Restoration of streamlets, ponds and springs
Coastal flads and gloe lakes are very rare today outside the Lapland region – as are natural streamlets, springs and ponds with an area of less than one hectare – and they are therefore protected. Before any tilling activities commence within their catchments, the risk of jeopardising a natural streamlet, pond or spring must always be assessed. If such a risk exists, the impact of the activities and their significance must be taken into account when a water permit is under consideration.
Streamlets that are no longer in their natural state can usually be restored through the methods used for streams. However, the scale of the waters should be borne in mind. In streamlet restoration, it is not necessarily advisable to set increasing the diversity of the fish population as a target, since the channel may be dry for part of the year. However, increasing the structural diversity of the channel is a good objective, on account of the landscape and recreation benefits achieved. The restoration of streamlets is also important, in view of their positive effects on downstream waters.
The status of ponds with an area of more than one hectare can be improved through restoration. The restoration methods are partly the same as those used for lakes. When planning pond restoration – and the same applies for lakes – special attention should be paid to reducing the external load flowing into the basin from the catchment.
Restoration often leads to significant changes in the state of small aquatic ecosystems. In the planning process, it should therefore also be considered whether the restoration methods need to be reported or are subject to a permit. It is also good to remember that in small, shallow basins, excessive growth of aquatic vegetation is a natural process in Finland. For this reason, the need for restoration should be assessed carefully.