Pärnu Catchment

Background

The Pärnu River is one of the longest rivers in Estonia, flowing from the Pandivere Upland to Pärnu Bay in southwestern Estonia. Its catchment lies on relatively flat terrain and is also one of the largest in Estonia, making it one of the country's most flood-prone river systems. The lower course of the river flows through the city of Pärnu, where it creates hydrological pressure and poses flooding risks. The catchment contains numerous peatlands in various ecological states. The most notable area is Soomaa National Park, which includes many raised bog peatlands.

The Problem

Overall, the catchment is heavily drained due to forestry, agriculture, and peat production. There is no clear understanding of how the current land-use situation affects water flow in the catchment or how it influences flow dynamics in the Pärnu River. It is also unclear how future climate change will affect the hydrology of the catchment and whether these effects could be mitigated through restoration measures and changes in current land use.

Restoration efforts

The most notable measure has been the removal of the Sindi Dam under the Pärnu River Restoration Project, which restored fish migration and natural river flow. In addition, peatland restoration has been carried out in areas such as Soomaa National Park by the State Forest Management Centre, financed through the EU Cohesion Fund together with Estonian state co-financing. Major restoration works have also been carried out in the Kõrsa and Lavassaare former peat extraction fields under the EU Horizon WaterLANDS project.

The main peatland restoration measures within these projects have been ditch blocking and subsequent rewetting. The activities within the SpongeBoost project help to improve understanding of the current water retention capacity of the catchment and provide insights into the most suitable future land-use and restoration scenarios that could deliver multifunctional benefits for addressing different climate-related challenges.