Rescue program

Rescue of the last of the original population in Rameno u Stříbrného rybníka

The Orlice oxbow is intensively influenced by clogging. A large amount of organic material from the bank vegetation, and aquatic and wetland plant remains cumulate and a high layer of mud with a high proportion of undecomposed organic material is generated. In some parts of the oxbow, anoxic conditions arise, which is unfavourable for many organisms. This problem was partly solved by sediment removals in 2001 and 2003. Two technologies of sediment extraction were chosen. In the central part of the oxbow, the sediment (1650 m3) was removed with an excavator in 2001 and the sediment was taken to an interdeck. This measure was funded by management resources of the NCA CR - Pardubice regional office. The lower part of the oxbow (i.e. between the oxbow estuary and the first flexion in the direction from the river) was dredged by a pump dredge and the sediment was transported through a pipe to a prepared lagoon. 1800 m3 of sediment were extracted, the amount of watered sludge was around 4500 m3. This sediment removal was carried out in 2003 and funded by the Programme of Landscape Care (Ministry of environment CR). Before the removal, vital colonies of Long-stalked pondweed (P. praelongus) and Red pondweed (P. alpinus) were marked. Plants in places endangered by extraction were removed and kept in containers in areal of stews of the Czech Fish Husbandry Association in Malšovice, Hradec Králové. After extraction, the plants were returned.


After both sediment removals, the oxbow condition and the sediment quality improved. However, due to sand intake from the Stříbrný Stream, previous undesirable conditions were restored. A strong dredging of the oxbow was observed in the area below the Stříbrný Stream estuary during construction of ponds in the municipal forests of Hradec Králové. Organic material from the bank vegetation covers the sandy alluvium in the TPA and the oxbow quickly fills. Further sand intake was stopped in 2013 thanks to sedimentation tank and weir constructed above the Stříbrný Stream estuary. In 2007, discussions were kept between NCA CR and the state organisation administrating state forests about undesirable clogging and land-filling of the oxbow. The project of sedimentation tank was prepared in 2010–2012. Its construction was to be funded from 2010–2012 Environment Programme, but because of changes of the project, the investor (Lesy ČR) decided to cover the expenses from their own sources.

As the sediment removals in 2001 and 2003 were only partial, a total revitalization of the oxbow near the Stříbrný pond has been being prepared since 2006. The Basin of Upper and Middle Labe Area Scheme was approved in 2009. This scheme includes Measure 24 – Revitalization of the oxbow in Malšova Lhota. Based on the Area Scheme, a request was submitted in 2010 for providing support from Environment Programme resources for the project “Data for subsequent realization – study of feasibility of revitalization measures and opening migration barriers on streams”. The project was approved. It contained preparation of data for 48 actions in the Labe basin, one of which is sediment removal from the TPA, labelled as number 1. Orlice, Malšova Lhota, oxbow revitalization (LA110023).

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