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Pre-proposal restoration project Station AAR00869
Ionela Tamasan
AM16
Environmental Water Management
December 2017
Supervisor: Jens Brøgger
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Contents 1. Project introduction ...................................................................................................................... 3
1.2 The connection between the Water Framework Directive and the project in Silkeborg
Municipality. ..................................................................................................................................... 3
2. Measures planned to carry out in the project............................................................................... 4
2.1 Phosphorus removal ................................................................................................................... 6
3. Consequences for the biological conditions in the stream, the surrounding areas, and protected
nature types .......................................................................................................................................... 7
4. Stakeholders involvement ............................................................................................................ 8
5. Conclusion..................................................................................................................................... 9
References .......................................................................................................................................... 10
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1. Project introduction
Lyngbygaard stream borders to north with Herskind and Sjelle, Galten Skovby to the
south and approximately 17 km west from Aarhus, it has approximately 25 km stretch,
and it is one of the main watercourses in Aarhus’s stream system. (Nielsen, n.d.)
The location of the stream, the project is focusing on, is station AAR00869 which is
located on a private propriety. The stream there, is running close to agricultural fields,
which makes it vulnerable to pollution, mainly Nitrogen and Phosphorus. On a 368 m
stretch the stream is running underground, throughout pipes, to emerge at a point and run
in to a protected bog, where a clear water coarse it is not visible. (p.m. Jens Brøgger)
Due to the current situation at Station AAR00869 concerns such as, biodiversity and
ecological status of the stream, arose. Furthermore, the protected bog must be taken in to
consideration due to the fact that the stream runs in to it. Any pollution the stream carries
in to the bog might disturb its fragile and rare ecosystem. (LASKOW, 2017)
The landowners have dug a ditch with a 188 m stretch on the foot of the slope in order to
increase the drainage of the fields. The ditch was constructed without permission from
the authorities, it is not a protected watercourse and therefore is allowed to modify it,
aiming to include it in the pre-proposal for the restoration. The ditch is canalised, and
supplied with drainage water from the agricultural fields which carries nutrients from the
fertilisers. Another concerning aspect is the ochre that is visibly present in the ditch. (p.m.
Jens Brøgger)
1.2 The connection between the Water Framework Directive and the project in
Silkeborg Municipality.
Water Framework Directive, the legislation in water field that acts at European level,
implemented in Denmark in December 2000, is mainly focusing on pollution caused to
aquatic environment by the agricultural practice. The first deadline for achieving a good
ecological stat of the water course was set in 2015, but due to the complex process that
involves productiveness of the process, the range of the extent and the legal
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requirements that sometimes can be difficult to adjust to a particular situation, the
deadline has been extended. (Boeuf, 2016)
The project conducted by the Silkeborg Municipality is indeed following the goals, the
Water Framework Directive aims for, i.e. overall, achieving a good water status.
(Meisner, 2014)
During 2014 until 2015, a project was conducted at the site by the Silkeborg
Municipality. (Meisner, 2014)
The aim for the project was to restore and improve the overall ecological state of the
stream, to improve and create a better habitat for fauna, improve the physical condition
in order to create possibilities for spawning for species such as salmonids. Another
objective pursued by the project was to boost the overall physical and ecological status
further downstream in the Lyngbygaard Å system, this objective being achievable by
reducing the nutrients that reach the stream along the way, mainly from the agricultural
fields lying along its stretch. (Meisner, 2014)
2. Measures planned to carry out in the project.
Is only reasonable to state that the ecological and physical conditions on the stretch at
Station AAR00869 are threatened by the nutrients that run off from the agricultural
fields that are on a sloppy terrain and furthermore from the dead organic matter that
reaches the stream body. The presence of weeds such nettles (urtica dioica) and
common rush (juncus effusus) are an indicator of rich soil. (Juncus efusus) (: A. E.
Schellman, 2008)
As mentioned, the stream runs in to the bog area which can be very much affected by
the pollution carried by it. (LASKOW, 2017)
The main restoration that will be carried at the site, will be an extension of the wetland.
Having the clay type of soil will be an advantage, mainly due to the high-water retention
properties a clay soil has. By creating a larger wetland area, the stream will have the
possibility to regenerate. (United States Environmental Protection Agency; Office of
Water, 2000)
The wetland will be extended with approximately 5m.
Wetlands act as a buffer zone between the pollution source, in this case the agricultural
land and the water body. Having the wetland next to a stream it impacts the ecological
and physical quality of the waterbody. Because the water is more still, the retention
time is longer, thus the microorganisms have more time to decompose the nutrients.
(Jill Kostel, n.d.)
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Another very important propriety a wetland has is to store a reader high amount of
carbon dioxide. (Carbon Sequestration 101)
In addition to the wetland extension, a buffer zone will be created along it with an
approximately 3m width, and further along the bog. The current legislation requires a
2m buffer zone for the bog, but giving the circumstances, an additional 3m will ensure
a better protection. (Miljøministeriet, By- og Landskabsstyrelsen, 2009)
Another important issue the project is focusing on, is the ochre present in the stream
and the wet area along it. Its presence is most likely to be a consequence of the drainage
that was made on the land. By changing the characteristics of the upper layer of the soil,
iron and sulphur was realised. Ochre can be very toxic for the life in the stream,
especially if the water pH level is lower than 7, as it is at station AAR00869. (Per Søby
Jensen, 2005); (p.m. Jens Brøgger) For our goal, to improve the ecosystem in the stream
as well in the wetland, to be achieved the ochre must be removed. A very simple method
to remove the ochre is to rise the water level, in order to create anoxic environment,
which will further stop the ochre realise. (Per Søby Jensen, 2005)
Other measures to be carried:
• Meandering the stream that runs above the terrain;
• Meandering the dich, to create variation and to improve the physical conditions;
• Remove the vegetation from the banks, where needed;
• Reprofiling stream’s banks;
• Block the drainage system in order to ensure water for the wetland;
• Build a small bridge above the wetland for the landowners to cross the stream
without disturbing the habitats in the water;
Fig.1 suggestion bridge building location
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Not least, due to the previous archaeological findings around the area of the stream,
precautions must be taken and if any findings, Moesgård Museum will be informed
about it immediately.
Fig. 2 cultural heritage
2.1 Phosphorus removal Aside the ochre removal another important goal, the projects pursues, by extending the
wetland is to remove the nutrients that otherwise will reach the stream and affect the
entire ecosystem. (Jill Kostel, n.d.)
The focus in this case is on phosphorus, a nutrient that is used as fertiliser on the nearby
fields. There are two input sources of P: atmospheric, which is usually in a very low
percentage, and run-off from the terrain nearby. When the P reaches the wetland area
it enters either as organic or inorganic form, and further it can be as particulate or
dissolved forms. While the dissolved inorganic P is bioavailable, the organic and
particulate forms often need to transform in to inorganic in order to become
bioavailable. (Jill Kostel, n.d.)
Once it reaches the wetland, P is uptake by plants, plankton, microorganisms, present
in the waterbody, this being associated with biotic mechanism, and it can also bond to
the soil particles, on the bottom throughout sedimentation, this being the abiotic
process. Storage capacity of P in plants is not for a very long time, the plants that have
assimilated P will eventually become detritus and the P will be realised again. One
efficient measure that can be taken, is to physically remove the organic matter and
undecomposed plant material from the bottom of the wetland in order to ensure
available storage space for new P. (Jill Kostel, n.d.)
A more long-term storage for P is the soil, due to the solid form it can take throughout
a complex mineral formation. In more acidic water, such it is at station AAR00869
(p.m. Jens Brøgger), P is fixed with the help of a more shapeless and poorly crystalline
forms of Fe and Al. (Jill Kostel, n.d.)
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The anoxic environment ensures a longer P retention, due to the low decomposition rate
of the organic matter. Minerals such as Al, Fe, Mg and Ca, present in soil can highly
influence the stability and retention level of the P and the minerals themselves are
dependent on the redox conditions that can sometimes change. As one more aspect to
be mention is the water table level of the wetland, the longer stable periods of flooding
during a year time, the safer is the P stored. (Jill Kostel, n.d.)
3. Consequences for the biological conditions in the stream, the
surrounding areas, and protected nature types
When talking about wetlands and whether they are beneficial or not is hard to find
arguments against them. The main reason we do not have them in high percentage
nowadays, is the lack of space, meaning that most of them are drained in order to ensure
more place for urban expansion, farming, or other industries. (Osmond, 1995)
A wetland can only be beneficial for a stream, acting as a filter for all the pollution that is
likely to run-off from the agricultural lands. The only disadvantage in this case is directed
towards the landowners that will need to compromise a small area of land that will no
longer be able to be used as agricultural field. (National Oceanic and Atmospheric
Administration , n.d. )
The changes the stream will be subjected will to a certain degree affect its biological
conditions. By changing it course the soil and implicit the flora and fauna within it will be
slightly disturbed, but since the stream will only be meandered where needed, reader high
population of flora and fauna remaining will have a chance to restore. Even the conditions
for salmonids are far from ideal, they are still expected to be present, in the stream closer
to station AAR00869. (Jackson, 2014)
When meandering the ditch, no much attention is required due to the high ochre content
that made quite impossible for any fauna to develop. (Per Søby Jensen, 2005)
The work that will be carried on the site might cause disturbances to a certain level, the
machinery used, and the overall engineering the project requires, is a very important aspect
that needs to be taken in to consideration. (Jackson, 2014)
When the project will be finalised, aside the current protected nature types, new protected
nature areas will be present, this will change the current ecosystem, the food chain, create
new habitats and along with this, different managing techniques, different approaches for
different requirements. (European Environment Agency (EEA), 2017)
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4. Stakeholders involvement
The landowners are overall satisfied with the conditions at the site. The physical state at
the moment is not an impediment for them when it comes to conducting their usual
activities. (p.m. landowners)
They are opened to cooperate with the authorities, as long as two requirements will be
fulfilled.
1. To receive financial support in order to work towards an improvement for the protected
area; (p.m. landowners)
• By extending the wetland and adding a buffer zone the landowners can obtain EU
found, if the management requirements are met. (International Cooperation and
Development - DG DEVCO, 2017)
They are mainly using the land in the vicinity of the stream for grazing and agriculture, and
the grassland is used for hay-making as well, therefore the second requirement is:
2. To maintain the access for tractors from one side of the stream to the other.
• The access will be still available for the landowners to cross from one side of the
stream to the other. This will be possible by building a small bridge over the
wetland.
During the hunting season, fall and winter the landowners are hunting small game such as
pheasants and larger game such as deer. As a suggestion for the project goals they will like
to see an improvement for the small game, wild ducks maybe and larger game such as red
deer. (p.m. landowners)
• Once the wetland is established game birds such as Tufted duck or Goldeneye duck
is very likely to come in to the area. (Carp, 1980)
Fig. 3 Tufted duck Fig. 4 Goldeneye duck
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5. Conclusion
If taking all aspects into consideration, overall the area around station AAR00869 and the
actual stream have a high potential for improvements. Of course, when working with a
restoration project there are more factors that need to be taken in to consideration, and not
always a middle way can be find. In this particular case, a very important saying will have the
landowners, and depending on to which extent they are willing to cooperate with the public
authorities a mutual agreement might be achieved. (Boeuf, 2016)
Environmentally speaking the project has the potential of high rate of success. Wetlands are
proven to be highly efficient when it comes to aquatic management. There are many examples
of project that are proven to be successful and they showed a reader impressive improvement
in the aquatic ecosystem as well as for other terrestrial habitats. (National Oceanic and
Atmospheric Administration , n.d. )
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References : A. E. Schellman, U. C. (2008, 10). Burning & Stinging Nettles. Retrieved from University of California
Integrated Pest Management: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74146.html
Boeuf, B. a. (2016). Studying the implementation of the Water Framework Directive in Europe: a
meta-analysis of 89 journal articles. Ecology and Society, 21.
Carbon Sequestration 101. (n.d.). Retrieved from NOAA Fisheries:
http://www.habitat.noaa.gov/coastalcarbonsequestration.html
Carp, E. (1980). Directory of Wetlands of International Importance in the Western Palearctic. In E.
Carp, Directory of Wetlands of International Importance in the Western Palearctic (p. 506).
IUCN.
European Environment Agency (EEA). (2017, December 01). An introduction to Europe’s Protected
Areas. Retrieved from European Environment Agency (EEA):
https://www.eea.europa.eu/themes/biodiversity/europe-protected-areas/europe-
protected-areas-1#parent-fieldname-title
International Cooperation and Development - DG DEVCO. (2017, 12 08). EU development
cooperation support to protected areas. Retrieved from European Commission:
https://ec.europa.eu/europeaid/sectors/environment/biodiversity-and-ecosystem-
services/protected-areas_en
Jackson, A. (2014, August 02). Flood Management. Retrieved from Geography AS Notes:
https://geographyas.info/rivers/flood-management/
Jill Kostel, P. s. (n.d.). Nutrient removal. Retrieved from The Wetlands Initiative:
http://www.wetlands-initiative.org/nutrient-removal/
Juncus efusus. (n.d.). Retrieved from Missouri Botanical Garden:
http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode
=c262
LASKOW, S. (2017, August 02). Save the Bogs, for Peat’s Sake. Retrieved from Atlas Obscura:
https://www.atlasobscura.com/articles/save-the-peatlands-conservation-bogs
Meisner, M. A. (2014). Tilladelse til restaurering af Bjørnholt Bæk ved Toustrup Stationsby. Silkeborg
Kommune, Silkeborg . Retrieved from
http://silkeborgkommune.dk/~/media/Borger/Miljoe%20energi%20og%20affald/Annonceri
nger/Team%20Vand/Realisering%20vandhandleplan/Tilladelse%20Bj%C3%B8rnholt%20B%C
3%A6k%20v%20Toustrup.pdf
Miljøministeriet, By- og Landskabsstyrelsen. (2009, June 24). Vejledning om naturbeskyttelseslovens
§ 3 beskyttede naturtyper. doi:978-87-7091-036-1
National Oceanic and Atmospheric Administration . (n.d. ). an introduction and user's guide to
Wetland Restoration, Creation and Enhancement . U.S Department of Commerce, National
Oceanic and Atmospheric Administration . National Oceanic and Atmospheric
Administration, National Marine Fisheries Service,Habitat Protection Division,Habitat
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Restoration Division Environmental Protection Agency. Retrieved from
http://www.habitat.noaa.gov/pdf/pub_wetlands_restore_guide.pdf
Nielsen, B. (n.d.). Sporene i Lyngbygaard Ådal. Retrieved from Spor i Landskabet:
http://www.spor.dk/sporene/midtjylland/lyngbygaard
Osmond, D. D. (1995). Major Causes of Wetland Loss and Degradation( Water, Soil and Hydro-
Environmental Decision Support System). Retrieved from NCSU Water Quality Group:
http://www.water.ncsu.edu/watershedss/info/wetlands/wetloss.html
Per Søby Jensen, L. A. (2005). Ochre.A watercourse problem we can deal with. (B. L. Madsen, Ed., &
D. I. Barry, Trans.) Denmark: Ringkjøbing County, Ribe County, SønderjyllandCounty, Herning
Municipality, Holstebro Municipality. Retrieved from
https://eaaa.instructure.com/courses/3091/files/folder/Literature?preview=108812
United States Environmental Protection Agency; Office of Water. (2000). Principles of Wetland
Restoration. Retrieved from USEPA: https://www.epa.gov/wetlands/principles-wetland-
restoration
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