The following flood management measures are classified as level 1. This means that they require minimum or no consultation with authorities such as the Yorkshire Dales National Park Authority (YDNPA) or Environment Agency (EA). The measures are usually low cost and simple to install, but extremely effective.
Increasing soil permeability – reducing soil compaction
Compaction is where soil has been squashed into a solid, impermeable layer, either at the surface or within the topsoil. This band restricts the movement of air, water and nutrients down through the soil profile.
The effects of soil compaction can be detrimental to grass and root growth, reducing the ability of grass to pick up nutrients, particularly nitrogen and water, from the soil. It creates conditions for waterlogging and poaching and increases the risk of runoff, leading to soil and nutrient loss. Wet soils stay colder for longer, reducing the number of available grazing days. They can also make harvesting difficult, which is likely to reduce the quality of the resulting silage. Runoff from compacted soils is 50-60% higher than on aerated healthy soils.* Soil compaction can be caused by a range of things, from grazing livestock to farm machinery.
*Agriculture and Horticulture Development Board (AHDB), 2016
Creating and managing buffer strips
Creating a network of grass strips next to watercourses and ditches – known as riparian buffer strips – can provide a physical barrier that helps restrict the flow of storm water, carrying sediment and nutrients, and preventing them from being washed from the field into the watercourse.
In-field buffer strips, as their name implies, are found adjacent to field boundaries and across fields. They can reduce overland flow impacting roads and neighbouring properties.
Planting and managing hedgerows
Hedgerows are an intrinsic part of the landscape within many areas of the National Park and owe their existence to the need to divide grassland into conveniently-sized grazing pastures for livestock.
Hedgerows provide excellent natural weather barriers and ideal habitat for farmland birds and wildlife species, but also perform a Natural Flood Management function by trapping and slowing water flow.
Well-sited and well-managed upland, floodplain and riparian woodland can contribute to the delivery of a host of outcomes. They provide important wildlife habitat, and increased canopy shade and shelter for water-based flora and fauna. They can also provide shade and shelter for livestock, and prevent damage to crops and soil erosion.
There is growing interest in the potential to use woodland measures to help reduce flood risk. The Forestry Commission (FC) has been directly involved in a number of trials and demonstration projects – for example, at Pickering. These projects have shown that looking after existing native woodlands and plantations, and targeting certain areas for tree planting, will significantly slow overland flow of water and reduce river bank erosion within that area.
Winter cover crops
A cover crop is a non-cash crop grown primarily for the purpose of ‘protecting or improving’ the soil in between periods of regular crop production. Cover crops can be used repeatedly as part of an arable rotation’s long-term strategy to reduce winter runoff and soil loss, improve soil quality and organic matter, and provide other benefits.
Agriculture and Horticulture Development Board (AHDB), 2015
Cross drains in farm tracks
Tracks provide a significant transport pathway for water and sediment. This creates problems with erosion of the track and deposition of sediment on farmland, roads or watercourses. Tracks are costly to repair, but are essential to the farm. A cross drain is a system to move water across a path or route and can be used to collect runoff from a vulnerable area.