Historically, humans lived in close contact with the natural environment and satisfied their needs from their immediate surroundings, imposing a relatively small and local impact. The emergence of a sedentary civilization and concurrent improvements in agriculture led to more densely populated settlements that needed to be located on the banks of rivers or near lake shores. Archaeological evidence and extant literature clearly verify the critical need for proximity to water. For example, Ibn Khaldun, a 14th century Arab historian, states: ‘In connection with the importation of useful things and conveniences into towns, one must see to a number of matters. There is the water (problem). The place should be on a river, or near plenty of fresh water. The existence of water will be a general convenience to the inhabitants’ (Khaldun, 2005).
These ‘conveniences’ included water for drinking, irrigation, cleaning as well as to power waterwheels. Early water resource structures represent a milestone in the long process of human intervention in the natural surroundings.
The ancient Persian people honored the Sun (Mitra), Earth (Zam), Fire (Atra), Water (Apm Prudut) and Wind (Vahyu). These dominant natural forces were worshiped as a pantheon of deities in a polytheistic framework, a pattern echoed by the Greek and Minoan civilizations as well. Even after the emergence of the monotheistic Zoroastrian religion (600 BCE) in ancient Iran, the three basic elements of Water, Fire and Earth remained as the most important natural forces to be reckoned with and water continued to retain is venerated status in ancient Persian civilization (Ghirshman, 1961).
The ancient Mesopotamian civilizations that flourished around 6,000 years ago occupied the area of contemporary Iraq as well as the western planes of modern Iran and it is no surprise then that Iran was also party to the construction of different water resource engineering structures that are considered among the oldest in the world.
The introduction of agriculture is duly regarded as a defining moment in which humans adopted a settled lifestyle that redefined social and cultural norms, such as professional specialization, the division of labor and the emergence of hierarchies and more complex power arrangements. In order to exploit water, farmers and engineers had to deal with technical challenges, such as storage, distribution, flood control and water quality. In designing and constructing rudimentary hydraulic structures, they relied heavily on empirical observation and trial-and-error methods in order to compensate for scarce knowledge and the absence of mathematical models that their modern counterparts enjoy. When one considers that numerous aspects of hydraulic structural design have changed little over the millennia, it becomes easy to appreciate how our ancient ancestors were the trailblazers of modern hydraulics (Moradi-Jalal et al., 2006).
Ancient civilizations relied on a combination of four main water resource structures: cisterns, channels, canals, and weirs or dams. Typically, a combination of such structures would be employed in most areas. In ancient Iran, a wide variety of canals transferring water to dry areas could be found branching off from major rivers, such as the Tigris in the west and the Hirmand which courses through the southeast of the Iranian plateau. The construction of extensive and intricate water resource structures required thoughtful site selection in addition to well devised water control methods aimed at improving the land for settlement and agriculture (Moradi-Jalal et al., 2007).
Water resource management was of particular interest during the Achaemenid era and building a large network of subterranean canals was only one of several fundamental public works projects. For example, King Cyrus also built the Ramjerd dam on the Kur River and commissioned the Jamshid canals to irrigate the Marvdasht plain in Fars province. There is evidence that King Darius wrote to the governor of Godates with an order to nurture vegetation, saying: ‘I appreciate your intention to improve my country by expanding fruitful trees and jungles in the north-west of Asia’ (Ghirshman, 1961).
The Persepolis complex was erected on a rectangular platform of 455 m length and 300 m width, located on a foothill of the modest Rahmat Mountain. On the other side of this mountain flows a river. Because the platform’s elevation is higher than the river, it was necessary to construct a small dam and build a network of canals and gutters to supply water to the complex; a main entrance reservoir was also installed in order to safeguard the precious diverted water.
The Marvdasht plain is also a high-altitude and rich flatland surrounded by the Tangeh-Balaghi Mountains. Across the plain from north to south-southwest flows the Pulvar River and it was the combination of this water source and the fertile plain that rendered the area desirable for the first Achaemenid capital. Canals were excavated to convey water from the Pulvar (Sivand) to suburb areas of the capital, and some ruins of these still exist on the northern side of Persepolis. In certain sections, it was necessary to carve masonry bedrocks for the canals, evident in the remains of the main regional irrigation canal which still exists. Considering the epoch, this 4-km canal was quite long, beginning at the Pulvar and following a steep, but declining, slope toward Persepolis where it was amenable to easier control during its approach to the complex (Nicholson and Le Strange, 1921; Feiz-Khah, 2004).
There exist remains of two earthen cascade dams 6 km northeast of Ghadr-Abad along the Pulvar River in the Didehgan valley of the Marvdasht plain which were built approximately 1 km apart. The dimensions of the first dam are 225 m long, 8 m high and with a bottom width of 35 m. It is oriented northwest to southeast in a valley where 40 m of its initial length was destroyed due to flooding and road construction. There is a reservoir behind the northeast side; on the southeast side of the dam, the remains of masonry walls belonging to a conveyance channel with cubic-shaped stones were found, stones evocative of the architectural style of Achaemenid civil works. The second dam is situated downstream of the first and is 230 m long and 50 m wide. Its current height is about 7-8 m but, due to recent damage and the absence of records confirming its original specifications, its initial height is unknown. Both dams have a clay core protected by borrow pit layers with coarse stone materials on both sides (Le Strange, 1983).
Surveys to identify material sources for palace and building construction were also undertaken and geological investigations found three significant masonry mines in the vicinity, including the Rahmat, Majd-Abad and Sivand mountain mines. Samples confirm that materials from the Rahmat and Majd-Abad mines were used most frequently for construction of the Persepolis complex. Despite the relative distance of the Majd-Abad mine, it served as the chief source of masonry materials. Although the Rahmat mine offers high strength stones, its rocks contain various faults which substantially compromise their quality. As a result, the main source of stone for Persepolis was the Majd-Abad mine (Zare, 2004).
Sumner (1986) also mentioned a site in the Marvdasht plain where there were remains of the so-called Soon irrigation system. It is not an unlikely place for rations in form of food and salary to be issued to workers engaged in canal repairs and cleaning within a 25 km radius. Presumably, the work groups camped near the canals but were supplied from other warehouses/mines rather than from the small farming villages. It is also known that tar was used for sealing canal grooves in order to safeguard against drainage beneath the Persepolis platform (Asgari, 2004), confirming that Achaemenid had almost a robust knowledge on geology, mineralogy and water resource management.
World History
