Degradation and Rehabilitation of Streams and Rivers

1
Degradation and Rehabilitation of Streams and
Rivers
Lesson 12
2
Summary

• river pollution
• point sources
• diffuse sources
• water abstraction
• structural changes to the river bed
• integrated river basin management

3
Point Sources

• Treated domestic and industrial effluents
• nutrients (N, P), Corg, salts, toxic substances
  (heavy metals, organic compounds)
• Untreated domestic and industrial effluents
• as above, but far worse
• Storm overflows
• as above, plus road runoff
• Fish farming
• nutrients, pesticides
• Accidental and criminal spills
• e..g., Sandoz, oil spills, criminal acts, etc.

4
Self-purification

• Input of (easily degradable) organic carbon
  increases heterotrophic organisms and further
  downstream autotrophic organisms
  (remineralisation)
• Input of limiting nutrients (P, N) increases
  primary production (autotrophic organisms) and
  further downstream heterotrophic organisms
  (biomass)
• Balance between Trophic stage and Saprobial
  index?

from Kummert R Stumm W (1989)
5
Diffuse sources
Ptot input to lotic waters, Germany 1995

• atmospheric deposition
• acid rain, heavy metals, organic compounds
• agriculture and forestry
• fertilisers, pesticides, effluents (surface
  runoff/drains)
• aquifer pollution?

Data in 1000 t (UBA 1997)
6
Water Quality Assessment

• Individual physical and chemical properties
• spot measurements or spatial/temporal means of
  conductivity, pH, orthophosphate, nitrate,
  oxygen, BOD, COD, individual or group of
  pesticides etc.
• Contaminant accumulation in biota or sediments
• e.g. PCB 153 or Cd in Dreissena polymorpha
• Abundance/missing of indicator organisms
• Liebmann I-IV
• Saprobiensystem, DIN 38410 for organic matter
• Lumped classifications (LAWA-Güteklassen)

7
Oxygen budget parameters

• Oxygen concentration, oxygen saturation index
• Biochemical Oxygen Demand (BOD)
• oxygen consumed by incubated water sample under
  standardised conditions within a given time span,
  i.e. five days (BSB5 in Germany)
• Chemical Oxygen Demand (COD)
• oxygen consumed by oxidation with strong
  oxidising agent (acidic dichromate) similarity
  to TOC
• BOD/COD lt 1 ratio gives indication of natural
  purification need/potential

8
Oxygen concentration development
Case study Rhine A 600 km stretch from
downstream of the Neckar influx to the Dutch
border Years 1970 to 1993 (source Bundesanstalt
für Gewässerkunde, Koblenz)
9
Oxygen and species development
Rhine river Time segments from 1900 to 1995
Elbe river Time segments from 1850 to 1995
(source Bundesanstalt für Gewässerkunde, Koblenz)
10
Barriers and water abstraction

• Hydroelectricity
• Problem for upstream fish migration
• sedimentation, changed communities and anoxia
  behind dam
• no flow below dam, especially in summer
• sound calculation of ecologically necessary
  minimum flow, renders some schemes uneconomic

11
River Course Regeneration

• Streamlining of rivers intensive agricultural
  use of floodplains
• river bed modification low habitat diversity
• Regeneration
• Identification of natural state (Leitbild)
• assessment of present situation (how close to
  nature?)
• Determination of regeneration aim and measures
• Digging out of artificial bedding/culverts
• only extensive agriculture along stream margins
  (Uferstreifen)
• only extensive agriculture in river floodplain
  (Flussaue)
• self-development prior to management
• Sustainable river course maintenance
• (Gewässerpflege, z.B. Wasser- und Bodenverbände)

12
Integrated river basin management

• European Water Framework Directive 1999
• Europäische Wasserrahmenrichtlinie (EU-WRRL)
• good chemical and ecological quality of all
  surface waters within 16 (126) years
• management plans for every river basin
• Wasserhaushaltsgesetz
• River basin management plan ( 36b WHG)
• Effluent treatment plan (18a WHG)
• New administrative organisations and management
  tools necessary

13
Why EMTAL?

• Active work at mid-elevation reservoirs since
  case study Harz BMBF project Osterzgebirge
  DFG
• Active participation at Elbe 2000-project of BMBF
• Focus and research groups exist for catchment
  management, not for reservoir catchements.
• Characdteristics of reservoirs and their
  catchments in regional planning, drinking water
  supply, leisure, settling, resources
  (Agriculture, Forestry), ...

Catchment-Management for Reservoirs in
mountaineous landscapes
14
EMTAL Vision

• Protected areas for clean surface, seepage, and
  ground water
• Inclusion of possible changes in the water
  balance through hydrological changes, including
  climate change scenarios
• Flood protection and energy supply
• Soil (erosion protection) as precaution indicator
• Safeguarding sustainable resource usage
• Securing natural landscape integrity
• Sustain economically beneficial usage of
  agricultural and forest land
• Recreation for visitors and residents, protection
  of an attractive landscape for tourism
• Intelligent allocation of appropriate industries,
  commercial and residential areas
• Development of socio-cultural identity to avoid
  social disparity

Modell europäischer Entwicklung WRR
15
EMTAL Conflict portfolio

• Usage current, future (Naturpark, Schutzgebiet,
  ... ?)
• Forestry intensive, extensive ?
• Agriculture intensive, extensive ? conserving,
  conventional
• Sport water, winter, fishing, hunting, hiking,
  ... ?
• Tourism concept, eco, recreation, adventure, ...
  ?
• streams industrial, communal discharges, ... ?
• Protection erosion, flood, forest, raw water
  ... ?
• Nature soil and water acidification,
  usage, climate change ?

Seasonal restrictions ?
Desired non-desired usage ?
16
Who does EMTAL ?
TUBAFIÖZ coordination Prof. Bongaerts
environmental management Prof. Heilmeier
ecology, LAI, land-use Prof. Matschullat
Geoecology, water quality, climate change Prof.
Schmidt soils, erosion modeling TU Dresden
Prof. Bernhofer climate change CTU Prague Dr.
Dostál runoff model control Beak Consultants
GmbH (Dr. Barth, Manja Grüner) data, GIS,
models Arcadis Consulting (Dr. Schröder)
project management Landesamt für Umwelt und
Geologie (Hr. Höhne, Hr. Friese) data and
demands Landestalsperrenverband des Freistaates
Sachsen (Hr. Pütz, Hr. Flemmig) data and
demands
17
EMTAL Vorphase
18
Lokale Akteure
Modellentwicklung/ Zieldefinitionen
Allgemeines Szenario
Individuelle Szenarien
Modulares Ökologisches Ökonomisches Modell
Mediation/ Abschätzung der Folgen
von Landnutzungsänderungen
Räumliche Planungs- simulation (GIS Modell
basiert)
Mediation
Existierende Modelle/Kenntnisse
Daten
Externe Mediation / Experten
19
Interdisziplinäres Verbundprojekt EMTAL
MEDIUM
Projektmanagement
Recherche, Bestandsanalyse (Systementwicklung, S
tatistik,...)
Datenbank, Datenpflege -interpretation
Bodenkunde (Erosion, IMPACT)
Regionales UW-Management (Sozioökonomie, ökon.
Analyse Recht Regionalentwicklung)
WEG
Hydrologie (Niederschlags-/Abfluß-Modell Vegetat
ionskunde-LAI etc.)
Sektorales und projektbezogenes
UW-Management (Ressourcenbewirtschaftung Tourismu
s, Industrie)
Wasserwirtschaft Limnologie (Bioindikatoren
WRRL)
Öffentlichkeitsarbeit Integration der
Stakeholder Bewirtschaftungspläne
Integriertes Management Monitoring, EU-WRRL
ZIEL
20
Questions

• List and explain threats for lotic aquatic
  resources
• Briefly discuss the meaning and objectives of the
  European Water Framework Directive (WFD)
• Discuss the risks of flooding versus the risks of
  drought
• What can be done to restore a stream/river? B)
  when should this be done? C) what are the costs
  involved?
• How can you restore a stream on a low budget?
• Do rivers/streams restore themselves without
  human interference? B) what would be the
  prerequisites to allow such a self-healing?
• How do we safeguard a maximum self-regulation
  (including provision of clean water) in regulated
  rivers (canals, etc.)?