The Zarqa River is the second largest tributary of the lower Jordan River, after the Yarmouk River

Yarmouk River

The Yarmouk River is the largest tributary of the Jordan River. It drains much of the Hauran Plateau. It is one of three main tributaries which enter the Jordan between the Sea of Galilee and the Dead Sea. To the south, are the Jabbok/Zarqa and the Arnon/Wadi Mujib) rivers...

. It is the third largest river in the region by annual discharge, and its watershed encompasses the most densely populated areas east of the Jordan River. It rises in springs near Amman

Amman

Amman is the capital of Jordan. It is the country's political, cultural and commercial centre and one of the oldest continuously inhabited cities in the world. The Greater Amman area has a population of 2,842,629 as of 2010. The population of Amman is expected to jump from 2.8 million to almost...

, and flows through a deep and broad valley (which is identified with the biblical Jabbok River) into the Jordan, at an elevation 1090 metres (3,576.1 ft) lower. The river is heavily polluted and its restoration is one of the top priorities for the Jordanian Ministry of the Environment.

Geologically, the Zarqa river is about 30 million years old. At the river's origin is 'Ain Ghazal

'Ain Ghazal

Ain Ghazal is a Neolithic site located in North-Western Jordan, on the outskirts of Amman. It dates as far back as 7250 BC, and was inhabited until 5000 BC...

, a major archaeological site that dates back to the Neolithic period. Archeological finds along the course of the river indicate the area was rich in flora and fauna in the past. The Zarqa river is well known for its amber deposits that date back to the Hauterivian of the lower Cretaceous (135 m.y.). A remarkable flora and fauna was reported from this amber reflecting a tropical paleoenvironmental prevailing conditions during the time of resin deposition (Kaddumi, 2005; 2007).

Etymology

The modern Arabic name, Zarqa (زرقاء), means "the blue river". The Hebrew name Jabbok derives from the word "baqoq", which means "to flow" or "pour out".

Biblical Jabbok

The Zarqa River is identified with the biblical

Bible

The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...

 river Jabbok (Hebrew: יבוק). The Biblical

Bible

The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...

 Jacob

Jacob

Jacob "heel" or "leg-puller"), also later known as Israel , as described in the Hebrew Bible, the Talmud, the New Testament and the Qur'an was the third patriarch of the Hebrew people with whom God made a covenant, and ancestor of the tribes of Israel, which were named after his descendants.In the...

 crossed the Jabbok on his way back to Canaan

Holy Land

The Holy Land is a term which in Judaism refers to the Kingdom of Israel as defined in the Tanakh. For Jews, the Land's identifiction of being Holy is defined in Judaism by its differentiation from other lands by virtue of the practice of Judaism often possible only in the Land of Israel...

, after leaving Harran

Harran

Harran was a major ancient city in Upper Mesopotamia whose site is near the modern village of Altınbaşak, Turkey, 24 miles southeast of Şanlıurfa...

. It leads west into the Sukkot Valley, from where one crosses over the Jordan and can easily reach Shechem

Shechem

Shechem was a Canaanite city mentioned in the Amarna letters, and is mentioned in the Hebrew Bible as an Israelite city of the tribe of Manasseh and the first capital of the Kingdom of Israel...

, as Jacob eventually did. The biblical cities of Zaretan

Zaretan

Zaretan is a city mentioned in the Bible, as the location where the Hebrews crossed the Jordan...

 and Adam

City of Adam

The City of Adam stood "beside Zarethan" on the east bank of the Jordan, it is called also "Damia". According to the Book of Joshua, the flow of the water was arrested, and rose up "upon an heap" at the time of the Israelites' passing over....

 are also at the mouth of the valley.

The river is first mentioned in connection with the meeting of Jacob and Esau

Esau

Esau , in the Hebrew Bible, is the oldest son of Isaac. He is mentioned in the Book of Genesis, and by the minor prophets, Obadiah and Malachi. The New Testament later references him in the Book of Romans and the Book of Hebrews....

, and with the struggle of Jacob with the angel (Genesis 32:23 et seq.). It was the boundary separating the territory of Reuben

Tribe of Reuben

According to the Hebrew Bible, the Tribe of Reuben was one of the Tribes of Israel.From after the conquest of the land by Joshua until the formation of the first Kingdom of Israel in c. 1050 BC, the Tribe of Reuben was a part of a loose confederation of Israelite tribes. No central government...

 and Gad

Tribe of Gad

According to the Hebrew Bible, the Tribe of Gad was one of the Tribes of Israel.From after the conquest of the land by Joshua until the formation of the first Kingdom of Israel in c. 1050 BC, the Tribe of Gad was a part of a loose confederation of Israelite tribes. No central government existed,...

 from that of Ammon

Ammon

Ammon , also referred to as the Ammonites and children of Ammon, was an ancient nation located east of the Jordan River, Gilead, and the Dead Sea, in present-day Jordan. The chief city of the country was Rabbah or Rabbath Ammon, site of the modern city of Amman, Jordan's capital...

, the latter being described as lying along the Jabbok (Numbers

Book of Numbers

The Book of Numbers is the fourth book of the Hebrew Bible, and the fourth of five books of the Jewish Torah/Pentateuch....

 21:24; Deuteronomy

Deuteronomy

The Book of Deuteronomy is the fifth book of the Hebrew Bible, and of the Jewish Torah/Pentateuch...

 2:37, 3:16; Joshua

Book of Joshua

The Book of Joshua is the sixth book in the Hebrew Bible and of the Old Testament. Its 24 chapters tell of the entry of the Israelites into Canaan, their conquest and division of the land under the leadership of Joshua, and of serving God in the land....

 12:2). The territory of Sihon

Sihon

Sihon, according to the Old Testament, was an Amorite king, who refused to let the Israelites pass through his country. The Bible describes that as the Israelites in their Exodus came to the country east of the Jordan, near Heshbon, King of the Amorites refused to let them pass through his...

 is described as extending "from Arnon unto Jabbok" (Numbers 21:24), and it was reclaimed later by the King of Ammon (Judges 11:13, 22). Eusebius places the river between Gerasa and Philadelphia

Amman

Amman is the capital of Jordan. It is the country's political, cultural and commercial centre and one of the oldest continuously inhabited cities in the world. The Greater Amman area has a population of 2,842,629 as of 2010. The population of Amman is expected to jump from 2.8 million to almost...

.

Course

The headwaters of the Zarqa begin just northeast of Amman, rising from a spring named Ain Ghazal ("Gazelle spring"). The river flows to the north before heading west. Rising on the eastern side of the mountains of Gilead

Gilead

In the Bible "Gilead" means hill of testimony or mound of witness, , a mountainous region east of the Jordan River, situated in the Hashemite Kingdom of Jordan. It is also referred to by the Aramaic name Yegar-Sahadutha, which carries the same meaning as the Hebrew . From its mountainous character...

, it runs a course of about 105 kilometres (65 mi) in a wild and deep ravine before flowing into the Jordan River between Gennesaret

Gennesaret

Gennesaret was a town alloted to the tribe of Naphtali, called "Kinnereth" , sometimes in the plural form "Kinneroth" . In later times the name was gradually changed to Genezareth, Genezar and Gennesaret...

 and the Dead Sea

Dead Sea

The Dead Sea , also called the Salt Sea, is a salt lake bordering Jordan to the east and Israel and the West Bank to the west. Its surface and shores are below sea level, the lowest elevation on the Earth's surface. The Dead Sea is deep, the deepest hypersaline lake in the world...

, at a point 1090 metres (3,576 ft) below its origin. At its higher reaches, the river banks are mostly steep and canyon-like. Near Ain Ghazal, two tributary wadis join the river, and it opens up into a shallow basin. It forms the border between the Jordanian administrative regions of Irbid

Irbid Governorate

Irbid or Irbed is one of the governorates of Jordan. It is located north of Amman, Jordan's capital. The capital of the governorate of Irbid is the city of Irbid...

 and Al Balqa.

The river is perennial, but with a very low base flow of about 2–million to 3 million cubic meters per month during the summer months, and as much as 5–million to 8 million cubic meters per month during the rainy winter months. This makes it the second largest tributary of the lower Jordan River, after the Yarmouk River, and the third largest river in the region by annual discharge. Irregular flood

Flood

A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...

s after rain storms may increase the flow to as much as 54 million cubic meters. The median annual flow is 63.3 million cubic meters. The total basin area is 3900 km² (1,505.8 sq mi) the largest in Jordan. A small dam, Al-Rwyha dam, near the village of Dayr Alla, marks the end of the upstream portion of the river, where it is natural and fast flowing with very clear water. There is very little agriculture along the banks of the river in this region, which are very rocky. Downstream from this dam, the water level is very low, and the river banks are intensively used for agriculture, as well as grazing by sheep and goats

The King Talal Dam

King Talal Dam

The King Talal Dam is a large dam in the hills of northern Jordan, across the Zarqa River.The King Talal dam was started in 1971, with the original construction being completed in 1977...

 was built across the lower Zarqa in 1970, and created a reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 with a capacity of 55 million cubic meters, and increased in 1987 to 86 million cubic meters.
When built, it was expected that the reservoir would supply water for municipal use in the Amman region. However, the current levels of pollution in the lake make the water unfit for human consumptions, and it is used for irrigation only.

Bridges

The new Jerash

Jerash

Jerash, the Gerasa of Antiquity, is the capital and largest city of Jerash Governorate , which is situated in the north of Jordan, north of the capital Amman towards Syria...

 Bridge crosses the Zarqa upstream of King Talal reservoir, on the road from Amman to Jerash

Jerash

Jerash, the Gerasa of Antiquity, is the capital and largest city of Jerash Governorate , which is situated in the north of Jordan, north of the capital Amman towards Syria...

. The bridge is the site of a gauging station where flow measurements are continuously taken.

In the city of Zarqa, several bridges, vehicular and pedestrian, cross the river. The earliest of these was built by the Chechen founders of the city. Current bridges include the Zawahreh Bridge, a vehicular bridge connecting Baha' al-Din Street with al-Zuhur Street and the another connecting Baha' al-Din Street with King Talal Street. Two pedestrian bridges connect al-Zuhur Street and Baha' al-Din Street, and Wasfi al-Tal Street and Petra Street.

Natural history

The geological origins of the Zarqa river are about 30 million years old, when the Great Rift Valley

Great Rift Valley

The Great Rift Valley is a name given in the late 19th century by British explorer John Walter Gregory to the continuous geographic trench, approximately in length, that runs from northern Syria in Southwest Asia to central Mozambique in South East Africa...

 was formed. A ripple effect of its formation was the creation of side-wadis. The Zarqa river carved into the western edge of one of these side wadis. The earliest exposed
formations in the area date from the Triassic

Triassic

The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

 and early Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 periods, and have been named Zerqa and Kurnub formations. The rock formations are marine sediments, remnants of the prehistoric Tethys Sea, which used to cover the area running roughly east - west, halfway across the present Dead Sea

Dead Sea

The Dead Sea , also called the Salt Sea, is a salt lake bordering Jordan to the east and Israel and the West Bank to the west. Its surface and shores are below sea level, the lowest elevation on the Earth's surface. The Dead Sea is deep, the deepest hypersaline lake in the world...

. Along the Zarqa, we find crystalline limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 alternating with shale

Shale

Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...

. The next layer is a 20-30 meter high layer of gypsum

Gypsum

Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...

, argillaceous marly lime, shales and iron-rich stone and sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

. This layer is rich in fossils. The Zarqa valley was an important passageway connecting the Eastern Desert with the Jordan Valley.

Flora

Archaeological finds of charcoaled remains indicate that poplar

Poplar

Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....

 and tamarix

Tamarix

The genus Tamarix is composed of about 50-60 species of flowering plants in the family Tamaricaceae, native to drier areas of Eurasia and Africa...

 used to grow along the banks of the Zarqa, with forests of wild oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

 growing on the hillsides. Today, tamarix thickets are still widespread in the floodplains, and the banks are cultivated with fruit orchards and vegetable fields. Along the course of Zarqa river, water is pumped directly and used to
irrigate crops of leafy vegetables such as parsley

Parsley

Parsley is a species of Petroselinum in the family Apiaceae, native to the central Mediterranean region , naturalized elsewhere in Europe, and widely cultivated as an herb, a spice and a vegetable.- Description :Garden parsley is a bright green hairless biennial herbaceous plant in temperate...

, spinach

Spinach

Spinach is an edible flowering plant in the family of Amaranthaceae. It is native to central and southwestern Asia. It is an annual plant , which grows to a height of up to 30 cm. Spinach may survive over winter in temperate regions...

, cabbage

Cabbage

Cabbage is a popular cultivar of the species Brassica oleracea Linne of the Family Brassicaceae and is a leafy green vegetable...

, cauliflower

Cauliflower

Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed...

 and lettuce

Lettuce

Lettuce is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. It is eaten either raw, notably in salads, sandwiches, hamburgers, tacos, and many other dishes, or cooked, as in Chinese cuisine in which the stem becomes just as important...

, as well as potatoes. Olive

Olive

The olive , Olea europaea), is a species of a small tree in the family Oleaceae, native to the coastal areas of the eastern Mediterranean Basin as well as northern Iran at the south end of the Caspian Sea.Its fruit, also called the olive, is of major agricultural importance in the...

 trees are also found along the river's banks. Tulips grow on many hillsides of the river, while in the springs area and the watercourse, water vegetation is found. Natural pine

Pine

Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...

 forests grow in the King Talal Dam area. Along the upstream banks, where the river runs wild, one finds the common reed

Phragmites

Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...

, oleander and Typha

Typha

Typha is a genus of about eleven species of monocotyledonous flowering plants in the family Typhaceae. The genus has a largely Northern Hemisphere distribution, but is essentially cosmopolitan, being found in a variety of wetland habitats...

 species. Since the waters of the Zarqa are highly contaminated, with high levels of organic matter and various chemical compounds (especially detergents and dyes), the use of Zarqa water for irrigation has significantly altered the biodiversity of the natural flora, and caused the disappearance of the majority of fresh water species.

Fauna

In prehistoric times, the area was rich with fauna, and 45 distinct animal species have been identified, half of them wild animals. Domesticated goat

Goat

The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...

s were the most common, and gazelle

Gazelle

A gazelle is any of many antelope species in the genus Gazella, or formerly considered to belong to it. Six species are included in two genera, Eudorcas and Nanger, which were formerly considered subgenera...

s were the most frequently occurring wild animal species.

Today, the area is still home to a diverse population of birds and mammals, and some of the breeding species found do not breed anywhere else in Jordan. Among the bird species found are the European Roller

European Roller

The European Roller, Coracias garrulus, is the only member of the roller family of birds to breed in Europe. Its overall range extends into the Middle East and Central Asia and Morocco....

, Desert Lark

Desert Lark

The Desert Lark, Ammomanes deserti, breeds in deserts and semi-deserts from the Sahara east through the Arabian peninsula and the Middle East to Iran, Afghanistan and Pakistan....

, Dead Sea Sparrow

Dead Sea Sparrow

The Dead Sea Sparrow , as its name suggests, is a breeding bird around the River Jordan, Dead Sea, and into Iraq, Iran and western Afghanistan. Breeding recorded in Cyprus but is probably extinct there now...

, Desert Finch

Desert Finch

The Desert Finch , sometimes called Lichtenstein's Desert Finch, is a large brown true finch found in southern Eurasia. Its taxonomy is confused, and it has formerly been placed in Fringilla, Bucanetes, Rhodospiza and Rhodopechys.It has an average wingspan of...

 and Blue-cheeked Bee-eater

Blue-cheeked Bee-eater

The Blue-cheeked Bee-eater, Merops persicus, is a near passerine bird in the bee-eater family, Meropidae. It breeds in Northern Africa, and the Middle East from eastern Turkey to Kazakhstan and India. It is generally strongly migratory, wintering in tropical Africa, although some populations breed...

. The King Talal dam has created a lake which is a habitat for migratory waterfowl and various fish species. Notable birds found in the lake area include the Little Bittern

Little Bittern

The Little Bittern is a wading bird in the heron family Ardeidae, native to the Old World, breeding in Africa, central and southern Europe, western and southern Asia, and Madagascar. Birds from temperate regions in Europe and western Asia are migratory, wintering in Africa and further south in...

, Cattle Egret

Cattle Egret

The Cattle Egret is a cosmopolitan species of heron found in the tropics, subtropics and warm temperate zones. It is the only member of the monotypic genus Bubulcus, although some authorities regard its two subspecies as full species, the Western Cattle Egret and the Eastern Cattle Egret...

s, Grey Heron

Grey Heron

The Grey Heron , is a wading bird of the heron family Ardeidae, native throughout temperate Europe and Asia and also parts of Africa. It is resident in the milder south and west, but many birds retreat in winter from the ice in colder regions...

s, White Stork

White Stork

The White Stork is a large bird in the stork family Ciconiidae. Its plumage is mainly white, with black on its wings. Adults have long red legs and long pointed red beaks, and measure on average from beak tip to end of tail, with a wingspan...

s, Common Teal

Common Teal

The Eurasian Teal or Common Teal is a common and widespread duck which breeds in temperate Eurasia and migrates south in winter. The Eurasian Teal is often called simply the Teal due to being the only one of these small dabbling ducks in much of its range...

 and Eurasian Coot

Eurasian Coot

The Eurasian Coot, Fulica atra, also known as Coot, is a member of the rail and crake bird family, the Rallidae. The Australian subspecies is known as the Australian Coot.-Distribution:...

. The lake's waters sustain stock of fish, some of which is indigenous species and some introduced species. The most common are Tilapia

Tilapia

Tilapia , is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapia inhabit a variety of fresh water habitats, including shallow streams, ponds, rivers and lakes. Historically, they have been of major importance in artisan fishing in Africa and the...

. Migratory birds also winter in the man-made pools which make up the Kherbit Al-Samra Sewage Treatment Plant, located in a broad depression close to Wadi Dhulayl, the main tributary of the Zarqa River. As many as 6,000 White Storks have been spotted roosting there. Mammals found in the area include the Common Otter

Otter

The Otters are twelve species of semi-aquatic mammals which feed on fish and shellfish, and also other invertebrates, amphibians, birds and small mammals....

 (Lutra lutra), and the Persian Squirrel (Sciurus anomalus). The otter is considered a threatened species.

History

'Ain Ghazal

'Ain Ghazal

Ain Ghazal is a Neolithic site located in North-Western Jordan, on the outskirts of Amman. It dates as far back as 7250 BC, and was inhabited until 5000 BC...

, the origin of the spring the feeds the Zarqa river, is a major archaeological site, dating back to the Neolithic

Neolithic

The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

 period. It was continuously occupied for more than two thousand years, and the earliest finds date to 7200 BCE. 'Ain Ghazal is one of the earliest known human settlements with evidence of domesticated animals. With a population of around 3,000 at its height, it was also one of the largest prehistoric population centers in the Near East, with about five time the population of neighboring Jericho. During a 1982 survey of the Zarqa valley, a number Early Iron Age

Iron Age

The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing...

 sites were discovered, concentrated along the banks of the Zerqa and its tributaries. One of them, Tulul adh-Dhahab

Tulul adh-Dhahab

The Tulul adh-Dhahab , Jordan, are two adjacent tells in Wadi az-Zarqa, a sidevalley of the Jordan Valley about an hour's drive northwest of Amman in Jordan. The western of the twin hills was populated at least from Bronze Age to Late Antiquity, a beginning of settlement in the Neolithic period is...

, is under further research now.

Zarqa

Zarqa

Az-Zarqāʔ is a city in Jordan located to the northeast of Amman. With a population of more than one million 1000,000. It is the country's second largest city after Amman. Zarqa is the capital of Zarqa Governorate . Its name means "the blue one".- Overview :Zarqa is Jordan's industrial centre, home...

, Jordan's second largest city, is built on the banks of the Zarqa River, and is the largest settlement along its course. The town of Zarqa was founded in 1902 by Chechen

Chechen people

Chechens constitute the largest native ethnic group originating in the North Caucasus region. They refer to themselves as Noxçi . Also known as Sadiks , Gargareans, Malkhs...

 immigrants. Its population grew rapidly with an influx of Palestinian refugees who fled the West bank

West Bank

The West Bank ) of the Jordan River is the landlocked geographical eastern part of the Palestinian territories located in Western Asia. To the west, north, and south, the West Bank shares borders with the state of Israel. To the east, across the Jordan River, lies the Hashemite Kingdom of Jordan...

 during the Six-day war

Six-Day War

The Six-Day War , also known as the June War, 1967 Arab-Israeli War, or Third Arab-Israeli War, was fought between June 5 and 10, 1967, by Israel and the neighboring states of Egypt , Jordan, and Syria...

.
The Zarqa River also flows through Jerash

Jerash

Jerash, the Gerasa of Antiquity, is the capital and largest city of Jerash Governorate , which is situated in the north of Jordan, north of the capital Amman towards Syria...

. Inhabited since the Bronze Age

Bronze Age

The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...

, Jerash was an important Greco-Roman city (Gerasha), home to noted mathematician Nicomachus

Nicomachus

Nicomachus was an important mathematician in the ancient world and is best known for his works Introduction to Arithmetic and Manual of Harmonics in Greek. He was born in Gerasa, in the Roman province of Syria , and was strongly influenced by Aristotle...

. The ruins of the city are well preserved and have been extensively excavated.

Environmental concerns

The Zarqa river is highly polluted

Pollution

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

. In many areas, raw sewage

Sewage

Sewage is water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains...

 flows untreated directly into the river through dry riverbeds (wadis), contaminating it and creating a stench which has been a cause of numerous complaints, particularly during the summer months. Though sewage treatment stations have been built in a couple of locations (including Ain Ghazal and Khirbet As Samara), these stations often receive more water than they can handle. Such overflow occurs during winter floods, as well as during summer months when the population increases with the return of migrant workers to Amman. During overflow, untreated water runs directly to the Zarqa river. As a result, the Zarqa's water is brownish colored, often with dense foam due to large amounts of organic matter. Other sources of pollutants are the illegal dumping of industrial waste, including those from textile factories, and batteries and oils from garages.

The river's watershed encompasses the most densely populated areas east of the Jordan River, and it flows through an industrialized area that is home to more than 52% of Jordan's industrial plants, including the Jordan Petroleum Refinery Company. During the summer months, treated domestic and industrial waste-water compose nearly all of the flow, and substantially degrade the water quality. Coupled with over-extraction of water from the underground aquifer

Aquifer

An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...

and the naturally low base flow of the Zarqa, this has created a major problem, described as one of Jordan's "environmental black spots". and has made rehabilitation of the Zarqa a top priority for the Jordanian Ministry of the Environment. The restoration project is estimated to cost $30 million dollars.