Facts and figures
Overview of facts and figures from the Noorderzijlvest Water Authority.
Key figures Noorderzijlvest
| Noorderzijlvest working area | Groningen north of the Eems canal, northwest Drenthe, and the Frisian part of the lake Lauwersmeer area |
| Size of our management area | approx. 144,000 hectares (= 1,440 km²) |
Number of councils our region | 9 local councils:
|
| WFD catchment | Nedereems, north Rhine |
| Natura 2000 areas in our management area | Lake Leekstermeer area: Norgerholt Fochteloërveen |
| Number of inhabitants in our region | 417,226 (as at 31 December 2024) |
| Number of pollution units (PUs) | 416,000 units declared |
| Noorderzijlvest employees | 316 employees. That's 300 positions. |
| Lowest point in our working area | -3.00 metre NAP lowest point in our area |
| Highest point in our working area | +12.10 metre NAP highest point in our area |
Surface waters
Key figures Noorderzijlvest
| Our primary watercourses | 2,233 kilometres |
| Our water authority ditches | 28 kilometres |
| Our ditches under inspection | 1,335 kilometres |
| Our balancing lakes (storage in case of disaster) as defined under Environment and Planning Act | 1,485 hectares |
| Our surface water pumping stations | 150 |
| Mills capable of milling in our management area | 17 mills |
| Our water authority weirs | 833 weirs |
| Our locks | 17 locks |
| Our inlets | 390 inlets |
| Our fish passages | 29 fish passages |
| The bridges over main watercourses in our region | 1,274 of which:
|
| Our culvertsin main watercourses | 7,451 culverts |
Flood defences (dykes and flood embankments)
Key figures Noorderzijlvest
| Primary flood defences Lauwersoog to Delfzijl (the Ommelanderzeedijk) | 69 kilometres |
| Regional and other flood defences | 486.7 kilometres |
| Amount of asphalt | 114 hectares |
| How many stony slopes | 51.5 hectares |
| Number of access and maintenance roads | 30 hectares |
| Amount of turf | 387 hectares |
| Quantity of fencing | 40 kilometres |
| Number of cross fences | 138 units |
| Number of dyke warehouses (workshops) | 6 |
| Number of posts for dyke surveillance | 8 |
Water treatment
Key figures Noorderzijlvest
| Treated wastewater per year | 63,750,000 m³ (= nearly 64 billion litres) |
| Number of pollution units | 416,000 units declared |
| Our wastewater treatment plants | 13 |
| Our sludge dewatering plant | 1 |
| Number of transport pumping stations | 113 sewage pumping stations under our own management |
| Our pressure pipes | 361 kilometres |
| Sewage overflows in our area | 453 |
| IBAs inour management area | 1217 |