Reducing diffuse pollution

CHALLENGE DESCRIPTION Diffuse loads come from many different sources and are therefore much more difficult to combat than point loads. Even today, different actors disagree on the main sources of diffuse pollution, although several studies show that agricultural pollution is the greatest in many, if not all, of the Baltic Sea Region catchments. It is often heard that it is argued that sparsely populated areas, forestry or wastewater treatment plant by-passes cause higher loads than estimated. This may be due in part to the fact that estimating the amount of diffuse load is challenging. In terms of agricultural pressures, we do not have sufficient measurements of different farming practices, soil types and climate zones. Diffuse loading can also be modeled but modeling also needs comprehensive measurement data so that the functionality of the model in different situations can be tested. The same applies to the effects of water protection methods. The effectiveness of a water protection measure is most often determined at the level of a field block or a small catchment area. When measures are assessed at the discharge point of a larger catchment area, the impact of the measure is often so small that it cannot be detected on the basis of sparse water sampling data. As there are several different land uses in the catchment area and at the same time several actors, it is essential to get the actors to talk to each other. The action can be a joint project in which the actors can contribute to a common objective, e.g. good water status. However, projects are often short-term, which does not guarantee long-term and targeted actions, which are almost always required to improve the status of water bodies, i.e. brooks, ditches, rivers, lakes and sea area. Therefore, there is a need for a formal permanent coordinator (catchment officer) to promote the improvement of river basin waters while allowing for interaction between different actors.

DESCRIPTION OF THE SOLUTION Before solutions can be made, the diffuse loads and their magnitude in the area must be assessed. In this work it is possible to utilize e.g. river basin management planning and proposed measures for the area. If model estimates of the magnitude of the diffuse load have been made in the area, they can also be utilized. The planning areas are typically large, and it is not yet possible to target measures on the basis of them. At this stage, it is good to involve the stakeholders in the area in the discussion, where the catchment officer first presents the characteristics of the area, the sources of diffuse loads and the estimates of their magnitude. Actors can then present their own thoughts on the loads in the area and their magnitude. Any erroneous assessments and perceptions should be reviewed together, and the catchment officer should justify why, for example, an individual loading source is, or is not significant. It is also important to present the uncertainties associated with the estimates, but at the same time emphasize the importance of the magnitudes of the different loads. Although it is usually not possible to make precise estimates of the impact of a mitigation measure, it would be useful to make some assessment of its effectiveness. Sometimes the effect of a measure is not necessarily so big to reduce the nutrient load as, for example, to increase recreational use in the area, to manage the landscape or to increase biodiversity. It is quite clear that a single measure is usually not enough, but a wide range of measures is needed. Once a common understanding has been reached on the measures to be taken, the catchment officer can begin to plan them in detail and seek the necessary funding.

POSSIBILITY OF ADAPTING THE SOLUTION Actors in the area may well disagree on how to improve the ecological status of the water bodies by reducing diffuse pollution. Therefore, it is important that all actors are involved and that their views are equally taken into account. The high proportion of nutrient loads caused by agriculture puts pressure to focus specifically on water protection measures that are effective in agriculture. However, measures must also be taken in forestry. In particular, drainage sectors – both forestry and agriculture – should be emphasized. In agriculture, a balance has to be struck between both production and environmental impact. Fertilizer levels need to be reduced, especially in areas with high soil phosphorus contents. If there is livestock in the area, manure processing could be the best solution to reduce over-fertilization in the area. The nutrient load caused by sparsely populated areas (scattered settlements) can best be solved with site-specific solutions or by joining the municipal sewer networks. Usually, the person responsible for environmental issues in the municipality will help in choosing a suitable method.

Farmers need to invest in environmentally friendly cultivation practices and promote the establishment of 2-stage ditches, wetlands and buffer zones, for example. Measures should be targeted at the places where they are most beneficial. Communities need to be activated to apply for funding for projects with a clear targeted implementation that promotes water protection. A catchment officer can also help to protect waters through voluntary work. When residents and actors in the area are committed to improving the state of the local waters, for example the rehabilitation of streams and the cleanliness of stream beds and lake shores can be promoted together. If there is a functioning water protection association in the area, it is worth setting up projects in cooperation with them. There is a lot of collected information on the effectiveness and targeting of measures, e.g. The WaterDrive project work package WP3.1 creates a website (web address here, when it is available) to guide you in choosing the right action.