Tackling flood risk management and land drainage issues

Holland Windmill _65277

NFU flood management and access adviser Mhari Barnes reports on a recent trip to Holland with NFU Vice President Stuart Roberts and Michael Sly, Chairman of the North Levels IDB: 

NFU Vice President Stuart Roberts recently returned from a knowledge exchange trip to the Netherlands, to help understand how we can tackle flood risk management and land drainage issues and in particular how this can be achieved at scale and with ambition.

Coastal flood defence

The trip began with a visit to Katwijk Pumping Station where the pumping capacity is a staggering 100 m3s-1. We then went on to see their amazingly innovative coastal flood defence system that has recently been installed in Katwijk. The carefully engineered dune system not only protects the popular seaside resort from coastal flooding but also provides over 600 car parking spaces and due to its structure and design is able to be 2m lower than a traditional defence. Therein, balancing the necessity for a coastal defence system, integrated with public access and recreation whilst preserving desirable sea views.

Stuart Roberts Holland Trip Katvijck coastal flood defences_65274

Pictured above: Katwijk coastal defences: innovative flood risk asset that also provides much needed parking, looks completely natural and has won awards for being a great, accessible open space.

Tackling future flood risk issues

We then headed to the historic university town of Leiden where we exchanged ideas on how to tackle future flood risk issues in the Rijnland Water Authority’s historic offices. The water authority was first formed in 1202. One of the main surprising findings was that even though over 50% of the Netherlands is at flood risk (40% from coastal flooding), there is a growing lack of awareness from members of the public of the flood threat, which we also find in England with over one third[1] of people in England at flood risk being completely unaware. With 53% of the UK’s power stations at flood risk and protected by farmers in Internal Drainage Boards (IDB’s), we also discussed how critical infrastructure is positioned and protected and, for the Dutch, arguably nowhere is more important than at Schiphol airport which is located 4 m below sea level.

Stuart Roberts Trip to London Leiden group photo and diggers on katvijck_65276

Pictured above: The NFU team with Innes Thomson and our hosts from Waterschap Rijnland, Leiden.

We went on to discuss funding of flood defences and land drainage with Rivierenland (river lands) Water Authority and compared the Dutch model to that of the English which was helped enormously by having Innes Thompson (CEO Association of Drainage Authorities) as part of our group. Within the Rivierenland water authority they provide protection from flooding, ensure land is farmable via drainage and treat wastewater for, on average, €1 per day per household. They also maintain 1000 different water levels across their region. We received a tour of the very impressive incident response control room (AKA ‘Calamity Room’), where members of staff and the board can remotely operate pumping stations and sluice gates and make sure the flood risk is managed during an event.

Stuart Roberts Trip to Holland incident centre river lands_65272

Pictured above: Rivierenland Waterschap’s incident room.

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Pictured above: Rivierenland Waterschap’s head office.

Flood management adaptation

The team from the NFU then travelled to the west of the Netherlands to the province of Limburg. Here we visited one of the Netherland’s largest flood management adaptation projects which is part of the Dutch ‘Room for Rivers’ programme. Before the late 1980s, this was one of the only areas in Holland which was not considered to be at flood risk as it is Holland’s only ‘hilly’ area, where the highest point is 300 m above sea level. However, in 1993 and 1995 there were two major flood events which were associated with increased urbanisation and over-managing the river, which lead to it bursting its banks and over 4000 m3s-1 flowing through the town of Wanssum.

The Ooijen-Wanssum Project is well underway and after 10 years of preparations looks to be completed within 18 months. This involves a mix of re-naturalising the river’s course by literally making room for water where over 300 ha of agricultural land has been reverted to a natural river landscape and the local farmers have been compensated by having their fields raised (yes, the fields where actually raised!) so that they remain farmable. This has also involved completely redesigning their traditional dyke defences (see photo below). The project has included hard-engineered defences including ring-dykes around urban areas, widening of bridges and the expansion of the river marina. The €280 million project’s incentive to the local population was the construction of a new ring-road which will help ease the congestion of the main road through the town that used to carry over 7000 vehicles per day. This project was an outstanding example of balancing farming, environmental, commercial and urban needs in a collaborative plan rather than see them as conflicting priorities.

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Pictured above: Ooijen-Wanssum Project: top left: new discrete flood defence walls designed to protect homes and businesses from flooding. Bottom left: raising of the land, agricultural land being raised to allow more room for the river and flood storage whilst creating more farmable land. Top right: project directors and NFU visitors. Bottom right: stage board where the arrow indicates the water levels during the 1993 flood. Photo credit: I. Thomson, 2019.

Runoff rates

The team went on to travel to Southern Limburg and see the agricultural research projects that the regional water authority is funding, which included analysing the runoff rates of fields of potatoes. We finished the trip by visiting some on-farm flood water storage reservoirs and meeting the Dutch Water Authorities Director General Albert Vermue to discuss mutual issues across a range of water topics.

Stuart Roberts Trip to Holland Water board map potato experiment_65271Left: Limburg Water Authorities agricultural research project on potato field rainfall runoff analysis. Right: 14th Century map of the Rijnland Water Authority.

Our main take home messages include:
  • Solutions cannot be found through blame.
  • Everyone must own the problem.
  • Farmer/landowner and community involvement throughout is crucial (60% of farmland in Holland is tenanted).
  • Increased awareness of flood risk is important and both countries need to work to improve this.
  • Be ambitious! In order to tackle the impacts of flood risk and coastal erosion which is increasing in magnitude and frequency with climate change we need to encourage ourselves and the Government to take a more ambitious approach to protecting agricultural land from flooding and coastal erosion and doing so in a way that seeks to balance both food production and the environment.

    Overall, the trip has been a real eye-opener for all involved. We went with an open mind and have embraced the opportunity to share problems and potential solutions that we have in England and have brought home some innovative ideas whilst took solace in the fact that, somewhat reassuringly, we aren’t the only ones struggling with the lack of awareness.

    After what we have learnt on this excursion, we believe that in the battle between food production and the environment water can be a unifying force.

    Last edited on: 28:05:2019

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  • Posted by: Robert Helliwell Posted on: 03/07/2019 11:24:39

    Comment: Does the Dutch government have a policy on badgers where drainage is concerned?

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