Review for water storage capacity

Every year we check in part of our management area whether the ditches still have the correct dimensions to provide sufficient water storage. We call this a water storage capacity inspection.

When there is heavy rainfall, it is important that ditches can store water. We therefore check whether the tertiary ditches still meet the correct dimensions. Tertiary ditches are ditches that primarily have a water storage function, they do not have a major influence on the water supply and discharge in the water system. Examples are ditches in contiguous natural areas or ditches on the plot of one private owner. Vegetation is allowed to remain in tertiary ditches. The plants contribute to water quality and life in and around the ditch. However, these ditches must be able to store water, which is why they must not become boggy. We check for water storage capacity during the inspection.

Requirements

The rules for the maintenance of ditches and associated structures (such as culverts, bridges, baffles and dams) are set out in the Maintenance Ordinance. The WatersRegister map shows where the ordinance applies. Here you will find the minimum dimensions (width and depth) at which ditches must be maintained and by whom.

Here's how it works

You will receive advance notice of the inspection for water storage capacity. If the ditch no longer complies with the dimensions, you will receive a warning letter (intention of administrative coercion). This means that dredging is required. You will have one year to do this. You must dredge the ditch to the solid bottom, or until it reaches the dimensions indicated in the Register map . If after one year the ditch is still not in order you will receive a so-called order under administrative coercion, and the enforcement process will start.

Contacts

The chimney team can be reached every weekday at 072-582 8282, or via the contact form.

Frequently asked questions inspection for water storage capacity

What is the inspection for water storage capacity?

During the inspection for water holding capacity, we check tertiary ditches for:

Landing: a ditch is landed when it is completely overgrown and the soggy, swampy bottom is (almost) passable. The ditch then turns into "land" and can no longer store water. At the lowest permissible level according to the level decision, there must still be water in the ditch.
The ditch should be fully connected to other ditches. This allows water to flow into tertiary ditches during precipitation. Culverts must therefore be clean. Dredge, fallen branches and other objects must not obstruct the flow of culverts.

What locks are being checked?

We check all tertiary waters in an area in the inspection for water storage capacity. The Register map water bodies indicates which ditches are tertiary. Using the aerial photograph and the Register map Waters we determine which tertiary water bodies may have reduced water storage capacity. We then inspect this selection of ditches outside.

What should I do if the ditch is silted up?

If it appears that the ditch has silted up, dredging is required. You have one year to do this. You can do this yourself, or you can hire a contractor to do it. The ditch must be dredged to the solid bottom, or to a minimum water depth of 30 centimeters across the full width of the ditch.

Contaminated/polluted dredge

Litter may have ended up in the dredge. The dredge may also be contaminated with heavy metals such as copper, lead, zinc or pesticides. If you suspect that the dredge in the ditch is contaminated, you can have it investigated. If it turns out that the dredge is indeed contaminated, the costs of the sampling and the additional costs related to the removal of the contaminated dredge will be reimbursed by the Water Board.

During which period may I dredge?

The best time to dredge is outside the breeding season. The period for the breeding season is March 15 to July 15. Therefore, the work can be done year-round except between March 15 and July 15. Do legally protected species occur in the ditch? If so, contact an ecological expert to determine an appropriate period for the dredging work.

I have had advance notice

HHNK sends a pre-announcement to maintainers before the inspection for water storage capacity takes place. In the advance notices we indicate when the inspection will take place.

I have received an intention to issue an administrative order

If the inspection for water storage capacity shows that a ditch for which you have a maintenance obligation does not meet the dimensions established in the Register map Waters, you will receive an intention for administrative enforcement. In it we request you to dredge the ditch before a specified date. You will have plenty of time for this. After this date we will check the ditch again. This letter indicates which ditch is concerned.

I have received an administrative enforcement order

If, after the date indicated in the letter (intention to enforce an administrative order), the ditch for which you are under an obligation to maintain has not reached the correct depth, you will receive an administrative order. In the administrative coercion order we again request you to dredge the ditch before a specified date. After this date we check the ditch again.

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

If it appears that the ditch still does not meet the correct dimensions after the date mentioned in the administrative order, we will contact the maintainer. Ultimately, we can then (have) the work carried out at the expense of the maintainer, or impose a penalty. These costs are considerably higher than if the maintenance party itself carries out the work or has it carried out. As water manager we are obliged to have a sediment and ecological survey carried out in addition to dredging, whereas private individuals or farmers usually do not. Such a study costs at least € 1,500. To this we charge an additional € 250 in administrative costs and can impose a fine of between € 100 and € 300.

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 is laid down in the Maintenance Ordinance and the Register map WatersRegister map . 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 and am going to hire an agricultural contractor. What machinery will 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 is laid down in the Maintenance Ordinance and the Register map WatersRegister map . For questions about maintenance obligations, 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.