C.4.2 Riffle in Głęboczek on the River Drawa – at Stary Młyn (km 162+250)
The Regional Directorate for Environmental Protection in Szczecin, the beneficiary of the project, is pleased to announce that on 26th October 2018 the final acceptance of works was made; it was the part C.4.2 task entitled: “Making a circular channel for fish and a footbridge within the task – Constructing a fish pass in Głęboczek on the Drawa near Stary Młyn (km 162+250)”, one of the subtasks of the LIFE13 NAT/PL/000009 project LIFEDrawaPL “Active protection of water-crowfoots habitats and restoration of wildlife corridor in the River Drawa basin in Poland/Czynna ochrona siedlisk włosieniczników i udrożnienie korytarza ekologicznego zlewni rzeki Drawy w Polsce”, co-financed by the European Union under the LIFE+ financial instrument and by the National Fund for Environmental Protection and Water Management in Warsaw (NFOŚiGW).
The upper Drawa is a small river with a great diversity due to numerous flow-through lakes on its course. Between lakes Rzepowskiego and Krosino it flows lively breaking through moraine systems. Due to the presence of significant gradients people have always tried to use its energy in various ways, blocking its run with weirs powering the mills, regulating and extracting gravel and stones as building material. As part of these activities, a mill powered by the energy of water dammed by the river weir in Głęboczek was created many decades ago on the section discussed. The effects of using the river can be seen in its ecological state, but also in the behaviour of the river during varying flows. These effects are also felt by its wild inhabitants, including ichthyofauna, which populations are divided, as well as the river’s ecosystem. The purpose of the circular channel was to eliminate the division of the Drawa’s ecosystem between Drawskie and Rzepowskiego lakes and Krosino. Due to the very poor technical condition of the mill remains in Głęboczek, a decision was made to build a fish pass, in this case a circular channel, except for the remains of damming. The construction of the device is the first in Poland and one of the first in Europe which uses the rules of a riffle-pool sequence in streams’ channels. Using the rules of creating balanced systems, a channel in a nature-like form was made, by choosing the grain size of armouring to the power of the stream. According to the assumptions, the device leads the water between the weir’s backwater and the water below in a varied way, creating layer which flow slower and faster, which facilitates overcoming the barrier to various groups of organisms. The Project’s Office Team in cooperation with scientists from the University of Szczecin has began monitoring research of the channel. During the trials, numerous individuals of many species of fish were observed, which used the restoration just after its opening.
The acceptance of works was attended by representatives of:
- National Water Managment Waters of Poland – Water Management in Drawsko Pomorskie
- Czaplinek district
- Contract Engineer together with the Construction Site Inspector
The total value of the completed task: 946 033,04 zł.
As a result of the task, the following was obtained:
- a new fish pass in the form of a natural stone-gravel circular channel which is 110 m long,
- a sequence of 3 stone-gravel riffles in the River Drawa,
- a footbridge,
- the project’s information board.
Down from the device in the Drawa channel, the remains of stone-gravel riffles were supplemented to reduce the bottom erosion and improve the state of the river’s and the valley’s habitat. Such flitches play a particularly important role in the periods of low states that have appeared in the region in recent years. Due to their presence, the biological diversity of the river’s ecosystem is also significantly increasing, giving a chance for a water-crowfoots rivers habitat to return completely, which is the main objective of the project. The riffles’ reconstruction was met with a particular kindness of canoeists, who can now more easily use this attractive section of the river. It is also one of the project’s aims to encourage some tourists to use other sections than in the Drawieński National Park due to restoring a good condition of the upper Drawa. This should reduce the pressure on the most valuable part of the Drawa, as well as to act as a sour to the communities’ development along the entire basin of the river in a sustainable manner.