By The Finnish Waterdrive team & Mikko Ortamala. Water Management Planner, MSc Environmental Ecolo-gy. Drainage Center of Southern Finland/ Water Protection Association of the River Kokemäenjoki

In Finland, the renovation debt concerning the basic/arterial drainage channels has been proven to be considerable, and due to changes in the agricultural context, the implementation of measures has become more challenging and complex.

One considerable factor/cause of the nutrient load from agricultural areas is the poor condition of the agricultural soils. The main reasons for this are monoculture as well as the insufficient drainage capacity and drainage depth of the drainage channels, leading to waterlogged fields and problems with flooding, which in turn has led to wetter, less ideal moisture conditions, in terms of both plant growth and soil bearing capacity. Additionally, monoculturally farmed fields with less than optimal water management tends to be compacted, which also worsens the infiltration and water storage capacity. The underlying reason for the whole situation is the repair debt of the drainage infrastructure in conjunction with soil subsidence, the increased flowrate of runoff as well as changed hydrological conditions due to climate change. The basic drainage needs to ensure the proper functioning of the field/tile drainage, which in turn is a basic requirement in order to maintain a good soil structure and good growing conditions. Improving the drainage will not necessarily alone improve soil structure and growing conditions, but a more comprehensive plan for improving the soil condition is often needed. Once the basic requirements for sustainable farming are met, environmental measures can be planned and implemented cost-effectively.

The drainage corporate bodies should once again, in collaboration with authorities and water management planners, uptake the responsibility for maintaining the condition of the basic drainage channels. Water management should also be an integrated part of the farm-specific advice.

Holistic agri-environmental water management contains field drainage and basic drainage, as well as comprehensive runoff management where also aspects such as biodiversity and fishery are taken into account. Holistic water management aims to remove problems with flooding and waterlogging on agricultural lands as well as to improve the growing conditions and the soil structure, and therefore decrease the nutrient and sediment load. A holistic approach seeks to, in a coordinate manner, improve the conditions for agricultural production and at the same time secure water and environmental protection.

A systematic, phased implementation on a catchment-scale is more likely to secure better results concerning both sufficient drainage on agricultural lands as well as decreased nutrient load. In order to decrease the renovation debt, a more systematic and planned approach should be strived for in contrast to the current unsystematic and random operating model/activities.

Information about holistic water management should primarily be targeted to farmers, landowners and drainage corporate bodies in the risk areas. The regional authority (ELY-centre) would be a natural actor to coordinate the targeting of funds to the most critical areas. A regional coordinator could be funded by state subsidies either through a project or a new form of support or service.

Some of the tasks of the drainage corporate bodies

Drainage corporate bodies

Restauration of drainage systems and drainage channels

Constructed wetlands

Two stage ditches

Filter ditches

Structure liming

Small wetlands

Phosphorus ponds Soil mapping

Based on River Loviisanjoki Renovation