Het Waterschapshuis · Publieke Dienstverlening Op de Kaart

Dutch source

Water authority data (IMWA and DAMO)

Six map services from Het Waterschapshuis with the assets of all 21 Dutch water authorities in one national model (IMWA): structures such as pumping stations, weirs, locks and culverts, flood defences and how they are built, surface water, water level areas, protection zones and the wastewater chain (sewage pumping stations, treatment plants, pipes). On 16 October 2026 it held 8,566 pumping stations, 53,137 weirs, 626,869 culverts, 37,419 water level areas and 317 wastewater treatment plants. Every object names its water authority. Via PDOK as OGC API, and for five of the six also as WFS and WMS.

Climate and environment Housing and landOpenAPIMap layerNetherlands · object (pumping station, weir, water level area …)

Up to date · updated 15 hours ago · checked 17:23

Pumping stations per water authority: most Hoogheemraadschap Hollands Noorderkwartier (2,293 pumping stations), then Wetterskip Fryslân and Hoogheemraadschap van Rijnland

Pumping stations per water authority, October 2026, in pumping stations. Total: 8,565; the largest 12 of 21 categories are shown. Hoogheemraadschap Hollands Noorderkwartier is 27% of the total. Counted from the waterbeheerder field of each pumping station. How finely a water authority registers its pumping stations differs.

Source: Het Waterschapshuis, Waterschappen Kunstwerken IMWA via PDOK (WFS) · opgehaald 25 oktober 2026Open the table Single block

Water authority structures by type: most culverts (626,955 objects), then bridges and fixed dams

Water authority structures by type, October 2026, in objects. Total: 956,399; the largest 12 of 18 categories are shown. Culverts is 66% of the total. Each type is a separate layer; counted per layer with resultType=hits.

Source: Het Waterschapshuis, Waterschappen Kunstwerken IMWA via PDOK (WFS) · opgehaald 25 oktober 2026Open the table Single block

What can you do with it?4 ideas

Getting started

Every pumping station in the Netherlands on one map

8,566 pumping stations, each with name, code and water authority. Hollands Noorderkwartier registers 2,293, De Dommel 60: the low-lying west pumps, the higher south and east hardly do.

Getting started

Where is sewage treated?

The wastewater chain API has 317 treatment plants, 2,815 sewage pumping stations and 101 emergency outlets. Find the plant near you and follow the pressure mains to it.

Advanced

Which water level applies where?

Water level areas (37,419) and water level decision areas (3,937) show how the land is divided into compartments with their own level. Overlay them on the AHN to see how far the water is below ground level.

Advanced

Mapping fish migration

1,526 fish passes against 53,137 weirs and 8,566 pumping stations. Work out per watercourse whether a fish can get past, or where the bottlenecks are.

How to process it4 steps

Pick the right API
There are six OGC APIs under api.pdok.nl/hwh/: structures (v2, 18 collections), flood defences (27), surface waters (5), water management areas (7), zoning (8) and wastewater chain DAMO (18). The collection list and dates are under /collections.
```
https://api.pdok.nl/hwh/waterschappen-kunstwerken-imwa/ogc/v2/collections?f=json
```
Pumping stations of one water authority
Filter on waterbeheerder (exactly the name as in the data), at most 1,000 per page; the next link in the response gives the following page. GeoJSON in degrees (CRS84).
```
https://api.pdok.nl/hwh/waterschappen-kunstwerken-imwa/ogc/v2/collections/gemaal/items?f=json&limit=1000&waterbeheerder=Wetterskip%20Frysl%C3%A2n
```

Counting with the WFS

The OGC API gives no total. The WFS of the same dataset does: resultType=hits returns numberMatched, also with a filter.

https://service.pdok.nl/hwh/waterschappen-kunstwerken-imwa/wfs/v2_0?service=WFS&version=2.0.0&request=GetFeature&resultType=hits&typeNames=stuw

Which fields are there?
/schema lists all fields with their type; /queryables the fields you can filter on (for gemaal only naam, guid, nen3610id and waterbeheerder).
```
https://api.pdok.nl/hwh/waterschappen-kunstwerken-imwa/ogc/v2/collections/gemaal/queryables?f=json
```

Interesting combinations

coördinaten

How high is the land in each water level area?

Compute the average ground level per water level area from the AHN. Large differences within one area point to wet or dry spots.

Combine with Actueel Hoogtebestand Nederland (AHN, national elevation model)

coördinaten (gemaal bij meetpunt)

Do pumping stations work harder at high water?

Find pumping stations near a Waterinfo station and compare the outside water level with the pump capacity (field maximalecapaciteit, often empty).

Combine with Waterinfo and Water Web Services

Similar sources

Waterinfo and Water Web Services
Water level and discharge measurements in national waters; the water authority data are the assets themselves, without measurements.
BT
Basisregistratie Topografie (TOP10NL, waterdelen) not in the index yet
National topographic map of all water, but without pumping stations, weirs or water levels.
Climate Impact Atlas (Klimaateffectatlas)
Maps of flooding and flood risk; the water authority data show which structures hold back or drain the water.

What to watch out for

Licences differ per API
Flood defences and surface waters are CC0. Structures, water management areas, zoning and wastewater chain DAMO are CC BY-SA 4.0: attribute and share alike. The INSPIRE version Waterschappen Hydrografie (api.pdok.nl/hwh/waterschappen-hydrografie) is CC BY-NC-ND 4.0 and therefore not open.
Many fields empty
The model has dozens of fields per object, but water authorities fill them differently. For the first pumping station in the API, name, capacity and function are empty; water level areas often lack the levels themselves.
No totals in the OGC API
The OGC API returns no numberMatched. Count with the WFS (resultType=hits), which exists for structures (v2_0), surface waters, water management areas, zoning (v2_0) and wastewater chain DAMO (v1_0), not for flood defences.
Registration differs per authority
A comparison between water authorities also reflects how finely they register. Hollands Noorderkwartier includes many small polder pumping stations.
Few filter fields
Each collection can be filtered on only a few fields (naam, guid, nen3610id, waterbeheerder, sometimes code). For other selections, fetch everything or use the WFS with a FES filter.

APIOGC WFS 2.0.0 · read 16 Oct 2026

StandardOGC WFS 2.0.0docs

Access no key

No key. Fees: none; access constraints: https://creativecommons.org/publicdomain/zero/1.0/deed.nl. from the description

Size8,520

features in waterschappen-kunstwerken-imwa:gemaal tested

Formats

application/gml+xml; version=3.2text/xml; subtype=gml/3.2.1text/xml; subtype=gml/3.1.1application/json; subtype=geojsonapplication/json

Base URL

https://service.pdok.nl/hwh/waterschappen-kunstwerken-imwa/wfs/v2_0

Endpoints 5

GET?request=GetCapabilitiesservice description
GET?request=DescribeFeatureTypefields of a layer (XSD)
GET?request=GetFeaturethe features themselves, with geometry
GET?request=ListStoredQueriesstored queries
GET?request=DescribeStoredQueriesstored query details

Layers and projections

Putwaterschappen-kunstwerken-imwa:putEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Sluiswaterschappen-kunstwerken-imwa:sluisEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Vuilvangwaterschappen-kunstwerken-imwa:vuilvangEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Coupurewaterschappen-kunstwerken-imwa:coupureEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Vispassagewaterschappen-kunstwerken-imwa:vispassageEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Hevelwaterschappen-kunstwerken-imwa:hevelEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Bodemvalwaterschappen-kunstwerken-imwa:bodemvalEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Duikerwaterschappen-kunstwerken-imwa:duikerEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Brugwaterschappen-kunstwerken-imwa:brugEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Stuwwaterschappen-kunstwerken-imwa:stuwEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Zandvangwaterschappen-kunstwerken-imwa:zandvangEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Aquaductwaterschappen-kunstwerken-imwa:aquaductEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Voordewaterschappen-kunstwerken-imwa:voordeEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
VasteDamwaterschappen-kunstwerken-imwa:vastedamEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Afsluitmiddelwaterschappen-kunstwerken-imwa:afsluitmiddelEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Gemaalwaterschappen-kunstwerken-imwa:gemaalEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Sifonwaterschappen-kunstwerken-imwa:sifonEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326
Verbeterinstallatiewaterschappen-kunstwerken-imwa:verbeterinstallatieEPSG:28992, EPSG:25831, EPSG:25832, EPSG:3034, EPSG:3035, EPSG:3857, EPSG:4258, EPSG:4326

Filtering from the description

OGC Filter Encoding (FES 2.0)

PropertyIsEqualToPropertyIsNotEqualToPropertyIsLessThanPropertyIsGreaterThanPropertyIsLessThanOrEqualToPropertyIsGreaterThanOrEqualToPropertyIsLikePropertyIsBetweenPropertyIsNullEqualsDisjointTouchesWithinOverlapsCrossesIntersectsContainsDWithinBeyondBBOXDuring

Parameters 6

`typeNames`	which layer: waterschappen-kunstwerken-imwa:put, waterschappen-kunstwerken-imwa:sluis, waterschappen-kunstwerken-imwa:vuilvang, waterschappen-kunstwerken-imwa:coupure, waterschappen-kunstwerken-imwa:vispassage, waterschappen-kunstwerken-imwa:hevel, waterschappen-kunstwerken-imwa:bodemval, waterschappen-kunstwerken-imwa:duiker, waterschappen-kunstwerken-imwa:brug, waterschappen-kunstwerken-imwa:stuw, waterschappen-kunstwerken-imwa:zandvang, waterschappen-kunstwerken-imwa:aquaduct, waterschappen-kunstwerken-imwa:voorde, waterschappen-kunstwerken-imwa:vastedam, waterschappen-kunstwerken-imwa:afsluitmiddel, waterschappen-kunstwerken-imwa:gemaal, waterschappen-kunstwerken-imwa:sifon, waterschappen-kunstwerken-imwa:verbeterinstallatie	from the description
`outputFormat`	e.g. application/json for GeoJSON	from the description
`srsName`	projection, e.g. EPSG:4326 for web maps (default EPSG:28992, RD)	from the description
`count / startIndex`	paging	from the description
`filter`	FES XML filter on fields or geometry	from the description
`bbox`	box in the chosen projection	platform

Fields 33 · waterschappen-kunstwerken-imwa:gemaal

Name	Type	Meaning
`geom`	geometrie
`aantaldoorstroomopeningen`	long
`afslagpeil`	double
`afvoercoefficient`	double
`breedteopening`	double
`categoriewaterkering`	string
`code`	string
`drempelpeil`	double
`filteruitstroming`	string
`functiegebiedgemaal`	string
`functiegemaal`	string
`guid`	string

Show all 33

Name	Type	Meaning
`indicatiewaterkerend`	string
`isonderdeelvanwaterkering`	string
`kerendehoogte`	double
`maximalecapaciteit`	double
`naam`	string
`nen3610id`	string
`ontwerpbuitenwaterstand`	double
`openingspeil`	double
`openkeerpeil`	double
`opmerking`	string
`richting`	double
`signaleringspeil`	double
`sluitpeil`	double
`statusleggerwatersysteem`	string
`statusleggerwaterveiligheid`	string
`statusobject`	string
`typeregelbaarheid`	string
`typewaterkerendeconstructie`	string
`url`	string
`waterbeheerder`	string
`fuuid`	string

Limits and pitfalls

At most 1,000 features per request (CountDefault). from the description
Paging supported: count and startIndex (ImplementsResultPaging). from the description
The same data are also an OGC API: https://api.pdok.nl/hwh/waterschappen-kunstwerken-imwa/ogc/v2 (GeoJSON, 1,000 per page, cursor paging). It gives no total; the WFS does. tested
GetPropertyValue returns one field without geometry, at most 1,000 values per request; page with startIndex and sortBy=nen3610id. tested

Try it HTTP 200 · 363 ms · 16 Oct

https://service.pdok.nl/hwh/waterschappen-kunstwerken-imwa/wfs/v2_0?request=GetFeature&service=WFS&version=2.0.0&typeNames=waterschappen-kunstwerken-imwa:gemaal&outputFormat=application/json&srsName=EPSG:4326&count=1&propertyName=naam,code,waterbeheerder,maximalecapaciteit,statusobject

{
  "type": "FeatureCollection",
  "name": "gemaal",
  "crs": {
    "type": "name",
    "properties": {
      "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
    }
  },
  "features": [
    {
      "type": "Feature",
      "properties": {
        "code": "30099GM",
        "naam": "",
        "statusobject": "gerealiseerd",
        "waterbeheerder": "Waterschap Hollandse Delta"
      },
      "bbox": [
        4.529966288846953,
        51.8075950623256
      ],
      "geometry": {
        "type": "Point",
        "coordinates": "…"
      }
    }
  ],
  "bbox": [
    4.52996628884695,
    51.8075950623256
  ]
}

Shortened response, saved at harvest time. Click the URL for the real, current response.

Read from GetCapabilities: layers, projections, formats, filters, limit · DescribeFeatureType: fields of waterschappen-kunstwerken-imwa:gemaal. Labels: from the description stated in what the api itself publishes. tested from our own small call. platform applies to every api on this platform, per its documentation. experience learned while building open data index.

How to fetch it

curl "https://api.pdok.nl/hwh/waterschappen-kunstwerken-imwa/ogc/v2/collections/gemaal/items?f=json&limit=5"

More from Het Waterschapshuis in our index

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All about Het Waterschapshuis