Facts & figures
Water system management
INFRASTRUCTURE MAIN WATER SYSTEM (BOEZEM)
Total Catchment area Fryslân
Catchment area of main water system (Boezem)
Catchment of separate main water systems
Surface area of main water system (Boezem)
Secondary dikes or levees (along inland waterways and lakes)
Under rehabilitation (2014-2019)
• rural areas
• urban areas
Local dikes or levees
INFRASTRUCTURE SUBSYSTEMS (POLDERS)
329,000 ha
301,400 ha
27,600 ha
18,650 ha
3,240 km
± 390 km
± 360 km
± 30 km
670 km
Pumping stations with discharge into Boezem
± 1,000
Pumping stations with discharge into the sea
2
Pumping stations with discharge into the IJsselmeer and the Lauwersmeer
3
Weirs
± 5,200
Inlet sluice gates
± 4,600
Water level regulating culverts
2800
Number of areas with a separate water level
± 8,200
Length of main drainage channels in the polders
± 5,900 km
Water courses under supervision of Wetterskip Fryslân
± 12,200 km
Other water courses ± 21,700 km
Pumping stations of the main water system (Boezem):
• electric pump station: J.L. Hooglandgemaal in Stavoren
1
Capacity per 24 hours:
max. 10,000,000 m3
• steam driven pump station: ir. D.F. Woudagemaal in Lemmer
1
Lenght of dikes along the IJsselmeer and Waddenzee
± 141,5 km
Capacity per 24 hours:
max. 6,000,000 m3
Length of dikes on the islands Ameland, Terschelling and Schiermonnikoog ± 43,6 km
Outlet sluice-gates 3
Outlet capacity per 24 hours
max. 8,000,000 m3
DEFENCE AGAINST DAMAGE BY MUSK-RATS
Inlet gates
5
Caught
Field work (hours) Catches per hour
Inlet capacity per 24 hours
max. 7,000,000 m3
1994103,910 45,286
2,29
3
200924,106
68,500
0,35
Mean annual outflow (period 1981-2010)
1,250,000,000 m
3
20142,777
44,302
0,06
Mean annual inflow (period 1981-2010)
190,000,000 m
Sea defence
Water quality
Financial information
WATER QUALITY MONITORING NETWORK
NET CHARGES
Number permanent sample locations
Official locations for swimming
Chloride sample locations (monitoring salinization)
175
31
72
TAXES 2014
Number of pumping stations
Length of pipes under pressure
Number of waste water treatment plants
Average volume of treated waste water per year
Total capacity of treated waste water expressed in population
equivalents (one population equivalent is 150 g COD per day)
Removal efficiency of organic material (BOD)
Removal efficiency of phosphate
Removal efficiency of total nitrogen Number of sludge dewatering plants
Capacity sludge filter presses (in tons dry weight per year)
276
814 km
28
85 mln. m3
1,394,453
99 %
86,8 %
87,8 %
1
17,000
MANAGEMENT OF CONTAMINATED SEDIMENTS
Sediment not appropriate for reuse
Restored sites (since 1995)
• Removed contaminated sediment
± 302,250 m3
20
± 400,750 m3
Management of waterways (shipping)
Length of waterways Provence of Fryslân and the Westerkwartier region
€ 133,300,000
€ 83,100,000
€ 50,200,000
± 167 km
WATER SYSTEM MANAGEMENT
Residents (per housing unit)
Buildings, protected by dikes (percentage of real estate value)
Buildings, not protected by dikes (percentage of real estate value)
Agricultural land, not protected by dikes, no polder (per ha)
Agricultural land, not protected by dikes, no polder, roads (per ha)
Agricultural land, not protected by dikes, polder (per ha)
Agricultural land, not protected by dikes, polder, roads (per ha)
Agricultural land, protected by dikes, no polder (per ha)
Agricultural land, protected by dikes, no polder, roads (per ha)
Agricultural land, protected by dikes, polder (per ha)
Agricultural land, protected by dikes, polder, roads (per ha)
Natural area (per ha)
Pollution tax (per unit polluted)
WASTEWATER MANAGEMENT
Tax wastewater management (per unit polluted)
€ 80,01
0,0632 %
0,0158 %
€ 10,71
€ 53,54
€ 32,12
€ 74,96
€ 42,83
€ 85,66
€ 64,25
€ 107,08
€ 4,40
€ 56,02
€ 56,02
Personnel
Formation in f.t.e. (full time equivalents) Number of employees
542
559
Surface control area: More than 355,000 ha (Provence of Fryslân including
the 4 Frisian ‘Wadden Islands’ and a part of the Westerkwartier region in
the Province of Groningen)
Number of municipalities: 27
Number of residents: ± 670,000
March 2015
WASTEWATER TREATMENT
Total net charges
Net charges water system management Net charges wastewater management