Water Environment Administration of Lakes in Japan

Home , Lake Biwa

October 27th, 2020

Seiji Tsutsui Director of Water Environment Division, Environmental Management Bureau, Ministry of the Environment

1 Contents

1. The current status of lake water quality and the issues

2. Development of water environment administration for lakes

3. The Law Concerning Special Measures for the Conservation of Lake Water Quality（Lakes Act）

4. Response to the new issues concerning lakes in Japan

5. Act for the Conservation and Restoration of Lake Biwa (Lake Biwa Act)

6. Present measures for Japanese lakes and the future direction

7. The domestic legal framework and Integrated Lake Basin Management （ILBM）

Ministry of the Environment 2 Importance of Lakes

• Approx. ９０％ of surface water is lake water • Water resource for human life and activities → for drinking, household, industrial, agricultural etc. • Flood control • Fisheries • Ecosystem etc.

Ministry of the Environment 3 Key words for implementation of ILBM

• Better basin governance through integration of the six factors:

①Organization/Structure

②Policies

③Participation

④Technologies

⑤Information

⑥Finance

Ministry of the Environment 4 The current status of lake water quality and the issues In Japan, preservation of water quality is pursued through environmental quality standards (EQSs) set up for each river, lake and sea area. The EQSs are poorly achieved in lakes due to their enclosed nature. Trends in meeting EQSs (BOD/COD) 100 河川Rivers94.6% ：95％

90 全体Overall89.6% ；90％

80 海域Sea79.2% areas；79％ 70

60 湖沼Lakes54.3% ；54％ 50

Overall全体達成率（％） 30 Rivers河川

20 湖沼の達成率が悪いLakes湖沼

10 Sea Ratio of water bodies meeting standards (%) standards meeting bodies water of Ratio areas海域

2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 Ministry of the Environment 5 History of lake environmental administration 1970 Water Pollution Control Act Uniform Wastewater Standard

While river water quality improved, eutrophication occurred in lakes: (blue/green algal blooms, red tides)

1982 EQSs for Lake Nitrogen and Phosphorus

1984 Lakes Act Fish death due to hypoxia (Lake Nakaumi) Basic Policy for Conserving Lake Water Quality Source：Shimane Prefecture.website Designated lakes (Plans to conserve lake water quality) Load regulation

2005 Revised Lakes Act Corrective measures for non-point runoff Protection of environment around lakes

2015 Act for the Conservation and Restoration of Lake Biwa Algal bloom in Lake Hachiro (2010） Source: Akita Prefecture. website Basic Policy for Conservation and Restoration of Lake Biwa (National) Lake Biwa Conservation and Restoration Plan（Shiga prefecture) 4 Ministry of the Environment Water quality conservation policies for Japanese lakes

Target Establishment of environmental quality standard National 【Basic Environment Law】 government

【Water Pollution Control Act】・Establishment of effluent standards National Uniform national standards government ・More stringent effluent standards Measures for ・Regulations for private companies Industrial Local gov’ts Measure, log and notify effluent pollution wastewater (Prefectures) →Penalize, Order to improve, other administrative guidance ・・Investment in pollution control Private ・Human capacity development companies

Measures for ・Construction of sewerage (Sewerage Act) National govt. Domestic ・Installation of Johkasou (Johkasou Act) etc. Local govts wastewater Individuals

Lake water Unique “Water quality conservation plan” for Local govts conservationF each designated lake based on 【Lakes Act】 Ministry of the Environment 7 Lake Basin Configuration Schematic: Factors causing algal blooms, putrefaction odors, damage to water quality, and poor bottom layer oxygenation

Precipitation, etc. NOx Naturally derived Nitrogen and hosphorus Chemical fertilizers & feed

Reduced fertilizer Wastewater from Waste treatment use policies Domestic factories and Groundwater wastewater Wastewater enterprises Sewage regulation infiltration treatment Nitrates/nitrogen Urban runoff Domestic Accumulation, nutrient build-up wastewater Food & Road cleaning Eutrophication raw Removal of nutrients by materials b mowing and fishing, etc. Lake bed accumulation & elution into lake water Ministry of the Environment 8 Special Measures Act for conserving lake water quality

Basic conservation policy for lake water quality (For all lakes)

Local governments request Cabinet to designate lakes (Total 11 lakes have designated incl. Lake Biwa and Kasumigaura)

Lake Water Quality Conservation plan for each designated lake (by local governments） Promotion of research & Pollution load regulation development of technologies Implementation of infrastructure Designation and conservation of construction such as sewerage protected areas around lakes system Regulation of small-scale animal Designation of non-point runoff husbandry & aquaculture countermeasures areas Guidance, etc. to other agents (If necessary) Regulation of total than regulated facilities pollution load control Ministry of the Environment 9 Location of Designated Lakes

かまふさ Kamafusa Dam Reservoir (Miyagi)

のじりこ Lake Nojiri (Nagano) Lake Hachirō (Akita)

すわこ Lake Suwa (Nagano) Kasumigauraかすみがうらびわこ (Ibaraki, Tochigi, Chiba) Lake Biwa (Shiga, Kyoto) なかうみ Nakaumi (Tottori, Shimane) しんじLake こ Shnji (Shimane)

いんばぬま Inbanuma (Chiba) てがぬま Teganuma (Chiba) Lake Kojima (Okayama)

Ministry of the Environment 8

Response to the new issues concerning lakes in Japan

(Emerging issues) o Pollution load flowing into the lakes is declining by water quality preservation measures up to now. o However, new challenges in the ecosystem have emerged such as massive overgrowth of aquatic plants and reduction of native fish and shellfish species

Ministry of the Environment 11 Lake Biwa Case Studies

Lake Biwa Data Nishiazaicho -shiotsuhama, (Resources)

 Source of water supply Shinasahicho  Rich natural -aiba, environment Takashima, Shimosaka  Fishery (North Lake) -hamacho,  Resources for Nagahama, tourism

 Shiga pref. area: 4017㎢ Imakatata, Otsu,  Catchment area： 3174㎢ Imahamacho, Moriyama,  Lake area: 670.25㎢  Shoreline total: 235.2km  Reservoir capacity: Approx. 27.5 bil㎥ (South  Max. depth:103.58m Lake)  Average depth: 41.2m

Tamanoura, Otsu,

Ministry of the Environment １０ Prevention of water pollution

琵琶湖 CODTrends in inflow load and COD in Lake Biwa

日 60000 4.0 kg/

mg/L 自然系Natural kg/day 3.5 50000 市街地系Urban 3.0 Sideways 40000

2.5 農地系Agricultural

ＣＯＤ 30000 2.0 産業・工業系Industrial 琵琶湖への流入負荷量の推移 Falling 1.5 20000 生活系Household Pollution load Pollution Environmental 環境基準ＡＡ類型１mg/ℓ 環境基準 Ⅱ類型０．０１mg/ℓ standards (COD) 1mg/L 1.0 COD CODConcentration濃度（北湖） 10000 (North Lake) 0.5 COD CODConcentration濃度（南湖） (South Lake)

0 0.0

1981 1982 1985 1986 1989 1990 1992 1993 1996 1997 2000 2003 2004 2007 2008 2011 2014 2015 2018 1983 1984 1987 1988 1991 1994 1995 1998 1999 2001 2002 2005 2006 2009 2010 2012 2013 2016 2017

Ministry of the Environment 119 Removal of invasive alien species (fish)

How foreign invasive fishes (Bluegill, Largemouth bass) are being eliminated

◆Trends in the estimated population of invasive fishes

） ton

（ Bluegill Largemouth bass Estimated invasive fish population fish invasive Estimated

Ministry of the Environment 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 12 Removal of invasive alien species (plants)

Invasive aquatic plants (Ludwigia grandiflora subsp. grandiflora, etc.）

◆Trends in habitats of invasive plants

Max. Year-end areas areas Ludwigia

grandiflora

） subsp.

grandiflora ha

（ Alligator

weed Habitat areas Habitat

2009 ・・ 2013 2014 2015 2016 2017 2018 2019 Ministry of the Environment 13 Removal of aquatic plants

Growth of aquatic plants (South Lake)

2011 2014

Average height of the plant colony（m）

◆Trends in aquatic plants cut for removal

Eradication Surface cutting

Eradication (t) Surface cutting (t) Ministry of the Environment 14 Reduction of fish catches

Fish and shellfish species inhabiting in Lake Biwa

（） Carassius auratus grandoculis （Gnathopogon caerulescens）（Corbicula sandai） ◆Trends in fish catches

Fish Shellfish Shrimps, etc.

770tons (2018) Fishcatches (tons)

Ministry of the Environment 15 Laws concerning conservation and restoration of Lake Biwa

○PURPOSE To help create a society that is symbiotic with nature through conservation and rebirth of the lake that is healthy and bountiful. ○Basic policies (Prescribed by the national government)

Basic guidelines concerning conservation and rebirth of Lake Biwa

○Lake Biwa Conservation and Restoration Plan (Prescribed by Shiga prefecture) Lake Biwa water quality

Measures for conservation and rebirth of Harmony conservation plans Lake Biwa Measures for water quality conservation in Lake Biwa ○Measures by the national/local governments ○ Financial support from the ・ Water pollution prevention measures ・ Conservation and rebirth of lakeside environment national government ・ Promotion of environmentally conscious agriculture ○ Coordination between the ・ Landscape management and conservation national and local governments ・ Improvement of education, etc. ○ Collaboration with parties concerned

Ministry of the Environment 16 Domestic lake conservation measures and the future direction

１ Implementation of lake basin water quality/environment management

◎ Management of basic data through monitoring of pollution load/water quality ◎ Integrated approach to effluent regulations and public works construction such as domestic waste water measures ◎ Enhancement of measures for non-point pollution

２ Target setting based on the characteristics of each lake and implementation/enhancement of measures

◎ Bespoke plans made for each lake (Long-term vision/improvement target, unique indicators) ・Indicator examples: transparency, evaluations from lake environmental research based on the five senses ◎ Improvement of lakeside environment

３ Promotion of collaborations with various stakeholders regarding lakes

◎ Continuous engagement between the local governments managing lakes and the stakeholders (local residents, fishermen, farmers, educational institutions, etc.)

Ministry of the Environment 19 Domestic laws and Integrated Lake Basin Management（ILBM）

[Domestic Legal Framework] [Implementing ILBM]

Water Cycle Act, Water Pollution Control Act, Better basin governance through integration of the Lakes Act, Lake Biwa Act, etc. six factors:

① Responsibilities of the national and local governments ①Organization/Structure

②Philosophy, Policies, Plans, Measures ②Policies

≒ ③Coordination/cooperation between parties ③Participation concern

④Technologies ④Implementation of research, development of

science and technology ⑤Information

⑤Reporting on the measures taken ⑥Finance

⑥Financial initiatives

Ministry of the Environment 20 Thank you for your attention.

Ministry of Environment website

http://www.env.go.jp/water/

Ministry of the Environment 21