Πηγή Αλμυρού

Pigí Almyroú - Almyros Spring - Almiros Spring - Almyros Heraklion


Useful Information

Location: 8 km west of the city of Heraklion, near Gazi. From Heraklion Motorway 90, exit Gazi, Rogdia, Ammoudara. Turn left, after 1.2 km left again.
(35.333144, 25.047112)
Open: No restrictions.
[2021]
Fee: free.
[2021]
Classification: KarstKarst Spring
Light: n/a
Dimension: Ø=55 m, Ymin=3 m³/s, Ymax=40 m³/s.
Guided tours: self guided
Photography: allowed
Accessibility: yes
Bibliography: D. Monopolis, N. Lambrakis, B. Perleros (2005): The Brackish Karstic Spring of Almiros of Heraklion, Crete COST ACTION 621 "Groundwater management of coastal karstic aquifers", Final Report, Office For Official Publ. Of The European Union, pp 319-326. researchgate
D. Alexakis (2016): Μanagement Options of a Brackish Water Spring. Case Study: Almyros Spring (Heraklion, Greece) Austin Journal of Hydrology, Volume 3 Issue 1, 2016, ISSN: 2380-0763 researchgate academia.edu
George Tsakiris, Mike Spiliotis, Savvas Paritsis, Dimitris Alexakis (2009): Assessing the water potential of karstic saline springs by applying a fuzzy approach: The case of Almyros (Heraklion, Crete) Desalination, Volume 237, Issues 1–3, February 2009, Pages 54-64
Marko Breznik (1989): Development of the brackish karstic spring Almyros in Greece, GEOLOGIJA 31, 32, 555-576 (1988/89), Ljubljana. online pdf
Marko Breznik (1978): Mechanism and development of the brackish karstic spring Almyros Herakliou Annal Geolog des Pays Helleniques. 1978; 29:29-46.
Address: Almyros Spring, Gazi 715 00.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.

History

1977 dam erected, to make the water potable.

Description

Πηγή Αλμυρού (Salty Spring), also known as Mati, is located at the northeastern side of the Psiloritis mountain range, where the mountains end and the fertile coastal plain begins on which Heraklion was built. The spring is only 800 m from the sea, and the water flows as river Almiros to the north and into the sea at the beach Ellinoperamata. The spring is exceptional for two reasons, first it is the biggest spring on Crete, and then it actually produces brackish water. The reason is simple, the cave system in which the water flows from the Psiloritis mountains to the spring has lower levels, which formed during times of lower sea levels, for example the last cold age. Those lower levels drained to the sea and so they are now below the sea level. When the seawater rose it filled the lower part of the cave system with seawater. Most likely there is a halocline, and the sweet water from the mountains flows on top of the heavier salt water, but due to turbulence it nevertheless mixes and become brackish.

Beneath the geologic and speleological features, this spring is actually quite nice. An almost circular hole filled with blue or turquoise water produces a small river. It is surrounded by white limestone rocks, the steep slope of the Psiloritis mountain range behind the spring.

The salt content of the spring differs over the year, or actually it differs with the yield. During winter rains the yield rises and the salt content is lower, the water becomes potable. The most obvious explanation is that there is so much sweet water but the same amount of salt water. More likely its the pressure and speed of the water, which also presses the salt water back to the sea. In the summer months there is little rainfall on Crete, the yield of the spring becomes much lower and the water is too salty for most uses. Unfortunately the water would be most valuable in the dry half of the year.

In 1977 an attempt to reduce the salinity due to hydrostatic pressure was made. For this reason a wall was built around the spring, to increase the level of the spring and thus the pressure on the salt water. The idea was to reduce the salt content by the higher pressure, whivh worked at other springs, but the attempt failed here. Today the dam is deactivated, just a concrete wall which obviously has no use.

The catchment area of the spring are the Psiloritis mountains and their sinkholes, for example on the Nida plateau. From the sinkholes the water flows to the spring in only 9 hours. But the surrounding hills like nearby Stroumboulas are also part of the catchment area. The border between mountains and coastal plain is actually a result of Tylissos-Kroussonas fault. This fault is also the weakness zone along which the water rises to the surface.

Although the gradient from the source to the mouth is quite low, the power of the river water was nevertheless used in several mills. The remnants of the mills, which were grinding corn, are still visible. The wetland along the river is called wetland of Almyros and is one of the most important wetlands of East Crete. All year round birds can be observed, and it is home to the endemic Cretan date palm (Phoenix theophrastii). A part of the water is used by the Public Power Corporation (PPC) plant for cooling the engines.