The run-off water from peat production is channelled in a controlled manner to downstream watercourses, also in flood discharge situations, i.e. when the snow melts in spring and during heavy rainfall, when the run-off from peat production areas increases. This affects the concentrations of substances with an environmental impact. Some of them increase and others decrease. Variation among peat production areas, seasons, and the years exist.
Peat production water protection structures, such as sedimentation ponds, are dimensioned so that suspended solids can be deposited and caught by them, also in flood discharge situations. The purification effect depends on the retention time and may weaken at times of increased flow.
Discharge peaks can be cut by storing water in production area ditches or vegetation reservoirs constructed for the purpose. This facilitates the functioning of existing water protection solutions, significantly reducing the load from suspended solids and bound nutrients.
Ways to reduce discharge peaks and make purification more efficient are being studied together with the University of Oulu in the SulKa project. The project is investigating how water storage can be increased e.g. by using areas removed from production to retain water. The seasonal load formation is also being studied, focusing especially on flood discharge situations such as snow-melting.