Bottleneck survey

During the summer months we check ditches that may be a bottleneck for water supply and drainage and are becoming overgrown with plants faster than other ditches. We call this inspection the bottleneck inspection. During this inspection we check whether the ditches and the important engineering structures are sufficiently maintained.

Requirements

The rules for the maintenance of ditches and associated structures (such as culverts, bridges, baffles and dams) are laid down in the Maintenance Ordinance. The Watershed Maintenance Ordinance states where the ordinance applies. It shows the minimum dimensions (width and depth) of the ditches that must be maintained and by whom.

Here's how it works

From the first Friday in June and the first Friday in August we check the ditches in the Heemskerker dune area. This is a vulnerable area in terms of water drainage because of the large difference in height and the relatively narrow ditches.

Starting the first Friday in July, we check all remaining ditches that we identify as bottlenecks.

Before the bottleneck inspection starts, you will receive a preliminary notice. If the ditch is not sufficiently wide and clean, you must clean the bottleneck before the date mentioned in the letter. The map in the announcement indicates the location of the bottleneck. Should this map still be unclear you can look up the location via the Map Bottleneck Inspection 2024 using the plot code(s) in the letter.

Example for search: type in plot code ABC00Z1234 as ABC00 Z 1234.

Nature protection legislation

When carrying out ditch maintenance, you must take into account nature protection legislationOmgevingswet). You must not harm any protected animals or plants and you must take breeding birds into account. If part of the ditch cannot be maintained due to breeding birds or protected animals or plants, please report this to the survey team.

For more information on this, please refer to the Ministry of Economic Affairs website(Information Nature Protection Act).

Contacts

The inspection team can be reached every weekday at 072-582 8282, or by using the contact form.

Frequently asked questions bottleneck survey

What is the bottleneck review?

Plants such as reeds and grasses grow in and along almost all ditches. Plants impede the flow and drainage of water. To prevent flooding, ditches must be kept clean and spacious. The bottleneck inspection is an extra check. The Water Board checks whether these ditches are sufficiently maintained.

When will the bottleneck review take place?

On the first Friday of June and the first Friday of August, a control takes place in the Heemskerker dune area. The Heemskerker dune area is a vulnerable area with respect to water drainage. Much seepage water flows out of the dunes. Since the area has a large height difference and relatively narrow ditches, rapid water drainage is necessary. Previously, this was also called the summer flood.

On the 1st Friday in July, the inspection of all remaining ditches identified by the Water Board as bottlenecks will take place.

I have received an administrative enforcement order

In the preliminary notice you received earlier we asked you to check whether the bottleneck along your plot/plots is sufficiently spacious and clean. During the inspection by the district water board, which took place after the date mentioned in the notification, it appeared that the bottleneck is not sufficiently wide and clean and still needs to be cleaned. In the administrative coercion order we request you to clean the ditch again before a specified date. After this date, the Water Board will check the ditch again.

What if the work has not been completed after the date specified in the administrative order?

Should it turn out that the bottleneck is not yet sufficiently clear and clean after the date specified in the administrative order, the Water Board will contact the maintenance party for a hearing. Eventually, the higher water board may perform the work at the maintenance party's expense. An additional €150 in administrative costs will be charged and a fine ranging between €100 and €300 may be imposed.

Frequently asked questions ditch maintenance and survey

Who should maintain the locks?

The district water board, the province of North Holland, municipalities, nature organizations, the railroad manager and the Department of Public Works (Rijkswaterstaat) have a maintenance obligation for most ditches in North Holland. But there are also ditches that half must be maintained by the owner of the plot along the ditch. If you live next to a ditch, you must maintain half of the ditch that borders your plot. The owner of the parcel across the street should maintain the other half. Cooperation is important then.

If a parcel abuts a large, wide ditch, a main watercourse, the parcel owner often must maintain only the walkways. The middle of the ditch is maintained by the water board or another agency.

Who exactly maintains which ditch and what type of ditch your plot borders on is laid down in the Maintenance Ordinance and the Waterways Legger. If you have questions about the maintenance obligation, please contact the inspection team.

When is a ditch well maintained?

A ditch is well maintained if: 

  • the ditch is free of flotsam or construction debris;
  • reeds and aquatic plants do not impede the water supply and drainage of the ditch;
  • the walkways are in good condition;
  • the shoring is well maintained;
  • the structures (such as culverts, bridges and baffles) are clean and in good condition. The owner of the structure is responsible for maintaining the ditch up to 3.0 meters on either side of the structure. Also on the side of the public road;
  • trees and plants are pruned above the water surface, at least to 3.0 meters above the waterline. 

Nature protection legislation

When carrying out ditch maintenance, you must take into account nature protection legislationOmgevingswet). You must not harm any protected animals or plants and you must take breeding birds into account. If part of the ditch cannot be maintained due to breeding birds or protected animals or plants, please report this to the survey team.

For more information on this, please refer to the Ministry of Economic Affairs website(Information Nature Protection Act).

Should I also clean culverts, and if so, how do I do that?

Culverts are very important for water supply and drainage. If dredging or other debris accumulates in the culvert, it can no longer fulfill its function. Culverts can be cleaned using water pressure.

What is a healthy ditch environment?

A healthy ditch needs oxygen. For the fish, plants and other living organisms, but also to process dead aquatic plants and tree leaves on the bottom; the decay process. The remains of the decay process remain on the bottom and form the silt layer, or dredge.

When there is little water in the ditch, oxygen is quickly depleted. Fish, plants and other living organisms can no longer live there. The quality of the water then deteriorates rapidly. So for a healthy ditch environment, it is important to have enough water in the ditch.

I am going to clean the ditch manually. What tools can I use?

  • duckweed hook: for picking up flap and duckweed
  • edge scythe: for cutting off riparian plants
  • grass shears: to clean up the slope
  • high-pressure sprayer: to hose down divers

I have a tractor or will hire an agricultural contractor. So what machinery do you use?

  • cutting basket: to remove aquatic plants from the ditch
  • mowing boat: if a ditch is too wide, you can (have) maintenance done from the water.

Did my (over)neighbors also receive a letter?

If your (over)neighbors' plot and your plot border the same ditch and both sides of the ditch need maintenance, they probably received a letter as well. However, this varies per schouw and per 'violation'. For your specific question, please contact the schouw team.

The card accompanying the letter is not correct/is not clear.

Contact the survey team and they will check your information and may be able to provide clarification on the map.

The ditch is not there (anymore).

In some cases, our Maps and aerial photos are out of date or an error has crept in. Please contact the survey team and they will check your information.

The ditch has already been cleaned.

You received a letter asking you to clean the ditch, but you have just done so. At the revisit date, you will find that the ditch is clean. You do not need to take any action.

I have commissioned a contracting company to do the maintenance, but they have not done it yet.

Contact the area manager at the general number 072 - 582 8282. Only he or she can grant extensions in certain situations.

I no longer own this plot.

If you are no longer the owner of the plot on the first inspection date, the new owner is responsible for the maintenance of the ditch. However, if you are still the owner of the plot on the first inspection date, the maintenance is yours.

Our system is connected to the data the Land Registry. It can sometimes take a while for the Land Registry to process the data. Please contact the survey team and they will check your data.

I disagree with the letter.

Contact the chimney team and they will check your information and can provide an explanation of the letter and your personal situation. The chimney staff will do their best to work with you to reach a mutually satisfactory solution. Should you still wish to object, the staff can inform you about the further procedure. You can also find the procedure on the page Objecting to a board decision.

I haven't had a letter.

Contact the chimney team, they can verify your information.

This person does not live (anymore) at this address.

You can send the letter "return to sender" giving reasons. Have you recently become the owner of a plot adjacent to a ditch and want to know if you are responsible for maintenance? Contact the inspection team, they will check your details.

I am not liable for maintenance.

Every owner of a plot adjacent to a ditch, whether agencies, businesses or individuals, is liable for maintenance for their half of the ditch.

If a parcel borders a large, wide ditch (a main watercourse), the parcel owner often only has to maintain the slope (embankment). The middle of the ditch is maintained by the water board or another agency.

Who exactly maintains which ditch and what type of ditch your plot borders on is laid down in the Maintenance Ordinance and the Waterways Legger. For questions about the maintenance obligation, please contact the inspection team.

I want to object.

Contact the chimney team and they will check your information and can explain your personal situation. The chimney staff will do their best to work with you to reach a mutually satisfactory solution to the situation. Should you still wish to object, the employees can inform you about the further procedure. You can also find the procedure on the page Objecting to a board decision.

I want to request a postponement.

We assume the maintenance was done before the inspection date. Are there crops on the land that cannot be harvested before the inspection date? Postponement of maintenance can be requested from the relevant area manager via the general telephone number 072-582 8282. With clean ditches, together we ensure that we keep water manageable in wet and dry weather.