[15] The direct drainage basin of the lake is small and covers an area of 5.7 square kilometres (2.2 sq mi).

Chemically, the lake water was classified below a good condition due to exceeding Class I values for mercury compounds, polybrominated diphenyl ethers, and heptachlor.

Most indicators positively affect the lake's resistance to degradation, especially its high average depth, location among forests, minimal percentage of water exchange throughout the year, and small area of direct catchment.

The only issues are the excessive length of the shoreline compared to the lake's volume and low thermal stratification of its waters.

The causes of this phenomenon are unknown; according to preliminary expert opinions, the inflowing tributaries supplying the lake have dried up, and there has likely been seepage of water towards the west.

There is also a hypothesis that deep wells belonging to recreational centers located along the shores of Głębokie Lake are responsible for lowering the water level.

[7] As remedial measures, it is proposed to bring water to the lake from the Obra river, either through a pumping system or through the surrounding wetlands.

[22] The water body was mentioned as early as 1390 when Wincenty of Chycina and his sons sold the villages of Kalsko and Rojewo along with five nearby lakes to the abbot and Cistercians in Zemsko for 300 grzywnas.

Thanks to this, the residents of the city could in accordance with ancient custom, fish in the lakes called Strzeleckie (now Głębokie) and Linye (Grążyk) with the consent of leasing, similarly to the river with nets.

[21] In the 18th century, a long-standing dispute over both lakes and the surrounding forests ensued between Międzyrzecz and the abbot of the Cistercian monastery in Bledzew.

The monastery had long owned forests and fields near the nearby Kalsko and asserted claims to the urban properties.

When the abbot demanded to see the royal privilege, the city council on 10 October 1647, sent a delegation with the document to Bledzew.