Deploying rainwater detention measures on farmland could see farmers paid to prevent flooding downstream from their lands, researchers in the SloWaters scheme told a conference on the project’s findings last Thursday.

SloWaters trialed measures on demonstration farms, such as soil banks around field boundaries, aimed at collecting rainwater during times of heavy downpours to release these waters slower into waterways in the hours after storm events.

The project found that bunds can be effective in slowing the release of rainwaters from lands and lessening waterways peak flow during flood events.

“All you need is for the take-off from the stream to be active during that period. You can store it then beyond the flood peak,” PhD candidate Darragh Murphy who conducted research as part of the project said.

“When we are talking about flood storage, we are talking about fields that are wet during that critical part of a flood and just a little bit longer than that part of the flood.”

Grass growth

Murphy found that winter grass growth slowed down in the areas where flood waters were accumulated in the field, but during summer months, grass growth was higher across the field where the measures were in place and in the areas where floodwaters were held.

The researcher explained that as measures are farm-specific, “tweaking” is often needed to ensure that flows in and out of the water retention measures are at optimal levels. “It will take tweaking but if someone has experience in this, they can do it quite quickly. I don’t think it will be left up to the farmer or the landowner to do it,” he said.

Dr Paul Quinn of the James Hutton Institute explained that real results can be achieved in mitigating flood damage when a series of rainwater retention features are installed by neighbouring farmers along a body of water.