D10: Impact of Contaminants - Hydromod

Integrated Water Resource Management for Important Deep European Lakes and their Catchment Areas
EUROLAKES
D10: Impact of Contaminants
FP5_Contract No.: EVK1-CT1999-00004
Version: 4.0
Date: 25/07/01
File: D10-vers.4.0.doc
Page 65 of 136
Forestry: Poor forestry practices have the potential to pollute water, damage watersheds
and destroy wildlife habitat. The natural ecological process that maintain a
healthy forest can be interrupted by conversion to a monoculture. The runoff from disturbed
areas can carry sediment, nutrients, pesticides and fertilisers. Surface and
ground water can be contaminated with these pollutants. The forest area of 299713 ha
is equivalent to 26.1 % of the total catchment area.
Amounts of Contaminants in the Catchment Area of Lake Constance
It could not be realised to get more information about pesticides via an assessment of
the used substances in the catchment area of Lake Constance. For each border state
there only exist details about the countrywide used pesticides as well as the recommendations
for their special use in the agriculture. From the recommendations of use it
could not be deduced the used substances or the amounts [MÜLLER 1993].
Data about Pollution Sources
Beside nutrients an increasing amount of other substances are admitted into Lake
Constance. The sources and possible effects are shown in the following figure.
natural indus- traf- naviga- agriculture and
non point
point sources caused
by accidents, discharges,
drain systems
f t t
Pollutants in Lake Constance
Hydrocarbons (especially petrol,
solvents, pesticides, herbicides)
heavy metals
non point point sources
accumula- acutementimpair-
oxygen consump-
f i l l t
tion
during the micobial re-
sediments animals and
l t burden of any member of the food chain
sub-lethal impairment
of the soil bio-
sub-lethalimpairments Figure 10-3: Diagram of source and effects of pollutants in Lake Constance [according to
UBR 1994]