Jökull - 01.12.1988, Blaðsíða 37

Groundwater Resources of Iceland
- Availability and Demand -
FREYSTEINN SIGURÐSSON
and
KRISTINN EINARSSON
Orkustofnun, National Energy Authority, Hydropower Division
Grensásvegi 9,108 Reykjavík, Iceland
ABSTRACT
The availability and hydrogeological nature of
groundwater in Iceland is very different in the geo-
logically younger formations - Late Quaternary and
Recent, as compared to the geologically older for-
mations - Tertiary and Early Quaternary. In the
former ones the bedrock is highly permeable, while
active and open fissure swarms enhance the permea-
bility as well as creating a strong anisotropy. This
results in a concentration of the groundwater fiow
appearing in springs or groups of springs with an
unusually high discharge. In the latter formations
the exploitable groundwater is mostly restricted to
sedimentary aquifers with a limited yield, which is
also subject to seasonal fluctuations. The groundwa-
ter in Iceland is generally low in chemical contents
andfreefrom pollution.
Extraction of freshwater for public and private
uses has been steadily increasing during the last
decades, and in the last years in an almost explosive
way, due to the rapid development of large-scale
fish farming in the country. This has intensified the
difficulties in freshwater supply and may in due
course lead to conflicts in the exploitation of fresh-
water, which sooner or later will callfor some cen-
tralized administration of this important national
resource.
INTRODUCTION
In Iceland freshwater has been considered an
easily available and inexpensive commodity. This is
understandable in view of the low population den-
sity - 2.5 inhabitants/km2, and high precipitation -
about 2000 mm/year. But in recent years the demand
for a reliable supply of clean freshwater has been
rapidly increasing. Some prime factors that
influence this development are:
• Population growth is rather high, with an annual
average of more than 10 per mil in the last decade
(Hagstofa Islands, 1984; Baldursson, 1987).
• Standard of living is getting higher. In recent
years the private consumption has been higher
than in the other Nordic countries (Hall and
Pétursson, 1987).
• New and more strict quality demands are being
made in the fish processing industry.
• An exceedingly fast growing and both qualita-
tively and quantitatively water-demanding fish
farming industry (Sigurðsson and Einarsson,
1986; Rannsóknaráð ríkisins, 1986).
In the meantime the consumption of freshwater
per capita has been amongst the highest in the
world. As it gets still higher, the imbalance between
the rate of exploitation and that of hydrological
investigations is made still more difficult to resolve.
The freshwater resources in Iceland are mostly
restricted to groundwater, as surface watér is fre-
quently polluted by dirt and mud. The source of dirt
JÖKULL, No. 38, 1988 35