International Water Management at Lake Constance H. G. Schröder Institut für Seenforschung Langenargen Lake Constance… …made by ice and water…15,000 years BP… Hans Strobl: Vorarlberger Naturschau • Altitude a.s.l. 395 m • Total surface area 535 km 2 • Maximum depth 254 m • Volume 49 km 3 •Length of shoreline 273 km • Overall length 63 km • Overall width 14 km • Catchment area 11 500 km 2 • Mean outflow ca. 370 m 3/s …determined by man since 10,000 years BP… from: Otto Hauser (1921) Leben und Treiben zur Urzeit • 1,500,000 people living in the catchment area of the lake • Local industry (engines, aircraft- and spacecraft equipment) and agriculture (hop, apple trees, vineyards) together with the inhabitants discharge sewage water equivalent to 3,200,000 people • Until the early 1970s the major part of sewage entered the lake without any treatment • Major tourist area in Germany • More than 2,500,000 visitors per year • 55,000 boats registered at the lake • Severe structural changes (land use for roads,parking, harbous, houses etc.) • Additional water pollution • Drinking water source for more than 4 million people (drinking water pumped at 25 sites at depth > 30m) • 170,000,000 m³ water / year = less than 2% of annual outflow • Water export from largest drinking water plant in Sipplingen via pipeline network to 500 cities and villages in Southern Germany “The boundaries between countries result from historical events, and, therefore, they do not coincide with the boundaries of the watersheds. As a consequence, several lakes and rivers mark the boundaries between countries or cross them. To effectively manage these water resources and protect them against pollution, the governments of the countries concerned must agree upon common rules and actions concerning this problem.” (RAVERA et al, 1980) ...in medieval times of Frederick Barbarossa... ... the catchment of Lake Constance was part of one Suabian county within the Holy Roman Empire... ...lateron a mosaic of small countries developped... ... and the catchment of Lake Constance was divided by numerous boundaries... ...Lake Constance is the only region in Europe where boundaries between the neighbouring countries never were formally determined... ...neither after the 30 years war in the peace contract of Westfalia 1648 nor at the Congress of Vienna 1815. The lake was always treated as common property: CONDOMINUIM CONDOMINIUM = common lake no boundaries + no administration + no responsability = common problems Lake Constance is a transboundary lake: The catchment area is shared by 5 countries (including 8 states or cantons respectively) ...a common problem in the 19th century: Fishery in Lake Constance... ...population growth lead to ...impoverishment of fishermen. national more fishing „solution“ transboundaryNot enough fish for to many poorproblem fishermen +/- + national higher yield benefit (?) Driving Forces Population growth D intensification of fishing Pressures Unrestricted P Exploitation Responses State Reduction of R ? S fish stock Impacts Poverty I of fishermen (DPSIR modified from EUROCAT 2002) 1893 Treaty of Bregenz IBKF Foundation Protection and breeding of the valuable fish species by international agreement on • invention of close seasons • regulation of minimium mesh size of fishing nets • restriction of licenses • installing of hatcheries 1893 IBKF Internationale Bevollmächtigtenkonferenz für die Bodenseefischerei International Conference of Representatives for Fishery in Lake Constance IBKF working procedure • regular annual meetings • principle of unanimity • IBKF decisions are base for administrative and political decisions in the partner countries • before the annual meeting the representatives meet with the fishermen • fishermen have their own IBF representative at the annual meetings • projects and expert groups are concerned with special problems such as waste water situation in the 1950s (1951: waste water committee) and lake trout project in the 1990s 1909 IBF Internationaler Bodenseefischereiverband International Fishermen Association of Lake Constance 1909 IBF Foundation International community of interest for the fishermen • since 1912 representative in IBKF • 1950 IBF waste water commission preceding the waste water IBKF committee Population Development 1950 -1990 Driving Forces Population Growth Agriculture Tourism Pressures Wastewater Buildings Harbours State Eutrophication Responses Structural ? damage Impacts Restriction of life quality (DPSIR modified from EUROCAT 2002) Polluted Lake Constance: EUTROPHICATION Platform and motor of water protection of Lake Constance since 1959 International agreement on: • Observation of the state of the lake • Confirmation the causes of its pollution • Recommendation of co-ordinated preventive measures • Discussion of planned utilization of the lake Organisation Commission Member states: Baden-Württemberg Bavaria Austria (Vorarlberg) Schweiz (Thurgau, St. Gallen, Graubünden) Deputy of Fürstentum Liechtenstein Observer of Federal Republic of Germany Permanent Expert Board Section Section Section „Lake" „Catchment" „Defense against damage" Early + Consequent = Sustainabl 100 Recognition Action Improvement 80 60 P(mg/m³) 40 1959 20 0 1950 1960 1970 1980 1990 2000 Early + Consequent = Sustainabl 100 Recognition Action Improvement 80 60 P(mg/m³) 40 20 0 1950 1960 1970 1980 1990 2000 Early + Consequent = Sustainable 100 Recognition Action Improvement 80 60 P(mg/m³) 40 20 0 1950 1960 1970 1980 1990 2000 Holistic View = Lake and Catchment Reduction of anthropogenic Nutrients and Pollution = decentralized and effective Algae and Biomass react Oxygen Contents increase Zooplancton reacts Composition of Fish changes • since 1963 blue (Research) Reports • since 1967 Guidelines for Prevention of Pollution • since 1974 green (Monitoring) Reports •1990 Bathymetric Map • since 1994 Seespiegel Catchment area of Lake Constance G E R M A N Y B a d e n - W ό r t t e m b e r g h c a Bodensee-Hochwasser 1999 : b u a S ch gger A W olfe h N c Berechnete Flδche zwischen Mittelwasser und Hφchstwasserstand a S t e o e f R e l d Singen e r A Ravensburg c h lbach n Mόh e en s rg s A u ere h nt Constance c U S c h a f f h a u s e n S Wangen i. A. Friedrichshafen A L r ge n AK Zeichenerklδrung Kreuzlingen E CO N N B a y e r n ά Flussgebietseinheit Rhein - Bearbeitungsgebiet Alpenrhein-Bodensee ST Lindau b A e Thema 5 - Karte Grundwasserkφrper NC ά berlingen E r l Staatsgrenze R h Bregenz i e T h u r g a u i n Rorschach n g Tiefenlinie B a d e n - W ό r t t e m b e r g D e St. Gallen o r n Radolfzell #S b r ir n Bad Waldsee e r D e u t s c h l a n d e r (50m Intervall; Ufernδhe 10m) h n c i A S e c a h k h c h A p p e n z e l l A u s s e r R h o d e n R e t o c S a n r e e A R e #S s t B s l r o e g t u A e e a Stockach h n c Wolf eg ger Ach z c er U h ach S F Feldkirch r n u A p p e n z e l l I n n e r R h o d e n tz Bodensee (Umriί linie) ά berlingen t Singen %U e #S #S Rav ensburg r Rad olfzeller utz Aach U L A U S T R I A s n S te eef r elde e e A a r A n c h i rg e e a Stadt / Siedlungsgebiet Konstanz Wangen im Allgδu h e n n #S i R Friedrichshafen O m b ere A rg a %U en S Kreuzlin gen B %U #S o A rge n h Vaduz c a nz d l lfe b g r A Flδche zwischen Mittelwasser Fischbach i ie e Lin denberg im Allgδu n v Konstanz #S L e l e S W I T Z E R L A N D A M Oberstaufen Frauenfeld T h u r g a u n h Lindau c #S t a B a y e r n U% s o Vorarlberg und Hφchstwasserstand U% R Liechtenstein Li e tz h Friedrichshafen c a Zeichenerklδrung Ar bon ί I O e i e l l #S U%Bregenz W #S A l Hard S t. G a l l e n #S t e Grundwasserkφrper Rorschach r Rhei n St.G allen Lustenau S u Trogen Dornbirn b Φster reich (zum Teil L iechtenstein ) #S e b %U rs U% a c Herisau #S n Bezau h i Helvetikum [RHE] e a U% h Hohen ems #S in r h am L a #S n c T n Kristallin [R HA] e a dq A p p e n z e l l - A R Altstδtten p #S r u a l e B n rt Appenzell A r re Molasse u. nφrdl. Flyschz. [RHE] i g b en n z e r e U% #S r n e o i ac h Nφrdliche Kalkalpen [RHA] h R G φtzis D e Chur G r a u b ό n d e n pin Rheintal [R HA] A p p e n z e l l - Ν R Al Ple ssur S c h w e i z Rankweil Sόdliche Flyschzone [RHA] #S F rut z Langenargen r e g Lut z Walgau [RHA] r l e a Feldkirch r r b n U% n a e H e k n d n i l i e a V o r a r l b e r g r n e t e n n s t n a e W i n k Baden-Wόrttemberg S chweiz e r B t n I r ll h h Uttwil e c n e e Bludenz i n i i n L Legend B s Fluvioglaziale Schotter Kluftgrundw asser U% Lindau enz %[ Al f Sόddeutsches Morδnenland Kluft- zum Teil Porengrundwasser Vaduz n Schwδbische Alb Karstgrundwasser g l lo V a Lake surface area e G #S d l s Porengrundwasser e L e Schruns it z G M r Bayern e e Sargans a R l Poren- zum Teil Kluftgrundwasser d h g Romanshorn #S rivers n e i a A i i e n bl Alpiner Raum See R u la Il Voralpiner Morδnen-Gό rtel l settlements e S t .