulent
decade, shifting the political balance from centralization to
decentralization.
In the midst of such turbulent years of post-LBCDP developments, one of the Committee members (Ms. Yukiko Kada) won
the 2007 gubernatorial election for the Shiga Prefecture, runningon a political plat form for decentralization of Lake Biwa–Yodo
River management. Among a series of political initiatives, shetook the political leadership for SPG to explore the viability of the
fourth stage policy in >Table 2 above, for the reasons that the“structural” flood control approach will no longer be a viableoption for the Prefecture in view of the budgetary constraints,
depopulation, and climate change and in view that the Shiga residents have fallen into the trap of false security provided by structural interventions. After a few years of heated political exchange
within the prefecture, further complicated by the strong sectionalism and bureaucratic behaviors of the SPG officials and thethen-prevailing public sentiment that flood control ought to fallwithin the responsibility of government professionals rather thanthemselves, the integrated flood management policy involving
the development of a new land use regulation was promulgated
for the first time in 2011 in Japan by SPG.

6

The disaster risk management approach adopted was intended
to reduce not only hazard but also exposure and vulnerability. The
approach adopted by the Prefecture is consistent with the conceptof Ecosystem-based Disaster Risk Reduction (Eco-DRR) and theGreen Infrastructure, gaining much attention globally today.
The following is a brief explanation of what is called theIntegrated Flood Risk Management (IFRM) approach developedby SPG.
(1) The Adding-Up Strategy
In 2006, SPG established a new office “Floodplain
Management Office” and located it alongside the River and Port
Division, as an addition to the Division whose responsibility traditionally was to control floods within the river channels, anorthodox concept for dealing flood incidents as stipulated in theRiver Law. Having been professionally so attuned to the traditional disciplinary approach, it was difficult for the Division staff
members to assume more than their historical mission to control a particular flood within the river channel. The new office
was tasked to undertake an additional aspect beyond the traditional flood control approach, i.e., to develop an approach for
dealing with those flood incidents having greater return periods
than the design period. The floods with such magnitudes would
overflow the river channel perimeters and inundate the riparianlands or floodplains, and their management will have to be metby the floodplain management plans to be newly conceptualized, rather than by the plans resorting to the traditional structural approach of flood control. This “adding-up approach”
taken by the then Shiga governor turned out to have successfully
realigned the policy direction of such a very conservative government organization with strong bureaucratic culture as thosebeing responsible for flood control, the issue domain involving
human lives (Kada et al. 2010).
(2) Floodplain Management Basic Policy
The Floodplain Management Basic Policy (2012) describes
the concept of the risk-based regulation for the land use andbuilding in the floodplain.
(a) Flood Risk Indicator: Methodology for Evaluating FloodRisk
To conduct the in-floodplain countermeasures, the risk distribution should be estimated as a basic information. For theriver administration, the performance index is the discharge
capacity expressed in the annual probability of exceedance(>Fig. 13).
SPG developed a numerical model to calculate flood risk
(Taki et al. 2013). The calculation procedure is shown in >Fig. 14.
A drainage basin model was introduced to predict rainfall runoff,channel flows, and overtopping or breach flow processes. The
drainage basin was divided into three zones (>Fig. 15), i.e., zone 1
is a mountain area; zone 2 is a river reach with a drainage basin;
and zone 3 is the main reach with a floodplain. The channel flow
was evaluated both in zones 2 and 3 by means of 1-D governing

511

512

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 13
Flood flow from various sources – facility safety vs. on-site risk

External Force
1/2  1/1000 Model rainfalls(based on the rainfall intensity formula of the SPG)

Numerical simulaon
Drainage model(Mountain area  Reaches & Channel
network  floodplain)

Probability of Damage
Lv.1  Lv.4⊡⊡ Fig. 14
Calculation of flow

Qbi

equations. In the floodplain of zone 3 and in the drainage area ofzone 2, a depth-integrated 2-D governing equations were
employed to predict flow depth, flow velocity, and fluid forces.
By computing the rainfall runoff and inundation process,the flood hazard risk of each mesh point will be specified interms of a matrix element. SPG formulated the risk matrix asshown in >Fig. 16 from the space-time distribution of the various return period floods. The rows of the matrix correspond tothe occurrence probabilities of various floods based on eightrainfall sizes. The columns indicate flood damage levels from 1
to 5. The risk matrix provides flood hazard risk maps reflectedby flood risk at all mesh points in a floodplain. The flood hazard
risk maps based on various rainfall events give useful information for promoting suitable land use.
The magnitude of damage can be classified into five levels:
level 1 (h ≤ 0.1 m) indicates no damage; level 2 (0.1 ≤ h ≤ 0.5 m)
indicates damage from inundation below the ground floor of abuilding; level 3 (0.5 ≤ h < 3.0 m) indicates severe damage frominundation above the ground floor; level 4 (3.0 ≤ h) indicates fully
submerged; and level 5 (2.5m3/s2 ≤ u2h) indicates completely
destroyed. The probability of occurrence of each flood event wasevaluated by means of its return period, namely, 2, 10, 30, 50, 100,
200, 500, and 1000 years, where h is depth (m) of the inundation
and u is velocity (m/s). The term u2h means the “fluid force.”(b) Risk-Based Land Use and Building Regulation⊡⊡ Fig. 15
Schematic of drainage basin

The land use regulation is applied for Area A, based on therisk matrix (>Fig. 16), where the expected damage frequency isdetermined, for example, as 0.5 m and over inundation for a
10-year flood. The zone is prohibited from inclusion in theurbanized promotion area stipulated by the City Planning Law.
Moreover, building regulation is applied for the Area B on therisk matrix (>Fig. 16), where severe damage frequency is
expected, for example, as 3.0 m and over deep inundation for a
200-year flood. The Shiga governor designates the Area B as theEvolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 16
Land use/building regulation area in the risk matrix

Flood Risk Reduction Priority Area. In cases where houses and/or apartments are already located therein, the resident’s agreement must be acquired as a binding condition. In the area where
the expected flood level exceeds the stipulated flood level, thenew buildings must have a room for evacuation.
Area A ( h ≥ 0.5 m by 10-year flood ) – Frequent damage
No one can expand the urbanization promotion area without elevating land over the flood level.
Area B ( h ≥3.0 m or u2 h by 200-year flood ) – Severe
damageNo one can build houses without a shelter over the floodlevel at least.
In Shiga, the wetlands will be protected by such a risk-based
land use and building regulation. In fact, we firstly tried to evaluate the ecosystem value for wetland protection, instead of theflood risk evaluation (>Fig. 17). Despite a few years of effort,
unfortunately, we were unable to find any legal basis in Japan to
set restrictions on private properties, based on the assessed ecosystem service values.

 he Kansai Initiatives in Integrated Rivers/Lake
T
Basin Management(1) Union of Kansai Governments
SPG formulated the basic policies for IFRM in 2012. Then a new
regulation was enacted in 2014 to ensure its effectiveness. The
regulation gave SPG a forceful tool to conserve wetlands in Shiga.
Wetlands provide for rich ecosystems and also serve for reducing
flooding risks by storing the flood water and moderating thedownstream water level rise. Therefore, such a risk-based
approach for flood management is an effective approach to conserve wetlands, making this SPG approach an exemplary case of

Eco-DRR, which also constitutes an important component program within the Comprehensive Flood Management (disasterprevention) cell of the illustration entitled “multi-policy solution
approaches for nonpoint source issues” shown in >Fig. 11. In themeantime, the above approach began to be more and more
accepted through the prefectural political process, and even by
MLITT, which itself was facing a shortage of national projectfunds and was inclined to shift toward a nonstructural approach.
At the same time, the IFRM model was considered to be one of
the key policy measures to adopt for the entire Lake Biwa–Yodo
River Basin within the Union of the Kasai Local Government(UKLG) that came into being in 2010, with seven prefectures in
the Kansai region as its members.
UKLG was born as the first wide-area (trans-prefectural)
union of local governments in Japan. Its role is to focus on thecommon aspirations of the member prefectures to provide thenecessary trans-prefectural local services to the population
across the Kansai region, making best use of common institutional and administrative approaches. As it turned out, in finallydeveloping the Union concept, very extensive studies were carried out by the preparatory office on the already existing overseas
cases of unions of local governments as well as that of national
governments, including the European Union established in 1993.
In accordance with the legal provisions, UKLG can enact
legislation in pursuit for noncontentious common objectives,
such as provision of public services as mentioned above, andenhancement of environmental and ecosystem improvementand disaster prevention and management, the key subject areasof integrated management of Lake Biwa–Yodo River Basin. The
Union initially set seven areas for region-wide administrative
action, i.e., disaster preparedness, promotion of tourism andculture, industrial promotion, healthcare services, environmental conservation, staff training, and certification examinations

513

514

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 17
Annual probability of flooding
above floor level (level 3, H≥0.5m) [red-­colored area corresponds to area A in the risk
matrix], Base map GIS data
source: The National Land
Numerical Information Service,Japan⊡⊡ Table 4
Members of the Union of Kansai Governments
Established December 1, 2010
MemberPrefecture

Major city(ordinance-­
designated)
President

Shiga, Kyoto, Osaka, Hyogo,
Nara, Wakayama, Tokushima,
Tottori
Kyoto, Osaka, Sakai, Kobe

Toshizo Ido (Governor of Hyogo Prefecture)and licensing. As of today, eight prefectures and four major cities
participate in UKLG as identified in >Table 4.
After a range of projects were implemented with success,
UKLG initiated a new project, i.e., the implementation of theabove Integrated Lake–River Basin Management System

adopted by SPG for the Lake Biwa Basin to be promoted in thewhole of Lake Biwa–Yodo River Basin, as presented below in (2).
(2) The Lake Biwa–Yodo River Basin Management Committee
UKLG launched in 2014 an expert group on Lake Biwa–Yodo
River Basin called the Lake Biwa–Yodo River Basin Management
Committee (BY-BMC). BY-BMC’s assigned tasks were two, i.e.,
one to review and formulate a conceptual framework for the governance of Lake Biwa–Yodo River from a basin-wide perspective
and another to undertake a feasibility study of the “Integrated
Lake–River Basin Management” implementation scheme.
BY-BMC consists of representatives from academic institutionsin the Kansai region, with professional background on river engineering, water environment, ecology, risk management, sociology, and water policy. Through 2 years of intensive discussion,
BY-BMC submitted a report to the Governor of Hyogo Prefecture
who is also the UKLG President, proposing a practical approach

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceto resolve such emerging issues facing the basin society as
increased flood/drought risks, ecosystem deterioration underglobal climate changes, and population declines in the region.
(3) The Lake Biwa–Yodo River Basin Challenges Identified as
Priority Issues for Study by UKLG
BY-BMC also pointed out eight subject areas listed below as
being the major challenges faced by UKLG, as follows:
1. Promotion of Integrated Flood Management and River
Improvement
2. Dissolution of multiplicity of water supply systems improving financial and service performances
3. Conservation of groundwater
4. Rehabilitation of aging water infrastructure
5. Restoration and improvement of overall ecosystem serviceof UKLG region
6. Promotion of comprehensive sediment management of
Yodo River Basin
7. Strengthening of the regional water crisis management
8. Restoration of locally specific water culture and enhancementof the upstream–downstream relationship for mutual benefit
The issues included in the above list have somehow either
been difficult for or left out of the traditional government sectors
working in the compartmentalized government structure. They
are also the kind of issues lost in the maze of compounded responsibilities or are being considered as fringe issues. The improvement of basin governance, with enhancement of individual efforts
and collaboration and cooperation among diversified actors, isbecoming extremely important. UKLG proposed that BY-BMC
continue to guide the studies to be undertaken by technical subgroups to be formed for the list of issues on a priority basis.

 nhancement of Risk Management
E
Through Basin Governance Improvement
As referred to Subsection “Historic transformations of the Biwa–
Yodo Basin” and the earlier subsections in section “Evolving
Basin governance for Integrated Flood Risk Management”, management of a lake–river–bay system such as the Lake Biwa–Yodo
River–Osaka Bay Basin has evolved through thousands of yearsof human–nature interactions cumulated as historical experiencein dealing with floods, water resource acquisition and discharge,
as well as environmental and ecosystem services. As a result, it isquite unlikely that there could suddenly be dramatic modifications/alterations of the historically acquired management
approach. Taki et al. (2010) made a proposition in reference tothe real-world applications of the concept of IFRM by SPG that“it is most appropriate to consider that the already existing river
improvement plans and programs (the range of obligatory
responsibilities in river management) be firmly set as given and6unchanged, and to only add a separate, additional and new
dimension of policy objective (e.g., floodplain management in
the case of flood control) that can fulfill the necessary increment.”
In other words, to realize integrated management of a river–lakebasin, it makes much more sense for the concerned stakeholder
organizations to collaborate, rather than to be institutionallyunited, in order for them to jointly identify possible areas andapproaches for collaboration on subjects of emerging importance. In other words, it makes more sense to aim at enhancing
the overall governance of the collaborating members without
being too preoccupied about the individual member’s exclusive
mandates and the delineated areas of responsibility. Suchapproaches will facilitate a better chance for consensus building.
Noting that, even within the same river basin, it is easy for the
sub-basin communities to exert their own concerns (perceptions) to be far too different from others, depending on where
they are located, i.e., upstream/downstream, left bank/right bank,or what standpoints they take on issues of concern, e.g., development vs. conservation; the basin society has to strive to share acommon vision (future image) to be able to overcome the differences for achieving the common goal. Such efforts are indispensable, regardless of how the government organizations undergochanges or how the financial resources are reallocated. >Figure 18
shows a conceptual sketch of a cyclic process for consensus building for reaching a single consented resolution.
In addition, as shown in >Fig. 19, in one cycle of efforts tosolve the problem, each river basin component such as administrative departments, NGOs, private enterprises, local residents, etc. ①
confirmed the current situation on a watershed basis, ② recognize
issues that are manifesting, ③ set frameworks and policies for collaboration and collaboration, and ④ cooperate and collaborate byrelated parties. Then return to ① to undertake improvements andinitiate the next task. This cycle can proceed simultaneously by the
number of tasks, and it is difficult to reach complete voting in one
cycle. Rather, it is better to consider moving forward from where
you can while constantly repeating this cycle.
To encourage such an upward spiral process effectively, a“stagehand,” who can integrate available knowledge and intelligence of society and environment in the basin, should be
required. According to the committee report, the “stagehand”
takes the five roles according to the step of the spiral-up process,as follows:
A. Accumulate knowledge and intelligence of basin environment and society.
B. Present state analysis and subject extraction.
C. Propose possible resolution or alternatives.
D. Prepare the table for discussion between stakeholders.
E. Compile a sharable vision successively.
The BY-BMC report suggests the administrative organizationfrom UKLG to be more a “stagehand” for the Integrated Lake–
River Basin Governance than the actual implementation organi-

515

516

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance⊡⊡ Fig. 18
A cyclic process for a single
resolution⊡⊡ Fig. 19
Governance cycle for the Integrated Lake–River Basin Management in the Lake Biwa–Yodo River BasinEvolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governancezation. UKLG was advised to form expert groups to work on someselected topics on a pilot project basis. UKLG should also conductbasin-wide status reading and mapping assessments. The indicators evaluated in the multi-scales give various incentives for action
to the basin actors, including individuals, NGOs, private sectors,
cities, prefectures, and national governments.

 volving Basin Governance of Participation:
E
Communities and Citizens
This section discusses the history of paddy agriculture as related
to the Biwa–Yodo Basin governance in Subsection “Historicalimplications of paddy culture as a basis of Basin governance’’, theresults of survey by the general public in the Shiga Prefectureand downstream region on the value of Lake Biwa in Subsection“Conflicts, contentions, and collaboration: A recent Lake Biwa
history’’, some historical reflections on LBCDP for the Shiga
general public in Subsection ‘‘Citizen awareness about the valueof Lake Biwa: The perceptional gaps’’, the concept of subsidiarity
in lake–river basin management in Subsection “Basin governance and the principle of subsidiarity’’, and the approach SPG
has adopted in the management of Lake Biwa, the so-called theLake Biwa Model in Subsection “Participatory governance: A
Lake Biwa model?’’.

 istorical Implications of Paddy Culture as a Basis
Hof Basin Governance
The Japanese political, socioeconomic, and cultural institutions
have revolved around the Emperor system infused with
Shintoism and Buddhism that gradually took shape during theclassical period (592–1185) and the feudal period (1185–1603).
The infused institution was supported throughout the period by
the autonomous and tax-free manors called Shoen estates thatwere owned and controlled by the Shinto shrines and Buddhist
temples, as well as by the Emperor palaces. Toward the middle offeudal period, the Shoen estates themselves grew more and more
independent and began to invite the rise of local military clans.
In the meantime, during times of severe floods and droughts,
widespread famines and catastrophic epidemics exasperated bywater use conflicts were not uncommon within and among the
Shoen estates. The relocation of the Emperor’s palace (the capitol) from Osaka, Nara, Kyoto, and Otsu and back to Kyoto areas
during the period between the seventh and ninth centuries isbelieved to have been caused by these water-related famines,
epidemics, and conflicts.
The management of the Shoen estates in the classical period
was to entrust the management authority to the village chief
controlling his subordinate peasants, which together were overseen by the landlords representing the temples, shrines, and pal-

6

aces. As time passed, this entrusted power structure of the Shoen
estates gradually eroded due to the increasing social disorders
and unrests caused by meager crops lobbed, for example, by
local clan intruders and outcast peasants. Thus, the Shoen-basedsocial power structure gradually got replaced by the paddy
farming village power structure; autonomous self-regulating
system, with stringent community rules to deal with crime control; trans-community conflicts; paddy infrastructure development; management and maintenance of irrigation infrastructure;
as well as flood control and drought management. These villages
were called “Soh-son.” The word “Soh” means “all members” and“Son” means “villages.”
Nonetheless, the Shoen system underwent further transformation during the Kamakura shogunate (1191–1333, the capitol
located in Kamakura), Muromachi Era (1336–1573, the capitol
located in Kyoto), and Azuchi-Momoyama Era (1573–1603, thecapitol located in Azuchi and Kyoto) still maintaining theimportant power base for many local lords. The feudal system
got firmly established in Tokugawa shogunate (1603–1868, thecapitol located in Edo, current Tokyo) with the Daimyos (theloyal local lords) more or less having taken over the Shoen system. During this period, the paddy farming villages were madeto submit the yearly harvest of rice as tax to the Daimyos and the
Shogun in return for the protection of the villages. The Yodo
River region (the current Kyoto and Osaka regions, collectively
called Kinai (meaning “close to the capitol,” consisting of Yamato,
Izumi, Kawachi, Settsu, Yamashiro territories)) and the Lake
Biwa region (called Ohmi territory, part of Kigai or “outside of
the capitol region) were very much under constant power struggles. Under such circumstances, the paddy farmers were continuously suffering from crop failures caused by occasional
floods and droughts, particularly in the more rural Lake Biwa
region. The sufferance of paddy farming villagers was doubly
strained because they had to pay their annual rice tax or tributeeven in years of meager harvests. Also, throughout Lake Biwa
and Yodo River regions, particularly in the fifteenth and sixteenth centuries, there were frequent water conflicts between the
upstream and downstream villages and occasional revolts
against the wealthy merchants working for the local Daimyos.
With no financial and technological resources, the villagers wereable to undertake only minor river improvement works. In the
Ohmi region, the villagers were further discouraged to undertake any improvement works that might increase the discharge
from the Seta River to downstream. Such works would increase
the flooding risk in the wealthier and more populated downstream Osaka, the thriving commercial center as well as thepolitical and military power center.
In the meantime, in the Ohmi region, it is said that the “Soh-­son” culture (the self-regulating management for paddy farmingwith stringent community rules having gradually superseded
the Shoen-based system of external control) somehow persisted
more prominently in the absence of strong local loads, thus

517

518

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceallowing the individual “Soh-sons” (Noda 2016) to be rather
independent. A characteristic of the Ohmi region also was thatthe paddy agricultural practices were dramatically affected by
the lake-level rise (causing flooding along the lake shore andalong and around the inflowing river watersheds) and fall (as aconsequence of droughts). The village chiefs and other leaders
such as Buddhist monks from local temples continually petitioned to the Tokugawa shogunate for large-scale dredging andchannel improvement of the Seta River whenever large-scale
flooding took place. However, no major intervention was carried out during the Tokugawa shogunate. In addition to theincreased flooding risk, such interventions would defy the military strategy to keep the river beds shallow for the Kinai soldiers(defending the shogunate) to be able to walk across the Seta
River to quash any uprisings around and beyond the Ohmi
region. Thus, the above “Soh-son” culture had to be firmly
passed on for generations to deal with various water-related
calamities at the village levels, implicitly even to the currenttime(Noda 1995). The long-time residents in Shiga tend to identify their affiliation more with Ohmi than with Shiga because of
their acquired sense of individual roles and responsibilities intimes of cultural and religious festivities, all related to the collective responsibilities to carry out the village traditions in firefighting, flood disaster prevention, water and crop management
during the rice planting and harvesting seasons, etc.

 onflicts, Contentions, and Collaboration:CA Recent Lake Biwa History
After many centuries of procrastination by the downstream
powers represented by the Tokugawa shogunate, in connection
with the extraordinary large-scale flooding events of 1885 and1889, the post-feudal Meiji Government (1868–1912, the capitol
located in Tokyo) undertook dredging of the outflowing Seta
River from Lake Biwa and installation of a weir at Nango in
1905. The combined discharge capacity increased from 50 to
200 m3/s and later to 400 m3/s with further dredging, ­successfully
reducing the flooding frequency in subsequent years, as
described in Subsection “Government responsibilities in flood
control and management”. On the other hand, the primary purpose of the construction of the Nango Weir was for flood control, not water resource development, and the drought-related
conflicts along the inflowing rivers to Lake Biwa continued until
as late as 1932. The manually operated wells began to be replacedwith electrically operated wells from about the 1920s.
Nevertheless, the problems still lingered in both the Lake Biwa
watershed and in the downstream Yodo River. In the case of former, there was still frequent fighting over the irrigation waterrights among the neighboring villages during droughts. Aninter-village water fight broke out along the Inukami River,resulting in ten villager deaths. Some 300 from the police force
intervened for 3 days before it ended with a great deal of animosity. This incident led to the local and national government
decisions to reform and modernize the paddy irrigation systems
in the Shiga Prefecture. The Inukami dam subsequently constructed in 1946 was the first irrigation dam in Japan, while thenational irrigation modernization project also began in 1947
along the Yasu River and in its basin. The irrigation modernization projects thereafter contributed to the gradual reduction ofagricultural water conflicts in the Shiga Prefecture and consequently reducing the need for the self-governance of paddy villages (Noda 1995).
During the years between the 1900s and the 1960s, theincreased water demands in the downstream Osaka area had tobe met mainly by an increase in the number of wells. Such anincrease resulted in extensive land subsidence due to the groundwater overdraft, causing a serious risk of coastal inundation. The
Nango Weir was replaced by the Seta Weir in 1961, increasing
the discharge capacity from 400 m3/s to 600 m3/s and also formeeting the growing water demand in Osaka and other downstream population centers along the Yodo River. In the succeeding years, the demand for water in the Greater Osaka area
further increased, particularly to provide water for the Osaka
Bay industrial belt zone for the development of heavy industries
such as ship building, iron and steel mills, allied chemicals, andpaper and pulp manufacturing. After several years of contentious disputes between upstream Shiga and downstream Osaka,
LBCDP was finally agreed and launched in 1972, with the agreement that some 40 m3/sec of Lake Biwa water would be sent
down to the Yodo River during times of severe droughts, that thedischarge capacity would be increased to 700 m3/s for flood control downstream, that around-the-lake levees would be constructed for flood control around the lake, and that various
environmental conservation measures would be introduced for
improving Lake Biwa water quality (Nakamura et al. 2012). The
historic upstream–downstream conflict involving the whole of
the Shiga Prefecture (the Ohmi region) and the whole of the
Yodo River downstream seemed finally to be resolved in completing LBCDP. Unfortunately, things were not that simple.
For one thing, another kind of Lake Biwa conflict emerged
soon after the inauguration of LBCDP. This time a group of environmentally conscious citizens and scientists in the Lake Biwa
and Yodo River regions sued the federation of national and local
governments (i.e., Shiga Prefecture; Osaka Prefecture; Central
Government; Water Resources Development Cooperation) in
1976 that implementation of LBCDP by the governments would
bring about irreversible environmental and ecosystem degradation for Lake Biwa and would not be beneficial for the Lake
Biwa–Yodo River society as a whole. After numerous rounds ofhearings and field studies, the court case was closed in 1989 infavor for the defendant body, with the final ruling stating basi-

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governancecally that the LBCDP shouldn’t be regarded as detrimental to thesociety, since the potentially accruable LBCDP benefit to society,in terms of the greater quantity of water resources and the reduction of flooding risks and associated damages, far exceeded theenvironmental and ecological impacts to the lake and its shoreline ecotone zones.
It took 25 years (1972–1997) to complete the LBCDP, after
two extensions of duration, from 1982 to 1992 and then from1992 to 1997. The LBCDP infrastructure development for water
resources had already been completed by 1997, despite the fact
the above economic decline significantly altered the profile of
the region’s water resource needs. By then, however, many of theheavy industries in the Osaka coastal industrial belt zone hadalready moved out of the country or changed their operational
practices to save energy which in turn reduced their water uses.
Thus, the prediction of water resources development needs thatformed the very basis of LBCDP was no longer valid. The above
two cases (the historic upstream–downstream conflict on the
management of Lake Biwa flood waters for one and the short-­
lived conflict on the LBCDP impacts on Lake Biwa environment
for another) are quite unique contextually, but they also suggest
many important lessons learned for other similar lake–rivercases elsewhere.
LBCDP has facilitated the necessary economic development
and environmental conservation infrastructure in the Lake Biwa
watershed region (i.e., the Shiga Prefecture jurisdictional area). It
has benefitted the Shiga Prefecture in terms of local economy andenvironmental amenity enhancement (e.g., lakeside amenities
such as ports and harbors, lakeside parks, agricultural land
improvement, afforestation, the levee cum ring road around thelake, etc.). The housing amenity improvements, particularly withmuch larger land parcels served with good water supply and sewerage coverage, have also attracted the migration of people as wellas business operations to the Lake Biwa region from the Greater
Osaka region. The general public and the media, although having
been intensely drawn to the court case deliberations some 10 years
before, also took the court decision for granted. Compared to the
pre-LBCDP era, the Shiga Prefecture population has increased
almost twofold. In other words, the social and demographic structure has been dramatically altered from a pre-LBCDP outdated
parochial living by the indigenous residents, to a post-LBCDP
suburban lifestyle by the migrant populations enjoying both the
newly created economic opportunities and the abundant environmental amenities. The general public therefore was not about tocomplain about the LBCDP accomplishments in general, i.e.,
improved economic status and environmental amenity improvement in terms of lakeshore park developments, improved roads,
new leisure and recreational facilities, and the like.
LBCDP also included many structural and nonstructuralcomponent projects for the improvement of Lake Biwa water
quality, including development of four regional wastewater sys-

6tems encircling the lake. Over the course of the project duration
between 1972 and 1997, however, such projects brought about
only minor improvements in lake water quality, not to mention
improvements in ecosystem health. On the contrary, the LBCDP
structural projects for water resource development and flood
control, such as construction of around-the-lake levees; excavation of roads for laying sewer pipelines underneath; transformation of the traditional cascading irrigation to the pipeline
irrigation; consolidation of smaller, individually owned paddy
lands to larger parcels to allow the use of agricultural machineries; transformation of forest and agricultural lands to housing
and industrial estates, etc., all contributed to the deterioration of
ecosystem integrity. This dramatic change in the profile of theLake Biwa watershed, now very urbanized and industrialized,
also meant the ecosystems which used to provide prolific fish
habitats have been lost. During the same period, quite extensive
land loss of the paddy wetlands also occurred along thelakeshore.
In addition, there were totally unexpected and unaccounted
for incidents about Lake Biwa that took everyone by surprise.
They are both related to the lake water level established anew inthe LBCDP design for meeting its flood control and droughtmanagement objectives.
The first incident pertains to the record drought of 1994,
when the lake water level fell down to minus 123 cm, breaking
the previous all-time low of minus 103 cm that took place in
1939. The drawdown of the lake water level, exhibiting theextensive dried-up lake bottom, particularly in some parts of theNorthern Basin, leading to extensive die-offs of benthic floraand fauna, causing a tremendous foul odor along the shore. In
addition, this drawdown may have triggered the sudden explosive growth of certain macrophytes of an exotic nature (e.g.,
Elodea nuttallii and Egeria densa) and of indigenous nature (e.g.,
Ceratophyllum demersum and Hydrilla verticillata) in theSouthern Basin, which persisted over the following decades tothe present date.
The second incident pertains to the impacts of new operational rules for the Seta Weir that began in 1992. The agreed
operational rule set forth in LBCDP to meet the flood control
and drought management needs began to cause a noticeable
decline in the natural spawning of the cyprinid fishes. Obviously,
the spawned eggs would dry up if the operational rule to raise or
lower the weir gates is followed, adversely affecting the Lake
Biwa fishery. The above two cases remind us of the views
expressed by the plaintiffs in the court litigation case discussed
in Subsection “Historical implications of paddy culture as a basisof Basin governance” that the lake would gradually be transformed more and more into an artificial reservoir and would
inflict serious long-term consequences in terms of the lake ecosystem deterioration, actually seemed to have been proven generally correct.

519

520

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance

0

10

20

30

40

50

60 (%)

Water quality conservation
Water quantity securement
Flood control
Nature conservation⊡⊡ Fig. 20
The difference in the awareness level between the Shiga
Prefecture residents and thedownstream Yodo River
residents (Noda 1995)

Shiga Pref.
Downstream area

Other

0%

20%

40%

60%

80%

100%

1995
2008
Drinking waterIndustrial water/fishery
Other

Irrigation water
LandscapeNature environment
Lifestyle culture itizen Awareness About the Value of Lake Biwa:
C
The Perceptional Gaps
In the contemporary context of managing a river–lake coastal
basin, the term “participation” is associated with such terms as“citizen” and “community.” The definition of participation is provided also in relation to the degree of mutual influence, for example, information sharing (one-way communication), consultation(two-way communication), collaboration (shared control overdecisions and resources), and empowerment (transfer of control
over decisions and resources), in the ascending order of extent(ILEC 2005). Several observations elaborate on the governancechallenges facing the Lake Biwa–Yodo River Basin. In the case of
the Shiga Prefecture, the residents are quite aware of the importance of Lake Biwa, not only as a source of water but also as aliving ecosystem as well as a fishery ground. Although not as contentious an issue as in the past, the gap in the sentiment about thevalue of Lake Biwa between the Lake Biwa residents and thedownstream Yodo River residents is rather significant, as illustrated below in the survey results on the subject.
Q1: How do the awareness levels of citizens and NGO/NPO
members in Shiga Prefecture differ from those in the downstream prefectures?
Shown in >Fig. 20 is the result of a survey undertaken in
1995 in connection with a record drought of 1994, involving a⊡⊡ Fig. 21
The difference in residents’awareness between 1995 and2008 (Noda 1995; Shiga
Prefectural Government 2008)

sample population of 3380 residing in the Lake Biwa–Yodo
River Basin that are more than 20 years old. It shows, for example, that regarding the most important issue facing Lake Biwa, asignificantly greater number of sample population in the downstream region considered “securing adequate amount of water”
as being most important, compared to the fact that a significantly greater number of people in the Shiga Prefecture considered “conservation of lake water quality” as being mostimportant. The preference structure in the downstream region
and in the upstream Shiga Prefecture was totally opposite
between the two respondent groups (Noda 1995).
Q2; How does the structure of priority concern in the value of
Lake Biwa differ between 1995 and 2008?
>Figure 21 shows the result obtained from a questionnaire
survey on the Lake Biwa water use categories undertaken in 2008
for a sample population of 3000 (Shiga Prefectural Government
2008), compared against the result obtained from a similar questionnaire survey undertaken in 1995 for a sample population of
2000. As it turned out, while the Shiga residents placed the greatestemphasis in 1995 on the quality of water to be used for drinking,agriculture and industrial activities, the 2008 survey results showmuch greater emphasis on the quality of water for fisheries, naturalenvironment, and landscape as well as a culturally fulfilling life.
Based on the study conducted on the relationships among
the number of years of residency significantly affected “theamount of knowledge about Lake Biwa” and also “affectionate-

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceness to the nature and Lake Biwa” and “the magnitude of humanties,” with these three factors influencing the assessment of
nature, as well as the waterfront environment (Hirayama andWada 2016). In addition, it was revealed that the environmental
enhancement activities promoted by the local citizen associations play an important role in encouraging the newly settled
residents to mingle together with the long-term residents, providing opportunities for them to actively participate in the lake
environmental-related activities (Hirayama et al. 2012).

 asin Governance and the Principle
Bof Subsidiarity
The concept of “Principle of Subsidiarity” is defined “as the ideathat a central authority should have a subsidiary function, performing only those tasks which cannot be performed effectively
at a more immediate or local level” (European Parliament 2012)
It originates from the Catholic teaching “that individuals canonly develop freely in society when what they can accomplishby their initiative is not given or taken away from them by ahigher authority” (Evans and Zimmermann 2014) but became
well known since “it was formally enshrined by the Maastricht
Treaty” that formed a basis for the establishment of theEuropean Community, later transformed to the European
Union. In the inauguration of UKLG presented in Subsection“The Kansai Initiatives in Integrated Rivers/Lake BasinManagement”, the Principle of Subsidiarity theme of theMaastricht Treaty of 1992 was referred in its preparatory study.
The details of that particular study are not available, but a similar study was carried out by National Institute for Research
Advancement (NIRA) (n.d.) on the ideal wide-area local government system in a decentralized society (i.e., on the federal
system and the “doshusei” regional administrative system inJapan). The study indicated that “These debates (having takenplace in Japan thitherto) typically centered on 1) the need toreform the prefectural governments; 2) the structure of theregional administrative system and management of the prefectural system (two-tier vs. three-tier system, etc.); 3) distributionof power between the central and the prefectural governments;
4) the redistribution of tax resources and the improvement offinancial efficiency; and 5) local demarcation.”In the meantime, the Principle of Subsidiarity was implicitly
included in the presentation of the nonpoint source pollution
issues in Subsection “Evolving governance in managing point
and nonpoint source pollution” as a crosscutting concept of thischapter. In connection to this subject, Pezaros (2001) writes,“From the point of view of competence, the intervention of the
EU in environment is based on the Subsidiarity Principle.” Thisphrase implies, to a great extent, reduction of agricultural non-6

point source pollution, particularly from “the over-use ofchemical fertilizers (nitrates, phosphates, potassium-based),….” The same light may be shed on the nonpoint source waterpollution issues in the Lake Biwa–Yodo River as presented in
Subsection “Beyond the conventional approach”. For example,
the paddy agricultural farmers in the Shiga Prefecture are provided with SPG policy guidelines to reduce the amount ofhighly contaminated (with fertilizers and paddy soil particles)
irrigation return flows back into Lake Biwa. Among the policy
guidelines is an ordinance enacted in April 2003 to certify environmentally conscious farming. Under the ordinance, the farm
products would be certified if they were produced using 50% orless of the fertilizer amount used by conventional farming(Japan for Sustainability 2005). This unique agro-environmental policy of SPG is a case in point of the Principle of Subsidiarity.
Although gradually spreading across Japan, the adopted policyby SPG is still an exception rather than the rule. SPG has theopportunity for two policies to increase their mutual affinity tosynchronically contribute to the basin governance enhancement in future.
In addition, the usefulness of promoting IFRM and otherpending list of activities described under subsection “The Biwa–
Yodo Basin Challenges Identified as Priority Issues for Study by
UKLG” falls within the realm of the Principle of Subsidiarity. Stoa
(2014), for example, states on the concept of Integrated Water
Resources Management (IWRM) that “As a foundational elementof IWRM paradigm, the rise to prominence of the Principle ofSubsidiarity has paralleled the widespread adoption of IWRM
itself.” The conceptual definition of IWRM, “a process that promotes coordinated development and management of water, land
and related resources, in order to maximize economic and social
welfare in an equitable manner without compromising the sustainability of vital systems …,” is inclusive in the concept of IFRM.
In relation to historically fostered “community participation” culture in the Shiga Prefecture, a brief treaty of the medieval “Soh-son” paddy agricultural village system in Japan, andits specific reference to the Ohmi region (current Shiga
Prefecture), was presented in Subsection “Historical implications of paddy culture as a basis of Basin governance”. The feature of “Soh-son” village governance was that individual“Soh-sons” were pretty much independent in making their own
political and administrative decisions while maintaining thementorship received from their local shogunate clan representing the region. The two sides were, in effect, playing complementary roles in the overall governance of the region,functioning similar to the way the Principle of Subsidiarity is
portrayed above. In the meantime, the subject of “community
participation” is also related to the above Maastricht Treaty andthe subsequent Aarhus Convention (i.e., the United Nations
Economic Commission for Europe (UNECE) Convention on

521

522

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance

Access to Information, Public Participation in DecisionMaking and Access to Justice in Environmental Matters)
adopted in 1998. There is an ongoing movement among the citizen groups considering the Japanese Government’s position on“citizen participation” in environmental issues still being inadequate and that the Japanese Government formally become asignatory of the Aarhus Convention to make sure the citizens
will be legally empowered to have access to a much broader
range of information on the contentious issues. It has not yettaken place.

Participatory Governance: A Lake Biwa Model?
Coincidental to the timing of LBCDP completion in 1997,
major revisions were made on the River Law of 1964, the very
law that provided the major policy guidelines for various
water resources and flood control infrastructures during theprevious decades. The Revised River Law of 1997 stipulates
two new ideologies, the first being to “improve and conserve
river environment” and the second being to “take into accountthe opinion of local residents” in developing and implementing the river management plans. Specifically, the law requires
stakeholder involvement not only during the planning stage
but also during the stage of operation and maintenance ofconstructed facilities. The promulgation of this 1997 Law,
together with a series of other environment-related laws promulgated in the 1980s and 1990s, signifies the dawn of the eraof environmental and ecosystem concerns with involvementof the public in managing rivers and their basins, a turning
point from the era of large-scale infrastructure developmentthat was widely pursued in the 1970s and 1980s, often accompanied by strong contentious sentiments among the environmental concerns.
In the meantime, focusing on the environmental and ecosystem concerns not adequately addressed within LBCDP, SPG
was able to launch a post-LBCDP plan of its own in 2000 called
the “Lake Biwa Comprehensive Preservation and Improvement
Project (LBCPIP), ” dubbed as Mother Lake 21 Plan (ML21Plan), being assisted by six national government ministerialand sub-ministerial agencies. In the introductory part of theplan, it states the need for post-LBCDP needs as “…, during thelast phase of the LBCDP, SPG began to consider how to ensure
the comprehensive conservation of the lake for future generations. ….” Further, it states on the intent on the preparation of
the plan as “The ultimate solution to these problems lies in therevival of an environmental culture …. The solutions must
begin with changes in the behavior of citizens of the prefecture
and the business sector ….” Being a vision plan rather than aproject implementation plan, the time horizon of the ML21
Plan was set at 2050 with review timings set initially for 2010

and 2020. Further, it states the roles to be played by the beneficiaries of the Plan as “The citizens, private-sector members,
local government officials and various other members in thecommunity should cooperate with each other to promotewatershed conservation. Specifically, it is important for them tolearn and understand each other regarding their, respectively,
unique situations and the associated issues in the upper, middle, and lower reaches of the river basin, by forming a partnership with each other, fostering profound understanding and asense of shared values about Lake Biwa, that will lead to theevolving process of proactive engagements among themselves.”
As part of the planning elements of the ML21 Plan, the measures of achievement were set to be improvements in (1) the
overall quality of Lake Biwa water with the aim to attain specificwater quality target levels; (2) the infiltration and retention
capacities of watershed soils, with the aim to identify and set
aside such lands; (3) the natural environment and landscapeecology, with the aim to acquire the network hubs for the purpose; and (4) the development of a river basin association eachmajor river basins. These achievements were to be measured
both in terms of quantitatively measurable outputs (such as
water quality) and qualitative outcomes (such as landscapeecology).
After 10 years of implementation of the ML21 Plan, however, an expert panel reviewing the first phase of ML21 (1999–2009) concluded in essence that a whole range of new issues
surfaced needing due attention for all four target objectives. It
also concluded as for item (1) above that the achievement target of pollution load reduction was gradually approaching, but
the ambient standards of water quality had not been fulfilled,
and, as for items (2), (3), and (4) above, little had been achievedor the achievements have been quite unsatisfactory. In addition, the panel pointed out the planning objective to be addedin the second phase of ML21 (2010–2019) as being (a) significant change in lifestyles; (b) prioritization of projects to beundertaken; (c) increased number of trans-sectoral activities;and (d) more proactive dissemination of visual image information for easy communication with lay citizens. The panel also
concluded that a platform called the “Lake Biwa Environmental
Citizen Forum (ML21 Forum)” needed to be established, andits outputs should be integrated into the formal governmental
process (Shiga Prefectural Government 2011a).
In retrospect, the ML21 Plan turned out to closely reflect the
two new ideologies having been stipulated in the Revised River
Law of 1997, i.e., first to “improve and conserve river environment” and second to “take into account the opinion of local residents” in developing and implementing the river management
plans. In particular, the philosophy through ML21 that its
Forum outputs be integrated into the formal government process implies that ML21 is now seeking what may be regarded, in
the absence of any useful term to explain, as “participatory gov-

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceernance”. The term, “participatory governance” is considered asa “variant or subset of governance theory that puts emphasis on
democratic engagement, in particular through deliberative
practices”, and as seeking “to deepen citizen participation in thegovernmental process by examining the assumptions and practices of the traditional view that generally hinder the realizationof a genuine participatory democracy.” (Fisher 2012). In addition, the “Soh-son” culture discussed in Subsection “Historicalimplications of paddy culture as a basis of Basin governance” inconnection with the presumed trait gained through history of
the “community self-governance” in the Ohmi region may beappropriately reminded in this context.

 asin Governance Improvement
B
for Ecosystem Restoration
 egal Frameworks for Water Cycle and Ecosystem
L
Restorations
In the meantime, two important legislative initiatives have been
introduced in Japan over the past years, one pertaining toachievement of a healthy water cycle (Japanese Government2014) and another pertaining to restoration of the Lake Biwa
ecosystem (Japanese Government 2015). The title of first one is“Basic Law on the Water Cycle” and of the second is “Lake Biwa
Conservation and Restoration Act.”
Under the water cycle law, the national government is toestablish a Water Circulation Basic Plan, recognizing that proper
water circulation is of crucial importance to environment, people, and industrial activities and that water is valuable national
property. Also, in cooperation with the national government,
local governments are required to take measures to improve thewater retention and recharge capacity by, for example, properly
managing forests and croplands, among many others. The law
requires that, to be eligible for facilitation of provisions by thenational government, the basin community needs to develop abasin water cycle plan, wherein the plan sets forth (1) clarification of the present and future water cycle challenges; (2) the ideal
situation or vision to fulfill; (3) specific objectives for meeting
water cycle maintenance and/or restoration; (4) specific means tomeet the objectives; and (5) indicators for describing the state of
the water cycle today and for describing the progress. As it turned
out, SPG proposed that Lake Biwa be considered a designatedbasin under this law and was granted this status, among a scoreor so of lake–river basins in other regions in the country.
The new Lake Biwa law basically facilitates the ML21 (which
is only a prefectural plan) in such a way that the national government provides the necessary resources, on the condition that
SPG meet certain basic requirements for such measures as (1)prevention of water pollution and improvement of water quality;

6(2) improvement of the water recharge capacity of forestlands
and croplands; (3) restoration of ecosystem integrity by meansof (3a) conservation and restoration of coastal natural environment, (3b) prevention of ecosystem damages by alien species offauna and flora, (3c) prevention of ecosystem damages by Great
Cormorant (Phalacrocorax carbo), and (3d) removal of macrophytes and other water weeds; (4) improvement and preservation of landscapes; (5) promotion of agricultural and fisheryindustries, tourism, transportation, and other means to promoteindustrial development, by means of (5a) promotion of ecologically friendly agriculture and development of such industrial
activities, (5b) appropriate conservation and management offishery resources, and (5c) promotion of tourism and transportation; and (6) promotion of education on these subjects. The
basin conditions the law stipulates are (1) that SPG and Shiga
residents endeavor to gain broad recognition and support fromthe Japanese people in general on the importance of Lake Biwa
and the need for its restoration in view of the seriously challenged situation with regard to its ecosystem; (2) that SPG andShiga residents endeavor to conserve the lake environments andto pursue diverse and prolific industrial activities while also
making sure to balance the two; and (3) to make sure to transcend the value of Lake Biwa to future generations. Since these
are among the key components of the ML21 Plan, it is expectedthat SPG and the prefectural residents will be in much better
position to fulfill the long-term aspiration of the ML21 Plan.
Although these new developments are encouraging and useful, the pursuit for sustainable governance of the Lake Biwa andYodo River Basin will have to be addressed in much broader perspectives, to which the Ecosystem Service Framework to be discussed in the next section may give some useful clues.

Ecosystem Service Framework
The concept of ecosystem service (ES) became well known inconnection with Millennium Ecosystem Assessment (MEA)
conducted under the auspices of the United Nations during theperiod between 2001 and 2005. It was coordinated by the United
Nations Environment Program (UNEP) and was governed by amulti-stakeholder board consisting of a large number of scientist and nonscientist members, with its objective being to “assess
the consequences of ecosystem change for human well-being
and to establish the scientific basis for actions needed to enhance
the conservation and sustainable use of ecosystems and theircontributions to human well-being.” The project outputs weresummarily reported in the publication Ecosystems and Human
Well-being – Synthesis: A Report of the Millennium Ecosystem
Assessment (Read et al. 2005).
The report defines the ES component services as consisting of:

523

524

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance

1. Resources Provision Services (PS) referring to the products
people obtain from ecosystems, including food, wood andfiber (e.g., jute, cotton, hemp, silk, and wool), fuel (dung andother biological materials serving as sources of energy), genetic resources (biochemicals), ornamental resources, andfreshwater (for human consumption and for generating electric energy).
2. Regulating Services (RS) referring to the benefits people obtain from the regulation of ecosystem processes, including
water regulation, erosion regulation, water purification andwaste treatment, disease regulation, pest regulation, pollination, and natural hazard regulation.
3. Cultural Services (CS) referring to the nonmaterial benefits
people obtain from ecosystems, including spiritual and religious values, knowledge systems (traditional and formal),
educational values, aesthetic values, social relations, sense ofplace, cultural heritage values, and recreation andecotourism.
4. Supporting Services (SS) referring to the services necessary
for the production of all other ecosystem services, including
heat energy, soil formation, nutrient cycling, photosynthesis
and primary production, and water cycling. Because water isrequired for other life to exist, it could also be included aspart of the supporting service.
The report then elaborates the relationship between these ES
component services and human well-being, including the basic
material needs for a good life, health, good social relations, security, and freedom of choice and action.
As for Lake Biwa, a study was undertaken in 2010 to apply amethodology for ES assessment called the Economics of
Ecosystem and Biodiversity, otherwise known as TEEB (Ministryof Land Infrastructure, Transport and Tourism 2011). In addition, a special committee appointed by the Shiga Prefecture
Governor undertook a study in 2011, submitting a report entitled “Proposal: Toward the Emergent Next Steps in theManagement of Lake Biwa and Yodo River Basin” (Shiga
Prefectural Government 2011b) which used the ES Framework
as a core concept. This report, although prepared for SPG, suggested the use of ES Framework for dealing with the emerging
challenges facing the Lake Biwa–Yodo River Basin, particularly
the upstream–downstream collaboration for achieving soundwater circulation in the Basin. The report later served as a useful
input for the BY-BMC for possible application to the whole of
the Biwa–Yodo Basin, as discussed in Subsection “Technologicaland managerial implications”. There is a whole range of other ES
application cases reported in Japan, but they mainly focus on
biodiversity conservation rather than lake–river basin
management.
Globally, a large body of literature has been generated on theapplication of ES to lake–river basin management over the past
decades. For example, Brauman et al. (2014), in their paper entitled “Ecosystem Services and River Basin Management,” present

a review of the status of its application in the EU region. They
state “This framework is inherently anthropocentric, organizing
ecological processes by their effects on human beneficiaries andexplicitly connecting ecosystem processes to human welfare.
The ecosystem services approach facilitates management of acomplex system by incorporating important aspects of risk-­
informed management” and conclude that “Overall, ecosystemservices are a useful tool for river basin managers because they
provide a coherent context to incorporate stakeholders andcomplex biophysical processes into a consistent, learning-based
management scheme.” Brils et al. (2014) in their book entitled
Risk-Informed Management of European River Basins present
summarily many cases of its application. They state “Risk-­
informed management involves the integrated application of
three key-principles: 1) Being well informed; 2) Managing adaptively; and 3) Pursuing a participatory approach. The authors
explain and underpin these principles in detail, offer inspiring
examples from practice, and connect them to the implementation of the European Water Framework Directive (WFD).
In the meantime, Costanza et al. (2017) state in their paper
entitled “Twenty years of ecosystem services: How far have wecome and how far do we still need to go?” that traces the history
since 1997 of the knowledge generated on the subject of ES ingeneral, natural capital, social capital, human capital, and built
capital collectively interact with the ES portion of natural capital.
They state “The ecosystems that provide the services are sometimes referred to as ‘natural capital,’ using the general definitionof capital as a stock that yields a flow of services over time. Herethe term ‘capital’ is useful to reconnect the human economy with
its ecological dimensions. In order for these benefits to be realized, (1) natural capital (which does not require human activity
to build or maintain) must interact with three other form of capital that do require human agency to build and maintain. These
include: (2) built or manufactured capital; (3) human capital; and(4) social or cultural capital. These four general types of capitalare all required in complex combinations to produce any humanbenefits. Ecosystem services thus refer to the relative contribution of natural capital to the production of various human benefits, in interactions with the other forms of capital. These services
do not simply flow to human wellbeing without these crucial
interactions. As a consequence, understanding, modelling, measuring, and managing ecosystem services requires a very transdisciplinary approach.” Their view is that “Built capital andhuman capital (the economy) are embedded in society, which isembedded in the rest of nature. Ecosystem services are the relative contribution of natural capital to human wellbeing, and thatthey do not flow directly.” It is therefore essential to adopt a
broad, transdisciplinary perspective to address ecosystem services, as shown in a conceptual sketch, i.e., >Fig. 1 of the above
paper. The views expressed by Costanza et al. are quite informative and trigger many useful thoughts, of which the following
discussion would hopefully be one.

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governance6⊡⊡ Fig. 22
Conceptual illustration of acyclic process of ecosystemservice restoration

 eaning of Regulating Service and Its
M
Relationship with Provisioning, Cultural,and Supporting Services
How is the above ES Framework related to the theme of thischapter, i.e., the evolving issues toward improvement of the
Biwa–Yodo Basin governance? To answer this question, we needto review the specific RS components in the context of lake–river basin management. They include:
1. Water regulation (e.g., reduction of runoff and flooding
magnitudes and incidences; aquifer recharge being strongly
influenced by changes in land cover; water storage potential
being affected by the conversion of wetlands or the replacement of forests with croplands or croplands with urban areas, etc.)
2. Erosion regulation (e.g., vegetative cover playing an important role in soil retention and the prevention of landslides)
3. Water purification and waste treatment (e.g., filtering of impurities and decomposition and assimilation of organic
wastes, detoxification through soil and subsoil processes)
4. Disease, pest regulations, and pollination (e.g., changing of
the abundance of human pathogens and disease vectors, reduction of crop and livestock pests and diseases)
5. Natural hazard regulations (e.g., reduction of damages
caused by large storms, flood water retention by lake andriver riparian wetlands, coastal ecotones such as mangrovesand coral reefs)
These RS features must have been inherent to any land–
water system in a pristine state (e.g., like during the prehistorictime). We need to take note here of the following two aspects of
RS in addressing the evolving basin governance issues. The firstis about the possible gap between the inherent RS capacity thatremains more or less unchanged over time as versus the PS
capacity that is likely to increase over time because of humaninterventions. The second is about the shifting balance among
the four component services, i.e., RS, PS, CS, and SS, over theevolutional history of basin governance.
As for the first of the two aspects, take for example, the caseof flood mitigation capacity inherently associated with natural
wetlands, i.e., natural RS. As the flow regime is transformed
from more lentic–lotic state in the prehistoric and early historic
era to a more hydrostatic–hydrodynamic state in the last centuries, the inherent RS capacity would become comparatively
inadequate against the increasing flood frequency and magnitude as a result of increasing pursuits for more PS. As a result,the shortage in the RS capacity of wetlands for flood mitigation
has to be compensated for by such facilities as levees and flood
control weirs that serve as artificial RS. Similarly, the magnitudeof the inherent RS assimilative capacity of nonpoint sources ofpollution became comparatively inadequate against the increasing quantity of pollution loads, as well as the increasing magnitude of the runoff coefficient. As a result, the reduced RS capacity
has to be made up for by such facilities as drainage and treatment ponds artificially constructed.
As for the second aspect, i.e., the shifting of balance between
RS and PS (as well as CS and SS in many cases), the current state
may be to pursue as much PS as possible, taking advantage ofthe inherent RS. Because the inherent RS would remainunchanged, while the pursued PS would increase, resulting in
an imbalance between the two, many cases indicate this imbalance would also adversely affect the quality of the CS, as schematically shown on the left-hand side of >Fig. 22. Over time, anecessary amount of RS must exist to support the level of PS
activities pursued by human interventions, not by nature. Thisregaining of the balance through many rounds of artificiallyintroduced cyclic process is shown on the right-hand side of>Fig. 22. This restoration process will require consideration for(1) institutions to manage the lake–river and their basins for the
benefit of all basin resource users; (2) policies to govern people’s

525

526

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceuse of such resources, and their impacts on the lake–river ecosystem; (3) involvement of people to facilitate all aspects of lake–river basin management; (4) technological possibilities andlimitations that are often quite dictating in regard to long-term
decisions; (5) knowledge and information of traditional, as well
as modern scientific nature, forming the basis for informed
decisions; and (6) sustainable finance to support implementation of all of the above activities. These six domains of actions
are collectively designated as Six Pillars of Governance(Nakamura and Rast 2014). The Six Pillars of Governance must
be strengthened to make sure the pursuit of above PS–RS balance is in the right direction, with involvement of a wide rangeof basin stakeholders. This proposed social science methodology is named “Ecosystem Service Shared Value Assessment(ESSVA)” and is currently being tested for some selected lake–river basins in Asia and Africa on a pilot-scale basis. The conceptual framework depicted as >Fig. 22 is also included in thereport for SPG (Shiga Prefectural Government 2011b) and also
in the UKLG study report (Union of Kansai Governments2016).
In summary, the ES Framework can be usefully applied toaddress the evolving issues toward improvement of the Biwa–
Yodo Basin governance by retrospectively projecting the outcome of past (historic) human–nature interactions within theBasin. The ES analysis should take into account the scales of spatial sphere (basin, sub-basin, upstream–downstream, natural
circulation, urban metabolic circulation, and trans-basin interactions), the scales of temporal sphere (geo-historical and historical transition from lentic–lotic to hydrostatic–hydrodynamic),
and the scales of perceptional sphere (individual experiences,
community traditions, upstream–downstream conflicts andcontentions, etc.) Balancing over time of PS, RS, CS, and SS andtheir trade-off analysis may serve as an important contribution
to the application of ES concept in the analysis of lake–river
basin governance into the future.

2.

3.

4.

Conclusions
The following are key observations of this chapter:
1. Many major lake–river basin systems of historical importance are known to have undergone long-term transformations of land–water linkage structures and flow regimes, i.e.,from a more lentic–lotic state (more natural) to a more hydrostatic–hydrodynamic state (more artificial). The governance challenges facing such a lake–river basin system also
underwent transformational history, though often quite implicitly. Taking into account the above general observation,
this chapter highlights the governance challenges facing the5.

Lake Biwa–Yodo River Basin, focusing on three thematic
subject areas, i.e., (a) point and nonpoint sources of pollution; (b) Integrated Flood Risk Management; and (c) governance of participation: communities and citizens.
As for item (a) above, the GIS outputs of point and nonpoint
source water quality trends over the past 20 years were presented in some detail. While the focused time span is only
on the order of a few decades, the assessed outputs represent
the cumulative historical stresses resulting from long-term
population dynamics, changes in industrial structures, andubiquitous land use changes having taken place over past
several decades, as well as the transformations of land–waterlinkage and flow regime having taken place over many centuries. The challenges facing nonpoint source issues are far
more encompassing than the point source issues, and there
is now growing interest in what are called the multi-policy
solution approaches.
As for item (b), while the subject of Integrated Flood Risk
Management (IFRM) approach proposed by SPG and possible adoption by UKLG focuses on the site-specific flooding risks of riverine floodplains, the background leading tothis proposed approach goes far back in history, including
the contentious trans-jurisdictional upstream–downstream
relationship. The inauguration of UKLG, a symbol of thedecentralized rather than the centralized decision-making
for basin governance, is hoped to successfully address otherchallenging basin governance issues, also having been left
unattended in the maze of sectoral approaches.
As for item (c), while a major focus was directed to the participatory governance for managing Lake Biwa for sustainable resource use and the so-called the Lake Biwa Model, full
appreciation of the evolving process requires understandingof the historical implications of the relationship between the
upstream Lake Biwa region and the downstream Yodo Riverregion. The unique participatory governance approach promoted by SPG also has its historic roots in paddy agriculture, as well as its cultural heritage associated with Lake Biwa
itself. On the other hand, there have been gradual demographic infusions from downstream, gradually diluting thesocial and cultural identity of the Lake Biwa region, a subjectof possible future study.
Finally, the ES Framework was applied to address the evolving
issues toward improvement of the Biwa–Yodo Basin governance by retrospectively projecting the outcome of past (historic) human–nature interactions within the Basin. The ES
analysis should take into account the scales of spatial sphere(basin, sub-basin, upstream–downstream, natural circulation,
urban metabolic circulation, and trans-basin interactions),
the scales of temporal sphere (geo-historical and historicaltransition from lentic–lotic to hydrostatic–hydrodynamic), as
well as the scales of perceptional sphere (individual experience, community traditions, upstream–downstream conflicts

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin Governanceand contentions, etc.) Balancing PS, RS, CS, and SS over time,
and their trade-off analysis, may serve as an important contribution to the application of the ES concept to the analysis oflake–river basin governance into the future.

Acknowledgments
We would like to thank the editors for invitation to contribute tothis publication and for their patience and guidance to complete
the manuscript. We also thank Dr. Walter Rast, Professor
Emeritus of Texas State University, for his editorial improvement comments.

References
Brauman KA, Meulen S, Brils J (2014) Ecosystem services and river basin management. In: Brils JB, Werner MG, Müller-Grabher D, Négrel J, Vermaat PE(eds) Risk-informed management of European river basins. Springer, Berlin/
Heidelberg, ISBN 978-3-642-38597-1, Online ISBN 978-­3-­642-38598-8.
https://doi.org/10.1007/978-3-642-38598-8_10
Brils JB, Werner MG, Müller-Grabher D, Négrel J, Vermaat PE (2014) Riskinformed management of European river basins. Springer, Berlin/
Heidelberg, ISBN 978-3-642-38597-1, Online ISBN 978-3-642-38598-8
BYQ (2017) Change in the river environment of Lake Biwa–Yodo River Basin.
http://www.byq.or.jp/ryuikizushu/index.html. Accessed 6 Jan 2020
CIRIA (2015) The SuDS Manual. CIRIA, London C753, 968pp. www.ciria.org.
ISBN: 978-0-86017-­760-9. Report No. C697
Costanza R, Grootb R, Braatc L, Kubiszewskia I, Fioramontid L, Suttone P,
Farberf S, Grasso M (2017) Twenty years of ecosystem services: How far have
we come and how far do we still need to go? Ecosyst Serv 28:1–16
European Parliment (2012) The principle of subsidiarity. Fact sheets on theEuropean Union. http://www.europarl.europa.eu/ftu/pdf/en/FTU_1.2.2.pdf.
Accessed 17 Dec 2018
Evans M, Zimmermann A (eds) (2014) Global perspectives on subsidiarity.
Springer. https://books.google.co.jp/books?id=LfckBAAAQBAJ&printsec=fro
ntcover&hl=ja&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false.
Accessed 18 Dec 2018
Fisher, F (2012) Participatory governance: from theory to practice, In: Levi-Faur
D (ed) The Oxford handbook of governance, Online Publication. https://doi.
org/10.1093/oxfordhb/9780199560530.013.0032
Fujioka, J (1983) Biwako yodogawa yamatogawa: sono ryuuiki no kako to genzai[Lake Biwa, Yodo river, Yamato river: the past and the present of theirbasins], Daimyodou, Japan (in Japanese)
Hirayama N, Usami M, Ide S (2012) Komyunithi sosiki ni yoru mizukankyou
hozenkatsudou no kappatusa no sai ni kannsuru youinbunseki; shigaken
moriyamasi wo taishoutoshite [Factor analysis about the water environment
conservation activities through community organizations: in the case of
Moriyama City, Shiga Prefecture]. Mizushigen kankyou kenkyu 25(2):88–94(in Japanese)
Hirayama N, Wada A (2016) Kyobunsankouzoubunseki wo mochiita
Biwakoryuuiki no genjyouhyouka ni ataeru youin ni kansurukenkyuu [Astudy on the factors affecting the status assessment of Lake Biwa Basin, using
the co-­variable structural analysis method]. Mizushigen Kankyo Kenyu
29(2):64–70
Hori T, Furukawa S, Fujita A, Inazu K, Ikebuchi S (2008) An optional design
framework of a flood control system including in-floodplain countermeasures based on distributed risk assessment – basic concepts and method-

6

ology –. J Jpn Soc Civ Eng B 64 (1):1–12 (in Japanese with English
abstract).
ILEC (2005) Managing lakes and their basins for sustainable use: a report for lakebasin managers and stakeholders. International Lake Environment
Committee Foundation, Kusatsu
Japan for Sustainability (2005, May 19) Shiga prefecture promoting green farming. Jpn Sustain Newsl. https://www.japanfs.org/en/news/archives/news_
id025933.html. Accessed 15 Dec 2018
Japan Meteorological Agency (2000) Precipitation data of Omihachiman District
Meteorological Observatory (in Japanese). http://www.data.jma.go.jp/obd/stats/etrn/index.php. Accessed 25 May 2018
Japanese Government (2014) Mizujyunkan Kihonhou [Basic Law on the Water
Cycle]. E-­Gov. http://elaws.e-gov.go.jp/search/elawsSearch/elaws_search/lsg0500/detail?lawId=426AC1000000016. Accessed 31 Dec 2018
Japanese Government (2015) Biwako no hozen oyobi saisei ni kansuru houritsu[Lake Biwa Conservation and Restoration Act] (in Japanese). E-Gov http://
elaws.e-gov.go.jp/search/elawsSearch/elaws_search/lsg0500/detail?lawId=42
7AC1000000075. Accessed 31 Dec 2018
Japan Sewage Works Association (2009) Gesuidou shisetsu keikaku/Sekkei
shishin to Kaisetu-Zenpen (in Japanese)
Kada Y, Nakatani K, Nishijima T, Taki K, Nakanishi N, Maeda H (2010) A studyof water policy based on life environmentalism: the position of environmental sociology in government policy. J Environ Soc 16: 33–47 (in Japanesewith English abstract)
Ministry of Land, Infrastructure, Transport and Tourism and Shiga prefecture(2002) Roadways traffic census. https://www.kkr.mlit.go.jp/road/oyakudachi/traffic_census.html. Accessed 19 Dec 2018, http://www.mlit.go.jp/road/
ir/ir-data/ir-data.html. Accessed 19 Dec 2018
Ministry of Land, Infrastructure, Transport and Tourism, Japan (2009)
Yodogawasuikei kasen seibikeikaku [Yodo river management and implementation plan] (in Japanese). https://www.kkr.mlit.go.jp/river/iinkaikatsudou/yodo_sui/qgl8vl0000000zy0-att/betten3.pdf. Accessed 15 Dec 2018
Ministry of Land, Infrastructure, Transport and Tourism, Japan (2011)
Yodogawasuikei kasen seibikeikaku Heisei 22 nendo Biwako no sougoutekina hozen no tameno keikakuchousagyoumu houkokusho [Task reporton the planning study on the comprehensive conservation of Lake Biwa forfiscal year Heisei 22], Urban and Regional Planning and Development (inJapanese). http://www.mlit.go.jp/crd/daisei/biwako_hozen/keikakutyousa.
pdf. Accessed 15 Dec 2018
Ministry of Land, Infrastructure, Transport and Tourism, Japan (2017) National
Land numerical information. http://nlftp.mlit.go.jp/ksj/index.html.
Accessed 20 Mar 2018
Nakamura M, Ogino Y, Akiyama M, Moriyasu K (2012) Evolving history of Lake
Biwa and Yodo River Basin management. In: Kawanabe H, Nishino M,
Maehata M (eds) Lake Biwa: interactions between nature and people.
Springer, Dordrecht, pp 371–417
Nakamura M, Rast W (2014) Development of ILBM platform process: evolving
guidelines through participatory improvement, 2nd edn. Shiga University
Center for Sustainability and Environment (RCSE-SU) and International
Lake Environment Committee (ILEC). https://www.ilec.or.jp/wp-content/
uploads/pub/DevOfILBMPP_en_2nd.pdf. Accessed 15 Dec 2018
National Institute for Research Advancement (NIRA) (n.d.) A proposal for awide-area local government system – revitalization of the nation and its
regions. http://www.nira.or.jp/past/publ/houko/i0502.html. Accessed 15
Dec 2018
Nishino M (ed) (2009) Torimodose! Biwako Yodogawa no genfukei [Get back!
The origical landscape of Lake Biwa and Yodo River] Sunrise Publishing,
Hikone (in Japanese)
Nishizawa M, Tachi N (2009) Ryuushutsu moderu ni okeru yuuko kouu ni kansuru ichikousatsu [An analysis of the effective rainfall precipitation using arunoff analysis model]. Gesuido kenkyy happyoukai kouenshuu[Proceedings of the Japan Sewage Research Association Annual Meeting
Proceedings] 46:368–370 (in Japanese)
Noda K (1995) Biwako kassui ni kansuru jumin anke-tochosa no gaiyo [Outlineof residents’ questionnaire regarding drought in Lake Biwa]. Mizushigen

527

528

6

Evolving Issues Toward Improvement of the Lake Biwa–Yodo River Basin GovernanceKankyo Kenkyu [Water Resources and Environmental Research] 8:87–95 (inJapanese)
Noda K (2016) Chiiki shakai no jizokukanousei to kyousouseigata kankyou gabanansu no kouchikukatei -Biwako chiiki no kankyoushi to chiikikankyou
NPO no tenkai purosesu [Sustainability of local communities and development of co-creative environmental governance - evolutional process of anenvironmental NPO and the environmental history of Lake Biwa region].
Kyoto furitsu daigaku gakujyutsu houkoku (koukyou seisaku) [Kyoto
Prefectural University Research Report (Public Policy)] No. 8. (in Japanese)
Osaka Kougyo Daigaku Yodogawa Kankyo Kyouiku Sentah (2008) Yodogawa
gaku [Yodo river disciplinary study]. Jyoushou Gakuen, Osaka (in Japanese)
Pezaros P (2001) The environmental dimension of the common agricultural
policy–an overview; In: Seminar ‘The CAP and the Environmental
Challenge–New Tasks for Public Administrations?’ European Institute of
Public Administration, Maastricht (NL) (14–15 May), p32
Prince George’s County Department of Environmental Resources (1999) Lowimpact development design strategies, an Integrated design approach.
Maryland, USA
Ransetu no sayama sa-an (no date) Kamojinjya no genkei - kodai chikei no hensen
https://ameblo.jp/dzf999tea-party/entry-12418231701.html.Accessed 15 Dec
2018
Read WV et al (2005) Ecosystems and human well-being: synthesis: a report ofthe millennium ecosystem assessment. Island Press
SAGA GIS (2018) System for automatic geoscientific analysis. http://www.sagagis.org/en/index.html. Accessed 15 Dec 2018
Schueler TR (1987) Controlling urban runoff: a practical manual for planningand designing urban BMPs. Washington, DC
Shiga Prefectural Government (2008) Shiga-kensei seron chosa [Shiga
Prefectural opinion survey of 2008]. Public Relations Division of SPG (inJapanese)
Shiga Prefectural Government (2011a) Biwako sougou hozen seibi keikaku
mazah reiku21 keikaku dai2ki kaiteiban [Lake Biwa comprehensive preservation and improvement project: Mother Lake 21 Plan 2nd term revision plan] (in Japanese). http://www.pref.shiga.lg.jp/biwako/ml21/
ml21keikaku.html. Accessed 15 Dec 2018
Shiga Prefectural Government (2011b) Biwako Yodogawa no korekarano ryuuikikannri ni mukete: Teigen [Toward the basin management of Lake Biwa andYodo River: proposal study committee on basin management of Lake Biwa
and Yodo River] (in Japanese). http://www.pref.shiga.lg.jp/d/suisei/kentouiinkai/files/teigen.pdf. Accessed 17 Dec 2018
Shiga Prefectural Government (2014) Lake Biwa guidebook. http://www.pref.
shiga.lg.jp/d/kankyo/env-info/files. Accessed 15 Dec 2018
Shiga Prefectural Government (2016) Shigaken ni okeru kikouhendou eikyou
hyouka torimatome [Report on the assessment of climate change in Shiga
Prefecture].
http://www.pref.shiga.lg.jp/d/new-energy/h28tekiou/files/
eikyohyouka.pdf. Accessed 15 Dec 2018 (in Japanese)

Shiga Prefecture and Kyoto Prefecture. Background Document for Preparationof the Fifth Lake Biwa Water Quality Conservation Plan (2006 through2010)
Stoa R (2014) Decentralization of water resources management. Utrecht Law
Review 10: 2. https://www.utrechtlawreview.org/articles/abstract/10.18352/
ulr.267/. Accessed 15 Dec 2018
Taki K, Matsuda T, Ukai E, Ogasawara Y, Nishijima T, Nakatani K (2010) Designfor flood disaster-­reduction system in a floodplain of small-­medium sized
rivers. Adv River Eng 16: 477–483 (in Japanese with English abstract)
Taki K, Matsuda T, Ukai E, Nishijima T, Egashira S (2013) Method for evaluating
flood disaster reduction measures in alluvial plains. J Flood Risk Manag
6:210–218
Union of Kansai Governments (2016) Biwako-Yodogawa ni okeru kadai to kaiketsu no houkousei ni tsuite [About the Lake Biwa–Yodo Basin issues and the
direction toward their resolution]. Biwako–Yodogawa ryuiki taisaku ni
kakaru kenkyukai houkokusho [Report prepared by the study group Lake
Biwa–Yodo River Basin management measures]. http://www.kouiki-­kansai.
jp/material/files/group/3/1473840164.pdf. Accessed 15 Dec 2018
USEPA (2000, October) Low impact development (LID) a literature review.
EPA-841-B-00-005.
https://nepis.epa.gov/Exe/ZyPDF.cgi/P1001B6V.
PDF?Dockey=P1001B6V.PDF. Accessed 15 Dec 2018
USEPA (2007) Cost-benefit of sustainable drainage system (SUDS) retrofit in
urban
area.
https://assets.publishing.service.gov.uk/government/
uploads/ system/uploads/attachment_data/file/290993/scho0408bnxz-ee.pdf. Accessed 18 Nov 2018
Wada K, Nishikawa K, Kishimoto N (2011) Control approach to non-biodegradable organic matter in roadway runoff. Water Practice & Technology 6(1).
https://doi.org/10.2166/WPT.2011.007
Wada K, Fujii S (2007) Pollution control measures of runoff from urban roadways. The 5th seminar on water and wastewater management and technologies. Kyoto, pp 47–53
Wada K, Fujii S (2010) Estimation of pollutant loads from urban roadway runoff.
Water Sci Technol 61(2):345–354
Wada K, Yamanaka S, Yamamoto M, Toyooka K (2006) The characteristics andmeasuring technique of refractory dissolved organic substances in urban
runoff. Water Sci Technol 53(2):193–201
Wada K, Takei N, Sato T, Tsuno H (2015) Sources of organic matter in first flush
runoff from urban roadways. Water Sci Technol 72(7):1234–1242
WEPA (Water Environment Partnership in Asia) (2018) Law concerning the special measures for the prevention of lake water quality. http://wepa-db.net/
info.htm?cx=016132075670832049537%3Aprpcna9emd4&cof=FORID%3A
11&ie=iso-8859-1&oe=UTF-8&q=lake+law%2C+japan&sa=search&siteurl=www.wepa-db.net%2Fdatabase.html. Accessed 15 Dec 2018
Yodogawa Gaidobukku Henshuiinkai (2007) Yodogawa monogatari [A story of
the Yodo river] Kousaido Shuppan, Hikone, Japan (in Japanese)