Aflaj Irrigation Systems of Oman, Oman

Inscribed as a World Heritage site in 2006, the property consists of five aflaj irrigation systems, namely Falaj Al-Khatmeen, Falaj Al-Malki, Falaj Daris, Falaj Al-Jeela and Falaj Al-Muyassar. It represents 3000 such systems still in use. The Aflaj World Heritage site is an outstanding example of a cultural landscape – a landscape made up of individual components (irrigation channels, agricultural land, settlement areas, and traditional management practices) that are all intimately inter-related and inter-dependent.
Inscribed under criteria (v), the Aflaj Irrigation system is representative of ancient engineering technologies that demonstrate long standing, sustainable use of water resources for the cultivation of palms and other produce in extremely arid desert lands. It represents former dependence of communities on this irrigation and sharing of water resources, underpinned by mutual dependence and communal values.

Al Falaj: A covered or exposed channel which is dug in the ground to collect groundwater, natural spring water, surface water, or runoff harvesting, so that the water in the falaj channel flows naturally by gravity only, without using machines.

The Falaj consists of a main channel, extending from the Falaj upstream known as Umm Al Falaj (mother well). This channel could be on the surface or underground according to the type of the falaj. It conveys water to the sub-channels which often exist inside the village or the area irrigated by the falaj.
These main channels are designed in a unique pattern, where two basic factors are considered; minimizing the water loss and not using automatic equipment for water transportation. All the main channels have a slope at a certain level to ensure the natural flow of water by gravity, starting from the groundwater sources, to flow to the village and branch out through the sub channels irrigating the residents´ gardens.

On most aflaj, water is distributed based on time units; namely the "athar" which equals half an hour, "Rubu'a" which equals three hours and "baddah" which equals twelve hours or twenty-four athar. In the past, a sundial was used consisting of a long pole (lamad) erected on flat land and divided into parts or lines. The shadow of the lamad was monitored from the west, from sunrise until midday. It moved toward the east until 6 p.m., which was the beginning of the night-time almuhadhara according to the stars.

Aflaj of Oman can be classified into three types according to the falaj upstream: Al Ghaili, Al Aini and Al Dawoudi. However, they are similar in the method of their administration and water distribution.

The water sources of Al Ghaili falaj are the surface running water at the top of the wadis. They are the worst affected by drought as their water flows from shallow underground reservoirs.

The sources of Al Aini falaj are the natural springs (Al Oyun). While the most famous are the Dawoudi aflaj, their water source is the mother well (Umm Al falaj). Al Aini and Al Dawoudi aflaj are characterized by the stability of the water flow compared to Ghaili aflaj.

Although historians are unsure of the true history of the Aflaj origin in Oman due to the lack of documents proving this, it is considered in Oman as an integral part of the social life of Omani society since ancient times, as it is the source of water upon which life and civilization were based. The lives of the Omani people are still linked to this system and therefore the history of the aflaj in Oman in terms of its establishment and the events that it passed through are a vital part of the Omani history.
The establishment of most villages and cities throughout Oman began with the Falaj and its flow on the surface of the earth, and perhaps it was behind the major migration of residents of the arid Arab desert, leading Oman to be the center of a civilization in this part of the world.

At the Aflaj World Heritage site, the irrigation system is just one component of an inter-related and interdependent landscape that developed because of water availability. These heritage sites include villages and agricultural areas, as well as administrative structures and traditional practices developed for managing water resources.
These aflaj gave rise to residential settlements in the falaj geographical vicinity and allowed the development of traditional human activities like agriculture, along with different kinds of food and vocational industries that persist to this current day.

The historical villages and buildings located within the boundaries of the World Heritage property are important elements that contribute to the outstanding universal value of the site. The architectural heritage of the buildings contributes to the site as a whole. Houses were built of locally available materials, such as mud bricks, earth and palm. It was evident that the grander houses (and possibly also the smaller ones) were commonly built of mud bricks made from earth excavated from adjacent land which had the additional advantage of lowering the level of the land and improving the flow of water from the falaj channel.

Falaj Al-Jeela, an Aini falaj, is located in Al-Jeela village, Willayat Sur in Al Sharqiyah governorate. Sited in a rugged mountainous area, it is the main water source for the village with a total length of 161m. It is an open channel, which starts from the wellhead and ends at the water catchment basin. Adjacent to the mountain the channel originates from a high solid rocky mountain area. A pure water source, it flows throughout the year irrespective of the increase and decrease of water levels, where its average flow reaches one liter per second.

There are around 90 towers strongly built and in good condition. Located 2,000m above sea level, their height ranges from 4-5 m with diameter 3-4 m. All of them are cylindrical and rounded on top. Some of them consist of two walls infilled with bricks. Visitors to Al-Jeela village will pass through many prominent sites such as Wadi Shab, located in Niabat Tiwi, Willayat Sur. It is one of the most renowned wadis of Al Sharqiyah governorate.

Falaj Al-Muyassar is considered a Dawoodi falaj reaching a depth of 50 m. It is one of the most significant aflaj in Willayat Al Rustaq with a high flow of water. The total length of its channels is 5,783m. It is characterized by its continuous flow as two different wadis composed of sedimentary layers feed it. The falaj water flow is 210 liters/second. The falaj flow tends to be constant, but affected by both wadis Al-Fara and Al-Sin flow, where it may increase to 900 liters/second during the rise in the water level and decrease to 100 liters/second during the decline of the water level.

Al-Rustaq fort is located at the foothill of Al Jebal Al-Akhadar on the fringes of Al Batinah plain in Willayat Al-Rustaq in Al Batinah governorate. It was first built in 1250 AD.

It consists of two storeys in addition to the ground floor. It includes dwellings, weapon stores, reception rooms, gates, a mosque, jails, wells and other utilities. This fort is characterized by its four high towers.

Falaj Al- Malki is considered a Dawoodi falaj and is one of the most ancient aflaj in Al Dakhiliah Governorate. It is named after Malik bin Fahm Al-Azdi. Its water flow is 50 liters/second. It is the largest in terms of its 17 branches, making it the longest falaj in the Al Dakhiliah Governorate. The total length of its branches is 14,875m. Most of the falaj's channels are underground at varying depths.

Falaj Al-Malki is considered the most important tourist feature in the area. The falaj area is renowned for its two ancient villages (Al-Nazar and Al-Yemen) where the original houses were built with traditional materials. The walled village of Al-Nazar is rectangular in shape with high walls and three corner towers with the main building including two of these towers. Al-Yemen is surrounded by a rock block wall tiled with porcelain and it is only 8 m away from the village of Al-Nazar. Ghar Jurnan is another visitor attraction at the site. A number of towers surround the site in the foothills, in addition to the large fort built during AL-Sayed Said bin Sultan’s era.

Falaj Al Khatmeen is considered a Dawoodi falaj in the Al Dakhiliah Governorate. Its flow is 166 liters/second. The total length of the falaj from the mother well to Sharia (the point at which water first appears on the surface of the earth) is about 2,450 m, with mother well depth of 17.5 m. It has no sub-branches. It is characterized by its three equal water divisions at the Sharia. When three equal balls are thrown prior to the dividing point each ball is carried away in one the three channels indicating the ingenuity of the falaj design.

Niabat Birkat Al Mouz is well known for its suburbs and archaeological features, as they blend together with the falaj to draw a spectacular picture of a beautiful Omani village. Bait Al-Radidah is one of the landmarks at the site, a building of two storeys dating back to the 17th century.
Visitors can explore the historical villages and Al Ya’ariba mosque in Birkat Al Mouz which is still used for prayers.

Falaj Daris is one of the most famous Dawoodi aflaj in Oman and is the largest falaj in Al Dakhiliah Governorate. It has a powerful flow that exceeds 227 liters/second. Falaj Daris has two branches: the main branch, which is about 1,700 m long with a source depth of 17.5 m, and a smaller branch, containing less water, 1,900 m long with a source depth of about 16 m. Both the large and the small branches join at a point called "Fardhat Al-Multaqa". The total length of all the falaj channels from the source to the demand area is about 7,990 m.

Nizwa Fort is the most prominent archaeological monument at the site. Built in 1668, the Fort is 24 m high with its outside diameter 43 m and inside 39 m.
Another famous ancient monument is Jami Nizwa (Nizwa Mosque). It has received the Royal Attention of His Majesty Sultan Qaboos bin Said when His Majesty gave directives to restore the Mosque at His Majesty’s own expense by applying the most updated architectural designs. The Mosque has maintained its role of being an educational institute. It is now called Jami A’ Sultan Qaboos.