Technical solutions

Existing solutions for PMF risk management

A range of solutions are already used to reduce flood and runoff risks at local and catchment scale. These contribute to slowing down water flows, improving infiltration, and reducing soil erosion.

However, despite their proven effectiveness, their implementation remains limited and uneven across regions. One of the main barriers is the lack of structured and harmonized data to properly assess risks and to evaluate the real impact of these measures, which significantly limits decision-making support for local authorities.

Find a few examples of the existing solutions for the mitigation of muddy floods, that are already used in most places:

Stormwater basin

A stormwater basin is an artificial temporary storage area that collects excess rainwater during heavy rainfall. It helps slowing runoff.

This solution has limits because the volume of water is too great and the flow is too fast. In addition, the storm water basin fills with muddy water contaminated by pesticides and other pollutants. This results in significant costs to treat the muddy water at wastewater treatment plants.

Natural flood storage area

Natural flood storage areas can consist of landscapes such as wetlands and floodplains. In case of heavy rainfall, they temporarily retain water and slow down runoff. They naturally filter water and reduce soil erosion.

However, they are biotopes, which means that when a muddy flood phenomenon happens, the biodiversity is destroyed.

Cover crops

Cover crops are plants grown between main cropping seasons to protect agricultural soil from erosion. They improve water infiltration and stabilize soil structure, which reduces muddy runoff. They also improve soil fertility and reduce nutrient loss.

Examples of cover crops are oat, mustard, oilseed radish and winter rye.

Hedgerow

Hedgerows are lines of schrubs or small trees planted along field boundaries to reduce soil erosion and mitigate muddy floods. They also improve water infiltration and actively reduce soil loss.

Unfortunately, they have been slowly removed from field landscapes, which increased the impacts of mudslides.

Fascine

A fascine is a bundle of branches made from flexible wood placed across slopes, at the edge of agricultural fields or along small valleys, to slow water flow and trap sediment. They are simple, low-cost and nature-based. They help reduce soil erosion.

Well-oriented furrows

When they are perpendicular to the slope, furrows can also slow water runoff. Instead of rushing downhill and creating muddy floods, water infiltrates the soil.

Although this solution is effective, it still needs complementary solutions.

MUDCAP solutions

The MUDCAP project will develop practical solutions that support better decision-making and that are designed specifically for local actors. Building on existing knowledge and solutions already used across NWE, the project will develop a transnationally shared approach for risk mapping, local risk assessment, and the evaluation of mitigation measures. A digital decision-support tool and a practical guide will be made available to help municipalities and river basin managers identify priorities and choose suitable actions. These solutions will be designed to be simple, useful, and directly applicable for people working on the ground, while also supporting the activities developed in WP2.

You will find them in this section.