The Conditions of the Recreational Function of the Area "Posázaví"
Authors: Muranský Stanislav 
Published: October 2023

This paper deals with conflicts, which are caused by recreational impetus of inhabitants of the city Prague on the surrounding areas. The nothern, eastern and western parts of this surroundings is fully used by the industries and intensive agriculture, so that the recreation does not find there enough possibilities for its full development. There only remain the shorelands along the larger rivers and their tributaries, e.i. Vltava, Berounka and Sázava. However the shorelands of the first two mentioned rivers are already fully used by recreation. If we take into account the traffic distance from Prague, there only remains the middle and lower shoreland of Sázava as development area. Of course, even here and mainly in the areas along the Sázava and her tributaries is comming to overlasting of those areas by recreation. All this area is economically undeveloped. From this reason it is suitable to fix two main tasks for this area, which are in further development one to another in this way to tune, to not come to the detriment of one or another. Adverse influence of the recreation would appear by her strong elemental nature, in the case of economical development, then, by unsuitable sort and size of the industries with oustanding negative consequences on the environment. From this reason it is useful to stipulate by country planning method the conditions for development of both above mentioned functions and to demonstrate the possibilities of optimal solution of the both interests. The studied area is a part of the watershed of Sázava, a zone of about 20 km in width, for which the river forms the axis from her mouth to the town of Havl. Brod. The average participation of the woodland is on behalf to the relief not too high, roughly 34 %. This combination of some adverse elements has conditioned a very limeted water retention of soils and has given rise to harmful forms of water erosion. Otherwise the main wood species are the coniferous ones, the spruce and the pine. The original broadleaved species, mainly the beech, the oak and the hornbeam have remained only in small areas above all on steep stony slopes along the river. The main recreational element is the river Sázava, which flows into the area with 4.30 m3/s, average year discharge. This rate of flow keeps on rising up to 25.5 m3/s at the mouth. The two large tributaries Želivka and Blanice come on the left bank. Both have extraordinary fluctuation, meanwhile the discharge of Sázava is near to the state average. At times of smaller discharges the water depth amounts to the average of about 30 cm. This does not appear to be favorable from the recreational point of view, even though it is improved by many weirs, which are however ununiformly spaced and in bad repair. The economic development of the area will be influenced among other things by the lack of raw materials (minerals). All the mentioned circumstances have led to a less intensive agriculture, to smaller participation of industries and to a spare development of the human settlements. Under these circumstances the region seems overcrowded with a permanent exodus of people to towns in search for work. From the active population 33 % is eployed in idustry and about 30 % in agriculture. In other respects the conditions are different from those of the state average. The average density of the population is about 70 inhab./1 km2, that is 66 % of the state average; also age structure, productive age etc. In the ten communities of over 2000 inhabitants there are only 21 % of the whole population, whille 79 % live in the villages. An important element of the development is the individual recreation which changes very sharply the current character of communities in the territory. In the season of recreation the number of inhabitants in these subareas multiplies several times. This occurs mainly in the shorelands where there are between 200-500 recreation cottages for 100-200 residential units of a standing settlement. Not even this relatively undevelopped area was spared from some adverse consequences of economical development. Most serious is the falling of dust around large quarries producing the graded gravel and grit. Further unfavorable consequences has the transport of those materials in tipping lorries. The pollution of the surroundings along the roads is caused by the dust out of transported stuff and by the vaste gases mainly in the badly ventilated valleys. However, far greater problems are created by the pollution of the water in Sázava and in some of her tributaries. The pollution varies in volume, kind and degree. The most serious are the waste from the agriculture and from the municipal systems which also discharge industrial waste. The last mentioned ones are about 100. The industries with the most adverse waste are operating ustream of the watershed. Still worst is that their seasonal operation (of starch and spirit industries) is coincident with the autumnal minimum of water level. But even in this reach the water of the river has an extraordinary high self-cleaning ability in the stony river-bed. This and many small tributaries with natural excellent water from wood lands improves the bad quality of the water in the short watercourse between Havl. Brod and Sázava. From this town downstream the water of Sázava is deteriorating again. Finally it is necessary to appreciate the great investments e.i. the reservoir on the stream Želivka and municipal water supply for more than 1 million inhabitants of Prague, the first reach of motorway and the electrification of the railway Prague-Tábor. The first investment is built in two stages. At the end of the first stage in 1971 3 m3/s is to be with-drawn for the municipal suply, in the second in 1985 then 6 m3/s. That will have an adverse influence on the water quality in Sázava because this river is today improved in volume of the discharge by the afore mentioned stream below its mouth with an average of 40 %. The influence of other two investments will be exclusively positive. The planned industrial investments will also deeply influence the economic development of the area. New large factories of the glassindustry will be constructed and several other plants reconstructed. In all these cases the operations will be modernized, the coal replaced by fuel oil, heating gaz and electricity. Also sewage treatment plants will be set up. It may be expected that no more further detorioration of the natural and life environment will appear. In conclusion we can say that it is possible to tune the investment development with the claims of the increasing recreation and that the realisation of the planned development without any deterioration of the environment will lead to the rise of the economic and social level of the area.