Drainage boards prepare for mowing after damp spring

At this time of year, internal drainage boards (IDBs) are preparing to commence their essential annual maintenance programmes to mow and repair watercourses and flood embankments across England’s lowlands.

After a wet first half to the year, forecasts remain variable with a typically British mixture of hot, cold, wet and dry periods as we run into summer. Water management in most lowland parts of England is now a careful balance between draining a surplus of water to retaining and supplying water. Due to the high precipitation and low evaporation up to the end of June, the groundwater is relatively high in a number of areas for the time of year, often at a level that is more typical in the spring.

The wet winter and spring makes the starting position favourable for water management in drier weather as the soil still contains a lot of water. However, winter flooding has left a legacy of bankslips, as well as damage to pumps and other water control assets yet to be repaired, especially across eastern lowland England. A relatively warm and damp spring has also provided strong growing conditions for water and bankside vegetation, which can inhibit capacity and flow within lowland pumped catchments.

Mowing is important. Internal drainage boards mow to prevent ditches and lowland watercourses from closing up, preventing flooding and allowing sufficient water to be supplied in times of drought and also helping to maintain good water quality in ditches and drains. On embankments it is important that the grass cover is strong, helping to protect them from slumping and crest failures. At the same time, ditches and embankments are a habitat for a variety of flora and fauna, and drainage boards want to promote biodiversity. That is why IDBs mow where necessary with care, and leave vegetation where possible.

You can read more about IDBs’ maintenance of lowland watercourses and embankments in this blog.

IDBs’ staff and contractors carry out the work. In certain areas, they will have to drive over private land. They must ensure that the employees can carry out the mowing work properly and safely with the machines. To do this IDBs use a maintenance strip prescribed in their bylaws. This is a protected zone next to a ditch or stream that they use to mow the ditch with a machine, to deposit the cuttings and to inspect the stability of the banks. The width of the maintenance strip depends on the location and is a maximum of nine metres. There may be no obstacles on it that would hinder the maintenance.

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