CONTENTSLakesRivers Groundwater resourcesProtection and water ecology

LAKES

They are glacial lakes formed after the Scandinavian ice sheet during

the Quaternary Period

The ice sheet covered entire Poland. The area of Pomerania was covered with ice the longest and that is why the glacier has made the most significant changes in the landform here and therefore there are the most lakes.

Moving forward, it left a lot of the material. It resulted in forming sandars.

The area became full of pits and hills.

After the withdrawal of the ice sheet, they were filled with water and so the lakes were formed.

LAKES

In the area of the municipality we have the following lakes:

Ribbon lakes – formed in a tunnel valley as a result of erosion of water flowing under glaciers.

They are narrow, long, with steep banks and varied form of the bottom, deeply indented into the ground.

They create a distinctive strings of lakes with the meridional course and perpendicular to the strings of terminal moraines (Jeziora Wielkie and Jezioro Wielkie Trzebońskie duże);

LAKES

Kettles – small but deep (up to several dozen metres) lakes, round or oval with steep slopes, often occur in the neighbourhood of eskers; they were formed as a result of melting glacier waters, falling from a considerable height through the cracks of the glacier

Lakes surrounded by eskers and drumlins - they fill longitudinal spaces which are dissociated during the formation of eskers and drumlins; the bodies of water are generally shallow and peat

RIVERS A River – is a natural watercourse, freshwater, flowing in the channeled by the

erosion riverbed, periodically flooding river valley. In Poland, it is assumed that the river is a watercourse basin with

an area of more than 100km²

The largest river in the municipality is Łobżonka it is a right tributary

of Noteć

It is an unregulated river

Its length is 69 km

It is a river with a large drop of 116 cm on1 km. It was the reason

for the construction of numerous water mills on the banks

rivers As a result of river activities a slow drainage of area and the lowering of

groundwater ensues.

The river originates near Gronowo from the numerous wetlands, it is also saturated by rainwater

The river often creates wide backwaters and marshy areas

Owing to its unregulated course and large drop, the river is attractive for tourists

GROUNDWATER RESOURCES In the area of the municipality we have the following groundwater resources:

subsoil water - formed at shallow depths (up to 2 m) in depressions, in river valleys and on the shores of lakes due to heavy rain.

They are subject to daily fluctuations in temperature and strong evaporation.

They often disappear during periods of drought

They do not form a continuous water table ie. they occur locally, usually in places with worse conditions of infiltration

GROUNDWATER RESOURCES groundwater - located below the vadose zone

They are formed by rainwater that seeps through the porous soil, and then accumulate in the layers of sand, gravel, or fractured rocks.

These zones are called aquifers.

Water table is a subject to seasonal fluctuations. They supply the rivers and lakes.

In the deeper layers groundwater is well filtered through the layers of sand, clay and gravel (phreatic water ).

PROTECTION AND WATER ECOLOGY In recent years, awareness regarding taking care of ecology and the

environment has been increasing

The amount of garbage and waste thrown into water decreased drastically

Waste is segregated and disposed of in the appropriate places

Construction of sewage treatment plant eliminated completely dealings with municipal and commercial waste water in rivers and lakes

Both the purity and quality of rivers and lakes in the area of municipality is increasing

Within the development of tourism the shores of many lakes have been settled and developed

PROTECTION AND WATER ECOLOGY At the same time in recent years, and especially after the Polish accessio to

the European Union there was a significant increase in the use of fertilizers and plant protection products by farmers.

Fertilizers and chemicals used in excess are washed away by rainwater and get into the rivers and lakes and consequently leads to hypertrophication of water and excessive overgrowth of algae which may contribute to so-called „algal bloom"

The decrease of oxygen which is also a threat to aquatic organisms takes place.

For this purpose, actions aimed at raising awareness about the excessive

amount of chemical fertilizers and pesticides are carried out among farmers