EFFECTS OF ALGAL BLOOMS ON
WATER QUALITY IN ISRAEL
NATIONAL WATER SYSTEMS
JACOB EREN
The B. Nesin Water Quality Laboratory, PO Box 700,
Nazareth Mekoroth Water Company Ltd. Israel
INTRODUCTION
One of the most striking phenomena associated with eutrophication of water bodies is
the massive occurrence of algae, called water bloom, which is usually dominated by one
species. In most cases the blooming organism belongs to the groups Cyanophyta,
Chlorophyta or Diatomaceae. But in some cases extreme developments of dinoflagellate
algae in fresh water have been described. There are reported blooms of Ceratium in some
Swiss lakes (Huber - Pestalozzi, 1950) and of Peridinium in England (West, 1908). A
heavy growth of the dinoflagellate Gymnodinium turned red the waters of Lake Austin in
Texas and caused fish kills (Jürgens, 1953). Fish mortality is attributed also to blooms of
Peridinium polonicum in lake Sagami in Japan (Hashimoto et al, 1968).
Although in some of the cases described, the lakes served as source of water for
different purposes, there was no mention how these blooms affected quality of water
pumped from these water bodies.
In Lake Kinneret (Lake Tiberias) which is located in the northern part of Israel there
is a heavy bloom of the dinoflagellate Peridinium westii almost every spring. The lake
serves as the main storage reservoir of the Israel National Water System which supplies
about 25% of the water to the country. Therefore the algal bloom in the lake affects
actually a large part of the water supply in Israel. In the present paper some of the effects
of Peridinium on the different aspects of water quality will be described.
THE ISRAEL NATIONAL WATER SYSTEM
The Israel National Water System (INWS) has been in operation since 1964 and
consists of open channels, pipelines and reservoirs. (Fig. 1). In 1971 it supplied about a
million cubic metres per day.
The water is pumped from Lake Kinneret at an altitude of 209 meters below sea level
and flows through open channel to Tsalmon reservoir, 38 meters above sea level. Here the
water is raised an additional 110 meters and flows through a second open channel to
Netofa settling basin with a capacity of 1.5 million cubic meters and Eshkol storage
reservoir with a volume of 4.5 million cubic meters.
From the storage reservoir the water flows through 108" pipeline to Rosh Ha'ayin,
then through two Yarkon lines southward. Along the Yarkon lines there are additional
reservoirs with capacity of 50,000 — 100,000 cu. m. and the two lines terminate at the
Zohar reservoir (8 million cubic meters). From here distribution network continues
throughout the southern part of the country.
There are outflows and inflows to the pipelines and due to this integrated network,
water from Lake Kinneret reaches most parts of the country. Water supplied by INWS is
used for irrigation, industry, domestic purposes and during winter also for enrichment of
aquifers.
195
WATER QUALITY IN ISRAEL
NATIONAL WATER SYSTEMS
JACOB EREN
The B. Nesin Water Quality Laboratory, PO Box 700,
Nazareth Mekoroth Water Company Ltd. Israel
INTRODUCTION
One of the most striking phenomena associated with eutrophication of water bodies is
the massive occurrence of algae, called water bloom, which is usually dominated by one
species. In most cases the blooming organism belongs to the groups Cyanophyta,
Chlorophyta or Diatomaceae. But in some cases extreme developments of dinoflagellate
algae in fresh water have been described. There are reported blooms of Ceratium in some
Swiss lakes (Huber - Pestalozzi, 1950) and of Peridinium in England (West, 1908). A
heavy growth of the dinoflagellate Gymnodinium turned red the waters of Lake Austin in
Texas and caused fish kills (Jürgens, 1953). Fish mortality is attributed also to blooms of
Peridinium polonicum in lake Sagami in Japan (Hashimoto et al, 1968).
Although in some of the cases described, the lakes served as source of water for
different purposes, there was no mention how these blooms affected quality of water
pumped from these water bodies.
In Lake Kinneret (Lake Tiberias) which is located in the northern part of Israel there
is a heavy bloom of the dinoflagellate Peridinium westii almost every spring. The lake
serves as the main storage reservoir of the Israel National Water System which supplies
about 25% of the water to the country. Therefore the algal bloom in the lake affects
actually a large part of the water supply in Israel. In the present paper some of the effects
of Peridinium on the different aspects of water quality will be described.
THE ISRAEL NATIONAL WATER SYSTEM
The Israel National Water System (INWS) has been in operation since 1964 and
consists of open channels, pipelines and reservoirs. (Fig. 1). In 1971 it supplied about a
million cubic metres per day.
The water is pumped from Lake Kinneret at an altitude of 209 meters below sea level
and flows through open channel to Tsalmon reservoir, 38 meters above sea level. Here the
water is raised an additional 110 meters and flows through a second open channel to
Netofa settling basin with a capacity of 1.5 million cubic meters and Eshkol storage
reservoir with a volume of 4.5 million cubic meters.
From the storage reservoir the water flows through 108" pipeline to Rosh Ha'ayin,
then through two Yarkon lines southward. Along the Yarkon lines there are additional
reservoirs with capacity of 50,000 — 100,000 cu. m. and the two lines terminate at the
Zohar reservoir (8 million cubic meters). From here distribution network continues
throughout the southern part of the country.
There are outflows and inflows to the pipelines and due to this integrated network,
water from Lake Kinneret reaches most parts of the country. Water supplied by INWS is
used for irrigation, industry, domestic purposes and during winter also for enrichment of
aquifers.
195