Minoans

The Minoan culture flourished during the Bronze Age in Crete. A systematic evolution of water management in ancient Greece began in Crete during the early Bronze Age, i. e. the Early Minoan period (ca. 3500-2150 B. C.). Wells, cisterns, water distribution, fountains, and even recreational functions existed. In prehistoric Crete rivers and springs provided people with water. Starting the Early Minoan period II (ca. 2900-2300 B. C.), a variety of technologies such as rainwater harvesting, wells, cisterns, gutters, channels, sedimentation tanks, and aqueducts were used. Also the Minoan architecture included flat rooftops, light wells, and open courts played an important role in the water management. The rooftops and open courts acted as catch basins to collect rainwater which flowed to storage areas or cisterns. Table 1.1 Provides the sources of water supply for some of the Minaon palaces and settlements.

During the Neopalatial period, ca. 1700-1400 B. C., Knossos was at the height of its splendor. The city extended an area of 75,000-125,000 m2 and had an estimated population in the order of tens of thousands of inhabitants. The water supply system at Knossos was most interesting; however, as Graham (1987) points out the sources and methods of supplying water are only partially understood. There were wells and an advanced system of rainfall collection for water supply. Terracotta pipe conduits (60-75 cm flanged to fit into one another and cemented at the joints) were used within the palace for rainfall collection and/or water distribution as shown in Fig. 1.5a. Possibly the piping system was pressurized. A water distribution system also makes possible the existence of an aqueduct. An aqueduct made of terracotta pipe could have crossed a bridge on a small stream south of the palace which carried water from a perennial spring on the Gypsadhes hill (Graham, p. 219, 1987). Figure 1.5b Shows a drainage channel and Fig. 1.5c Shows a rainfall harvesting system made of carved stone that collected water from the roof and directed it to a cistern. Unfortunately, around 1450 B. C. the Minoan palace was destroyed.

A very interesting drainage system also exists on the northeastern side of the palace as shown in Fig. 1.5d. Alongside the stairway is a small channel consisting of a series parabolic-shaped stepped chutes that convey rainwater down steam to the sedimentation tank or basin. According to Viollet (2003) each step has a vertical drop of 16 cm and the length of each step is 43 cm with the vertical distance from the top of the step down to the top of each chute is 13 cm.

The Minoan settlements used rainfall collection and cisterns over a 1,000 years before the classical and Helenistic-Greek cities. Cisterns were used to supply water (store runoff from roof tops and court yards) for the households through the dry summers of the Mediterranean. The two earliest large cisterns of Minoan Crete were built in the first half of the IInd millennium B. C., which was the time of the first Minoan palaces at Myrtos-Pyrgos (Cadogan, 2006). These cisterns remain an unusual attribute of the Minoan settlement, as the Myrtos River has been able to supply water to the base of the Pyrgos hill. Both cisterns are circular with vertical walls and rounded bottom. The walls and bottom are coated with white lime plaster 1-2 cm thick (Cadogan, 2006). Similar round structures exist at Knossos, Mallia, and Phaistos, which have been called granaries, but according to Cadogan improbable because of the locations at the bottom of hills. It would have been difficult to prevent water from running into the round structures during a storm (as illustrated in Fig. 1.6a). The main drain at the southern end of the palace is shown in Fig. 1.6b.

Fig. 1.5 Water components in Knossos. (a) Pipes made of terracotta. (b) Drainage channel. (c) Carved stone elements of rainfall harvesting system collecting water falling from roof. (d) Stepped water channel and sedimentation (desilting basin). Along the stairway is a small channel (for rainwater collection) consisting of a series parabolic-shaped stepped chutes that convey rainwater down stream to the sedimentation tank or basin (copyright permission with L. W. Mays). Color version available in Appendix