Engineering the restoration of a coastal freshwater wetland:
a sluice-and-canal scheme in Rodia Swamp, Amvrakikos,
Greece.
Menelaos Theocharis1, Thomas Arapis,2 and Stamatis Zogaris3
SCIENTIFIC THEME
This paper presents the technical infrastructure and aims of an attempt to restore
freshwater input into a formally degraded coastal freshwater wetland area in Greece.
Ecological restoration is an important aspect of sustainable development within
protected natural areas and this approach to water and land use management is
essential where water resources have suffered from overexploitation and where
biodiversity conservation is of overriding importance.
STRUCTURE OF THIS PAPER
Introduction
Ecological restoration of wetlands is poorly developed in the Mediterranean. Although a
network of proposed protected natural areas in Greece includes over 125 Natura 2000
sites with wetland habitats, most Greek wetlands suffer from environmental
degradation. One of the most widespread pressures concerns the deterioration of
coastal freshwater wetlands due to poorly-planned water exploitation and agricultural
intensification (Zalidis & Mantzavelas, 1996).
Fig.1. Study area. Location of the Rodia Swamp
restoration project is shown with an asterisk.
Amvrakikos, in western Greece, is one of the country’s largest wetlands of international
importance. The most significant part of this coastal wetland in terms of its biodiverisity
is the Louros river floodplain and the Rodia Swamp (27 km² in size); the largest reeddominated swamp in Greece. This freshwater wetland has progressively been
deteriorating since the early 60’s when efforts were taken to embank the entire stretch
(1) Dep. of Crop Production Tech. Educ. Inst. of Epirus, 47100 Arta, Greece, e-mail: theoxar@teiep.gr
(2) OIKOS- Nature Management LTD, 14 Ermou str. GR-14121 Iraklio Attiki, Greece. Email: oikos@hol.gr
(3) HELLENIC CENTRE FOR MARINE RESEARCH, Institute of Inland Waters, P.O. Box 712, GR-19013,
Anavyssos, Attiki, Greece. Email: zogaris@ath.hcmr.gr; Internet www.hcmr.gr;
of the Louros river for flood control and agricultural development. Due to the increasing
influence of brackish water from the adjacent saline lagoons, Rodia Swamp’s
vegetation begun to change quickly after the river embankment construction completely
disrupted natural river flooding of the swamp. Since the ‘70s the swamp’s varied reed
communities died-back, water salinities increased with declines in biodiversity and
biological productivity (Lawrie, 2002).
Aims of this investigation
A disrupted hydrology has brought about wholesale changes in the Rodia Swamp,
including the degradation of critical habitat for several threatened bird species that are
dependent on freshwater wetland resources (Zogaris et. al. 2003). Primary aims of this
project include a relatively low-cost infrastructure to rehabilitate the degraded
ecosystem through the regulated transfer of water from the river to the adjacent swamp
(OIKOS LTD, 2003).
The restoration infrastructure and preliminary results
In 1999 a Life-Nature project (LIFE 99 NAT/ GR/ 006475) initiated a suite of
conservation works and studies that included an action to restore the connection
between the river Louros and Rodia Swamp in order to enhance habitats for threatened
birds and the freshwater biota. Several approaches were studied, but the most effective
was the creation of a simple system of sluices and ditches which can regulate the
quantities of water introduced into Rodia Swamp from the Louros river. The project was
completed on July 1st 2003, and included: two sluices and water transport ditches (from
the river to the sluices); and, two 1000 m. long canals in the swamp. The canals are 6
m. wide and 1.5 m. deep and can transport 134000 m3/day of water from the river to
the swamp. This amount of water represents only 13,17 % of the Louros river’s water
during its low flows in summer and should have no negative effects on the river’s
downstream health especially since flooding should be scheduled primarily during highwater periods in order to imitate natural flood-pulse patterns. After the sluices were
opened during an initial trial, rapid changes in the biodiversity and hydrology of Rodia
Swamp were observed. The infrastructure can effectively flood the entire area of the
upper part of Rodia Swamp, and therefore represents one of the largest riverine
wetland restoration projects in Greece.
CONCLUSION
The initial positive results of this restoration infrastructure should encourage carefullyplanned restoration works in other Mediterranean wetlands. Water management in
wetlands is an integral part of nature conservation and sustainable development. It is
vital that water management be integrated into a master plan to manage and protect
water and biodiversity throughout the river basins of the Amvrakikos Gulf. The longterm success of the completed infrastructure depends on such an approach for
integrated environmental management.
REFERENCES
[1] OIKOS LTD. (2003). Conservation and Management of Amvrakikos Wetlands. Final
Activity Report for the project “Conservation management of Amvrakikos Wetlands”.
Life-Nature B4-3200/99/006475. Unpublished Life-Nature Report.
[2] Lawrie, V.(2002). Do water depth and salinity influence the structure and
composition of the reed beds of Rodia Swamp, Amvrakikos Greece? M.Sc. Ecology
Dissertation. University of Wales, Bangor.
[3] Zalidis, G.C. & A.L. Mantzavelas (1996). Inventory of Greek wetlands as natural
resources. Wetlands 16 (4): 548-556.
[4] Zogaris, S., D. Papandropoulos, H. Alivizatos, Y. Rigas, V. Hatzirvassanis & N.
Kardakari (2003). Threatened birds at Amvrakikos. Athens: Koan/OIKOS LTD. (In
Greek).