It is a postglacial lake in the Lubuskie Lake District, 6 m deep. It is located to the north of Ostrów, near Sulęcin. The lake has the shape of a kidney, with its long axis in the north-western direction and south-eastern direction.
The bottom in the central part of the lake is not diversified, almost flat, but from the western shore it descends rapidly to the central part. It has the smallest inclinations in the peninsula area and in the south-eastern bay near the outflow. The lake is surrounded by small hills overgrown with a pine forest on the western and southern side. Right at the water side, there are some alders and birches, in particular numerous near the outflow.
In the northern part some fallow land adjoins the lake; it is now used by anglers as a car park. A few picturesque poplars grow at the lake shore as well.
The outflow from Ostrowskie Lake is a short, left-bank tributary of the nearby Postomia River. The lake shores are overgrown with a belt of common reed, with some reedmace and reed mannagrass, on average 3 to 6 m wide. A part of the southern shore is not overgrown at all as it is a bathing site. In some parts of the shoreline we can find white and yellow water lilies, particularly extensively growing in the outflow bay. The bottom is largely overgrown with two species of hornwort: rigid hornwort and soft hornwort, as well as chara species reaching as deep as 3 m. This creates good spawning conditions as well as good conditions for the development of young fish.
Although Ostrowskie Lake is not large, it is frequently visited by anglers because of its attractive stock of fish. The dominant fish species are the tench and pike. For many years the lake has been stocked with fry by the Polish Angling Association "Okręg" in Gorzów Wlkp., and the lake's patron has been PAA Branch no. 1 in Sulęcin. Many fish species can be found here, such as the roach, bream, rudd, tench, crucian carp and carp. Predator species are also to be found, e.g. the zander, eel, pike and wels catfish. The lake is frequented by anglers, which is why many small fishing platforms have been built here.
Morphometric data concerning Ostrowskie Lake:
water table area: 10.7 ha
maximum depth: 4.6 m
The text has been prepared on the basis of a guidebook entitled "Between Warta and Pliszka Rivers".