Geografie 1970, 75, 219-233
The Opatovice Channel and Its Historico-Geographical Development
The Opatovice Channel in the Pardubice district, East Bohemia was built at the beginning of the modern era between 1498-1514 by Vilém of Pernstejn and Helfenstejn (born approx. in 1435, died in Pardubice on April 8, 1521). He was one of the highest officials at the royal Court in Bohemia. In 1491 he bought the Pardubice and Kunětická Hora estates from the son of George of Poděbrady, the count of Münstenberg and Kladsko. The channel served the purpose of bringing water from the Elbe to a system of new ponds built in the area between Opatovice n. L., Bohdaneč and Semín on the right (so-called Bohdaneč) bank of the Elbe. (Encl. 1.) The channel supplied water to 2.700 hectares of ponds. The largest of them were the following: Velká and Malá Čeperka, Oplatil, Bohdaneč, Rozkoš, Semtín and Sopřeč. The extensive building of ponds had very bad consequences for the country people. Besides inundations accompanying the breaking of dams and flooding roods and meadows, several villages were often flooded. Water from the Oplatil pond flooded Velké and Malé Kavčiny, water from the Rozkoš pond flooded the villages Bystřec and Nivčice. At the end of the XVIth century the water from the Bohdaneč pond flooded the village Pěžice (Bohemian Archives 1899, A. Profous 1947-1957, Fr. Roubík 1959). Pond economy flourishing at the time of living and after the death of Vilém of Pernstejn started to deteriorate in the XVIIth century as a result of the Thirty Years War. The building of an extensive pond system connected with the Opatovice Channel was greatly favoured by the extremely favourable morphological conditions of the area. Its builders took advantage of the old Elbe valley, the so-called Bohdaneč Gate, along which the Elbe used to flow in the interglacial R-W from Hradec Králové through Bohdaneč to Přelouč (K. Žebera 1946, 1956). In the interstadial W2-W3 - in connection with subsidences taking place in the Pardubice and Sezemice area - the Elbe cut its present bed east of Kunětická Hora (Z. Lochmann-R. Schwarz 1965). The thickness of fluvial deposits in the Bohdaneč Gate fluctuates between 4 and 15 m. In some places they are covered with wind-blown sand. The pre-Ouarternary substratum in composed of Upper Turonian marls - coniak exposed in the slopes of the Bohdaneč Gate. Fluvial and eolian deposits - in which the channel was cut - are well permeable. Consequently there was a considerable loss of water by seepage in the channel. In comparison with the channel called Zlatá stoka (similar water supplier in the Třeboň area, South Bohemia, built between 1506-1520) cut predominantly in impermeable Tertiary clays, and supplying water to an area of approximately 2,200 hectares at an average flow capacity of 1,5 m3/sec, the Opatovice Channel supplied water to a slightly larger area (2,700 hectares) at an almost double flow capacity (aprox. 2.6 m3/sec). The channel has been existing for over more than 450 years, and has served its original purpose up to the present even if most of the ponds have ceased existing. Up to the XIXth century practically no improvements were necessary. At the end of the XIXth century its section under Semín was rebuild to empty to the Elbe (originally it emptied to an old meander) - Fig. 3. A more considerable change in the direction of the original channel had to be performed when the need arose of a water supplied of a flow capacity of 16 m3/sec for the purposes of the Opatovice water power plant (finished in 1959) - Fig. 2. To be able to supply the required volume of water, the initial part of the channel had to be re-excavated (northeast of Opatovice n. L.) the slow capacity being then 18,5 m3/sec. The flow capacity in the old channel section was only 6.2-6.6 m3/sec, and from this volume 4 m3/sec were consumed by the former Morávek mills in Opatovice n. L., leaving the remaining 2.2-2.6 m3/sec to cover all requirements of other consumers. Total lenght of the channel after its reconstruction makes at the present 32.690 km, the difference in the height of surfaces making 23 m (mean gradient 0,70 %}. The width of the channel in its upper course makes 15 m, between Opatovice n. L. and Podůlšany 8 m, towards Neratov narrowing down to 7 m, near Semín to 5 m, and close to its mouth to 2.5-3 m. The altitude of the Elbe surface above the weir in Opatovice n. L. makes 225 m, the surface at the channel mouth under Semín being 202 m above sea level. An increasing channel traffic soon required the construction of other technical instalations (Opatovice weir, network of water suppliers, flood-gates, etc.). At the same time six new mills were built. Also the ancient Pernstejn water main in Bohdaneč - built as early as in 1515 - obtained its water from the channel. Along wooden pipes the water was brought to sand filters being then used as drinking water. At the present the channel provides water predominantly for the ponds. (Besides some smaller ones, only 3 of the original large ponds have survived, i. e. Bohdaneč pond, Sopřeč pond and jezero). Other large consumers of the channel water are as follows: the Opatovice water power plant (the main consumer since 1959), the destillery in St. Ždánice (since 1850), fish-ponds and the swimming pool in Bohdaneč, and the Kladruby breeding farms (since 1796). Also mills in St. Ždánice, Bohdaneč, Výrov and Semín depend upon the channel water, besides other industrial plants and factories all of whom participate in lowering its flow capacity. Almost the whole channel has been preserved in its original form up to the present time, representing an outstanding work of ancient water system. In 1781 - at the time of the reign of Maria Theresa - tendecies were felt to cease using the channel at all. After loud protests, however, on the part of all neighbouring villages as well as industrial plants concerned in the consumption of its water, it was decided that it would go on serving its purpose.
