Frequently asked questions changes Water Board Ordinance

The Water Board Ordinance contains the rules HHNK uses to protect its waterways, flood defenses and roads. Currently, amendments to the Water Board Ordinance are available for review. We have noticed that some of the amendments raise questions. On this page we answer the most frequently asked questions.

For consideration

Our Executive Board has adopted the amendments in draft form. They are available for inspection through www.officielebekendmakingen.nl and at our office, Stationsplein 136 in Heerhugowaard, until November 17, 2024. You can make a Make an appointment appointment online via our contact form or call 072 582 8282. Views may still lead to adjustments in the changes. The final amendments will be adopted in December and will take effect January 1, 2025.

Theme: low-lying area

What does designation as a "low-lying area" mean?

Since the Omgevingswet came into force (as of Jan. 1, 2024), it has been mandatory to attach to every rule imposed by a government an area where that rule applies. We call this restriction areas or areas of operation. In the Water Board ordinance that is currently available for review, the 10% most inundated plots per polder during extreme precipitation are included as a new operating area. For each polder, these are the parcels of land where the greatest volume of water temporarily reaches ground level if the water system overflows during extreme precipitation. A permit requirement is attached to these parcels for raising them.

Including the operating area does not change the land's zoning or uses. It means that the State Water Board indicates that as of Jan. 1, 2025, those parcels may not be raised without compensatory measures (assuming that the new proposed rules take effect Jan. 1, 2025). Elevating without compensation would otherwise remove the storage space currently found at that location during those extreme showers and cause that excess water to find a place elsewhere, possibly resulting in even greater nuisance and damage. This would lead to the transfer of water nuisance risks.

By including the new operating area, the State Water Board is establishing a factuality. During extreme showers, it is unavoidable that the water system may overflow its banks and temporarily occupy a spot at ground level. The Water Board knows from model analysis and practical situations which places store the most water at ground level in that situation.

How was it determined which areas were designated as "low-lying areas"?

The proposed amendment has a long history. In short, on the basis of analyses per polder we have Map which cadastral parcels per hectare receive the largest volume of water during extreme precipitation. These 10% of plots per polder where most of the water ends up at ground level have been included in the Map as 'low-lying area'. 

We realize that in some cases the data may be 6 years old, as it comes from the model analyses that ran from 2018 through 2021. We are also aware that in those intervening years there may have been spatial developments that meanwhile have caused the Map to be incorrect in some locations. Should you believe that certain plots have been incorrectly designated, we would be happy to hear from you. The fact remains, however, that in case of extreme precipitation, water at ground level cannot be avoided. If those spots are raised, then the problem is shifted and transferred to other plots within the polder.

Below we outline the process of how the proposed change came about. 

A new methodology was delivered in 2017 to use the latest tools to Map as precisely as possible the consequences of an exceptional downpour. 

In the period 2018-2021, according to this new methodology, the entire management area of HHNK was calculated in a water system analysis and an inundation image of the entire management area was determined using hydrological model analyses with recurrence times once every 10, 100 and 1000 years (based on the KNMI climate scenarios from 2014). The hydrological models include the entire water system (all watercourses, culverts, bridges, weirs and pumping stations), the elevation model of our area based on the Actueel Hoogtebestand Nederland (AHN) and the different soil types based on the soil map of the Netherlands. The results of that water system analysis were recorded in the report Protection Water Flooding Noorderkwartier 2 (hereafter referred to as BWN2 study).  

The inundation images from the BWN2 study were compared with the various flooding images that have occurred in practice in the management area of HHNK in recent years. The June 2021 flooding was the largest flooding period in which about half of the HHNK management area experienced extreme precipitation and water temporarily at ground level. With this comparison, it could be confirmed that the inundation image from the BWN2 study corresponds very well to real-life flooding situations. Both show the same places where water reaches ground level first and for the longest time. 

The insights from the water system analysis were written down in the Water Flood Control Handling Framework. During the development of the Handelingskader it was also sent in consultation to the interest groups and co-authorities in the management area of HHNK. In the meeting of April 13, 2022, the general board of HHNK approved the Handelingskader. 

Also on November 25, 2022, the room letter Water and Soil Steering was released from the Ministry of Infrastructure and Water Management. This parliamentary letter includes a number of structuring choices that guide spatial developments in the coming decades. One of those choices is choice 13: "We reserve the 5% to 10% of deep polders for water storage, preferably the deepest parts. In this way we prevent flooding due to persistent rainfall or peak showers. No new construction is allowed here unless it does not interfere with water storage capacity."

In consideration of the Chamber letter, HHNK has prepared advisory Maps in early 2023. On these Maps it is already established that a C and D label is given in terms of suitability for those most inundated locations.

With the publication of the Kamerbrief, based on the inundation image from the BWN2 study, an analysis has been made for each polder on which cadastral parcels per hectare will receive the largest volume of water during extreme precipitation. These 10% parcels per polder where most of the water ends up at ground level are included on the Map as 'low-lying area'.

How did the owners of the parcels listed as "low-lying area" learn about this?

In addition to designating low-lying areas, several amendments have been included in the Water Board regulations. Each of these amendments may lead to new permit obligations or, conversely, to the loosening of existing permit obligations or to changes in boundaries of the areas where the rules apply. All these amendments are announced by publication in the Water Board Bulletin. The current amendment to the Water Board Ordinance was published in draft form in Water Board Bulletin 2024, 21048 dated October 4, 2024. Owners can submit views against the proposed amendments during the period from 4-10-2024 to 17-11-2024. During the public inspection period, the Water Board organized a number of information sessions for residents, public authorities and interest groups. At the end of the view period, a note responding to views will be prepared in which the comments made will be responded to. The comments submitted may possibly lead to a modification of the proposed decision. Those who have submitted views will be informed how their views have been dealt with.

The move to include "low-lying areas" in the water board ordinance follows:

  • limit flooding action framework adopted by the General Board of the State Water Board which includes the rule raise = compensate (April 2022 adopted by CHI);
  • The room letter Water and Soil steering from the Ministry of Infrastructure and Water Management (Nov. 25, 2022);
  • The national policy advice following the July 2021 disaster in Belgium, Germany Limburg: "You can't prevent, you can prepare" (Dec. 19, 2022);
  • HHNK's Water and Soil Stewardship advisory maps (spring 2023).

As such, the amendment fits within already established and public policy. 

The operating areas included are the 10% most inundated parcels per polder during extreme precipitation events. By doing so, the Water Board establishes a factuality. By including the operating area, the zoning or use of the land does not change, but the Water Board indicates that from January 1, 2025 (when the new ordinance takes effect), those parcels may not be raised without compensatory measures.

Can you object to a plot being designated?

No appeal can be filed against a Water Board Ordinance. This is because the Water Board Ordinance is a decision with generally binding regulations. According to Article 8:3, paragraph 1, opening words and under a of the General Administrative Law Act (hereinafter Awb), no appeal can be lodged against that type of decision. 

It is possible that an exception does apply to the designation of a restricted area in a water board ordinance. However, case law on this is not clear, so it could be possible that a filed appeal will be declared inadmissible.

Are water rates reduced by the fact that a parcel is designated?

No, this change will not affect water board fees.

Is there any financial compensation if parcels decrease in value due to a designation?

Owners of plots of land designated as low-lying areas cannot apply for disadvantage compensation immediately after adoption of the Water Board Ordinance. Only when a concrete environmental permit for raising the land (with the condition for compensation) is granted, then disadvantage compensation can be claimed. Then the damage must have actually occurred. So it is not possible to receive compensation by applying for an environmental permit without doing anything with it. If a plot is sold after adoption of the Water Board Ordinance (for example, to a developer), the damage is foreseeable for the new owner and is also not eligible for compensation. If an owner himself decides to raise a parcel of land after the Water Board Ordinance has been adopted pursuant to an environmental permit and he/she was already the owner before the Water Board Ordinance was adopted, then there could be compensation for loss. In that case, the request for disadvantage compensation will be handled in accordance with HHNK's disadvantage compensation ordinance in force at that time (currently: HHNK 2022 Regulation on Disadvantage Compensation).

Attached is a link to the operating area'low-lying area'.

If you have a dike or a ridge of soil on your land for several years or a high ditch side, can you use it for compensation if you lower it and so the soil there becomes lower?

If someone raises a plot by lowering land on their own land or somewhere else, the compensation requirement could be met. If an already low spot is further excavated and with that (with the released soil) other low plots of land that are also inundated are raised, then on balance the storage space at ground level remains the same and the compensation requirement is met. This will have to be examined per situation by means of a permit application.

Theme: Paved surface

Compensation; should it apply to a plot path? Does it also apply to grass pavers?

A paved lot path counts as paved surface, even if grass tiles are used for this purpose. 

Depending on the location and surface of the paving to be applied, different rules apply: For the application of paved surface in a (protection zone of a) water barrier, a permit obligation applies from 25m2. For the application of paved surface outside this zoning, a permit obligation applies above 2000m2 ( see Article 2.74 of the Ordinance). In these cases, the degree of compensation will be stipulated in the permit.

When paved surface is added between 230 m2 and 2,000 m2, the degree of compensation is determined by the general rule set forth in Article 2.77:

  1. In area without level decision requirement, water runoff from paved surface must be infiltrated into the soil and retained within the same restriction area. 
  2. In areas with water table obligation, water will preferably be infiltrated into the soil insofar as this does not cause groundwater nuisance to surrounding parcels.
  3. If an infiltration facility is used, the Requirements for this must be discussed with the Water Board.
  4. To the extent infiltration is not possible or desirable pursuant to the first or second paragraph, the newly added paved surface will be compensated for by excavating 15 percent of its area as widened or new surface water within the same watershed.

Based on this general rule, it can be concluded that to the extent that water runoff from the paving is infiltrated into the soil, no surface water needs to be dug as compensation (see paragraph 4 above). It thus depends on the location and construction of the lot path whether this paving must be compensated for by digging or widening surface water. If grass paving is used, the likelihood of water being infiltrated into the soil is greater than with dense paving. The same applies to the installation of a lot path further away from the watercourse compared to a path right next to the water. 

An initiator should make his own assessment of this and inform the Water Board by providing information about the proposed activity and whether or not to implement compensatory measures. 

Theme: Compensation at damping

To compensate for attenuation, can you then also lower a plot by digging it down, for example, if you have a high ridge along the ditch or if you have had a heap of soil (sort of a dike) on your land for years?

To comply with the general rules for the construction of an access dam, compensation is achieved by widening an existing surface water body or digging new surface water with at least the same surface area within the same water level area. The moment an initiator wishes to compensate in a different way, a request for a custom rule can be submitted. The Water Board will then assess whether the proposed method of compensation adequately meets the interests of the Water Board. 

Theme: Roads

Will water board charges go down in the Edam-Volendam area because the roads are now no longer managed by Hoogheemraadschap Hollands Noorderkwartier (HHNK)?

HHNK levies road charges only in the municipalities where HHNK has roads under its management. The municipalities of Wormerland and Edam-Volendam will take back the management and maintenance of the roads in question as of 1-1-2025. This means that for the levy year 2025, residents and owners in those municipalities will no longer find a road charge on the assessment from HHNK. Water system levy and treatment levy will still be due, but the total assessment amount from HHNK will decrease. The municipalities will probably have to raise their tax rates somewhat to cover the costs themselves.