Streams

'Small streams' are small watercourses that rarely dry up. Typical are the low average water level and the high banks.

This stream is fed by a spring in the Raspaille forest, which is located on the flanks of the Bosberg. On the slope, calcareous water bubbles out of the soil and streams spring up.

Some inhabitants of this stream are the freshwater woodlouse, the amphipod, a particularly lively animal that resembles a small shrimp and the larva of mayfly. This larva has gills that can flutter in order to optimally absorb oxygen from the water.

An important parameter for water quality is dissolved oxygen. Running water can absorb more oxygen than standing water. This oxygen is important for the self-cleaning capacity of the watercourse.
The determination of the biological water quality is based on the Belgian Biotic Index or BBI. This is based on the presence of invertebrates such as worms, leeches, snails, beetles, larvae of flies, mosquitoes, dragonflies, ...
In determining the BBI, not only the number of different species plays a role, but also their susceptibility to pollution. Highly polluted water contains few different species and only animals that can survive in oxygen-poor water.
The Biotic Index gives a value that fluctuates between 0 (extremely poor water quality) and 10 (very good water quality).

Departement Omgeving