Leenders, K.A.H.W.. Verdwenen Venen. Een onderzoek naar de ligging en exploitatie van thans verdwenen venen in het gebied tussen Antwerpen, Turnhout, Geertruidenberg en Willemstad. 1250-1750. Brussel/Wageningen, 1989. (ISBN= 90-5066-053-3 and 90-220-09991-2)

(Lost Peatlands. Research of the situation and exploitation of now disappeared peatlands in the area between Antwerpen, Turnhout, Geertruidenberg and Willemstad. 1250-1750)

This study consists of two main parts. In the first part the situation, size and depth of the former peat cover are discussed. In the second part the historical context and importance of the removal of this peat cover is given. The research area is practically a square 50 by 50 km (30 by 30 mi) region northeast of Antwerp. Since 1830 this region has been divided between the Netherlands and Belgium. We must discriminate between a low laying part (less than 2 m (7 ft) above sealevel) in the west and north; and a higher part (rising up to 30 m (100 ft) above sealevel) in the middle, east and south.

Studied region In the five centuries spanned by our research (1250 - 1750) a major part of the research area saw a important transformation. About 1250 two major landscape types existed in the research area. In the southeastern half lay the Kempen landscape, characterised by its sandy soil and widly spaced small villages. In the northwestern half 900 square kilometer peat dominated the landscape. Small settlements only existed in a few relatively well drained places. Five centuries later the Kempen landscape had spread over the whole of the higher laying part of the region, while in the lower part a landscape of young sea clay polders had developed. A number of interacting factors determined this evolution.

The original situation was mainly determined by physical-geographical factors. In the northwestern half of the research area the peats were very important elements in the landscape into which the first mediaeval people ventured. These pioniers settled especially at sites that were well drained by brooks and offered places that were dry enough. They left the peats untouched. Situation, size and depth of these peats, which have completely disappeared since then, were discussed in detail. On the "high part" of the research area these peats were of a very flat hangmoore-type.

In the lower parts they lay mainly very flat. Some typical high domed peats were made probable in both the higher and lower regions. The peat of the research area was connected with the Holland peat of the low parts of the Netherlands in western and northern directions. In the northeastern direction it was connected with the peat of the "Langstraat"-region. The lower part of the research area had really the character of a continuus peat area, with here and there a sandy hill and along the Sceldt a rim some kilometers wide, where the peat in a early phase already was covered with a thin layer of clay.

Former peat areas We found three main peatcomplexes concentrated in the northwestern half of the higher part: east of the dunes of the western cliff, east of Roosendaal and a very expanded peat area in the triangle Wuustwezel - Princenhage - Rucphen. In southward direction these peats reached up to 16 or 17 meter above sea level. In the great peat areas on the higher terrain well over half or even two third of the area was covered with peat. Apart from some expansive and related peats a number of smaller peats was present.

In the southeastern part of our research area, where the sandy soil always was dominant, peat only was present in the valleys of the brooks and in natural lakes. Here, probably about 5 % of the total surface area was covered with peat.

With exception of the neighbourhood of Antwerp, the research area had up to around 1250 a perifere position in respect to demographic, economic and political developments in the then central provinces of the Netherlands: Flanders, Brabant and Holland. Around 1250 the expansion of Flanders couldn't find any more space within that county. To provide for the fuel needed by their cities during a longer period, Flamish entrepreneurs at first brought the peats of Northern Flanders into production. Around 1263 they began colonizing our research area for the exploitation of the peat reserves. These reserves were only partly used within the first decennia; the rest remained in reserve until the middle of the 14th century. Assisted by an acute financial crisis of the lord of Breda, Flemish cloisters, institutions, nobleman and citizens could buy in a short time great expanses of peat. In the short period 1260 - 1300 a number of new settlements appeared. Of them Steenbergen and Zevenbergen attained an urban character. The turf production culminated within forty years of the start. The region produced by then probably a quarter of the whole turfproduction in the Netherlands. Northern Flanders produced an comparable quantity of turf in this period.

Round about 1300 this colonial period ended. Entrepreneurs from the region itself took control of the peat digging and selling ("moernering") and the Flemish withdraw slowly from this bussiness. The new peat buyers expanded the peat digging over the whole of the northwestern part of the research area. They dug turf canals up to levels of 10 and even 16 meter above sealevel. These canals reached lengths of 10 or 20 kilometers. Nevertheless the turf production slowed down after 1300.

The peat was not only dug for turf production. From peat that was found near to sealevel, salt could be extracted. In the Antwerp Polders the clay covered peat surface had since the 11th century been reclaimed for agricultural production. A little later agricultural reclamation started in the neighbourhood of Geertruidenberg. The period 1250 - 1350 can be seen as the most important mediaeval reclamation- and expansion phase for the northern part of the research area.

We do not have accurate population information from this period. So, only a rough estimation is possible of the proportion of the population that was directly or indirectly connected with the peat exploitation. We think that this proportion did not exceed 5 %. After 1400 it declined to even lower levels. The villages in our region must have been of a predominantly agricultural character. The turf commerce was mainly concentrated in the export harbours. As the biggest demand for peat diggers occured in the same season as the most labor intensive period of the agricultural exploitation, namely in summer, it is probably that the peat diggers were often attracted from other regions, but we found only a few signs of such a labour migration.

An extended infrastructure was created for turf production. The export harbours, that were turfmarkets at the same time, were connected with the peat areas by 19 turfcanal systems. The main canals attained a total length of more then 320 kilometers (200 mi). The length of the secondary canals cannot be estimated as most of them have disappeared or were never accuratly documented. Every canal was compartimented by locks with a mean distance of 800 meter (0.5 mi). The number of locks must have been 300 to 400. During many years the number of barges on these canals amounted to over 150. Here and there in the peat areas water reservoirs were constructed to collect water. With this water it was possibly to supply the canals of enough water to allow navigation.

While the turfproduction in this region decreased, it increased in the northern Netherlands. The portion of the turf market that was provided by the research area declined therfore quickly under 5 %. In the same period the economical centre of the Netherlands shifted from Flanders over Brabant to Holland. In the same way as our region provided the turf for the Golden Ages of Flanders and Brabant, the northeastern parts of the Netherlands produced the turf for the Golden Age of the province of Holland.

The technical knowledge of the turf industry was imported from Flanders into our region, where it was augmented. Aquaducts were build, to help the canals cross the brooks; bigger barges were developed and also salt production in ring dikes within the tidal floodplains seems to be specific for the northwestern part of our research area. As the turf production in more northern parts of the Netherlands occured mainly some two centuries later than in our region, it is conceivable that the augmented knowledge was exported again to northern provinces in a later period. An example of techniques, received from Flanders, further developed in our region and again passed to the North, is the procedure of "slagturven". This technique (for gathering submerged peat) was only introduced in the province of Holland at about 1530. Creation of a new topsoil to give the agricultural exploitation of dug-out peat areas a better start, however seems to be an innovation that was only introduced later and in the North.

So we can place the great mediaeval reclamation and "moernering" period in the northern part of our region in a great wave that swept over the Netherlands from Flanders over Brabant and Holland to the North of the Netherlands. This wave consisted of flourishing economical conditions, associated with reclamation for agriculture and fuel production, and the development and passing on of the required knowledge.

Not only the production of turf or salt declined during the final phase of activities in the peat area. The agriculture and animal husbandry on peat (or on peat with a thin claycover) declined too. In the 15th century all peat reserves in a strip from Bergen op Zoom to Breda were already sold off and partially even dug out. This geographically split the new turf concessions. The northern group changed character at the same time. Floodings hit this low laying region as they did the region along the Sceldt. These floodings were partly provoked by the peat exploitation itself. The new concessions in the North were therefore mainly concerned with salt production in temporary ringdykes: so called "moerdijken". After 1460 this kind of exploitation ceased. Only the rim of the Holland peat along the higher terrain east of Oudenbosch remained in agricultural use. In the southern group the peat exploitation was now completely concentrated on turf production. In the run of time the size of the concessions diminished and since 1400 the new concessions lay more and more concentrated. Authors that only knew of this last phase, have been misled to believe that the turf production in this region was only of miner importance. In the final phase around 1700 only the peat areas in De Nol (west of Kalmthout) and in the south western part of Zundert remained in production. The transport of turfs on the two latest turf canals ended in 1733 and 1743.

The consequences for the landscape of all these activities were the most dramatic in the north of the research area. The surface of the soil became lower as consequence of the exploitation of the already low laying soils whith a thick peatlayer in it. This created the possibility of flooding by sea water. Whether and when flooding should occur, was mainly determined by the protection provided by dikes. Along the Scelt the dikes could withstand these floodings with varying success. Here, and also in the Grote Waard in the northern part of the research area, disaster struck after long delay. Really every part of the Sceldt region was during one or even more periods of many decennia under the influence of the tide, flooding twice a day major parts of it. Under such circumstances a mighty claylayer was deposited, so that - after rediking - the peaty character of the soil was completely lost. Only a few polders could escape this development.

On the contrary the northwestern part of the region was flooded little by little. There the tide penetrated slowly in a region without dikes. Dikes were only built when it was to late to stop this development. This process of slow flooding began around 1250 in the north of Tholen and reached its eastern boundary in 1422 by swallowing the Grote Waard.

The flooding, occuring here and elsewhere in the low part of our research area, could not be explained by a rise of the sea level or of the storm flood frequency off the coast of Zeeland. Two factors, an external and an internal, seem to explain the intricate flooding pattern better. The external factor was the changing height of the tide in the research area as consequense of the development of sea arms in Zeeland. The relation between the development of the Honte and the flooding along the Scelt north of Antwerp is the clearest example of this relation. Eventual changes in the sea level could at most have indirect influence by the creation, deepening and widening of the sea arms. Developments that occured deeper in the interior were mainly determined by the form of these sea arms, which form affected the height of the tide at their ends. The lowering of the soil, unequal from place to place as consequence of the peat exploitation can, as internal factor, add to this an explanation for the geographical diverging character and timing of the floodings. We can only guess in how far a regional lowering of the soil in the low peat area, as consequence of the peat exploitation in general and the improved drainage through the newly formed sea arms at low tide, contributed to these expanding floodings.

The end of the agrarian peat exploitation in the low part of our region was forced by these floodings. Turf digging and salt production remained possible during a few decennia, with salt production predominating for economical reasons. The saltproduction was however discouraged by the ever thickening sediments on the peat, the prospect that undisturbed growth of the mud flats and marshes would make the endikement of profitable arable clay soils feasible in later years, and to a lesser extent the import of french salt. Saltproduction stopped around 1460.

In the higher part of the region the danger of flooding by sea water did not exist. As the peat was cleared, the sandy subsoil became topsoil. Even after the end of the commercial exploitation of turf, the farmers went on with turf digging and turf reaping. In that way they removed the leftovers of the peat. What the farmers left, weathered in the heath or was crumbled by the reclamation plough and wasted by oxidation under the new and dryer soil conditions. Before the reclamation the turfed off region became poorly drained as soon as the old canals ceased functioning. Under these conditions a wet heath came into development, with locally new peat formation.

In contrast to the peat areas of the north of Flanders and the northeastern part of the Netherlands, the turf digging was immediately followed by agrarian reclamation only at some places in our research area. We suppose that the responsibility for this different development lies in the fact that the peat was mainly sold for turf production, combined with the absence in most cases of any reclamation initiatives by the regional and local lords.

The length of time between the end of the turf digging on one spot and the agrarian reclamation determined mainly how many traces from the turf digging period could be saved in the agrarian landscape. In early reclaimed places even 13th century traces are recognizable in the midst of many elements of the younger Kempian landscape. In the early 20th century reclaimations on the contrary rarely anything is recognizable from this older periode. Especialy the canals determine the character of the landscape by their great length and by the long rows of high trees or lower bushes that stand along them.

The peat of the lower part of our research region is now hidden from view by younger clay, silt and sand deposits while the peat of the higher part was carefully cleaned up by the farmers, after the removal of the main peat reserves by commercial turf production. Thus a once important and commercially interesting peat layer disappeared. June 7th, 2005

© Copyright : K.A.H.W. Leenders