Brief summary of the meeting on 15 May 2019 on The value of almost lost knowledge

Organised by KIVIA Department ofLand Use and Water Management

Programme:
15h00 to 15h25 - Govert D. Geldof: On complexity and acting at the source, the capillaries.
15h25 to 15h50 - Albert Corporaal: Spongity and catchment
15h50 to 16h10 - Break
16h10 to 16h35 - Ronald Wentink: Drop(sge)wijs
16h35 to 17h00 - Chris Griffioen: Back to the "small"

Acting at the source, in the capillaries

by Govert D. Geldof

We used to be so stupid

I start with an example of water management many years ago. The story was told to me on 27 November 2008, at a water conference in Mashhad, Iran. A ministry interpreter provided the simultaneous translation. You will find it on page 141 of my most recently published book.

"More than three millennia ago, people in Persia started building qanates. These are masonry underground canals, running from mountain ranges towards the river. From the qanates, lands were irrigated. They were managed by the Buneh, a kind of water board. Let's say an irrigation board. The men of the Buneh maintained the qanates and ensured a fair distribution of water. Naturally, many farmers felt they were getting too little water. Even then, people knew that if there was a dispute between two parties, a third party had to be appointed. In this case, that was the local barber. This fulfilled a pivotal function. The barber shaved and cut the Buneh's men for free and was paid from a share of the farmers' agricultural proceeds. This created mutual dependence. If people were dissatisfied with the Buneh's men, their beards grew. They made every effort to prevent that. Also, stories were told in the barber's workshop. Exchange of practical experiences took place there. At the barber's, you heard the latest news. As a result, water management was fully socially embedded. People knew that their craftsmanship was an essential part of the system they managed. The Persian word for irrigation is therefore Ab Yari. Ab is water, Yari means cooperation. Irrigation for the Persians was and is water cooperation."

A closer look at this way of doing things reveals that (1) practice was central and (2) it looked not only at water, but also at social embedding. Qanates were part of Persian culture. Worldwide, you find examples like this throughout history, with the Romans, Incas and also in the Netherlands. I myself live in the Tzummerpolder, an area that already in the 10th century had a brilliant water system with top yields for farmers. There was hardly any salinity damage and the soil remained healthy.

Ever better tools

In modern times, we are getting more and better tools at our disposal. When I started working, four of us still shared a PC. Mathematical models were limited in performance and engineering structures - such as dams, locks and pumping stations - were operated manually. We often went into the field to see how water systems functioned, placed our own monitoring wells and talked to farmers and field staff. We tried to understand how water systems worked in practice. We used spreadsheets to calculate the consequences of measures. Gradually, the tools became more sophisticated, faster, more integrated and more comprehensive. Increasingly, we filled our days behind our own PCs. The number of meetings increased.

Means become ends

At some point, tools became so complicated that it became an end in itself to handle them properly. To feed algorithms, huge amounts of data need to be collected and the large number of stakeholders in water projects necessitates more and more frequent meetings. How can you still match all that? Gradually, we have started to focus more and more on what is measurable and modelled - the main structure of water systems - and the water systems in the capillaries have fallen out of the picture. Water boards are shedding the small watercourses.

Climate change

In studies on the impacts of climate change, it is becoming increasingly clear that measures at source, in the capillaries, are most effective. Healthy soil holds more water, can store a lot of water and those who fully understand the hydrology of a ditch can work miracles. In towns and villages, a game is taking place around homes, in backyards and flowerbeds, with residents playing a starring role. Every square metre is different. The knowledge to act there successfully is still there, but is in danger of being lost. For many, the small-scale is not interesting enough.

The challenge

When it comes to knowledge, the challenge is to retrieve the wisdom of 'the past' and connect it to the achievements of modern times. This means seeking out more complex realities and occasionally daring to apply simple means. Or 'just' drawing up a water balance on the back of a cigar box, if they still exist. By understanding how people used to manage water and combining that with the technical capabilities we now have at our disposal, the chances of facing climate change with wisdom increases.

Spongity and catchment area

by Albert Corporaal, Hasselt

Over the past decades, we have paid a lot of hydrological and hydraulic attention in our country to defending ourselves against too much water: we have raised the dykes because the expected high tides were getting higher and higher, we have increased the discharge capacity of all kinds of waterways because more and more water had to be drained from upstream, and so on. To cap it all, the peak discharge will come under further pressure when the intensity of the showers is expected to become very heavy from time to time. In short, we seem to have to keep defending ourselves as and when, and technically we seem to be able to do so all the time and are in a position to cope with the runoff and related threats. But in the meantime, drought and the likelihood of periodically increasingly severe drought also seems to be increasing: we are going to suffer more and more frequently and more frequently from water shortages, both in the growing season and in the winter half-year. And on balance, the future prospect of more drought and even faster (and better.....) runoff creates an 'uncanny' feeling. Fortunately, especially in areas with predominantly free-flowing water, we recognise such risks better, and relevant water boards have for some time been employing a 'triad of measures' to keep reported risks manageable. In the way of seeing advocated here, the author goes one step further, something he has elaborated for the Vecht(e) basin in Overijssel and adjacent Germany: in a booklet on the subject, he points to the possibility of starting to exploit the sponginess of the landscape, and he proposes to bring the resistance of the landscape into play. The stance is to retain precipitation upstream and only allow maximum delayed discharge after necessity. The next step is then to first - given drought - stockpile the water, and only then to start storing it in more downstream situations, only to let the water drain as a last resort. The triad has been 'extended' to a quintet. This quintet of measures aims to make our environment hydrologically and hydraulically suitable for the coming future in which both drought and flooding are on the agenda. The first calculations concerning the Vecht river basin show that this new approach is sensible, sustainable and affordable. It is even an alternative to all kinds of downstream measures, such as the ever-increasing dyke heightening.

Besides all kinds of technical provisions and adjusted sequencing (from three to five), it requires a change of thinking on the part of those potentially involved, which has yet to be embedded socio-economically. It also requires stakeholders in the river basin to feel mutually responsible for and involved in each other's hydraulic and hydrological problems. It requires cooperation, both nationally and internationally.

Crucial to success is always starting in the capillaries of the system, i.e. 'at the top' of the river basin, so also at the top of each sub-basin. For example: for the Vecht, we should not only think of measures in 'Münsterland' that are good for the Netherlands, but also take measures in southeast Drenthe to ensure that the Coevorden-Vecht region does not experience peak loads in the Vecht: you should not pass on the problem, but work together.

In fact, the same applies to so-called 'flood control' in the Meuse and Rhine systems. Put energy into the tributaries and their smaller systems, which can prevent peak loads from occurring in the main system. Moreover, it can contribute to groundwater levels in times of water shortages. If we just accept that the Rhine and Meuse appear to be increasing their discharge, we will have to defend ourselves even more against water, i.e. raise the dikes even more. And as a nasty side effect of the increased discharge, periodically, especially during rainfall shortages, we get more and more frequent and intense navigation problems: the drained Rhine and Meuse become increasingly difficult and even non-navigable.

Drop(sge) of water flows back to the drop

by Ronald Wentink

In the new housing estate Colmschate in Deventer, excavations in 2004 found a house plan from the 7th century BC. At that time, people were looking for a suitable place to live and to get food so they could survive. Therefore, they also often lived far apart to have enough space. Man adapted to the environment. Gradually, however, urbanisation set in with people living much closer together and dividing space according to different functions.

Urbanisation brought with it new problems such as rainwater runoff from all the paved surfaces. This disturbed the natural water balance, where in an unbuilt area most of the rainwater infiltrates or evaporates. More and more water started to run off quickly, leading to local flooding, increased soil desiccation and higher temperatures in urban areas. A good example of this is the Roman Empire in Italy. The Romans devised solutions like raised pavements along the road in which sewage and rainwater were drained. Stepping stones allowed pedestrians to get from one side of the road to the other with dry feet. They also collected rainwater from roofs for use as drinking water, among other things.

Today, the problems are more extensive due to the scale of cities in our times and climate change. To cope with these, we need to restore the natural water balance, so more infiltration and evaporation in the urban area and less run-off. We also need to provide temporary buffers to collect rainwater. Doing this as close as possible to the source, the falling raindrop, will prevent (unmanageable) large water flows. So we need to get to work in the capillaries of the system. This will not happen overnight. We will therefore have to deal with large water flows for some time to come. The Roman solution of aqueducts remains a robust solution to reduce or prevent water damage in homes and businesses. The trend of flat slab paving from door to door, as is often found in shopping streets and malls, does not help. We are in danger of forgetting the lessons and experiences of the past with this. We will have to (re)design our city smartly when the opportunity arises. That could be during a sewer replacement, road reconstruction or utility works. So we need to hitch a ride with other interventions in the city. Then we can construct facilities such as permeable pavements and/or water-storing roads, wadis, underground infiltration facilities, etc. Gains can also be made on one's own property. By not tiling the garden but (partly) greening it, the amount of run-off rainwater is reduced and infiltration is promoted.

But perhaps we should move towards a completely different structural way of designing the city. Less paving, more greenery. Or, where paving is necessary, use it to buffer water underneath. We can also use roofs more as a second ground level by greening them and using them as gardens or for urban horticulture, for example. There are more and more examples in the Netherlands of streets and neighbourhoods being climate-adapted. These are not a sum of all technical requirements, but are more focused on people's well-being. This requires adaptation from designers and users of public space, but also from residents with regard to their own gardens. A joint task that will benefit us all.

Back to the "small"

by CJH Griffioen

In their presentations, Govert Geldof, Albert Corporaal and Ronald Wentink indicated that the key to achieving a robust sustainable water system lies at the source of the catchment, at the capillaries of the system. However, the knowledge and experience of this "small" is in danger of being lost.

What knowledge and experience is relevant to deal with the small?

First, it is necessary to have knowledge of the design assumptions, shortcomings and functioning of the current system ( experiential knowledge) in practice. For example, for the sandy area of Salland, in the 1960s and 1970s, a major approach was taken to water management. Work was then done from large (downstream) to small (upstream). Uniform agricultural standards were used, aimed at rapid discharge of water in a normative situation. Groundwater played little or no role.

After that time, enlarging and accelerating the discharge based on the "you ask and we turn" principle continued until around the 1990s. This was done without much thought and again based on standards. During that period, underdrains and drainage systems were constructed and small ditches were further enlarged again. In addition, landowners accelerated the drainage of water from their own land.

The consequences of the drainage works soon became apparent. Water flooding in downstream areas had increased and Dehydration of agricultural and natural areas had occurred throughout the area.

These problems were solved by large-scale again often downstream projects (building pumping stations, raising dykes, large-scale storage, enlarging watercourses). In addition, large-scale supply plans were implemented and the need for irrigation from ground and surface water increased sharply.

The (measured course) of the groundwater levels shows that the drainage works caused the normative high water level to drop sharply. But the average highest and lowest levels have also dropped in an undesirable way. In addition, the dynamics of the groundwater gradient, which is important for nature, has strongly decreased.

Undesirable increases in water nuisance or desiccation have thus largely been caused by the design of the system. Water level management cannot compensate for the negative effects of the system's layout.

To turn the tide, the Water Boards and the then Rural Area Service launched the Waternood (Water System-oriented Norming Design and Dimensioning) system in 1998. The main features of this approach are that the design must be based on groundwater requirements under normal conditions, and because conditions are different for each area, customisation is necessary. In 2000, the central government came up with the three-stage strategy: Retention, Storage, Drainage. The essence of this is that in wet times water should be retained upstream as much as possible.

In summary, the solution to the current problems of drought and flooding, as well as the consequences of climate change, can largely be eliminated and absorbed by cleverly designing the capillaries of the system. However, knowledge and experience with this "small" is insufficient or in danger of disappearing because:

the "big" is considered more interesting,

customisation is difficult,

the required social cooperation/coordination is difficult,

the connection between ecology, hydraulics, hydrology, land use, landscape is complex,

the input of experiential knowledge is difficult.

In addition to the knowledge and experience functioning of the current system, the knowledge of :

Preparation and interpretation of water balances (precipitation, evaporation, discharge, inflow, storage) over different periods( 10 years, year, dry period, wet period ). In particular, knowledge of the influence of storage (in ground and surface water ) is lacking.

The relationship between groundwater and surface water including knowledge of.

The influence of a level change ( how fast and how far does it affect)

The resistance between surface water and groundwater

Understanding the draining effect of the watercourse and the effect of water supply .

Knowledge of the flow of water through vegetated watercourses and its use in watercourse design. Especially in upper reaches, vegetation can contribute to water retention (storage) and contribute to the desired ecology. This knowledge is indispensable for applying the principles of Building with Nature in ordinary ditches with a hydrological function.

Knowledge of possibilities of water storage and retention on land.

No matter how good the design is, there is always a situation where the system is not designed and water will end up on land. This involves knowledge of:

Where will the water be. How does it steam across the land. How to ensure that each area " collects its own water".

Lecture: The value of almost lost knowledge

By Chris Griffioen (KIVI Division of Land Use and Water Management), Govert Geldof (Geldof CS), Albert Corporaal (Landscape Ecologist) and Ronald Wentink (Tauw).

Location: TAUW, Handelskade 37 in Deventer (room 6008/6009)

The KIVI Section for Land Use a Water Management is organising an inspiring afternoon on "Almost lost knowledge".

Increasingly, when solving water management problems (too wet or too dry), large-scale solutions are sought, such as building pumping stations, barriers or modifying rivers and large downstream watercourses. However, effective sustainable solutions are often at the scale level of the farmyard, ditch and backyard. For various reasons, these solutions are increasingly out of the picture as knowledge about how water management (ground and surface water) works at this scale, especially under normal conditions, is in danger of being lost.

Some think that over time we have become increasingly clever in water management. We show that this is only partly the case. Precisely because people used to have less powerful computational tools, they had to be clever in other ways. We will show how people already had top agricultural yields along the Wadden coast from the 8th century onwards, without salinisation damage, and how effective flow fields were in the eastern part of the Netherlands.

We will discuss 15 May the opportunities that exist and the knowledge needed to engage the entire landscape for water management in the future, for both urban and rural areas. This requires connecting modern knowledge with practical ways of working at the small scale level. Both reinforce each other and make our work more inspiring and less complicated. In doing so, we do sound the alarm: knowledge about the latter is in danger of being lost.

Participation fee:

- Free for KIVI members and students

- Others € 25,00 (incl 2 month donor member) or € 120,00 (incl 12 month donor member)

Register via the registration button on the right.

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