Rezultaty badań fizycznych i chemicznych wód dopływów środkowej Drawy w roku 2007/2008

Mimo dużego zainteresowania turystycznego Pojezierzem Pomorskim - badań wód Drawy i jej dopływów nie ma zbyt wiele. Dorzecze Drawy, jednej z piękniejszych rzek pomorskich, obejmuje: Pojezierze Drawskie, Pojezierze Myśliborskie, Pojezierze Wałeckie, Kotlinę Gorzowską [6]. Środkową Drawą przyjęto nazywać odcinek od ujścia rzeki z jeziora Lubieszewskiego (Lubie) do Elektrowni Kamienna. Powierzchnia zlewni środkowej Drawy stanowi 1/3 ogólnej powierzchni zlewni Drawy [3]. Dopływają do niej: Drawica, Korytnica, Słopica, Bagno, Stary Potok, Sitna, Ciek Leśny podlegają różnej działalności człowieka. Natomiast dolny odcinek dorzecza środkowej Drawy należy już do Drawieńskiego Parku Narodowego

Analysis of water of middle Drawa river tributaries were executed on the basic physical and chemical parameters. Left-bank tributaries of middle Drawy such as: Drawica, Korytnica and the small tributary to Adamowo Lake in Drawno, so-called Bagno, and also right-bank: Stary Potok, Sitna, Ciek Leśny were included in investigation of water quality. Parameters in water of middle Drawa flowing from Lubie Lake were accepted as a reference to tributaries. Measurements were conducted since March 2007 till February 2008, regularny once a month (fig. 1). The water was taken in the current on depth of 0.2 m. Sampling points on water - courses were located in following places: 1 - below place of Drawy flow from Lubie Lake; 2 - after outflow of Drawica river from Mąkowarskie Lake; 3 - 1 km before Słopica inflow to Drawa; 4 - after outflow of Korytnica from Nowa Korytnica Lake; 5 - 50 m before inflow of water - course (Bagno) to Grażyna Lake; 6 - after Stary Potok outflow from Trzebuń Lake; 7 - 1 the km before Sitna inflow to Adamowo Lake, below weir dam; 8 - 200 m before Cike Leśny outflow to Krzywy Róg Lake. In water samples taken from those points following parameters were determined: temperature, content and saturation of oxygen, reaction of water (pH), BOD, conductivity and only in 4 points chemical parameters. Generally the waters of drainage basin have good quality. However individual tributaries have elevated level of separate parameters. Level of phosphates is especially disturbing. Admissible values of water quality parameters, regarding phosphorus given in Decree of Environment Minister from February 11 2004, are clearly crossed, and those waters also require the repair system. Other investigations [4, 7] also show on raised content of phosphorus in river basin of middle Drawa.