Theoretical and Practical Aspects of Rivers Revitalization

D Journal of Earth Science and Engineering 2 (2012) 145-154 DAVID PUBLISHING Theoretical and Practical Aspects of Rivers Revitalization Martin Ner...
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Journal of Earth Science and Engineering 2 (2012) 145-154

DAVID

PUBLISHING

Theoretical and Practical Aspects of Rivers Revitalization Martin Neruda1, Irina Tichonova2 and Dmitry Kramer2 1. Department of Nature Sciences, Faculty of Environment, University of J. E. Purkyne, Usti nad Labem City 40096, Czech Republic 2. Department of Industrial Ecology, Faculty of Biotechnology and Industrial Ecology, Mendeleev University of Chemical Technology of Russia, Moscow 125047, Russian Received: October 12, 2011 / Accepted: November 28, 2011 / Published: March 20, 2012. Abstract: Rivers always were a very important element of site’s landscape and ecosystem. They served as sources of drinking water and food products and even as a natural protection from enemies. River management conception of 19th and most of 20th century almost eliminated a lot of rivers from city landscape. In this review, the best examples of rivers revitalization such as revitalization of Panke River in Berlin, revitalization of Cerny Potok stream in Czech Republic and others are studied. Key words: Rivers revitalization, banks strengthening, meander, habitats improvement, community involvement.

1. Introduction Throughout many centuries people founded cities along riverbanks. Almost every city in Europe has its own river net. Rivers in cities served as a source of drinking water, fish source, helped to establish trade ways through navigation and served even as a natural protection from possible enemy assaults. River management conception of 19th and most of 20th century, that assumed channelization and covering of river due to increase flood protection, almost eliminated a lot of rivers (especially small ones) from cities landscape and greatly affected river conditions which led to significant changes in ecological systems of the city. At the end of 20th century people finally realized that city rivers are not only the possible source of flood threat but also can serve as a recreational areas, improve the aesthetic picture of the city and become a natural island in urban territory. Several river revitalization projects began to implement all over the

Corresponding author: Martin Neruda, Ph.D., main research field: rivers restoration. E-mail: [email protected].

Europe such as the River Restoration Center in Great Britain and Reuris project in Central Europe. These projects also involved some rivers outside cities, which were affected by agricultural and milling uses. The main goal of these projects is to restore natural conditions of riverbed and riverbanks along with establishing possible benefits for local community, which is often involved in revitalization projects.

2. Revitalization Projects: Best Examples 2.1 Project for Revitalization of River Panke in Berlin River Panke flows in the east of Germany. It’s a tributary of River Spree. Its length is 27 km with 18 of them in the city of Berlin (Fig. 1). Basin area is 201 km2 with 250,000 of habitats living in the area [1]. At the moment the current state of river is estimated as strongly or completely disturbed. Revitalization project includes several stages:  Conceptual planning (2008-2009);  Construction planning (2010-2013);  Authorization process (2012-2013);  Construction period (2014-2017). Project also includes intensive cooperation with

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Fig. 1 Map of Panke River [1].

local community and local authorities. The interdisciplinary, integral planning approach was used in this project that should lead to achieving better results than originally expected. Due to diversity of river flowing area and its current usage the complete restoration of it to nature standards is impossible. Appropriate section of the river will be developed as ecological focus area with high ecological quality status. These will be connected by routes with regular distance of less ecological potential [2]. What is planned to do:  The 14 mostly unconquerable barriers (weirs and dams) will be substituted by rough stone ramps or extension of the river course;  In the appropriate places, trees and bushes will be planted so it would stabilize the river course and prevent erosion. Also it would implement the

shadowing of river and therefore prevent an excessive temperature rise in the summer so the content of oxygen would remain on high level;  There will be several shallow zones for developing sandbanks for mussels, reed belts for dragonflies, rest areas for juvenile fishes etc.. In possible places widening of the river will be realized. The main goal of the project is to restore natural riverbed with sandbanks and small islands for vegetation, stone rocks and dead trees for developing diversity of river course (Figs. 2 and 3). These elements must be put into the river properly and safely for improvement of flood protection. The regular maintenance is also required. 2.2 Revitalization of River Isar in Munich (Isar Plan) River Isar flows in Austria and south-east part of Germany in Bavaria (Fig. 4). Its origin is in Alps

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Fig. 2 Panke river vision [2].

Fig. 3 Panke river vision—one of the studied part [2].

Mountains. River Isar is the second largest tributary to River Danube. Its length is 295 km and basin area is about 9,000 km2. Mean water flow is 175 m3·s-1. The name “Isar” comes from two celtic words: “ys”-fast and “ura”-river, water. Isar has a lot of tributaries with the largest being Amper and Loisach.

From ancient times river was used as a trade way. From 1920s river also was used as an energy source. Twenty-eight hydropower stations were built on it which led to canalization of huge part of riverbed and only small part of the river stayed in original riverbed for prevention of area drought [1].

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south. River Morava forms natural borders between Czech Republic and Slovakia and then between Austria and Slovakia [1]. River flows through such big cities as Olomouc and Bratislava and flows into Danube in Bratislava Děvín. Main tributary of Morava is River Dyje. The implementation of the project for revitalization of 700 meter-long part of the River Morava in Olomouc should start in 2011. The main goals of the project are improvement of flood protection, increasing of river segmentation, vegetation planting, providing Fig. 4 Map of Isar River [1].

The implementation of Isar Plan began in 1995. Its main goal is returning the natural essence to the river. Aims of the project were flood protection, restoration of natural landscape and improvement of recreational potential of the river [3]. Construction works started in February of 2000 and included five stages with last of them ended in 2010. The total costs for implementing the “Isar-Plan” amounted approximately 35 million euros. The following operations were done:  Rock bank strengthening was removed in several parts of riverbed, river was widened and banks were filled with gravel;  Concrete plate were substituted with loose stone ramps, upper plain part of the river was flattened so a new access to the river was made;  Water quality was brought to drinking level with the help of several water treatment stations that also use UV-disinfection of water. Thus, the river became a popular place for leisure time for Munich citizens. 2.3 Project for Revitalization of River Morava in Olomouc River Morava is a tributary to River Danube. Its length is 354 km, basin area is 26,658 km2, and mean water discharge is 120 m3·s-1. River’s origin is located in the north-west part of Moravia on the Králický Sněžník Mountain near border between Czech Republic and Poland. General direction of river flow is

access to the river in alluvial areas. Aims of the project include: 

creation and improvement of habitats for fish and

crustaceans, increasing biodiversity of river habitants; 

improvement of flood protection;



arrangement of recreational area in alluvial zone

of the river with cycle and pedestrian paths, swimming areas and children playgrounds; 

arrangement of green zone and park in the area of

river flow. During the implementation of the project, the following activities will be made: bifurcation of the actual riverbed and modelling a low central holm; presence of the convex gravel deposits; alternating pond and ford sections; using river wood for embankment; dividing a right side bank ledge into two elevation steps; plant a bank vegetation; construction of a new path, and the dam crest will be strengthened and used as a cycle path (Fig. 5). Total costs of the project are estimated in about 350 millions of Czech crones with 30 millions of them to be spent on river restoration [4]. 2.4 Revitalization of Cerny Potok Stream Cerny Potok stream has its origin in the nature reservation “Cerna louka”, which is situated in Ore Mountains near village Adolfov, approximately 10 km from Teplice town. Stream has two right and two left tributaries. Its total length is about 5 km including part of the stream that flows in Germany.

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Fig. 5 River Morava in Olomouc before (left picture) and after (right picture) the implementation of its revitalization project [4].

The name of the stream means “Black stream”. According to one version it was named so because of high content of humic acids, which originate from natural clefts and peat soil situated in reservation. In 1960s and 1980s stream was ameliorated, river channel was straightened and banks were strengthened with stones. Riverbed was deepened and fortified with nine stones and concrete weirs. It made increasing of flow velocity and groundwater level lowered. The drainage system that was also made that time consists of several plastic tubes remains untouched and slowly collapse. In the years 2001-2003, it has been revitalized 2 right hand tributaries and 2 left hand tributaries in the scoped area. It has made more than 25 pools and vegetation was planted. But most of trees and bushes didn’t grow because of lack of maintanance and tough climate of the site. In August 2009 new revitalization project started. Revitalization arrangements were split to two parts: technical and biological. Technical part contained stream revitalization. Biological part contained trees and bushes planting [5]. Total cost of the project amounted 6,533,010 Czech

crones. 2.4.1 Technical Arrangements A new shallow channel was made which has the shape of natural rivers. New channel has good meanders and has several pools and riffles in its bed, which help to stabilize it. Fortification of river banks has not been done. Because of geographical conditions the new channel in several parts crosses the old channel that is now used as a network of few bid pools. There are small dams in the old channel. They are made just from soil dredged from new channel and wood pilots. So they form a pool cascade (Fig. 6). 2.4.2 Biological Arrangements In August 2010, planting of trees and bushes of various types was implemented. Trees were planted with the minimum distance of 2 meters, bushes have the minimum interval of 1 meter. 2.5 Project for Revitalization of River Ohře in Karlovy Vary River Ohře (Eger) is a left tributary to River Labe and flows through Czech Republic and Germany. Its total length is 316 km (65 in Germany and 251 in Czech Republic). Its total basin area is 6,255 km2, mean water

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Fig. 6 Stream’s new channel (left picture) and pool cascade in the old channel (right picture). Source: own photos.

discharge is 38 m3·s-1. River Ohře is the third biggest river in Czech Republic. Its origin is located near the bottom of Schneeberg Mountain in Bavaria. River flows through such cities as Cheb, Karlovy Vary, Klášterec nad Ohří, Kadaň, Žatec, Louny, Terezín and flows into Labe in Litoměřice. River has several major tributaries: Odrava (right), Svatava (left), Rolava (left), Teplá (right) and others [1]. The river’s name (Eger) takes its origin from celtic word “Agara” which means “salmon river”. Water of river Ohře is used for irrigation, for hydropower purposes and for flooding Most Lake also. In recent years in the region of Karlovy Vary River Ohře wasn’t used for agricultural needs and its valley was used as a scrap-heap. The implementation of the revitalization project of the river started in 2010 and should be finished in 2011. The main goals of the project are restoration and development of natural potential of river’s valley and restoration of biocenter in Karlovy Vary (Fig. 7). Aims of the project include:  increasing biodiversity in the river’s valley;  improvement of flood protection;  arrangement of cycle and pedestrian paths in the river’s valley. During the implementation of the project the riverbed will be meandered, scrap-heap will be removed, trees and other vegetation will be planted, children playgrounds and paths will be arranged. Total costs of the project will amount 25,900,000 Czech crones and also it is planned to assign 10,000 Czech crones every year for maintenance of river’s natural

condition [4]. 2.6 Revitalization of River Hauphton-la-Skerne and Darlington

Skerne

in

River Skerne is a tributary to river Tees and it flows in County Durham, England. Its total length is 40 km, source is situated in hills that are rich in magnesium limestone between cities of Trimdon and Trimdon Grange and it flows to river Tees in Hurworth Place. River Skerne flows through several settlements like Fishburn, Bradbury, Hauphton-la-Skerne and Darlington [1]. Hauphton-la-Skerne and Darlington river flows in town park area are surrounded by housing estate and industrial buildings. Over the past 200 years it has undergone straightening and deepening for flood control and drainage. Housing development, gas and sewer pipes and electricity cables severely limited restoration possibilities for river. The project implemetation was carried out from 1995 to 1998. Aims of the project include:  Restoration of 2 km of the river in terms of physical features, flood management, habitat diversity, water quality, landscape and access to the community;  Application of innovative restoration techniques and best management practice within the urban territory;  Development of complex monitoring system for further knowledge and understanding of revitalization process and practical demonstration of the results to local community and wider audience.

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Fig. 7 Revitalization project of River Ohře in Karlovy Vary [4].

Fig. 8 River Skerne before (left picture) and after (right picture) implementation of the revitalization project [6].

During the project implementation riverbed was meandered where it was possible, new channel was created and the old one was filled. River banks were reprofiled to reach more natural conditions. Flood plain land was lowered to store water in times of high flows. Sewer system and outfall system was improved and shallow wetland on lowered floodplain were created. New habitats were created, along with several new paths along the river banks, new bridges and areas of public access to the river (Fig. 8). The site of river’s flow was vegetated with the help of local community [7].

2.7 Revitalization of Hermitage Stream in Havant Hermitage Stream flows in housing estate called “Leigh Park” in the small park of small town called Havant that is situated near city of Portsmuth in Hampshire County. In 1970s stream was locked in concrete channel to improve flood protection. The implementation of the revitalization project was carried out in the part of stream of 1.5 km long from 1995 (beginning of preparation stage) to 1999 (beginning and ending of construction works in the stream). Local community was actively involved in the project partly

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due to educational purposes. A lot of local citizens took part in the project as volunteers. Aims of the project include:  ensure that the existing level of flood defense was maintained;  restore/improve the stream to a more natural river environment;  create a green and pleasant place for all to enjoy for recreation, amenity, education and wildlife. During the implementation of the project the hydraulic model of channel was created to develop the system of flood protection. Concrete plates were removed from stream banks and were substituted with gravel to make river more accessible to local community. Trees and plants were planted on the stream banks and two pedestrian-cycle paths were arranged to provide quick access to the center of the city (Fig. 9). Also a playground for children was arranged [8]. 2.8 Revitalization of River Cheonggyecheon in Seoul River Cheonggyecheon is a tributary of the Ham River, the main river flowing through Seoul, the capital of South Korea. Its length is 8.4 km [1]. River Cheonggyecheon flows through historical center of the city and was a source of drinking water and washing water. The original name of the river was Gaecheoni, which means “open stream” in Korean; the current name Cheonggyecheon literally means “stream”. Flooding of the Cheonggyecheon has always been a

problem for Seoul. Due to improve flood protection river was regularly dredged. From the beginning of 20th century riverbank population significantly increased, with the river acting as a sewer and there were serious problems with floods. The Japanese colonial government drew up plans to cover the river and works were carried out from 1937 to 1961. In 1971 a construction of an expressway over the river was finished and the river was essentially forgotten. In the late 1990s it was decided to remove the expressway and concrete covering and establish the Cheonggyecheon as a riverside recreation area. This was part of overall Seoul urban revitalization project. The implementation of the revitalization project was carried out in 2005. The main goal of the project was not to restore the original image of the river but to create an open area in a landscape dominated by skyscrapers and to create a wildlife corridor along with park and exhibition areas. In addition to removing the expressway and concrete cover, the design incorporated new roads, a sewerage and storm water pipe network and had to allow for flooding. The water for the river is pumped from nearby Ham River via a water treatment plant. This supplies enough water to maintain an average stream depth of 40 cm. The riverbed contains many artificial weirs and fountains, ensuring the water oxygen content stay high. In the further downstream, there is good enough water quality

Fig. 9 Hermitage Stream before (left picture) and after (right picture) the implementation of revitalization project [8].

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Fig. 10 River Cheonggyecheon before (left picture) and after (right picture) the implementation of the revitalization project [6].

for invertebrates and fish to establish permanent populations. A survey on the ecology of the stream conducted in 2007 found 30 species of birds and 13 species of fish inhabiting the stream environment. In addition to aesthetic benefit the removal of the expressway has led to a decrease in air pollution. River became a popular place for walks and recreation; you can see a lot of sculptures along the bank and in the evening riverbed are lighted by multi-colored neon lights (Fig. 10). Total costs of the project amounted 360 millions of dollars, also a lot of money is spent every year for maintaining the site. This project is a very good example of transition from modernist vision (channelized and covered river) to a post-modern concept where the aesthetic function as a civic park is as important as the biophysical function of the river itself [9].

3. Conclusion So, as it can ben seen from these examples, the most common techniques for river revitalization is turning its valley into a city park area that is easily accessible for local citizens and is beneficial through ecological, economical and social points of view. Such multidisciplinary approach is a key to success for such projects, especially in terms of getting money for their implementation from authorities. Another important thing is to establish a good relationship with local community (even involve it into project’s implementation as volunteers) as it will make it much easier to succeed.

The other important thing is getting money for project implementation. Panke River revitalization project is financed by the city of Berlin and German state. Financing of “Isar Plan” is devided by the city of Munich (45%) and Free State of Bavaria (55%) [3]. Revitalization projects in Czech Republic are (and were) financed by European Union Operational Program “Envorinment”, Reuris Project is financed by cities’ investors [4, 5]. Revitalization of River Skerne and Hermitage Stream was financed by River Restoration Center that in turn gets money from UK government [7, 8]. Cheonggyecheon River revitalization project was part of overall Seoul urban revitalization project and was financed by authorities of Seoul [9]. Another possibility for financing of river restoration’s project is Lottery fund, as Connswater in Belfast City in Northern Ireland. So the main money sources are federal and local budgets, but private investors can also participate in such projects.

Acknowledgments The authors gratefully acknowledge funding support for this research provided by the grant “Green Network Ore Mountains, Cíl 3/Ziel 3, No. 100011436”.

References [1] [2] [3]

Wikipedia—The free encyclopedia website, http://www.wikipedia.org. The Right Time Was Yesterday, Senate Department and the Environment, Berlin Town Hall, Berlin, 2010. Innovative Projects in the Urban Development Area, Werkstatt-Stadt Home Page,

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Theoretical and Practical Aspects of Rivers Revitalization http://www.werkstatt-stadt.de. P. Kolář, L. Krejčí, M. Krejčí, N. Perečková, Reuris Revitalization of Urban River Spaces Examples of Good Practice-Study, Union for Morava River, Brno, 2009, pp. 39-41, 46-52, 85-86, 93-94. M. Neruda, E. Molnár, P.M. Crory, U. Voigt, M. Beyhan, A. Dogan, et al., Environmental Water Management: A Project Report, Faculty of Environment UJEP Ústí nad Labem City, 2010. Yandex Search System Home Page, http://www.yandex.ru.

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River Skerne Brochure, The River Restoration Center Web site, http://www.therrc.co.uk/pdf/manual/MAN_2_1C.pdf (accessed Sept. 15, 2011). The newsletter of the River Restoration Centre, Silsoe campus, Silsoe, Beds [Online], (6) (2000) 4-5, http://www.therrc.co.uk/newsletters/issue6.pdf. (accessed Sept. 15, 2011) (newsletter) T. Davie, Fundamentals of Hydrology-Routledge Fundamentals of Physical Geography, 2nd ed., Routledge Taylor&Francis Group, New York, 2008, pp. 171-172.

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