Søren Ladegaard Andersen, Denmark.
ABSTRACT
Description and analysis of a project dealing with the re-establishment of nature in the valley of the Varde Å and the meadows along the Ho Bugt (bay).
The project deals with an area of 3.500 hectares of low-lying land. The intention is to raise the groundwater level in this area, to ensure better breeding and resting places for bird and animal life. One of the additional objects of the project is to reduce the nutrients leaching into the Waddensea.
The project has started with a pilot study covering among other things terrainmodel, geology, agriculture, economy and legislation. Subsequently a comprehensive land consolidation scheme has been started.
One of the main characteristics of the project is, that is based on voluntariness. Paradoxically may this voluntariness be one of the main reason why the project has not come further than a pilot project comprising 60 hectares of land.
ZUSAMMENFASSUNG
Beshreibung und analyse von dem Renaturerungsprojekt in Varde Auental und in den Auen entlang der Bucht von Ho.
Das Projekt umfasst eine Fläche von 3.500 Hektar niedrigliegenden Gebieten, wo beabsichtigt wird, das Grundwasserspiegel zu senken, um dem Vogel- und Tierleben bessere Brut- und Rastplätze zu sichern. Gleichzeitig zielt das Projekt darauf, das Stickstoffauswaschen ins Wattenmeer zu vermindern.
Das Projekt wurde mit einem grossen Voruntersuchungsprojekt eingeleitet, u.a. umfassend Terrainmodell, Geologie, Landwirtschaft, Wirtschaft und Gesetzgebung, nachfolgend erfolgte eine umfassende Umverteilung des Bodens im Gebiet.
Das Projekt ist charakteristisch dadurch, dass es sich auf freiwillige Teilnahme basiert. Die Freiwilligkeit ist paradoxerweise einer der wesentlichsten Gründe, weshalb das Projekt nicht weitergekommen ist, als die im Pilotprojekt umfassten 60 Hektar.
RESUME
Description et analyse du projet de rénaturalisation dans la vallée de la rivière de Varde Å et le long de l’anse de Ho.
Le projet a compris une superficie de 3.500 hectares d’espaces bas, où on a l’intention de baisser le niveau de l’eau souterraine, afin d’améliorer les étapes et retraites pour la mise bas des oiseaux et des animaux. En même temps le projet a l’intention de réduire l’érosion d’azote dans le mer.
Le projet a été ouvert par un projet préliminaire comprenant un modèle du terrain, de la géologie, de l’agriculture, de l’économie et un modèle législatif. Ensuite une répartition assez impotante des terrains a été accomplie.
Le projet est caractérisé par le fait qu’il se base sur une participation de bon gré. Le principe de bon gré est paradoxalement la raison pour laquelle le projet n’a pas jusqu’à aujourd’hui compris plus que les 60 hectares du projet préliminaire.
BACKGROUND
The Valley of the Varde Å and the meadows around Ho Bugt are subjugated series of international declarations, which have the purpose to secure and protect the nature.
The area is by restrictions under the EC Bird Protection- Ramsar and EC Habitat conventions. It is also included in an international cooperation scheme between Holland, Germany and Denmark which has preservation and improvement of the natural ecosystems in the Waddensea on its agenda.
Danmark has, according these conventions, the obligation to put an effort in the conservation of the natural environment of Varde Å valley and the meadows around Ho Bugt.
The valley of the Varde Å and the meadows around Ho Bugt are a significant and important nature area. The significance of the Varde Å valley lies in the fact, that it is the last estuaries that is not regulated by dikes or sluices. It has had a very rich animal and plant live. The area is today intensively cultivated, mainly for the, EC supported, production of dried fodder pellets from grass. This intensive type of production conflicts with the wish and obligation to preserve the natural ecosystems in the area.
This situation has been the background for the National Forest and Nature agency to start a preliminary investigation concerning the possibility to execute a nature restoration project in the area. The object of such a nature restoration project is to reduce the impact of agricultural use on the area, to (re)create the rich animal and plant live and to reduce the discharge of nutrients in the area.
It is envisaged that this can be accomplished by raising the groundwater level in the area. It is presupposed that the required changes in the agricultural production process can be settled with the areas users on the basis of compensation payments.
The preliminary investigations, as a preparatory stage of an agricultural and environmental project, started in the beginning of 1996.
The region of interest covers an area of approximately 3500 ha. The area is enclosed by a net of major roads and covers all protected nature reserves (salt water marshes, fresh meadows, fens, bogs and moors) in accordance with §3 of the Act on the Protection of Nature in the area. The area covered by the planned nature restoration project is somewhat smaller, approximately 2800 ha.
The project is prepared in cooperation with the National Forest and Nature agency, the Ministry of Agriculture, the private landowners committee, Varde agricultural Association, the Association of family farmers, and the county of Ribe.
The purpose of the preliminary investigating is to obtain a clear insight in the conditions for and consequences of the planned project in the Varde Å valley. The investigations cover four major areas:
LANDINSPEKTØRGÅRDEN VARDE-GRINDSTED-TARM
Landinspektørgården has participated in many of the preliminary investigations related to the project in the meadows around Ho Bugt and the Varde Å valley.
In order to introduce some background information about the writer, the role of the Landinspektørgården in this nature restoration program will be described.
Landinspektørgården is one of the larger Danish landsurveying companies with a total staff of 30 persons. The firm is privately owned and has offices in 3 cities; Varde, Grindsted and Tarm. The firm is characterized by the execution of a widespread combination of traditional and technical/legal assignments such as: Terrain- datamodelling, legal advice and consulting assignments for private and governmental clients. There is a tendency towards assignments outside the traditional area covered by landsurveying firms. They comprise now around 50% of the total assignments of the firm.
Landinspektørgårdens history can be traced back over around 135 year. It has always been the firms policy that it is essential to be up-to-date with the latest trade and technological developments. It has proven to be of vital importance to be able to utilize the latest technology in the increasing competition.
The firm has, confirm this policy , in 1994 as one of the first private Danish landsurveying companies, adopted the GPS technique and invested in the necessary equipment. The equipment comprises of two-frequent receivers which support the Real Time Kinematic measurement principle. GPS techniques have had a large impact on the efficiency of measurement. Especially the collection of data in large open areas has benefitted from this technique. The firms knowledge and experience with the technology has secured the participation in many other nature restoration projects.
The Varde Å valley and the meadows around Ho Bugt are located inside Varde, Blåvandshuk and Esbjerg municipalities, which form a part of the traditional service area of Landinspektørgården . In order to service an assignment of this magnitude is it necessary to have the required technology at your disposal. In addition to this, has the firms experience and knowledge relating to nature restoration projects contributed to its participation in this specific project.
The firm has in relation to the preliminary investigations been involved in two major areas of investigation: Geology, Terrain, Hydrology and Technical systems and Law and Planning. The firm has produced a digital terrain model covering the total area of interest and has been involved in the planning of a land consolidation scheme. In addition to this has the firm been represented in the project steering committee .
PRELIMINARY INVESTIGATIONS
The preliminary investigations were executed during 1996 and consisted of a number of technical and agricultural/economical surveys of the Varde Å valley and the meadows around Ho Bugt. The main purpose of these investigations was to create background and basis for the implementation of a agricultural and environmental project.
The required tasks were defined in detail by a steering committee. The steering committee was kept up-to-date during the execution of the various tasks, so any required change in the procedures could be implemented on short notice. Landinspektørgården has been involved, via the steering committee, in the planning and execution of the surveying of a digital terrain model for the area and in the planning of a land consolidation scheme. The investigations should result in a description of the technical, economical and biological consequences of raising the groundwater level and the effects of introducing of low-impact cultivation.
The major objectives of the project are:
Fig.: Chart 1:100000 covering the project area.
The preliminary investigations cover, as mentioned before, four major areas: Nature - Culture - Environment, Agriculture - Economy, Geology - Terrain - Hydrology - Technical systems , Law and planning.
In the following sections will the main results of the different investigations be discussed.
NATURE - CULTURE - ENVIRONMENT
Nature:
The Varde Å valley and the meadows around Ho Bugt have been an important area for different wading birds. Many species disappeared or diminished during the 1970's. This was mainly caused by an increasingly effective drainage and subsequent intensivated use of the area and the increased use of fertilizer in the area. The frequent harvest of grass and the dehydration of the area destroyed the birds possibilities to find food and quiet nesting sites.
Biologists predict, that there is a good possibility that, many species of birds will return to the area in case the groundwater level will be raised and a low impact type of cultivation is introduced. If a nature restoration project covering the areas along Varde Å and Ho Bugt would be implemented, could the area on the basis of its size alone, become a favorite region for birds.
The project will also have a positive impact on the insect-, animal- and plant live in the region, which due to the course of nature will lead to an increased food resource for birds in the area.
Photo 1.
Culture:
It is not expected that a raised groundwater level will have any specific impact on the cultural and historical values of the area. Almost all known prehistoric settlements and sites are located on high ground and are therefore placed outside the project area.
There will be an impact on outdoor activities, such as hunting, where a stricter regulation will have to secure the peace in the area.
Environment:
The Varde Å has a total catchment area of around 1090 km² with 33 fish farms and 16 waste water treating plants discharging in it. The river also receives water from the cultivated and fertilized areas in the catchment area, these areas cover around 65% of the total catchment area. Introducing low impact cultivation in the Varde Å valley and the meadows around Ho Bugt will reduce the amount of nutrients being washed into Ho Bugt and the Waddensea. These areas have in the past, been hit by algae bloom and oxygen level reduction.
It is foreseen, that the capacity of meadows situated downstream in a catchment area to remove or immobilize nutrients, especially nitrogen, will decrease the amount of nutrients washed into Ho Bugt and the Waddensea in a substantial way.
AGRICULTURE - ECONOMY
Agriculture:
The areas around Varde Å and Ho Bugt have mainly been used to grow grass. This has traditionally been utilized for grazing, hay production and as source for the industrial production of dried fodder pellets. Only a very limited area is cultivated with corn and oilseed rape.
Area usage in 1996 is outlined below:
The project covers a total area of 2800 ha. 1700 ha is used as grassland. 725 ha is used for the production of dried fodder pellets. Silage production covers 50 ha . The remaining 325 ha is not used.
Raising the groundwater level will result in an extensivation of the cultivation in the valley. Large areas can in the future only be used for low impact hay production and grazing. The raised groundwater level will increase the uncertainty in production planning in the lower areas. Some areas will become completely unuseable for agricultural activities. They will transform to reed lands and scrubby areas. Some areas will have to be mowed in order to keep them cleared.
In those cases where a raised groundwater level is to be combined with a reduced use of fertilizer, will the resulting drop in the protein level of the grass, result in a loss of economic value in relation to the production of dried fodder pellets
Economy:
It is expected ,that the introduction of low impact cultivation and a raised groundwater level will result in a drop in earnings. Calculations have been made that seek to estimates the expected loss of income. They should result in a basis for the future evaluation of the actual economical consequences of the individual farmers. This should result in a compensation scheme, that is easily evaluated by the individual farmer and in a system, that is based on the production as it is today.
Ownership situation and land consolidation:
Around 2100 ha inside the project area is privately owned. An additional 200 ha is owned by the authorities. The privately owned area is divided in 378 properties. On the smaller properties account the meadow area for around 50% of the total area. This percentage lies around 20% for the larger properties.
The situation in the Varde Å valley is characterized by a large number of small properties. This will make the anticipated land consolidation scheme to an important instrument in the project.
An analysis of the wishes of the landowners and the existing spread of the properties in the area indicates a considerable requirement for such a consolidation scheme. The scheme shall secure the formation of large coherent areas. These areas, preferably with an independent water control situation (drain system) , are of the greatest importance for the successfullness of the project.
In relation to this attempts the Ministry of Agriculture to buy suitable properties in the area. This can be properties inside the valley but also in the surrounding region. These properties can be used as compensation land in the land consolidation scheme. The land consolidation scheme is managed by Landinspektørgården.
Three land consolidation schemes were started after completion of the preliminary investigations: Varde Å valley South, Varde Å valley North and one in the Ho Bugt area. The land consolidation schemes are instigated with a close connection to the nature restoration plan. They aim to establish coherent areas with similar interests with regards to cultivation type and water control. It is besides this, the intention of the schemes to improve on the spread of parcels for the individual properties.
GEOLOGY - TERRAIN - HYDROLOGY - TECHNICAL SYSTEMS
Geology:
As part of the preliminary investigation, profiles to a depth of 450 - 800 m were taken in order to acquire detailed knowledge of the geology in the area. These were supported by numerous shallow profiles (4 - 7 m).
A model of the formation of the valley was created based on the information acquired in this way. The outcome shows, that character and shape of the area are the result of different formation periods. It is expected, that in the future there will be a further rising of the areas close to Ho Bugt while the rest of the valley area will remain as it is.
Terrain:
The project area was for survey purposes defined to include all areas below 5 m DNN (Danish Normal Null). This results in an area size of around 3500 ha. The actual restoration project covers a much smaller area. The survey area was selected in this way to ensure a reasonable safety margin and to prevent boundary problems in the following model calculations.
The actual measurements were taken with the use of GPS Real Time Kinematic equipment, mounted on small four-wheel motorcycles. This technique assures a fast and reliable sampling of position data (X, Y and Z) in the terrain. A totalstation was used in those places were the motorcycles could not be used. The terrainmodel is build from data points sampled at an interval of approximately 25 x 25 m. All ditches are surveyed at the nodes and all technical installations, roads, etc. are measured.
A total of 90.000 points were sampled to be included in the model. A standard digital chart product, called TOP10DK (A product of the Danish National Survey and Cadastre), was used to supply the background scenery.
The model shows, that the terrain in the western part of the Varde Å valley (and closest to the sea) has an average height between 1 - 2 m DNN. The terrain in this area has an elevation which is typically above those of the areas more to the east. This is caused by an increase in marine deposits when approaching the sea.
The terrain around the Ho Bugt slopes very smoothly up and has a very similar character in the total area. The elevation increases with the distance from the shore. The average height around the shore line is 1.25 m. DNN.
Photo 2.
Hydrology:
The previously discussed terrain model has been one of the inputs for the construction of a computer model describing the hydrological situation in the area.
The model describes the existing hydrological situation but can also describe the results of the various envisioned changes in the drainage situation.
The model includes besides the terrain model, data concerning rainfall, evaporation, ground water level and flow, water flow characteristics of streams and ditches and additional data from the preliminary investigations.
During summertime groundwater can be found at a average level of 60 cm below terrain. In wintertime this level is raised approximately 40 cm. There is generally no open water on the meadows apart from occasional flooding during the autumn and with extreme storm surges.
The hydrological model shows for different scenario what would happen if all ditches were removed for the area. This will create an environment were open water will be the common situation rather than an exception. Many areas with open water will be created, especially during spring. It is predicted, that there will be open water areas and humid meadows even in the middle of summer.
This can in practice be realized by filling up all the ditches or, more practical, by blocking them with boards. The last system also allows a prompt reaction on erroneous closures or and allows the possibility to adapt in favor of any changes desired.
The model shows with some restrictions, what may happen in the valley if the ground water level is raised. In practice it is possible to plan and predict the results of different ground water levels in smaller subregions.
In this situation it is assumed, that each of these individual areas regulates their own water disposal.
Photo 3.
Technical installations:
It is not expected, that a raise in ground water level will have much influence on the very few buildings and roads in the area. However, some problems relating to the disposal of waste water from isolated buildings are anticipated. These should be solved as part of distinct projects for the various parts of the Varde Å valley and the meadows around Ho Bugt.
LEGAL SITUATION AND PLANNING
The biological and environmental values of the area in general conform to the principal planning for the region.
The regulations of the following international treaties apply to the area: the EC Bird Directive, the Ramsar convention, the EC Habitat Directive and the international Waddensea cooperation scheme.
The Varde Å is the only river in the Waddensea area with a non regulated estuary. This unique quality places an obligation on Denmark to seek the preservation and restoration of this special area.
The interventions required for execution of the planned nature restoration project are regulated by the following national laws and may require dispensation from their regulations: the Act on the Preservation of Nature, the Water Way Act, the Planning Act and the Act on Agricultural Properties.
Finally the area is covered under the Regional plan of the county of Ribe. The planned project shall be in accordance with the Regional plan. The valley of Varde Å and the meadows around Ho Bugt are a high priority lowland area, where nature should be preserved and (re)created.
DISCUSSION
During the last centuries there has been a extensive reduction of wetlands in Denmark. This was caused by widespread drainage and land reclamation schemes stemming from the wish for more and more areas suitable for agricultural production.
In the last years there has, supported by a string of (inter)national regulation, been a tendency to (re)create wetlands, deregulate streams and waterways and introduce low impact cultivation in those areas. Numerous projects have been started which have the promotion of nature and environment, the improvement of bird and animal live and the diminishing of nutrient leaching as their objectives.
The nature restoration project in the valley of the Varde Å and the meadows around Ho Bugt is such a project. The project is not completed at this stage, so no results can be evaluated yet.
The preliminary investigations that have been undertaken prior to the project show how and with what consequences such a project could be completed.
The conclusions of the preliminary investigations back the implementation of a nature restoration project.
The nature- and environmental investigations support the possibility to create a important breeding and resting area for birds. They also indicate, that the chance for success of the project will increase with the size of the area involved.
The technical investigations show, that there are no serious circumstances which could stop the completion of the project. Some of the more isolated farms may experience problems with the disposal of waste water. The investigations dismiss the possibility of an increased risk for floods in the area. This is, although not previously discussed, not an irrelevant subject in this area. During a storm surge in 1990 many houses were flooded in the town of Varde, ca. 10 km from Ho Bugt.
The investigations in the agricultural and economical area outline a practical strategy to the implementation of the project. A sound economical foundation should be in place before commencement of the project so that the private landowners can be convinced of the necessity to participate.
This foundation is created by a precise analysis of the economical losses expected in case the project is completed. Economics are very important criterion for the success of the project. Most will chose to continue in the present-day situation, if there is no reasonable economic stimulus to participate in the project.
It is possible that, in such a case, some of the project objectives can be reached through individual voluntary agreements on the basis of general environmental provisions. As the implementation of a nature restoration project will have a longterm binding character will most owners opt for a policy of wait and see combined with individual agreements which can be terminated at relatively short notice.
This scenario only increases the importance of a sound economical stimulus.
It is therefore extremely important that all economical consequences for the individual farmer are clarified before commencement of the project or any part of it.
The project has been instigated by the local Agricultural Society. They have secured a widespread accept and support for the project and initiated the preliminary investigations of the area. It has proven to be important to work via local and centralized steering in this kind of projects. Equally important is it to clearly define the object(s) of the project and to ensure conspicuous announcements from the steering authorities with the start of the project.
To ensure the required local support it is necessary to supply precise, punctual and invariable information. This information should be supplied at a fitting moment, as a lack of information can, at any time, lead to rumours and subsequently to a atmosphere of distrust and condemnation.
Wide spread use has been made of television, door to door leaflets, news paper coverage and individual information to the farmers involved, through their professional organizations. It is certain, that this has contributed to the widespread acceptation of the project in the region.
It is important that the local population feels that the central steering authorities take notice of their wishes before they agree to a certain solution. This has therefore been one of the main areas of interest in many of the preliminary investigations.
It may be striking, that voluntary participation is one of the intentions stipulated by all parties involved. Some may view this as logical, righteous if not democratical, but the principle of voluntariness can also be a source of failure in projects like this.
If voluntariness results in a geographically spread participation will it be impossible to create large coherent areas with individual controlled groundwater level, as was one of the objects of the project.
It is a kind of a schism, to see voluntariness placed in such a prominent position in these type of projects, when Denmark through international agendas is obligated to preserve and restore the natural ecosystems.
Initially, applications of some 70 landowners from the Varde Å valley and the meadows around Ho Bugt were received. The area covered by their properties amount to a total of 528 ha. Unfortunately are the geographically spread through the whole of the region.
Those landowners who expressed their interest in the project, but want to wait for the necessary participation in a specific area, can agree to a voluntary agreement on the environmental friendly management of their properties. These agreement can later be conformed to actual participation in the project.
Land consolidation schemes should be the solution in uniting those properties, that wish to be included in the project or to "move" those who are not interested outside the area. It is envisioned, that the overall project, due to this problem, will be executed through the realization of smaller projects in the area.
Three land consolidation schemes have been started in the area. The Ministry of Agriculture has allocated the means to buy property in the valley, but this has not been very successful.
There is, with the preliminary investigations completed and the possibilities for subsidizing clarified, a sound basis for the individual owner to decide on his point of view in relation to participation in one of the land consolidation schemes.
There is a wide consensus with regard to the situation in the legal area. All parties involved have had ample opportunity to influence the decision making process through participation in the project steering group. It will be obvious, that the project will require dispensation from the regulations of the Act on the Protection of Nature and the Regional planning of Ribe county.
It should be considered if the EC subsidy for the production of dried fodder pellets should be changed because it is obvious that this is a latent source of disinterest among the landowners. Furthermore, should the regulations from the Act on Agriculture be evaluated in relation to the possibilities of the individual landowner to participate in one of the land consolidation schemes and thus in the nature restoration project.
One of the objects of this type of project is to (re)store wet meadows in the low areas of the project region, that will increase the selfcleaning capability of the ecosystem. It is required to secure a low-impact cultivation over a long period, which in itself may not be in conflict with seasonal or exceptional flooding, in order to create a long term solution to this problem. Central in this program should be a process of negotiation where a reallocation of the property situation is established in such a way that suits the proclaimed political ambitions of the project in an optimum way.
The key in the implementation of nature restoration projects is to achieve as many object as possible in the form of visual results in the landscape.
The prospect for the project in the valley of the Varde Å and the meadows around Ho Bugt lies with the implementation of partial projects in the region.
A pilot project which covers around 60 ha will be started in 1998. This project should show how a raised groundwater level will effect an area. The groundwater level will be raised to around 10 cm below terrain during the winter period and to 30 cm below the surface during summertime.
During these experiments will the land consolidation schemes continue in an attempt to create larger coherent areas where groundwater level can be raised.
REFERENCES:
Lodsejerudvalgets publikation "Operation Engsnarre" Vedr. driftsaftaler og jordfordeling. Juni 1997.
Følgegruppens publikation "Operation Engsnarre" Nyhedsbrev Nr. 1 november 1997.
Miljø- Energiministeriet, Skov- og naturstyrelsen. "Varde Ådal og Ho Bugt enge"
1997, ISBN : 87-7279-054-7.
Miljø- Energiministeriet, skov- og Naturstyrelsen. "Naturgenopretning af Varde Ådal og Ho Bugt enge" Hovedtema 3. November 1996.
Miljøministeriet, Skov- og Naturstyrelsen. "Nature management in Denmark" 1992
ISBN : 87-503-9677-3
Hans Skotte Møller. "Restoration of wetlands in Denmark. Policies and practical examples." 1994.
Hans Skotte Møller. "Conservation, management and restoration of wetlands. 1995