Riparian Forest Restoration and River Bank Protection, Evrotas River, Greece

Riparian forest Restoration in Greece
Area characterisation: 

Evrotas River Basin is a predominantly rural river that has intensive water quantity and quality problems due to over utilization of the water for irrigation and intense agricultural pollution.  During November of 2007, intensive precipitation with total accumulations of up to 600 mm fall over the watershed in a period of a week resulting in significant erosion and damage to infrastructure. Significant river bank erosion occurred during that event as well as significant damage of the Evrotas riparian forest. As part of the LIFE-EnviFriendly Project, 120 m of river bank length of an agricultural field was restored near the City of Sparta.  The restoration was comprised of s stone hedge combined with a riparian forest restoration.

Slideshow:

River bank erosion due to the November 2005 flood.  3 m of the bank was eroded from an agricultural field located next to the river. River bank protection with large bolder riprap and riparian forest restoration using 200 poplar trees. Poplar trees were spaced 1.5 m apart. Multilevel groundwater wells were installed before and after the poplar tree to determine reductions in nutrient concentrations The site as was in the beginning  of the restoration period in 2007 Google earth view of the site in 2018
Objective: 

The objective of the LIFE-EnviFriendly project was to demonstrate low cost, nature based solutions that if used by all farmers within a watershed it will improve the water quality of the waters significantly.  The NbS used in this case was a riparian forest restoration coupled with a river bank erosion protection.

Actions: 

A bank restoration system using large stones following the rivers curvatures to stabilize the bank and the riparian zone from future flood events was designed and constructed. The selection of large (80cm diameter) stones was made for two reasons: they can alleviate the power of future floods as...

Potential impacts/benefits: 

The bank erosion was restored using a stone hedge of large boulders and moreover a riparian forest of 200 poplar trees was planted. The collected data from the monitoring of ground water quality allowed for the estimation of the nitrate reduction taking place at the riparian zone. Denitrification was not expected to contribute significantly in the reduction of nitrates due to the relative high dissolved oxygen and redox potential. Therefore the potential reduction is attributed to poplar tree uptake. The nitrate flux reduction was calculated for the length of the riparian zone for two equally divided parts. The water flow was calculated from the piezometric gradient between the wells, and then the difference between the concentrations resulted in the calculation of the flux. On the average, the riparian forest provided a 70% reduction of nitrates in the groundwater. Consequently, phytoremediation in conjunction with river bank erosion controls is suggested as a combined efficient nature based solution, low cost – high gain, for non-point source pollution of nutrients.

The Riparian Forest Restoration as a Nature Based Solution, ten years after implementation the river bank was stabilized and the riparian forest was restored and as a result we had

  • Increase Biodiversity.
  • Increase quality and quantity of green and blue infrastructures.
  • Improve connectivity and functionality of green and blue infrastructures.
  • Carbon sequestration and storage.

The benefits from the NbS include improvement in riparian resilience to floods, protection of agriculture, enhanced biodiversity, groundwater quality improvement and adaptation to climate change impacts.

This NbS can promoted and “subsidized” by Common Agricultural Policy because it improves the quality of groundwater.

Transferability of the result: 

The demonstrated NbS is low cost-high impact solution that can be easily be adapted to other rivers.  However, there are significant barriers that prevent wide spread implementation.

Policy/Legislation Barriers:

  •   Before any action, legislation requires to establish the floodplain of the reach for the 1 in 50 years flood.  This means that the farmer should obtain the following studies: topographic, hydrologic, hydraulic studies – erosion control studies –forest restoration study – environmental impacts study.
  •   The studies are approved and permits should be obtained from the Municipality, the Region (three Departments – water, environment and forestry), the Ministry of Environment

Financial Barriers – who pays the bill?  The cost for every 100 m restoration is about 10000 €, however, at least another 10000 € for the floodplain study and the permits.

Technological Barriers– who decides which technology to use? Rip-Rap vs Rip-Rap and riparian forest.

Market and Communication -

  •   No established market for NbS solutions
  •   NbS is not part of the communication language and everyday consideration of both the public and private sector
  •   No promotion
Lessons learned: 

The NbS Benefits were the following:

  •   The riparian forest enhanced the stabilization of the river bank
  •   Restoration of riparian forest - the forest was naturally extended to close the gap of riparian vegetation created by the flood.
  •   The riparian forest reduced nitrate-N pollution to river by 70%
Financing: 

LIFE project are financed by 50% by EU funding and 50% by Greek funding

Contacts: 

Nikolaos Nikolaidis, Technical University of Crete, School of Environmental Engineering, University Campus, 73100 Chania, Greece

email: Nikolaos.nikolaidis@enveng.tuc.gr

Goals:

  • Restoring ecosystems and their functions

NBS Actions:

  • Multi-functional nature-based watershed management and ecosystem restoration

Keywords:

Afforestation, Biodiversity, Carbon sequestration, Carbon sequestration and storage, Climate change, Cropland, cropland, Ecosystem services, EnviFriendly, Green infrastructure, Landscape, Mediterranean, Nature-based solutions, Rivers and lakes, Stakeholders, Sustainability, Think Nature, Improve connectivity and functionality of green and blue infrastructures, Increase infiltration / Water storage, Improve water quality, Increase Biodiversity, Increasing infiltration, Increase quality and quantity of green and blue infrastructures, Reduce drought risk

Client:

Prefecture of Laconia

Design team:

Nikolaos P. Nikolaidis and the HersLab team

Technical University of Crete, School of Environmental Engineering, Chania Greece

Awards:

The demonstration was work was part of a LIFE05 - EnviFriendly project. EnviFriendly was awarded the Best-of-the-Best Life project award in 2010 (LIFE05ENV/Gr/000245 EE).

Publications and reports:

Nikolaidis, N.P., F. Stamati, D. Moraetis, 2008. Impact of phytoremediation and bank erosion control in the minimization of nitrate loads to the river. Technical report 68pp +Index 4pp. In: Nikolaidis N., N. Kalogerakis, N.Skoulikidis, K. Tsakiris, (Eds), 2005-2009. Environmental friendly technologies for rural development. Life-Environment project, LIFE05ENV/Gr/000245 EE (Envi-Friendly).

http://www.envifriendly.tuc.gr/en/progr.php?allid=1

Demetropoulou, L., N.P.  Nikolaidis, V. Papadoulakis, K. Tsakiris, Th. Koussouris, N. Kalogerakis, K. Koukaras, A. Chatzinikolaou and K. Theodoropoulos, 2010. Water Framework Directive implementation in Greece: moving towards participatory governance – the case of the Evrotas River Basin Management Plan, Environmental Governance and Policy, 20, 336-349

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