Lakes & Reservoirs: Research and Management 1995 1: 3-29

Lake Biwa: Have sustainable development objectives
been met?
M. Nakamura
Lake Biwa Research Institute, Otsu, Japan

Abstract
The need to control and manage the effects of urban, industrial and agricultural development on Lake Biwa,
Japan’s largest lake, led to the formation of the Lake Biwa Comprehensive Development Project (LBCDP). This
article describes the nature and effects of the development, how the LBCDP was conceptualized, implemented andmanaged, and comments on its effectiveness. Although the basic objective of the project was to promote
development of the Keihanshin region by providing additional water, other important objectives included theconservation of the natural environment, the promotion of public welfare, and the restoration of water quality. To
achieve objectives on a sustainable basis, extensive political, legislative, social, technological and environmental
matters needed comprehensive consideration. This article considers such matters in detail.

Key words
Lake Biwa, Lake Biwa Comprehensive Development Project, wastewater, w a t e r legislation, w a t e r
management, water quality.

PART I COMPREHENSIVE DEVELOPMENT
PROJECT
Introduction
Lake Biwa, the largest lake in Japan, is located in theuppermost reaches of the Yodo River Basin in central
Honshu Island and occupies one sixth of the prefectural
territory of Shiga (Fig. 1). In the downstream reachesof the basin are metropolises such as Kyoto, Osaka andKobe and other small municipalities in Kyoto, Osakaand Hyogo Prefectures. The total population ofthis region is 13 million, for which the lake supplies
water for domestic, industrial, hydroelectric and irrigation purposes.
Throughout history, there have been conflicts inwater use and management between upstream Shigaand downstream areas, with respect to flood control,
water resource development and more recently towater quality management.
As for flood control, the communities in theimmediate surroundings of Lake Biwa had suffered
many severe floodings for centuries before the central
government finally agreed about 100 years ago to amajor dredging of the Seta River, the only outflowing
Accepted for publication December 1994

river from the lake. Seta Weir, the single artificial
water flow control facility of the lake outflow, was also
constructed about this time. With these and other flow
control measures introduced over the past century,
flooding is no longer a major threat either for Shiga orfor downstream areas.
As for water resource development, the demand forlake water by the downstream megalopolises in the
1960s led to the Lake Biwa Comprehensive Development Project (LBCDP) (Nakamura 1991; Nakamura
and Akiyama 1991). In this, the development of new
water resources amounting to 40 m3/s has been agreed
upon by Shiga and downstream prefectural andmunicipal governments, as well as by the National
Government.
This additional amount of water was to be madeavailable upon completion of all originally scheduledlakeshore reinforcement works and other compensatory public works projects for Shiga Prefecture by
the end of 1982. After experiencing difficulties in
implementation of an array of component projects
within the originally scheduled 10 year project period,
the project term was extended for an additional 10
years u p to the end of 1992, with integration of
additional projects for environmental conservation.
By the end of 1992, almost all water resource develop-

M. Nakamura

4

ment projects were completed, but not all of thecompensatory public works, leaving the Shiga Prefectural Government to propose the release for downstream communities of only 27 m3/s of additional water
on an ‘as-needed’ basis. The downstream governments
reluctantly agreed to the tentative arrangement.
The LBCDP is a plan involving such project
categories as nature and environmental conservation,
flood control and water resources development. An
array of large-scale component construction works,
costing billions of dollars to the region and the nation,
have been and will continue to be undertaken until theend of 1996when the project period is due to terminate.
In the meantime, lake water quality has deteriorated
over the past several decades due to population growthand various development activities within the catchment area. Some environmentalist groups have been
putting blame on LBCDP itself. Shiga Prefecture is
now under pressure to improve lake water quality

through various wasteload reduction measures as wellas in-lake restoration. The prefecture has also indicatedits frustration recently by arguing that downstream
governments should bear, in addition to the amount
paid within the framework of LBCDP, part of the cost
incurred for undertaking lake water quality improvement projects on a sustainable basis, much of thebenefits of which accrue to downstream users. The
proposal originally received a rather cool reception
from downstream governments who claimed that thecontribution to environmental conservation components of LBCDP was meant for that purpose. The
Ministry of Construction facilitated the establishmentof Water Quality Conservation Funds to diffuse thisissue to which all neighboring prefectural governments were invited to contribute. Shiga Prefecture iscurrently attempting to develop a post-LBCDP scheme,
the realization of which is yet unknown.

Pref.

Fig. 1. Lake Biwa and the Yodo

River region. Source: Anon 1991a.

5

Sustainable development of Lake Biwa

Lake Biwa-Yodo River Basin
To understand the history of water resource development and water quality conservation of Lake Biwa, it
is important to recognize the unique geographicalfeature of the Lake Biwa-Yodo River Basin and upstream-downstream relations with respect to water
resource development of Lake Biwa.
The lake measures 63.5km in a north-south
direction and is divided into two sub-basins at theconstriction point approximately 16 km from thesouthern end. It has a total surface area of 674 km2, a
volume of 27.5 billion m3, and a shoreline length of
235 km. Its catchment area is 4.7 times the area of thelake itself, and its boundary more or less coincides
with that of the prefecture, constituting 96% of prefectural land (Fig. 2). The catchment area consists offorest-covered hills and mountains (60%),paddy fields

and other farmlands (25%), and urban and industrial
areas. The prefectural capital, Otsu, has an approximate population of 240000 and is located a t thesouthern end of the lake. Some 400 rivers and streams
flow into the lake, but there is only one natural water
course flowing out of the lake, Seta River, and two
canals passing lake water to Kyoto. The lake serves asa source of domestic and industrial water for both
populations within the lake catchment area and thedownstream population and industrial centres in the
Keihanshin Area (Fig. 3).
I t also serves for irrigation of paddy fields in thelake basin flat lands and for hydropower generation a t
some distance downstream of the outflowing river.
Lake Biwa has been the most important natural asset
for the prefecture, and Shiga residents have had a
special attachment to the lake throughout history

Fig. 2. Topography in the Lake

Biwa catchment area:(0)mountains;

N(m)hills; ( H )low areas. comparisonof the boundaries of Shiga Prefecture and Lake Biwa drainage basin:d rainage basin boundary;'(-1

prefecture boundary; ( 8 )inthe prefecture, b u t outside thedrainage basin;in the drainage
basin, but outside the prefecture.
From LBRl and NlRA (1984).

(a)Prefecture

M. Nakamura

6

has had direct access to lake water unlike other downstream metropolises. The Seta River reaches to theprefectural boundary between Shiga and Kyoto. Within Kyoto Prefecture, it is called Uji River. Uji River is
met by Kizu River and Katsura River at the KyotoOsaka Prefectural boundary, and the downstream
stretch from this point is popularly called the Yodo

because of their dependency on the lake for fishingand transportation.
In the past century or so, the water-use pattern haschanged significantly due to various water resource
development activities (Fig. 4, Table 1). The two canals
linking the lake and Kyoto were constructed in 1890
and 1912, respectively. The City of Kyoto, therefore,

Water supply lor:
tap waterindustry
agriculture
otherselectric power

Water supply lor:
tap waterindustry
17.47
agriculture
others

12.96

Lake Biwa

0.48

43.32

Water supply lor.
tap waterindustry
agriculture

42.32
14.85
16.80

industry
agriculture

7

Fig. 3. Water uses in the Lake
Blwa-Yodo River Basin: (-1Ibarrage;0 ) dam; (0)generating station.

Osaka B a y

Unit = m3/s. From Anon (1991a).

Highest water level

do river improvement project
IIyo(dredging
of Seta River)

t

h

E

v

Yodo River river
Basic plan for improving
water control project Yodo River water systemc----l-Construction of new (Seta River)
regulating gate

1.43m

A

27.10.1917

L

0

I

2"

4.12.1939 ?level
1

1870

I

1880

1

I

1890

I

I

1900

I

I

1910

I

I

1

1

1930

1920

Year
Fig. 4. Changes in the water level of Lake Biwa. From Anon (undated).

1

1

1940

2.9 1973
I

l

1950

l

1

1960

29.11.1978
I

'

1970

l

l

1980

Sustainable development of Lake Biwa
River. The flow contribution to the Yodo River of theUji, Kizu and Katsura Rivers are, respectively, 64%,
18%and 15%.
The official designation of the whole of the Yodo-Uji
and Lake Biwa water bodies is the Yodo River System.
Its total catchment area, as observed at Hirakata,some 20 km upstream of the river mouth, is 7281 km2.
According to Ministry of Construction statistics, its
annual average flow, high flow and low flow are,respectively, 177.6 m3/s, 226.8 m3/s and 117.0 m3/s.
At present, the metropolitan regions of Osaka, Kyoto
and Kobe depend almost exclusively on the Yodo Riverfor industrial and municipal water supplies. Thus,
Lake Biwa accounts for water supplies amounting to
20 billion tons per year, and serving as many as 12
million people living in the Keihanshin Area including
Shiga. Lake pollution, therefore, has been of serious
concern not only for those living around the lake but
also for those receiving water from the Yodo River.
The history of Lake Biwa and Yodo River water
management was one of a conflict of interests and theresolution between Keihanshin Area downstream,
particularly the Greater Osaka Region, and the Shiga
Prefecture upstream. For centuries, the communities
Table 1. Lake Biwa-Yodo River Basin: Water resource development

activities
Year

Development activities

1874

Installation of Torii River water signpost
Construction started on 1 st Lake Biwa canalConstruction of 1s t Lake Biwa canal completedPlan for improving Yodo River drafted
Large flood
Construction of regulating gate completed
Construction of 2nd Lake Biwa canal completed
Uji Power Plant completed
Severe water shortage
Winter time discharge started
1st river water control project completed
Basic plan of improving Yodo River water system drafted
New regulating gate completed
Work under basic plan of improving Yodo River water
system completed

1885
1990
1896
1896
1905
1912
1913
1939
1943
1953
1954
1961
1967
1971
1972
1972
1982
1982

Basic plan of implementing constructions in Yodo River
water system
Special decree for LBCD Act enacted
LBCD Plan draftedSpecial decree for LBCD Act modified
LBCD Plan modified

7
in the immediate surroundings of Lake Biwa experienced severe flooding of their agricultura1 fields
before the government finally agreed, about a century
ago, to a major dredging of the Seta River at the outletof the lake, in combination with the construction of
Seta Weir, the only artificial water-flow control facilityof the lake outflow. It is located a few kilometers
downstream from the lake outlet. The weir, constructed
in 1905 and renovated in 1961, controls the lake waterlevel and discharge rate to Yodo River. The flood
frequency and the flood damage in the lake catchment
were drastically reduced after the weir construction.
The demand for water, particularly for industrial
uses, began to increase sharply as the country entered
the era of economic growth a decade or so after theend of the War.
In the downstream stretch of Yodo River, the Hanshin Industrial Belt established in pre-war years began
to thrive with unfulfilled demands for more water.
Exploitation of groundwater soon became constrained
due to competition of use among industrial establishments and to land subsidence caused by overdrafts ofwater. Industries were then forced to look for alternative sources of water. Domestic water supply needs
also began to increase in the Yodo River areas after
suburban cities joined Osaka in gaining access to Yodo
River water.
Japanese economic growth gained momentum by
the mid-1950s (Fig. 5), and there was significant interest in the development of a comprehensive development plan of Lake Biwa water resources by the downA

fl
I I
1890

I

,

1900 1910

0

I

1920

1930

I

I

1950 1960 1970

I

1980

Year

Fig. 5. Long-term growth trends of the Japanese economy:
average economic growth rate. From Minami and Kiyokawa(-1(1987).

M. Nakamura

8

stream population and industrial centers. After nearly
two decades of political pressure on Shiga Prefecture,
consisting of demands by downstream interests andthe initiatives by the national government ministries,
Shiga Prefectural Government finally agreed to ascheme for the comprehensive development of Lake
Biwa.

The concept of the LBCDP
The conceptual basis
The development of the water resources of Lake Biwa
provides socio-economic benefits to the downstream
Osaka and Kobe regions in the form of urban andindustrial development. Shiga Prefectural residents,on the other hand, were concerned that they might
simply accede to downstream demands for additional
water without direct benefit from the transaction.
They were more likely to suffer from additional discharge of lake water through the Seta Weir, since itwould necessitate alteration of existing, or the construction of new, lakeshore facilities for coping withthe lowered water level. The conceptual basis of thecomprehensive development plan was, therefore, basedon the following considerations:(1) Since those living around Lake Biwa have historically made a livelihood out of the lake, the lake
ought not to be considered as a mere impoundment or
reservoir.
(2) The lowering of the water level ought to be kept
within limits considered reasonable to those immediately affected.
( 3 ) The development of additional water resourcesof Lake Biwa ought not to benefit only those who makedirect use of it downstream but also those who are
disadvantaged upstream due to lost opportunities.
The balance of conflicting interests of Shiga Prefecture upstream and Hanshin Region downstream
required the development of a concept totally new tothe water resources management policy-making institution. The consensus involved the following basic
principles:(1) The Project will comprise two major components,
one being water resources development, and the other,regional infrastructure development particularly forcommunities around the lake.
(2) The Project will be funded predominantly by
the national government and the downstream local
governments.
( 3 ) The Project, being a large scale regional development project with national implications, will be draftedby the Prefectural Governor of Shiga and be approvedby the Prime Minister of Japan.
The Project was designed to consist of three
categories of component projects, namely those
designed to contribute to the conservation of Lake
Biwa environments, to mitigate flood and coastal
erosion, and to facilitate downstream municipalities
and industries the use of an additional 40 m3/s of water(Fig. 6).

Outline of LBCDP
The basic objective of this project was to promote
development of the Keihanshin region by providing
additional water amounting to 40 m3/s, to compensate
the Shiga residents for the possible adverse impacts of
the lowered water level (assumed to reach as low as- 1.5 m below the current normal level), and to improve
simultaneously the socio-economic status of the Lake
Biwa watershed communities. However, such a largeWater quality
conservation
Conservation

utilization ofnatural environment

Improvement of
in-flowing river

7

flood control-

Conservation andimprovement ofcatchment areas

Water utilizationin the prefecture

utilization

Fisheries

Water utilization in
downstream areas
Fig. 6. Basic framework of the LBCDP.

Sustainable development of Lake Biwa

9scale development project would have not only regional
implications but also national ones. In particular, there
would be a need for a cost-sharing scheme involving
national as well as downstream local governments sothat the heavy financial burden on the upstream local
governments could be lightened.
With such considerations in mind, the ‘Special
Measures Act for Lake Biwa Comprehensive Development’ was enacted in June 1972 (Table 2). As stated in
Article 3 of the Special Law, the LBCDP was draftedby the Governor of Shiga Prefecture and was approvedby the Prime Minister. The particulars of this project
were set in accordance with the basic policy thatemphasized the importance of the preservation anddevelopment of Lake Biwa and its catchment area.
The Project also provides for administration offacilities to be constructed within each project, management of Lake Biwa and its shorelines, and operationof the Setagawa Weir. The project plan, which determines the outline of component projects, sets forth the
purpose, volume and particulars of each of the 21
projects for local area improvements. These are to be
carried out mainly by municipalities in Shiga, Osakaand Hyogo prefectures and by the prefectural governments themselves pursuant to three major guidelinesof the basic policy. The water resources development
projects and the Lake Biwa flood control projects areto be conducted mainly by the Water Resources Development Public Corporation.

However, due t o the rapid change in social andeconomic conditions of the nation during the ten year
period, the Lake Biwa environment and the situation
surrounding the LBCDP also changed, resulting in
the emergence of various problems not adequately
taken into consideration a t the time of enactment.
In particular, because of the decreased growth of
the Japanese economy since the first oil crisis in1974 (Fig. 5), public investment was severely curtailed,
and the LBCDP had achieved only 40% of the goals
stated in the Project plan by the end of March 1982. In
addition, the trend in the demand for water, which
decreased soon after the oil crisis in 1973, had castsome doubt on the validity of the very basis of the
project scheme (Fig. 7).
Furthermore, the water quality of Lake Biwa
deteriorated more rapidly than earlier anticipated,necessitating the implementation of remedial measuresby revision of the original component projects. The
major incidents of significance during this period may
be listed chronologically.

Extension of the terms of the Special
Measures Act and revision of the Project plan

E

This act, enacted 1972, had a limited validity period of
10 years and was to be terminated in March 1982.
Table 2. Basic structure of the Special Measures Act for the LBCDPArticleMunicipal

0
0

1

c

.-0

E
Z
l
’L
4

400

479

/

t/

Description

Purpose of this law
Particulars of development and conservation projects
Procedures to be used for decisions and revision of theplan

Preparation of a yearly plan for individual projects
Responsible agencies
Co-operation among the concerned bodies

8,9,1011
12

Measures for restoring the living conditions of local
peopleInvolvement of the national government
Proposed scheme for cost sharing
Establishment of the Lake Biwa Administrative Fund

1965

1970

1975

1980

1985

Year
Fig. 7. Water consumption trends in the lower reaches of the Yodo

River Source Shrmazu 1989

M. Nakamura

101977 The first sighting of a freshwater ‘red tide’(confirmed annually since).
1979 The Eutrophication Control Ordinance enacted
for the first time in Japan by Shiga Prefecture.
1981 Taste and odour problems associated with Lake
Biwa water became highly noticeable.
The Shiga Prefectural Government thus consulted
with concerned national government agencies for an1973 The sudden increase in international petroleum
prices (the first oil crisis) and its severe impacts on theJapanese economy.
1976 The environmental impact study conducted on
the construction of an artificial island in the southernend of Lake Biwa as a wastewater treatment plant.
Litigation against the implementation of LBCDP
submitted to Otsu District Court House.
Table 3. Component projects in LBCDP and costs

Projects Component

Planned Cost

1972-81 Cost

1982-91 Cost

1972-92 Cost

(1971 price)(price of year)(1981 price)(unadjusted sum)

A. Conservation

A-I

Water quality
Sewerage system

59 00099 633257 940357 573

Nightsoil system

2 938

9 268

4 262

13 530--~~Refuse disposal-

Lake surveillance system-

City parks
Natural parks
Acquisition of conservation areas

Stockbreeding waste management

2 163

2 163

20 000

20 000

-

16423

16423

-

84 1

841

2 775

686

7 400

8 086

4 832

505

1621

2126

3 650

566

1632

2 198

Roads

62 86360 5751 1 1 331

171 906

Ports and harbors

7193

35

4321

4 356

Conservation total

143 251

171 268

427 934599 202

Rural sewerage

A-2

A-3

Conservation

B. Flood control
B-1. River-relatedRivers47 33046 64968 975115624Dams

20 20010424

71 09081 514

Erosion control

22 5091 5 793

35 34751 140Afforestation

14 39325 87527131

53 006

Mountain management

20 32020118

18 94739 065

124 752118859221 490

340 349

20 44663 6501 5 379

79 0298-2. Catchment-related

B-3. Flood control total
C. Water utilization

C-I. In-prefecture use
Water supply
Indust. water supply

5 920

1 0 447

7 978

18425

Land improvement54117

74 755143 080217835

Fishery

5118

3 254

5 046

8 300

Fishing ports

1033

1455

255

1710

C-3. Water utilization total

86 634

153 561

171 738

325 299

72 000118305

141 695

260 000

426 637

561 993962 857

1 524850

C-2. Fishery

D. Downstream use

Flow control and water management
Grand total
Costs in Y million Source: Shiga Prefecture.

Sustainable development of Lake Biwa
extension of the validity period of the Act and therevisions of the plan as follows:(1) To extend the validity period of the special act
for an additional ten years to allow for the completionof the initially planned projects.
(2) To revise the Project by adding projects dedicatedspecifically to water quality management.
(3) To maintain t h e c u r r e n t special financing
measures for project implementation.
At the national assembly in December 1981, therequests by the Shiga Prefectural Government asstated above were approved almost wholly, and the‘Partially Revised Special Measures Act for Lake Biwa
Comprehensive Development’ was enacted, promulgated and put into force in March 1982. Four additional
categories of projects were added to the original 18
categories. They included construction of agricultural
dairy waste management facilities, rural community
wastewater treatment systems, solid waste management systems, and water quality surveillance andmonitoring systems. The total expenditure swelledfrom the original Y426.637 billion to Y1524.85 billion.
Table 3 provides details of the costs of component
projects.
In addition, there arose a need for renewed efforts
for co-ordination between upstream and downstream
local governments, and a consensus reached in May
1982 stipulated the following basic agreements.
(1) To establish a forum of joint study by the concerned local governments on the management of water
quality of Lake Biwa-Yodo River Basin.
(2) The joint financial obligation of the downstream
governments was determined as Y36.0 billion.
(3) To extend the pay-back period for the Y5.0 billion
left over from the previous years for an additional 10
years.
(4) The actual release of the additional flow of lakewater, amounting to 40m3/s,would begin only after
the compensatory works have been completed.

The emerging issues
The terminal year of LBCDP as specified within thespecial act was 1992, and the component projects werethen at various stages of completion. Table 4 indicatescompletion rates in 1988, as an example. Those projects
concerned with increasing the flow through the Seta
Weir down through the Seta, Uji and Yodo Rivers
were reasonably close to being completed in time. The
progress of compensatory public works projects forinfrastructure development, however, had been lessthan satisfactory. A great deal of effort is needed for11

implementation of the remaining portion of the projects, and for instituting transitional measures such as
extending further the project period. Shiga Prefectural
Government, the downstream governments and thenational government are reported to have agreed toextend the term of LBCDP till the end of 1996, inorder to complete remaining projects.
In the meantime, the court case on the 1976 litigation
concluded, allowing LBCDP to continue as planned,
and water demand began to increase again, particularly domestic consumption, due in p a r t to thechanging lifestyle of the people. The Shiga Prefectural
Government will take transitional measures to release,
Table 4. Project completion rates of LBCDP in 1988

Completion rates
Name of project

Conservation
Sewerage system
Nightsoil treatment facilities
Stockbreeding environmental improvement
facilities
Rural sewerage system
Refusal disposal facilities
Water quality monitoring facilities
City parks
Natural parks
Public ownership natural conservation

Roads
Ports and harbors
Total (for conservation)

(YO)

64.1

87.7
78.3
61.6
36.5
40.1
29.5
40.9
52.2
70.7
19.0
65.0

Flood control
Rivers
Dams

64.2
30.7

Sabo works
Afforestation and forestry paths
Mountain management
Total (for flood control)

62.8

Water utilization
Water works
Industrial water works
Land improvement for agriculture
Fisheries
Fishing ports
Total (for water utilization)
Lake Biwa flood control and water resources
development
Grand total
From lmai et a/. (1989).

75.4
98.0
62.8
93.4
80.0

70.8
89.1

96.2

77.8
91.8
71.9

M. Nakamura

12

steadily, 27 m3/s of lake water down through the Seta
River and hence to the Yodo River. Thus, the original
and the most important aspiration of LBCDP, that is,
the management of lake water for flood and erosion
control and for flow augmentation to satisfy downstream demands, is about to be realized.
As the facility construction phase of LBCDP comesto an end, there emerged new issues of importancesuch as: (i) the proper operation and maintenance offacilities constructed in connection with the Project;(ii) management of the lakeshore fronts uncovered due
to lowered water levels (up to 1.5m); (iii) the establishment of new operational rules for the Seta Weir;and (iv) the acquisition of necessary funds for various
undertakings of a managerial nature hitherto notaccounted for in project funds.

0.6

The conservation of the Lake Biwa environment a t
the completion of LBCDP would not be adequate with
only those provisions stated above. The managementof the aquatic environment of Lake Biwa has entereda new era. Concern for the conservation of water
quality has become more serious today than in theearlier days of LBCDP. There is an emerging realization that there would be a need for a more comprehensive concept of management of Lake Biwa andYodo River system, particularly for countering thedeterioration of water quality of the lake at a rate
which seems to be much greater than before. Concentrations of total nitrogen and phosphorus in the lake,
as measures of water quality trends, are indicated inFig. 8.

L

h

-I
\

0,

-E

Southern Lake

0.4

LNorthern Lake

0

1 1

1966

in Northern Lake

I

I

I

I

1970

1975

1980

1985

I
I990

Year

23,

30

-

2o

-

I

7
Southern Lake

3
L

0
Jz
v)

0

c

-Q 10
(d

4-l

0

I-

Attainment target
in Southern Lake1.-.-.-.-.-.-.-.-.-_-._._________________.-.-.-.-.-.-.-.-.-.-~-.-.-..
LL-.-. _ _ _ _ _ . _-.- -. . _ . _ .

TATta in m en t t

In Northern Lake

a

w

-

Fig. 8. Water quality trends in

Lake Biwa, as indicated by concen-

Northern Lake

trations of total nitrogen and phos-

Sustainable development of Lake Biwa

Implication of LBCDP

13

One can make many observations on the implicationsof this large development project, keeping in mind
that the approach taken to realize this project andmany of the issues raised in the process of implementation will have significant bearings on the conceptualization of similar developmental projects undertaken
in other (particularly developing) countries in future.

some and less for others, to accommodate thesechanges.
The implication is that projects with long implementation duration will require timely re-evaluation andnecessary modification, and the facilitation of suchmodifications will require substantial additional
financial commitments. Sometimes such re-evaluation
may call for fundamental change in the original
concept of the plan.

Historical timing of conceptualization andimplementation of the Project
LBCDP was conceptualized at a time when Japan was

The concept of basin-widewater management

undergoing considerable economic growth. There wassignificant development pressure and momentum
building up in the nation for greater access to water
resources, and at the same time the mobilization offinancial resources for such a massive project appeared
feasible. Given the pressing needs for water resourcesby the downstream population and industrial centersthen, the issue at that time was when to launch the
project and how could politically satisfying arrangements be arranged between upstream, downstream
and national interests.
I t would probably not have been possible to realize
this project in Japan at any other time than in theearly 1970s and in any other form than the current
form, balancing downstream interest in water resources with upstream interest in regional development, and balancing resource development with environmental conservation.
The implication is that the present generation will
enjoy the satisfaction of having accomplishedthe project,
but at the same time it will have to bear the responsibility for the consequences of the decision, bethey newly generated economic benefits, costs for restoring disturbed ecological integrity, or any otherconsequences not properly accounted for at present.

Long duration of the project implementation
A complex development project such as LBCDP often
takes decades to complete. As the social and economic
situations change over the project duration, sometimes
drastically, the nature of the project will have to bemodified with additional costs of adjustments. In thecase of LBCDP, they were incrementally reassessed
and readjusted, while maintaining the basic framework of the development project. The societal needs
for water have changed, the environment and theecology of the lake have changed, and the level ofawareness of the public of the value of the lake has
also changed. Facilitation had to be made, more for

One of the subjects attracting growing interest amongwater management specialists is an approach called‘basin-wide water management’. In the case of Lake
Biwa, it would be the management of the whole of theLake Biwa-Yodo River Basin as a single unit. How
does LBCDP fare in this respect?
Simply stated, the upstream and downstream jurisdictional entities in the Lake Biwa-Yodo River Basinhave conflicting interests in the management of water
quantity on the one hand, and non-conflicting interestsin the management of water quality on the other. As
for water quantity, the conflicts are softened throughmonetary transactions for undertaking compensatory
public works, the very basis of LBCDP. For water
quality, the conflicts do not exist in the sense thateveryone wants lake water quality improved, and it
costs money to do so. The problem is that we do notknow how much it will cost and who will have to bear
this cost. Parts of the expenditures on water quality
improvement are defrayed through the natural andenvironmental conservation component of LBCDP.
Although the original expectation was that the amountof investment under this category would be sufficient
for realizing significant improvement in Lake Biwa
water quality, it has not yet proven so.
In addition to the environmental conservation component of LBCDP, the prefectural government of Shiga
has always wanted governments downstream to joinin creating water quality conservation funds specifically aimed at accelerating the improvement of water
quality of Lake Biwa through such activities as controlling nutrient run-off into the lake. Let us consider
this issue given discussion of similar issues elsewhere.
If we confine the scope of water quality improvement
just to water supply, the justification for the need forsuch conservation funds may prove difficult. Downstream communities may be able to get clean water byresorting to improved treatment technology for muchless than what they may have to contribute to funds toimprove the lake water quality itself. If, on the otherM. Nakamura

14

hand, the lake has been sustaining growing development pressure of all kinds coming from downstream
communities as well as the entire nation, and a broad
spectrum of intangible benefits has to be passed on to
the entire population in the basin over many generations to follow, then it would not be unreasonable toask downstream governments to bear the burden ofenhanced clean-up efforts upstream.
How convincing such an argument would be depends
not only on the willingness of the population to pay forsuch long-term objectives, having full understandingof the value of protecting the lake, but also on its
capability to pay.
The implication is that the emerging structure of
the basin-wide water resource management would be
dictated by the capability of the people and governments to adjust to emerging factors in water quantityand quality, many unknown a t the time of project
inception.

Assessment of benefits and costs of the
Project accruing to future generations
Since LBCDP is such a massive project and has transgenerational implications, the full benefits and costs
accruing to future generations in the Lake Biwa Basinhave yet to be assessed. I t is not known if society would
mature enough to accept the concept of environmental
and water resource sustainability to the extent ofmaking further efforts to reduce water consumption
and waste production activities on land, or if it would
simply let supply dictate the demand for more waterand production of more wastes.
Would future generations hail this generation forhaving implemented the plan? Would they lament the
disturbed ecological integrity of the Lake Biwa environment? Would they say that they would have done thesame to develop Lake Biwa, or would they say thatthey would have done otherwise?
The implication is that the lake, watershed, socioeconomy of the region and the whole environment
surrounding the lake should be carefully monitored toenable future generations not only to assess the Projectin retrospect, but also to take whatever measures they
deem appropriate and necessary then to develop andconserve Lake Biwa and its environment.

PART II EVOLVING ISSUES IN LAKE BlWA
WATER QUALITY MANAGEMENT
Framework of Analysis
Few lakes in the world possess the intricate history ofhuman-nature interaction, which characterizes thatof Lake Biwa, the largest and, in virtually all possible
aspects, the most important lake in Japan. To understand the lake, its limnology, ecology and environment,socio-economic implications, resource values and allother features, one would almost have to live at thelake and sense the weight of its history. Lake Biwa
today reflects humanity’s unique interaction with thelake over centuries, and it also reflects, of course, what
it will bequeath to future generations.
Important subjects requiring analysis for a thoroughunderstanding of evolving issues in Lake Biwa water
quality management include:(1) National, regional and local legislation, which
provide the basis for economic development, land use
and land development, and water quantity and quality
management.
( 2 ) Legal framework for land-use control and its
relationship with the development of major waterpollution control programmes.
(3) Water use trends and the development of locallyappropriate water management systems, particularly
for the agricultural use of water and run-off control.
(4)Major water quality conservation measures forthe control of domestic, industrial and agricultural
pollution loads.
(5) Development of eutrophication control ordinances, particularly with respect to initial driving
movements, legal, social and policy implications,
impacts generated both in terms of actual control ofeutrophication and socio-political significance.
(6) Intricate mechanisms of interaction between
local government agencies and prefectural residents
in dealing with lake water pollution incidents.
(7) LBCDP development process, contents, progress,
and its implications and impacts.
The development of interactions between these subjects is the most important feature about Lake Biwa.
It may be summarized as follows:(1) Lake Biwa is the largest Japanese lake both inarea and volume and has been the single most important water source in the western part of Japan throughout modern history.
(2) For its irreplaceable tangible, as well as intangible, natural resource values, the prefectural residents have historically shown extreme attachment, toan extent perhaps unparalleled in any other lake inJapan.
(3) It has only been a century or so since constructionof major control facilities for water resource development and flood control have been undertaken, and it
has only been a little more than a few decades sinceSustainable development of Lake Biwa

15

the prefectural government began to engage in serious
and systematic pollution control activities.
(4) The history of the development and conservationof the lake catchment area reflects extremely intricate
policy decisions, sometimes resulting from severe
conflicts of interest among various national, regional
and local entities a t various levels of the decisionhierarchy.
(5) There emerge, therefore, many complex structures of interaction among major decision-making
bodies, such as governments, industries, citizens, andothers, both with respect to development and conservation policies involving the lake and the catchment.

Legislative basis for development andconservation
Regional development
Japan is a nation with a highly hierarchical decisionmaking structure and the central government sets thebasic policy direction in most issues of general national
concern. Setting national and regional development
policy, of course, falls within this category of hierarchical decision-making. Legislative measures concerning regional development are many; they areclassified according to their designated objectives (Fig.
9). The seven classes of legislation are: general,

Comprehensive NationalDevelopment Plan
(Comprehensive National Land Development Law)development-block, special region, land-related, individual project, long-term planning, and other typesof legislation.
Development plans for regions and prefectures will
have to be prepared closely in response to the framework established within long-term national development plans. The National Land-use Planning Law of1974, which sets the basic framework for the planningof national lands, includes, for example, stipulations
on prevention of uncontrolled development and speculative activities. The national land-use plan in Shiga
Prefecture was prepared in 1977 pursuant to theframework established in this law. The revised prefectural plan was prepared in 1986 also in accordancewith the Revised National Land-use Planning Law of
1985.
The national government also took very strong
initiatives in the development of the overall plan ofnational reconstruction and economic development
throughout the post-war period. The regional development plan of the Kinki Region, which encompasses
Shiga Prefecture and five other downstream prefectures including the Keihanshin Industrial Zone,
has been developed and implemented according to theoverall framework established in the national planssuch as the National Comprehensive Development Planof 1962 and the New National Comprehensive Develop-

Lake Biwa Comprehensive Development Proiect(Special MeasuresAct for Lake Biwa-

Siga PrefecturalComprehensive Plan-

Lake Country EnvironmentalPlan

ComprehensiveDevelopment)

Kinki Region Improvement Basic Plan
(Kinki RegionImprovementLaw)
Chubu Region Developmentand Improvement
Basic Plan (Chubu Region Development)
Water Resources Development Basic Plan
(Water Resources Development Law for

Yodo River)I

Construction Enforcement Basic Plan
NafiOMl Land Use Planning(River law)
Other national plans related to the-Siga Prefectural National Land Use Plan

conservation and development of
Lake Biwa and its surroundingareas
J

Fig. 9. LBCDP and regional development plans. From lmai et a/. (1989).

M. Nakamura

16

ment Plan of 1969. The intense industrialization andurbanization through the 1960s and the major part ofthe 1970s in downstream prefectures, together with
Shiga's own comprehensive development plans of 1963
and 1967, had great impacts on the profile of the Lake
Biwa catchment area. The quality of lake water began
to show signs of deterioration about this period for the
first time in the long history of the lake.

Water management and water allocation
Water legislation may be categorized into thosedealing with river management, forests, sea-shores,
land-slide and flood control, water resources andutilization, and water quality conservation. Amongthese categories, those concerned with water quality
Conservation are dealt with below in order to highlighttheir slightly different orientation from the others.
The remaining two categories of water legislation
exhibit, as in the case of legislation concerning
regional development, a very strong degree of centralization of management authority, Rivers of any
significant size are under total control of the Ministryof Construction. Hydroelectric power generation is
the responsibility of the Water Resources Development
Agency, a semi-governmental body closely affiliatedwith the Ministry of Construction. And water supply
is the responsibility of the Ministry of Health andWelfare. All except a few were enacted prior to 1965;
they have not been revised to any significant extent
since. In effect, it is reasonable to state that water is anational rather than local matter in Japan.
The legislation specially enacted for facilitating thedevelopment of Lake Biwa, the Special Measures Act
on Comprehensive Development of Lake Biwa, may be
regarded as one such water legislation. The act stipulates the undertaking of a number of facility construction and development projects concerning theconservation of the lake and its catchment area, together with an agreed formula to mobilize financial
resources. These projects are to be undertaken ascompensation for lowering the lake water level by amaximum of 1.5m below the officially recognizedwater level. The additional water withdrawn from thelake through the Seta River is for use by downstream
metropolises and industrial complexes. The special
measures act, however, is not exclusive in that it is tobe applied with other relevant legislation, particularly
for regional and prefectural development plans, already in existence.

Water quality conservation
The hierarchical structure of government activities
also dictates the way in which other issues of national
concern including environmental conservation aredealt with. The national government, for example, hastaken initiatives in providing the broad framework on
pollution control by enacting required legislation on
the protection of water, air and other environmental
resources. Of a series of laws concerning the environment, the ones of greatest importance are the Basic
Laws of Pollution Control (1967, revised in 1970) andthe Water Pollution Control Law (1970). Together theselaws marked the beginning of the era of environmental
conservation after decades of near total disregard ofenvironmental conservation in the name of post-war
reconstruction and extensive national growth by meansof industrialization. Many local laws on environmental
conservation were enacted following these two key
laws. The Revised Shiga Prefecture Anti-Pollution
Ordinance of 1972, for example, has its basis in the
Revised National Basic Law of Pollution Control of1970.
Note, however, that there has been a significant
number of cases involving environmental issues where
local governments took an initiative in establishing
the basic framework of legislative action. The firststep in post-war anti-pollution legislation was not anational legislation but the ordinance on the control ofindustrial pollution enacted by the Tokyo Metropolitan
Government. The Eutrophication Control Ordinanceof Shiga Prefectural Government, enacted in 1979,
was also one of the most outstanding examples of thiskind. The ordinance was designed specifically tocombat eutrophication of Lake Biwa and it stipulated
regulations on the control of phosphate-containing synthetic detergents and the control of discharge of industrial effluents containing nitrogen and phosphorus.

Facilitating the development pressure:
Altered land and water uses
Before commenting on the development and conservation dynamics to be discussed below, it would beappropriate to review the relationship between theimpetus of economic development and the resultant
changes in water quality, as well as the process offulfillment of water quality and quantity requirements
for development activities. The discussion will centre
around two basic issues: land and water uses.

Sustainable development of Lake Biwa

17

Land use
As indicated, the basic framework for the use ofnational land is dictated by the National Land Use
Planning Law of 1974 (Fig. 10). To overcome theshortcoming of land use planning practices prior to
the enactment of this law, the law stipulates the needfor determining overall land-use schemes, superseding,if necessary, any existing plans established within theframework of sectoral legislation. In effect, the law
empowered the governor of a prefectural government
to set five land-use areas, that is urban, agricultural,
forest, natural park and natural reserve areas. The
closer determination of land-use categories will takeplace as needed based on established procedure.
As for the Lake Biwa catchment area, a major partof the flat lands surrounding the lake has for many
years been dedicated to rice growing crop lands. The
land-use patterns first began to undergo noticeablechange in the 1940s. Filling of lagoons around Lake
Biwa took place just before the Second World War
and immediately afterwards, primarily for the purposeof increasing rice production, though they were neverreally made use of for that purpose. Filling parts ofthe south basin of the lake itself took place in thePlans related to land use

1960s, basically for converting wet lands into arable
and/or habitable lands. What appears to be grossmismanagement of land began a t about this time,principally due to the introduction of a new set oftransportation routes enabling the south-eastern partof the lake to be included in the marketing networks of
the Keihanshin industrial region. The outcome of thischange was haphazard exploitation of the then prevailing agricultural farm lands. Many projects, which
involved the conversion of farm land into industrial
estates and residential establishments, took place in arather piecemeal fashion during the periods of intensive industrialization and urbanization between theearly 1960s to mid-1970s.
The urbanization of the Lake Biwa catchment area,
particularly in the south-eastern portion under thestrong influence from the Keihanshin economic zone,
testifies to the unique land-use problems of the region.
The area stretching northwards had long been coveredby extensive paddy fields until an almost sudden influxof industrial activities and associated population
migration brought about change in the late 1960s(Fig. 11). However the urbanization occurred in apiecemeal fashion because of the reluctance of land

National Land Use Plan

1

National Plan

serve as baseFig. 10. Relationships among land use and development plans. From lmai eta/. (1989).

Plans related to comprehensive development

M. Nakamura

18
owners to succumb to developmental pressure all at
once and the ad hoc siting of industries and housing
estates due to topographical variability of the paddy
fields. In addition, the traditional agricultural lifestyleof the region had to be altered to adjust to thisindustrial and urban invasion. In effect, the changes
involved four events. First, the region, which for
centuries had been dedicated to paddy field agricultural lifestyles, had to be changed to accommodate forthe demand for an industrial labour force. Second,
multiple crop production became less and less popular
because of unstable markets for non-rice crops. This
resulted in the gradual polarization of farmers; somewould grow only rice crops, but others would totally
give up farming. Third, the exclusion of lowlands
from zoned priority urban development districts
resulted in haphazard delineation, spurring further
piecemeal urbanization. And fourth, land value
appreciation was phenomenal and could no longer
sustain intact land use for farming alone.
The combined effect of these changes in the context
of the internal agricultural structure was the uniquely
Japanese urbanization of land which had once been
dedicated to paddy-field cultivation. The impacts ofurbanization are many, but some typical problems,aside from those of water quality mentioned in sections
to follow, include: (i) rainwater drainage a t newly
converted industrial and housing development sites(previously absorbed by paddy fields); (ii)groundwater
inflow and infiltration problems in lowlands; and (iii)
facilitation and accommodation for previously urbanized areas, with appropriate legislative provisions so
as to achieve reasonably consistent land use.
The description of land use within the Lake Biwa
catchment area would not be complete without discussion of forestry management. The present forest
area covers a little more than half of the entire prefectural land. In the past, typical problems associated1601with forest management included deforestation. For
example, the Tanakami mountain range in the southern
region of the basin has long been extensively clearedby timber logging operations used for constructing
temples and shrines in Nara and Kyoto centuries ago.
More recently, growing population pressure and thedemand for firewood has resulted in the exhaustion of
deciduous forests, particularly during the period when
Japan was almost totally isolated from the rest of theworld (1639-1854). These exploitative activities contributed to the denudation of forests and the resultant
severe flooding and siltation problems of many of theLake Biwa river systems.
In recent decades, the problems associated with theuse of forested land have become more subtle. As in
the case of agricultural lands (paddy fields and othercroplands), the forest edges have slowly but steadily
been cleared and graded for various developmental
purposes including housing and industrial estate development. In the process, the forest has slowly lost its
capability to function as a reservoir of precipitatedrain and snowmelt, and contributes also to run-off into
nearby streams of nutrients contained in the precipitation. It is claimed that the amount of nutrientsdischarged from forested land today amounts to almost
as much as that discharged from agricultural fields.
The major difference between agricultural and forest
run-off is that, in the former the nutrients originate
from fertilizers, but in the latter mostly from rainwaterand soil and are difficult to control without properly
maintaining forests.
Upon introduction of the National Land Use Planning Law, the prefectural government was given theopportunity to correct the situation and realign fragmented land parcels dedicated to many different uses.
But the lands once allocated for different uses havebeen difficult to convert back to uses consistent withthe desired planning framework. The development ofland-use schemes consistent with existing land uses
and appropriate future development goals of the prefectural government will continue to be a challenge
for the prefecture.

Water use

1956

1961

1966

1971

1976

1981

1985

Year

Fig. 11. Trends in industrial siting in Shiga Prefecture From lmai et
a/ (1989)

One of the most outstanding modern features of Lake
Biwa water use and allocation is that the agricultural
sector has the biggest share (amounting to 93%of thetotal) of the water withdrawn from the lake, despite
the fact that the prefecture bas undergone significant
industrialization and urbanization in recent decades.
Throughout history also, the agricultural sector has

Sustainable development of Lake Biwa
had the oldest and most complex water-use practices
and well-established customary rules of withdrawal.
Industrial and municipal demands, which began toincrease in the 1960s, had to compete against agricultural demand. The resulting impacts were twofold: (i) the establishment of a new rule to supersede
the current destabilized and ad hoc water use andallocation rules; and (ii) the need for serious efforts tocontrol of point as well as non-point pollution. It became
clear also that there was a need to balance water uses
where they competed for scarce water supplies. The
variety of sources serving to supply Shiga communities
is indicated in Fig. 12.
Agricultural water use. Agricultural waters havebeen obtained throughout history in one of three
ways. At or near the foothills, particularly on theFig. 12. Sources of water supplies serving communities in Shiga[R)all or more than z/3 from lake water, (01 lake water and underJake water and surface water, (Ul all or moreground water,[m)than */3 from underground water, (D) underground water andsurface water Source Shiga Prefecture

19

eastern side of the lake where there is a large numberof irrigation ponds. The ponds were the only source ofwater for centuries in the high altitude fields or fields
distant from the lake. They are still used today, but incombination with other means of water supply andbasically for auxiliary purposes. Irrigation in the flatlands, however, depends on either or both groundwater
pumping and water withdrawal from the lake, thelatter being particularly prevalent in the delta regionsof major river systems. Irrigation from the lake has
evolved over centuries of agricultural practice. For along time before electricity became available, creek
water was pumped or scooped by manual labor. In the
Meiji era (1868-1912), lowered lake water levels necessitated direct withdrawal by electric pumps.
As agricultural water demand increased after theSecond World War, it became necessary to ease severe
water allocation conflicts between upstream and downstream communities in the lake catchment area. Manydams of significant scale were constructed along rivers.
At the same time, the use of lake water for irrigation
became possible even in regions distant from the lakeas extensive irrigation network systems were constructed. In effect, the network created flows in thereverse direction. As a result, areas previously irrigated by groundwater began to shrink. The combined
effect of the expansion of lake water irrigation areas
upstream and of river water irrigation areas downstream was significant lake water pollution, and thisphased out previous repetitive water use throughdendritic or cascade channels.
Industrial water use. As for industrial waters, water
use has been very much dependent on industrial types
and sizes. The early days of industrialization in Shiga
were very much dictated by textile industries, particularly of synthetic silk-thread, rayon. Today, majorindustrial categories in the prefecture are assembly
industries such as electronics and light machinery
which require water in only limited quantities. The
amount of water used by all categories of industry is
1.36 x 106 m3 per day, of which the manufacture of
textiles, chemicals (pharmaceuticals), plastics, pottery,electro-machinery and vehicular machinery are themajor consumers. With respect to water-use patternby industrial size, those with employees numbering
between 100 and 300 use the greatest amounts ofwater. Many of these industries do not have thefinancial resources to invest in water recycling, particularly because they are not large enough to enjoy
economies of scale. They are also the most likely sourcesof point-source pollution, so that the effective control

M. Nakamuraof waste discharges from these industries will become
the key to achieving significant reduction in waterpollution. There is a very important linkage between
agricultural water and industrial uses in that theimplementation of large-scale irrigation systems has
greatly increased the opportunity for groundwatercontamination, resulting in serious damage to theoperations of textile industries requiring uncontaminated groundwater. On the other hand, groundwater
users have been avoiding direct confrontation withsurface water users who pollute groundwater by continuing to extend well depths to deeper and cleaner
aquifers.
Domestic water use. The supply of drinking water
has its own history. Prior to the introduction of piped
supplies, a major portion of drinking water was extracted from nearby streams and wells. Today, approximately 60%of water supplied by domestic water supply
systems originates from Lake Biwa. The single mostimportant factor affecting the increase in domestic
water supply in recent times has been the population
migration from Keihanshin region into the prefecturaljurisdiction. The provision of water to these new
migrants was a precondition for housing development
activities, an unavoidable consequence of industrialization and urbanization of the prefecture. Today there
are six municipalities, twenty-six townships, one waterutility agency, and one association engaged in theprovision of water supplies, and 97.5%of prefecturalresidents are supplied with piped water.
As the population continued to increase, it became
more and more difficult to develop dependable watersupply systems and to find suitable water sources.
This resulted in the regionalization of water-supply
systems. Currently, there are two regional watersupply systems both of which withdraw water from
Lake Biwa (except that one draws water in part froma dam located upstream of Yasu River).
Traditional water usage in lake-front communities
was quite efficient in that there were self-regulatory
efforts preventing the direct discharge of used water
to streams flowing into the lake; waters were held fora period in a small holding pit prior to discharge to thereceiving stream. In addition, the amount of usedwater generated by households was much less when
there were no water-supply systems, as most washing
was done directly at water fronts. When piped watersupply systems were introduced in the agricultural
and/or fishery communities, they effectively destroyed
the traditional style of water management. Now that alarge percentage of the population depends on lakewater through piped water supply systems, lake conservation and lake water use have become synonymous
to many Shiga residents. This has brought about aninteresting situation with respect to Shiga residents
and the residents of downstream prefectures in thatthey now share a common concern and sentiment
about the future of lake water quality. This has neverbeen the case before. At the same time, those engaged
in agricultural and industrial activities have beenplaced in the situation where they will have to face theconsequences of degraded water quality resulting fromtheir own actions.

Land and water use interactions
Several important observations may be made on land/
water interactions, particularly with respect to thedeterioration of water quality, both of rivers (streams,
paddy-field channels and household ditches) and thelake. Including some events already mentioned briefly,
they are:(1) Agricultural run-off problems due to: (i) conversion of semi-natural intake and drainage channels
to large-scale irrigation networks; and (ii) expanded
irrigation areas resulting in increases in fertilizer andpesticide run-off.
(2) Impacts from the siting of industry resulting in:(i) discharge of inadequately treated wastewater fromsmall to marginal industries; (ii) discharge or release
into the environment of previously unregulated chlorinated hydrocarbon contaminants such as trichloroethylene and tetrachloroethylene; and (iii) high groundwater levels of newly prepared industrial sites causing
infiltration problems and making industries vulnerable
to inadvertent failures of manufacturing and/or wastewater treatment operations.
(3) Problems created by household wastewaterespecially: (i) discharge into drainage canals leading
to contamination of irrigation waters; (ii) coverage by
the regional sewerage system is still confined to limitedareas, so that most houses resort to on-site treatment
systems for only toilet wastewater, excluding kitchen
and bathroom wastewater.
(4)Impacts of forest clearing over decades/centuries;
though limited in scale today this has resulted in
topographical features clearly responsible for nutrient
run-off.
Further information is necessary before a morethorough analysis of land and water use interactionsin the Lake Biwa catchment area can be attempted.
Some of the major factors already known to havecontributed to the intricacy of the interaction areSustainable development of Lake Biwa

21

Studying the state of the lake

described above, but there are many others still to beclearly identified. The structure of land and wateruses within the catchment area is now subject to more
complex sets of dynamic forces than a t any other timein history.

Surprisingly, these questions have still not beenanswered scientifically and precisely. In terms oforganic pollution loads generated on land, the deterior-

Coping with environmental stress: An
assortment of conservation efforts

Table 5. Calendar of pollution episodes

Year

As stated, the Lake Biwa catchment saw significant
changes taking place following insurmountable development pressure exerted by the national development
policy and which resulted in intensification of development activities downstream of the lake system (Imai etal. 1988, 1989). The most obvious outcome was analmost sudden surge of environmental stress on thelake, particularly its southern basin (the SouthernLake). To illustrate this, Fig. 13 indicates the longterm decrease in lake transparency and Table 5 documents major events attributed to lake pollution. For
centuries, Lake Biwa has had no large aquaculture
farms such as fish pens and fish cages and mostnutrients accumulated in the lake originated on land
and were transported to the lake in rivers and streams.
Thus, for an extended period the lake as a whole
maintained a fairly stable ecological balance, a consequence of its large self-purification capacity. Being
a confined body of water, despite the large water
volume, the deterioration of water quality, and hencea disturbed ecological balance, was sudden once pollution load inputs exceeded a threshold. In terms ofgeological time, it was almost instantaneous. I t was
not much earlier than the late 1960s that this becamea reality. The balance sheet of pollution, therefore,
was of prime interest to those concerned. Who is (was)responsible? What actually happened?

E

10

2.

=

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Pollution

1955-59

Disturbance at the filtration plant was noted for the
first time

1960-64

Sudden change in zoobenthos began
Elodea nuttallioverspread the lake

1965-69

Corbicula sandai began t o decrease
Thick growth of Elodea nuttalliattained its peak
Musty odor of tap water was noted for the first time,and has been noted intermittently sinceEgeria densa invaded the lake

1970-74

Water quality further deteriorated
Elodea nuttalli declined and was replaced by Egeria
densa
Some bathing resorts in the Southern Lake closed
Corbicula sandai nearly died out and was replaced by

1975-79

Corbicula japonica
Egeria densa was dominant in the Southern Lake
Freshwater red tide occurred, and continued t o benoted every year till 1984
Ordinance Concerning the Prevention of Eutrophicationof Lake Biwa was promulgated1980-84

Egeria densa decreased sharply
Both Egeria densa and Elodea nuttalli began t o revive
Water bloom was noted in a part of the Southern Lake

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22

ating water quality could be attributed approximately
equally to domestic, agricultural and natural sources.
However, exactly what events trigger physical, biological and chemical interaction of natural and humanmade substances to bring about eutrophication is still
uncertain.
Furthermore, the dynamics of pollutant generationon land have undergone significant changes over the
past decades, making it still more difficult to be scientifically accurate. There is now a greater number ofpeople and industries, resulting in the generation ofgreater amounts of pollutants. Industrial point sources
such as discharges of toxic substances have been controlled, thanks to the introduction of stringent regulations and rather severe enforcement efforts since the1970s. But discharges from small to marginal industries and from households have been on the increase.
Today, discharges of gray waters from individual
households (due to the absence of sewerage systems)
are said to be major contributors to lake pollution.
There have also been changes in agricultural practices.
A great majority of paddy-field farmers today areweekend farmers, resorting to highly mechanized production practices and generous use of fertilizers andpesticides. This was not the case 30 years ago. Then,
individual paddy fields had semi-natural channels
connecting individual fields in which a significant
degree of trapping of outflowing nutrients took place.
But after the institution of the paddy field land reformproject, highly streamlined inflow and outflow control
channels were constructed and are thought to be inpart responsible for nutrient run-off in larger quantities than before.
Today there are concerted efforts to study and monitor the state of the lake and the process of eutrophication. Lake Biwa Research Institute, a research institute dedicated to basic and applied multi-disciplinary
research on Lake Biwa, was established in 1981. It is
unique in Japan and is also regarded as unique internationally. Routine monitoring of the state of the lake
is conducted by another centre also under the management of the prefectural government. The center conducts water quality monitoring for 25 major rivers
and takes regular samples of lake water from 47
sampling points located in the lake. Automatic monitoring is conducted also a t six sampling stations in thelake and four river stations.
In all, an assortment of conservation measures had
to be introduced to cope with the rapidly deteriorating
environment subjected to extreme development pressure on a large portion of the catchment area. A brief

M. Nakamura
outline of these pollution control measures is presented
below for domestic, industrial and agricultural wastewater, together with a discussion on water quality
monitoring and the Eutrophication Control Ordinance.

Management of wastewaters
Of the three categories of wastewater most easily
recognizable, domestic wastewater has attracted
greatest publicity in the recent past because Shiga
residents realized that the planned construction ofsewerage systems around the lake will take considerable time and by the time they are complete the lake
may already have been irreversibly eutrophied. According to the latest statistics, only some 30%of the population have been connected to public sewerage systems.
There are four regional wastewater collection andtreatment systems (Fig. 14). Two are partially completed and in use. They will eventually collect a major
portion of domestic wastewater and some non-toxic
industrial wastewater. The remaining population must
be served by one of several wastewater management
systems, including nightsoil collection and treatment
systems and on-site household treatment systems ofvarious kinds. For example, the city of Otsu has its
own sewerage system, but its service area is confinedto the western side of the lake. The rest of the population is served by one of two regional systems partiallyin operation, but with areas in the outskirts of the citywhich the regional systems will not service in the near
future. Households in these areas resort to on-site
treatment units. Most household systems marketed in
the past treat only toilet wastewater, and gray water,that is, kitchen and bathroom wastes, are discharged
into ditches, streams and eventually reach the lake
through river systems.
Industrial wastewaters are generally regarded ashaving been brought under tight control, particularly
after the institution of the Water Pollution Control
Law. There has not been serious violation of the law asin the past, due to stringent enforcement, awarenessof the public media, reports by citizens of any sort ofspill incidents, and the realization by industry thatillegal discharge of pollutants involves high penalties.
Discharge of substances potentially harmful to theenvironment and public heakh is regulated by theWater Pollution Control Law; discharge of nutrientsthat cause lake eutrophication is controlled by the
Eutrophication Control Ordinance and the Clean Lake
Act.
Aside from the established effluent standards underthese legislation, there are permit systems for indus-

Sustainable development of Lake Biwa
trial operations. Industries engaged in activities withthe potential for inadvertent discharge of toxic
materials are subject to a permit system. Similarly,
those industries or premises discharging wastewaterin quantity are also subject to a permit system, together
with annual surveillance and imposed self-monitoringof discharge wastewater quality.
Agricultural wastewater, including dairy waste-

23

water, is also regarded as a serious pollutant of thelake. The approaches for pollution control of this typeof wastewater differ from such point sources as domestic and industrial discharger. As for paddy-field
cultivation, pesticides and fertilizer use is of greatest
concern. The recent changes to agricultural practices
for improving productivity have yet to provide thesolution to improving the efficiency of pollution control.

Fig. 14. Map of sewerage services,

as of 1989 (0)planned district
map, (m)municipalities where operation has already started, (municipalities where seweragework
was already laid out, ( 0 )municipalities where sewerage work not
yet laid out, (A1 sewerage disposal
center Source Shiga Prefecture

M. Nakamura

24

Various measures to improve the efficacy of pesticideand fertilizer application are being made, both interms of management practice and technological innovations. Point injection of fertilizer at the root of therice seedlings is being tested and is gradually being
accepted by farmers. Recycling of irrigation water,
drawn into the irrigation network by large pumps, isalso proposed and under investigation for technicaland economic feasibility. In addition, the environmental monitoring center conducts paddy-field discharge monitoring at the time of spring cultivationand fertilizer application to check for incidents ofgross pollution.

Eutrophication control ordinance
These pollution control efforts are not by any means
unique to Shiga Prefecture. If anything is unique
about pollution control in the Lake Biwa catchment
area, it must be the spirit and symbolism reflected in
the Eutrophication Control Ordinance enacted after
the first ‘red tide’ occurred in 1977. Perhaps the mostimportant aspect of the whole sequence of events,
leading to the enactment of the ordinance and its
implementation afterwards, were public initiatives inrefraining from the use of synthetic detergent containing phosphorus. At the height of the movement
and immediately after the enactment of the ordinance,
almost 90% of households surveyed were willing tocollaborate and not use phosphorus-containing detergents. With an assortment of provisions in the ordinance, including regulations on industrial dischargesof phosphorus- and nitrogen-containing wastewaters,
the water quality of the lake seemed to show slight
improvement within the first few years. However,lake water quality has since remained more or less thesame. Various land development activities and continuing inflow of non-point sources of pollution areblamed as the major contributing factors.

the natural environment; (iii) general welfare of theconcerned public; and (iv) restoration of water quality.
Specific projects were to be prepared by the prefectural government, presented a t public hearings,
and submitted by the Governor of Shiga Prefecture to
the Prime Minister through the Secretary General of
the National Land Agency. The LBCDP, as stipulated
in the act, came into effect in December 1972.
Objective (i) was the primary objective, as the nameof the Project indicates, and needs little elaboration.
Objectives (ii) and (iii) were more a reflection of thedesire of the prefectural government to share in development benefits, and they were approved by the
National Government. Objective (iv) had not beenheavily weighed in the original bill. In the process ofdeliberation, however, concern was expressed byvarious quarters- including scientific and environmental groups-over exploitation of the environment. This concern was responded to. The tone of the
final bill, therefore, was much more sympathetic toenvironmental conservation than the original bill. In
fact, when the time limit was extended for a n
additional ten years in 1982, substantial addition wasmade to the projects categorized under objective (iv)to reflect an inclination toward environmental conservation than compared to ten years before. In summary,
the LBCDP is:(1) A large-scale development project for water
resources development with trans-generational implications.
(2) A highly political undertaking, like other projectsof this nature, with respect to its design and implementation.
(3) A project which had to meet changing needs
over the time between its conceptualization and realization, and which will have to be responsive to theneeds of future generations, on both development andconservation accounts.
It is not, however, a project dedicated, by any means,
exclusively to environmental conservation.

Water quality component of LBCDP
With respect to water quality management, what does
the LBCDP imply? The Special Measures Act for
Lake Biwa Comprehensive Development was enacted
in March 1972 as a 10 year time-limit legislation. Its
overall aim was to undertake construction of water
resource development facilities to allow for the lakewater level to be sufficiently lowered to meet the thenrapidly growing downstream water demands. The act
stipulated the following as its intended basic objectives:(i) utilization of water resources; (ii) conservation of

Development and conservation dynamics
Dynamics of development efforts
The dynamics of development efforts in the past several
decades could be described in many ways. However,
one of the most obvious and most important forcing
functions has been, of course, major policy decisions of
the national government. Throughout its modern
history, the Shiga Prefectural Government, like allother prefectural governments, has been subjected toSustainable development of Lake Biwa
strategic regional development programmes under
the national umbrella development policy framework
which have collectivelyunderpinned national economic
achievements in the post-war decades. Regional development efforts are facilitated through appropriate
legislation, the principal legislation being the National
Comprehensive Development Law of 1950.In the courseof nearly 40 years after enactment, four national comprehensive development plans were prepared. In Shiga
Prefecture, six prefectural development plans of major
significance were prepared, the current plan in 1987.
A series of development activities took place in theforty year period, the most important being the completion of major transportation arteries, such as RouteNo. 1 Highway, New Tokaido Railway Express Line,
Meishin Express Highway, Biwako Oohashi Bridge,
and Oomioohashi Bridge. In addition, industrial estatesof varying sizes either moved in from Keihanshin
Region or were newly established, particularly along
the south-eastern edge of the lake. In effect, thedynamics of development efforts have reflected historical events, that is, local development efforts had tobe responsive to national and regional development
needs as well as local inclinations.
Another important observation on the dynamics ofdevelopment is that development efforts result, ofcourse, in a variety of impacts on all phases of dev-

25

elopment activities. These include industrial structuring, social and demographic alterations, land andwater use changes, and increasing environmental
stresses. The industrial structure has changed overthe past four or five decades, allowing secondary andtertiary industries to overtake primary industry interms of output. The social and demographic alterations, such as changes in lifestyle, community structure, labour force structure, and even cultural andeducational opportunities and facilities, are of greatsignificance in characterizing societal dynamics. Landand water use changes have already been discussed,
but the fact that the changes took place, in terms ofdevelopment history of the catchment area in so shorta span of time, should be recognized explicitly.
Of course, the LBCDP constitutes an importantelement of development dynamics. It is in part closely
linked to the framework of regional development, but
it could well be regarded historically and nationally asa unique undertaking to consolidate the overall social
capital specially focused on an unsurpassable natural
resource of the nation, Lake Biwa. How it fares in theformula of the dynamics of development efforts is nota simple analysis because of difficulties in assessing
socio-political implications in addition to difficulties
in quantifying economic and social benefits.

April, 1979
12th Prefectural opinion poll
(July, 1980: Enforcement of
Lake Biwa Ordinance)

April, 1980
Opinion poll on the consciousnessof

citizens
April, 1981
Opinion poll on Lake Biwa issues

August, 1987
15th Prefectural opinion poll
August, 1983
16th Prefectural opinion poll

August, 1984
17th Prefectural opinion poll

August, 1985
18th Prefectural opinion poll
August, 1986
19th Prefectural opinion poll
August, 1987
Previous: 2Mh Prefectural opinion poll
August, 1988
Latest: 21st Prefecturaltopinionpol

Fig. 15. Trends in public aware-ness in the use of soap: (0)use
only soap powder;mostly use
soap powder or soap powder andnon-phosphorous synthetic detergent; (0)use little soap powder oronly non-phosphorous synthetic
detergent; ( 8 )have no idea. FromJICAALEC ( 1 991 ).

(a)

M. Nakamura

26
Table 6. Sequence of environmental events, 1973-80 and 1981 to the presentYears
1973-80

Sequence of environmental events(1 ) Causes of environmental disturbance:

Intensification of industrial activities
Increased population migration
Development activities including those specified in LBCDP(2) Apparent deterioration of environmental integrity:
Disturbance of plankton life-cycles resulting in large-scale red tides
Large-scale marginal filling of the lake and reduction in natural lake fronts(3) Impact and damage to basic public facilities:
Clogging of water treatment filter-beds(4) Enhancement of citizens' awareness of environment:
Sense of alarm on the deteriorating quality of drinking water
Loss of opportunities for water-front activities(5) Message from environment to citizens:
Taste and odor problems(6) Citizens' demand on government:
Banning of phosphorus-containing detergents
Regulation of discharges of nutrients from industries

1981 to date

Moratorium on development activities(7) Citizens' initiatives:'Use-soap' movement (see Fig. 15)
In-house reduction of pollution loads(8) Message from environment to government:
High N and P concentration in lake waters
Algal blooms(9) Government action:
Regulatory actions on phosphorus-containing detergents
Monitoring of industrial wastewater discharges
Control of agricultural run-off
Instruction of environmental impact assessment(1) Causes of environmental disturbance:
Non-point, non-specific sources of pollution
Development activities including those specified in the revised LBCDP(2) Apparent deterioration of environmental integrity:
Continuing incidents of algal blooms including by Uroglena americana and Microcystis(3) Impacts and damage to basic public facilities:
Pollution of local streams
Disappearance of certain invertebrates and 'ayu', an indigenous fish species(4) Enhancement of citizens' awareness on environment:
Strong sense of loss of 'good old days' of clean streams and drinking water free of taste and odor(5) Message from environment to citizens:
Continuing taste and odor problems(6) Citizens' demand on government:
Non-point source pollution control measures
Intensification of litigation against LBCDP(7) Citizens' initiatives:
Establishment of 'environmental co-operatives'(8) Message from environment to government:
N and P concentration a t standstill(9) Government action:
Development of an overall environmental management plan
Initiation of environmental education and planning assessment

The interactions of these nine events are indicated in Fig 16 From lmai et a/ 1989

27

Sustainable development of Lake Biwa

Dynamics of conservation efforts
The dynamics of conservation efforts in the Lake Biwa
case are unique on the one hand and typical on theother. It is unique because Lake Biwa has uniquefeatures with respect to its geography, hydrology andsocio-economy. The conservation measures had to be
responsive to this uniqueness. It is typical also in thatmany of the conservation measures introduced havebeen representative of a particular time in Japan andtypical of the manner in which the government andthe citizens dealt with the emerging issues.
One of the most important features of Lake Biwa isthat the lake and its catchment area and the prefectural jurisdictional area almost totally coincide. Thus,
people living within the catchment area are directly
reminded that they have their own role to play inwhatever endeavours for achieving environmental
integrity operate. Figure 15, which shows trends inthe public awareness of the effects of using soap
powder, is indicative. I t is this coincidence that hasbrought about the unintended partnership, as it were,
between government and residents.
Two periods may be distinguished as far as the
dynamics of conservation efforts are concerned, 197380 and 1981 to the present (Fig. 16). The sequence of
events and responses is summarized in Table 6.
While factors contributing to the dynamics of conservation efforts change over time, the basic structureand substance of the dynamics remain fairly intact.
Nevertheless, new initiatives and developments continue to be introduced in the government-citizen
partnership. The future trend appears to be a greater
involvement of citizens with genuine concern, and thedevelopment of mechanisms to facilitate their involve-

1
Administration f

Residents +Phenomenonof pollution

Effects,
damageFig. 16. Diagram illustrating cause-effect interactions between
pollution, public reaction and local government response. See Table
6 for explanation of numbers. From lmai e t a / . (1989).

ment. This may be further supported by the increasingease by which information is disseminated and transmitted through various means at all levels.

Policy organs and instruments as constituentsof the dynamics
Lake Biwa development and conservation policies havebeen formulated in response to various national andregional initiatives and requirements. Thus, a widearray of policy organs has participated in some mannerin their formulation. These organs could be categorizedaccording to their position in the governmental hierarchy such as: national government vs local governments; governmental sectors of responsibility such as
agriculture vs industry; regional economy and intraregion political positions such as Shiga vs downstream
prefectures; economic zones such as Keihanshin vsconcentrated industrial establishments within prefectures; or forms of political influence, such as bureaucracy vs citizens. Each such organ has played its rolein pursuit of specific objectives.
The intricate dynamics of both development andconservation and the involvement of a variety of policy
organs are the result of many centuries of a richhistory of human-nature interactions in an area which
has been very important socially, economically andpolitically. While interactions of policy organs of thetype described for Lake Biwa may seem typical forcases involving important water resources elsewhere,
the Lake Biwa case is unique in many respects; thelong history of human-lake interaction has createdindigenous institutions and management practices,
aroused particular sentiments in opposing viewpoints,
and provided a unique sense of balance among concerned policy organs. Thus, a complex mixture ofpractices, sentiments and a sense of balance has
resulted in what appears to be the unique Lake Biwa
experience.
A wide array of policy instruments has been introduced in the process of achieving individual policy
goals. Legal instruments, of course, have been themost powerful, and some attempts have been madeearlier to clarify the maze of laws, regulations andordinances for land and water management. Economic
and financial instruments have been introduced invarious forms a t several levels of economic policy
decisions, many in direct response to national development plans. Both public and private sector investments
have had great impacts on the shaping of regional
welfare in the Lake Biwa area. Information, more
often in the area of environmental conservation than28

M. Nakamura

other areas, has played a critical role in the political
dynamics in the handling of Lake Biwa issues. A
typical example is provided by events which followed
the enactment of the eutrophication control ordinance.

Policy assessment perspectives
The basic objective of this paper was to illustrate
events associated with change in Lake Biwa in termsof increasing socio-economic development pressure
over time and shifting emphasis on resource values,
impending lake management issues, and policy
measures and their intricate relationships. However,the paper does not fully assess objectively many
important questions pertaining to the evolution ofmanagement policies of Lake Biwa and its catchment
area. No comprehensive literature on this subject iscurrently available, although there is some on confinedareas of analysis. Extrapolation of such analyses tounderstand the evolutionary whole of intricate policy
interactions would be meaningless. No literature exists,
perhaps, because there has been no neutral perspective
when Lake Biwa is brought to the arena of objective
analysis. This study will also fail the test of neutrality
because it too represents a particular perspective.
However, attempts to assess the overall evolution of
Lake Biwa management policies are worthwhile andthere are ongoing attempts to shed some light on otherimportant questions as:(1) Have there been adequate coherency and consistency in the legal instruments introduced and implemented?
(2) Has there been sufficient facilitation in the
allocation of natural as well as economic resources
within the context of achieving sound management of
Lake Biwa environments?
(3) Have we succeeded in maintaining regional
integrity in terms of economic development and environmental conservation, perhaps a t the expense ofdeterioration of water quality in Lake Biwa?
(4) Have we succeeded in attaining a satisfactory
level of local autonomy as well as local initiatives bothin terms of mobilization of national, regional and local
resources, and of having prefectural residents sufficiently involved in critical policy decisions for the soundmanagement of Lake Biwa and its catchment areas?
This paper attempted to highlight certain aspects of
the above questions. It is hoped that these attempts
will open avenues of future analysis and assessment
which cumulatively will lead to better understandingof the value of Lake Biwa and the ways in which it
could be preserved better for future generations.

ACKNOWLEDGEMENTS
This paper is based on material prepared for the JICA
Training Course on Environmental Technology (Water
Quality Management) and f o r The World Bank
Seminar on Economic Development and Environment
Management, 15 November-5 December 1992, Kota
Kinabalu, Malaysia. Much of the paper is derived
from excerpts from the Lake Biwa Case Study conducted for UNCRD/ILEC/UNEP Expert Group Workshop on RiverfLake Basin Approach to Environmentally Sound Management of Water Resources. I am
deeply indebted to the case study members with whom
I had the privilege to work from 1987 to 1990. Sincere
appreciation is also extended to the journal editors forextensive editorial assistance.

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(in Jpn.)Anon. (1991b) White Paper on the Environment. Shiga
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Imai K. et al. (1989) Lake Biwa Case Study of 2ndYear, Evolution of the Lake Biwa Resources Management and Environmental Conservation Policies.
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29
Shimazu T. (1989) Mizushigen no Kaihatsu wa Hitsuyo
K a (Is water resource development necessary?)
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