Facts and figures

Overview of facts and figures from the Noorderzijlvest Water Authority.

Key figures Noorderzijlvest

Noorderzijlvest working areaGroningen north of the Eemskanaal, northwest Drenthe, and the Frisian part of the Lauwersmeer area
Size of our management areaapprox. 144,000 ha (= 1,440 km²)

Number of municipalities in our working area

9 municipalities:

  • Axles
  • Eems Delta
  • Groningen
  • The Hogeland
  • Central Drenthe
  • Northeast Friesland
  • North Field
  • Tynaarlo
  • Western Quarter
WFDriver basinLower Rhine, North Rhine
Natura 2000areas in our management area

 
Lauwersmeer:

Leekstermeer area:

Norgerholt

Fochteloër Moor

Number of inhabitants in our working area417,226 (as of December 31, 2024) 
Number of pollution units (PUs)416,000 units declared
Noorderzijlvest employees316 employees. That's 300 positions.
Lowest point in our working area -3.00 m NAP lowest point in our area
Highest point in our working area+12.10 m NAP highest point in our area

Surface waters

Key figures Noorderzijlvest

Our primary waterways2,233 km
Our water board ditches28 km
Our locks under the chimney1,335 km
Our water storage areas (storage in case of disaster)
according to the definition under the Environment Act
1,485 ha
Our surface water pumping stations150
Mills capable of grinding in our management area17 windmills
Our water board weirs833 weirs
Our locks17 locks
Our inlets390 inlets
Our fish passages29 fish passages
The bridges over main waterways in our working area

1,274 of which:

  • 86 under maintenance by the water board
Our diversin main waterways7,451 divers

Flood defenses(dikes and quays)

Key figures Noorderzijlvest

Primary flood defenses – Lauwersoog to Delfzijl (the Ommelanderzeedijk)69 km
Regional and other flood defenses486.7 miles
Amount of asphalt114 ha
How much stone rolling51.5 ha
Number of access and maintenance roads30 hectares
Amount of turf387 ha
Quantity of fencing40 km
Number of cross fences138 pieces
Number of dike warehouses (workshops)6
Number of posts for dike surveillance8

Water purification

Key figures Noorderzijlvest

Treated wastewater per year63,750,000 m³ (= nearly 64 billion liters)
Number of pollution units416,000 units declared
Our wastewater treatment plants13
Our sludge dewatering plant1
Number of transport pumping stations113 sewage pumping stations under our own management 
Our press lines361 km
Sewage overflowsin our area453
IBAs inour management area1217