Flood risk areas in the City of Pori have to be protected. That is why flood control actions are needed in the delta of River Kokemäenjoki. The aim of the City’s Flood Control Project’s is not to prevent floods because they are part of its nature and continuing development. The aim is to ensure water flow in delta’s smaller beds if the main bed is being blocked.

The objective of this thesis was to explain flood control possibilities that could be done in the delta of River Kokemäenjoki. Delta has formed in the Bay of Pihlavanlahti where its nature conservation is based on the area’s natural development also known as succession and species diversity. According to the evaluation suggested flood control actions will not significantly weaken the delta’s nature values. The aim of thesis was not to compare the given alternatives but to find possible solutions to execute cutting and dredging actions in the delta of the River Kokemäenjoki.

The thesis was done to the City of Pori. Thesis was done to support the decision making in the city’s Flood Control Project. The work concentrated on the river delta’s bed network which is already partly closed because of the increased amount of vegetation. Suggestions for different flood control actions are done by comparing earlier reports and interviews. To fulfil the City of Pori’s flood control successfully the viewpoints of every parties need to be adapted one another. The aim was to match those views together with the ongoing climate change.

The delta of the River Kokemäenjoki is also part of Natura 2000 network. All flood control actions made in that area require permits. The laws obligates that viewpoints of every parties need to be taken into consideration. However, the fulfilment of suggested flood control actions primary depends on the public administration and its will to fulfil society and nature policies.