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Revitalization of the upper Drau River in Austria

Last update
2013
Summary
At three different sections of the Austrian Drau the river bed was enlarged and restoration works have taken place. Moreover, 25 ha of riparian forest were created as well as meadows, lakes and several river branches.
Position
Latitude
46.748666
Longitude
12.96743
Project
NWRM
National Id
Austria_01
Installation date
2006-2011
Contact
Sabine Tutte, ACTeon
RBD code
AT1000
Transboundary
1

Location of the project
The project side lies close to the Italian border in the west of Klagenfurt. The revitalized parts of the Drau are between Spittal i.Dr. and Oberdrauburg.
NUTS Code
AT21 - Kärnten
Involved Partners
Authority type Authority name Role Comments
National water authority
Federal Ministry for Agriculture, Forestry, Environment and Water Management, represented by the Carinthian State Government, department 8- Competence Centre environment, Nature and Water conservation, subdivision water management
Initiation of the measure
Execution
Other
Torrent and avalanche control, section Carinthia, regional management supervision 4 Upper Drau Valley and Müll Valley
Implementation
reconstruction of the open check dam
National water authority
Carinthian State Government, department 8, competence centre environment, water and nature protection, subdivision Nature Conservation and National Park Law
Other
supervision of nature conservation measures
Research institute / University
University of Vienna
Monitoring
Analysis of the river bed before and after the LIFE Project, Study of the composition of the fish fauna, calculation of the transported bedload in the Feistritzbach
Research institute / University
Ökoteam
Monitoring
search for indicator species in order to document the improvement of the ecological state
Local water authority
Agrarian Regional Office of Villach
Implementation
Purchase of land
LIFE Nature
Financing
Project Control for the EU
Architects/Engineers
REVITAL Ziviltechniker GmbH
Implementation
Project Coordination
Architects/Engineers
DI Dr Peter Mayr and team
Monitoring
geodetic survey of the river
National water authority
Federal Ministry for Agriculture, Forestry, Environment and Water Management (rural development section) department II/4
Financing

Climate zone
cool temperate moist
Temperature
7
Precipitation
1100
Annual rainfall range
1200 - 1500 mm
Runoff
73,8
Runoff range
600 - 750 mm
Elevation range
625
Slope range
0-1%
Vegetation class
In the surroundings of the upper Drau one can find a big variety of different landuses: forest, meadows, fields.
Water bodies: Ecological Status
Poor
Water bodies: Chemical Status
Failing to achieve good
Water quality status
Given that water quality improvement was not an objective of the project, no information is available.

Project scale
Meso
Project scale specification
Although the enlargement of the river bed was done on a length of 5 km the affected length of the river/region around the river is 68 km. The surface of the project region (river and surroundings) are 976 ha.
1 ha meadow lakes, 25 ha riparian forests
Performance timescale
5 - 10 years
Project area
26
Size
5
Size unit
km
Lifespan
Eternity, exception: the river “decides” to search itself a completely new bed
As already explained the erosion of the river bed (the Drau became deeper and deeper) determined the choice of measures. Another point to mention is the availability of land. Next to the negotiations with farmers a reallocation of land took place. Plots were exchanged between farmers and the project responsible. Depending on the size of riparian buffers available the measurements were adapted.
A good ecological status should be achieved for the Drau river. The measurements combine habitat diversity with passive flood protection. Secondary the regional tourism department supported the project by designing picnic areas, positioning info points and marketing the project.
Design capacity description
Since flood protection wasn’t the main target of the project quantitative data is missing on the success of the implemented NWRM. Monitoring may be done in future. After Norbert Sereinig it is moreover difficult to describe effects on water retention. The flood plains are designed in a way that already quinquennial and decennial floods enter the floodplains completely.
The availability of land determines which measures can be used and how expensive the implementation of the measures will be.
The erosion of the river bed should be stopped. This goal determined the choice of measures.

Total cost
€ 4,475,000
Costs total information
total costs of the project
Costs capital
€ 3,930,000
Costs capital information
Construction, staff, journeys, measuring instruments, gauges
Costs land acquisition
€ 670,000
Costs land acquisition unit
€ (total value)
Costs land acquisition information
Purchase of land
Costs operational
10000 €/yr
Costs operational information
Monitoring of the river bed
Costs operation maintenance information
No special, project-linked expenses.
Every few years maintenance has to be done as on every other river like cutting grass or trees.
Costs maintenance
0 €
Costs maintenance information
No project-specific maintenance needed
Economic costs other annual
98000
Financing authorities
Authority name
European Union
Type of funding
EU-funds: LIFE+
Financing share
33 %
Comments
1.5 Million €
Authority name
Torrent and Avalanche Control
Type of funding
Sub-national funds
Financing share
4 %
Comments
0.2 Million €
Authority name
Carinthian State Government
Type of funding
Sub-national funds
Financing share
4 %
Comments
0.2 Million €
Authority name
Federal Ministry for Agriculture
Type of funding
National funds
Financing share
60 %
Comments
Forestry, Environment and Water Management 2.7 Mio €

Policy context
The river bed is too narrow and there is a lack of brash and pebbles. As consequence the river bed became deeper, bank stabilization got insecure and flood plains inoperable.
Community involvment
Yes
Design consultation activity
Activity stage Name Key issues Comments
Implementation phase
public inaugauration feasts e.g. for the new dam or the different enlarged riverparts
Implementation phase
information day for school children
Implementation phase
tree planting event for children
Design phase
tourism concept, guided routes within the national park
Other
post card showing before after pictures of the drau
Implementation phase
VIP event: Mimi Hughes (marathon swimmer and environmental activist swam through the drau until danube
Policy target
Target purpose
Runoff control
Improved Biodiversity
Increase Water Storage
Target Remarks
Flood control and flood risk mitigation
Soil formation and maintenance
Biodiversity and gene-pool conservation in riparia
Policy pressure
Pressure directive Relevant pressure
WFD identified pressure
Physical alteration of channel/bed/riparian area/shore of water body for agriculture and transportation.
Pressures remarks
Bed load balance shall be achieved. Due to missing pebble supply the Drau river bed became deeper and deeper. Thus the groundwater level decreased, bank stabilization became insecure and flood plains inoperable.
Policy impact
Impact directive Relevant impact
WFD identified impact
Altered habitats due to morphological changes
WFD identified impact
Damage to groundwater dependent terrestrial ecosystems for chemical / quantitative reasons
Floods Directive identified impact
Property
Floods Directive identified impact
Infrastructure
Requirement directive
Requirement directive Specification
Requirement directive remarks
A good ecological status of the Drau should be achieved in order to meet the demands of the WFD.
Policy challenges requirements
The project follows a master plan for the development of the river. With RIWA-T technical guidelines are established that give priority to passive flood protection and take into account the ecological functions of a water body .
Contractual arrangements
0
Arrangement type Responsibility Role Name Comments
Part of wider plan
1
Wider plan type
Wider plan type Wider plan focus Name Comments
Catchment-based
Water
water body-development-concept
Plan made in the middle of 90s (93 or 94). Programme for the whole river Drau.

The monitoring is still ongoing for the riverbed. It is controlled whether bedload balance is reached and whether the erosion of the bed is stopped. Given that the Drau is let more freedom to form its river bed monitoring is done how the shape of the river develops. The biological monitoring is accomplished. The number of fisch, amphibian and insect species were counted
Maintenance
There are no project-specific maintenance requirements. As for every river every few years grass will be needed to cut as well as trees.
Catchment outlet
-Assessment of aerial photos
- Geodetic survey of cross profiles (echolot)
- Laserscanning with drones
- Steel plates are on the bottom of the river in order to measure the transported load in size and volume with ultrasound
- Life space mapping
3250000
Total expenses for the implementation of the project given to regional companies, planning offices.
The tourism department definitetly benefitted from the Drau project but this cannot be quantified yet.
Hydrological effects
Until mid 2011 28000 km3 were mobilized by the open checked dam and 16000 km3 arrived at the Drau. As consequence the bedload balance could be improved and the riverbed stabilized.
Information on retained water
No quantitative data. However riparian forests were planted and buffer stripes installed along the river shore. These measurements favour an increase of water storage capacity.
Information on increased water storage
No quantitative data. Side arms were reconnected to the main channel and the riverbed itself was enlarged. As a consequence storage capacity must have increased.
Information on runoff reduction
no data available
Water quality overall improvements
N/A info
Information on Water quality overall improvements
Riparian forests may act as buffers for diffuse pollution input for water from fields (nitrogen, phosphorous, herbicide flux).
Soil quality overall soil improvements
N/A info
Information on Soil quality overall soil improvements
No monitoring is done on this aspect since it was not targeted in the project.
1
Number of amphibian species multiplied by six.
Number of insect and fish species increased as well, new habitats and higher habitat quality for fish and their breeding, more than 100 spider and ground beetle species several of which are endangered or threatened by extinction .
Ecosystem impact climate regulation
Increased permanent biomas
Information on Ecosystem impact climate regulation
Given that buffer strips, riparian forests and meadows were created/restored permanent biomas has increased.
Ecosystem provisioning services
0
Information on Ecosystem provisioning services
no information available

Key lessons
By adapting open check dams the bed load balance of a river can be improved. The reconnections of side arms, the creation of riparian forests and meadows support a greater biodiversity.
The adaptation of open check dams to improve bed load balance is possible. The widening of the river bed and the reconnection of side arms create larger habitat diversity and as consequence the number of species in the area rises.
Success factor(s)
Success factor type Success factor role Comments Order
Attitude of the public
main factor
<p>Since the revitalization measures on the Drau are a subsequent project to former projects and measures, much less publicity had to be done. The responsibles hadn't to face the fears and worries of farmers and citizens.</p>
1
Existing staff and consultant knowledge
main factor
<p>20 years of experience exist on restoring the river to a more natural state. Moreover, there is good cooperation between the different stakeholders for nature conservation and hydraulic engineering.</p>
2
Other
secondary factor
<p>The regional touristic department supported the measure and furthermore helped to merchandise the Drau project. They looked amongst others at the following questions: How to design picnic areas? Where are the best places for information boards? How can we conduct tourists through the region?</p>
3
Attitude of decision makers
main factor
<p>The purchase of land was combined with a reallocation of land process. Lots were exchanged between farmers. There were a lot of farmers willing to give land for the project and there was also political support of the action. A company constructing/operating hydropower plants had bought lots in the 90s. After their project of building 4 new power plants on the Drau was refused they were nevertheless ready to give their lots to the project partners for a fair price.</p>
4
Barrier
Barrier type Barrier role Comments Order
Other
main barrier
The project had to be replanned several times since farmers didn't want to sell ground or sell it for very high prices. Others changed their opinion suddenly and new possibilities openend up.
1
Lacking coordination between authorities
secondary barrier
There is always tension between the disciplines agriculture, nature protection and hydraulic engineering which have different priorities.
2
Driver
Driver type Driver role Comments Order
Other
main driver
Erosion of the river bed was observed (becoming deeper and deeper). There was furthermore a risk that floodplains fall dry and can't operate anymore, as well as a risk of a falling ground water table.
1
Flexibility adaptability
Since the river has freedom to form its bed, it will adapt the measures on its own. The adaptation of the measures by humans is linked with huge costs and difficult to execute.
Transferability
There has to be knowledge about the original characteristics of the river. Was it a branched or meandering river?
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