The northern Reservoir-System

Dr.-Ing. Christof Homann Catchment

Germany The

Main River: Rur Catchment Area: 2087 km2 Inhabitants: 1,1 Mio. Rur Catchment

North • Lowland • Agriculture and industry The Netherlands • Flood protection • Precipitation 600-700 mm

South Belgium • Low mountain range up to 620 mNN • Forrests • High precipitation up to 1200 mm • Linked system of reservoirs Reservoir-System Total Volume: 302 Mio. m3 Wehebach reservoir Düren

Dreilägerbach Storage basin Obermaubach reservoir Hauptsee

10 Reservoirs Storage basin Roetgen o 7 WVER Kall reservoir o 3 water supply companies o drinking water reservoir

Perlenbach reservoir

Olef reservoir Reservoir-System

Storage basin OBERMAUBACH

HAUPTSEE Storage basin HEIMBACH

URFT reservoir OBERSEE Reservoir-System Objectives

Protection against floods • 70 Mio. m3 storage volume • reduction of the Rur peak discharge from 307 to 60 m3/s Low-water enrichment • NNQ of 0,45 m3/s increased to 5 m3/s Provision of Water (Total System) • 80 Mio. m3/a for drinking water (600.000 inhabitants) • 100 Mio. m3/a für industrial use Power generation • 60 Mio. kWh/a (minor role) • Start in 1905 for refinancing of (art nouveau power station) Reservoir-System

465 mNN dam

RUR URFT dam URFT WEHEBACH reservoir 322,50 mNN PAULUSHOF dam 251,80 mNN

RURTALSPERRE OBERSEE HAUPTSEE 281,50 mNN SCHWAMMENAUEL 281,50 mNN

Storage basin HEIMBACH 214,00 mNN Storage basin OBERMAUBACH 165,00 mNN RUR

KERMETER - gallery

Powerstation HEIMBACH Reservoir-System

Opponent Tasks ▲ Low-water enrichment and provision demand full reservoirs ▼ Flood protection demands empty reservoirs

Solution • Computer aided Lamellae operation plan • Different volumes for flood protection storage in summer and winter • TALSIM software: Computer aided dimensioning of distribution of water between reservoirs Reservoir-System Lamellae Plan

50 60 25 17 40 11

6 5 Reservoir-System Lamellae Plan

• Long-time simulation (100 years) of reservoir behaviour • Optimization of rules of operation • Targets: - Avoidance of spilling over of Rur reservoir - Minimum discharge of 5 m3/s - More natural discharge behaviour - Aspects of recreation Reservoir-System Hypolimnion-level control for the Olef reservoir

1. Discharge according to Lamellae plan 2. Preceding discharge relative to an expected flood inflow volume • Dependent on current reservoir-content • On basis of measured inflow (1960-2006) 3. Reduce discharge on basis of hypolimnion- forecast . • Computation of forecast-series with TALSIM • Forecast on the basis of statistical analysis of computation results (for time-period may to september) Reservoir-System Hypolimnion-level control for the Olef reservoir

Epilimnion

Thermocline

Hypolimnion drinking Extraction zone water

Sedimentation AMICE

Contribution of the WVER to AMICE: ‹ Provision of hydrological data for the Rur tributary ‹ Provision of knowledge for natural retention measures, flow control measures, alarm systems and crisis management ‹ Development of adaption strategies to mitigate climate change effects ‹ Implementation of modelling and risk analysis for the river Rur to prepare adaption of the reservoir flow control AMICE

General Objectives of Action Plans • 1.08./1.09 Measures in water management • 3.23. Rur reservoirs, models • 3.24. Rur reservoirs, risk assessment • 5.08. Site visits AMICE

General Objectives of Action Plan • 1.08./1.09 Measures in water management • 3.23. Rur reservoirs, models − Model implementation, calculation of current and ¨ future situation − Operational rainfall-runoff models for the whole Rur catchment area − Operational 1D-2D hydraulic models of the river Rur • 3.24. Rur reservoirs, risk assessment • 5.08. Site visits Climate scenarios

Humidity szenarios: Time periods: • dry • 2021 to 2050 • wet • 2070 to 2100

Resulting in four scenarios: Szenario 1: dry, 2021 to 2050 Szenario 2: wet, 2021 to 2050 Szenario 3: dry, 2070 to 2100 Szenario 4: wet, 2070 to 2100 Measured reference period 1971 to 2000 hydrological simulations

• 3 simulation periods • 1960-1990 (d), 1971-2000 (h) • 2021-2050 (dry, wet) • 2071-2100 (dry, wet)

• 2 temporal resolutions (1h, 1d) • hourly: ExUS (N), KLAVE (T) • daily: E-OBS 2.0 (Haylock, 2009)

• 2 rainfall runoff models (NASIM, GR4J)

• evaluation for HW, MW, NW climate scenarios

• Input for scenarios: delta-approach

• NRW-change-signals from ZWEK-project •REMO •CLM • WETTREG •STAR

Table 1: changes in mean temperature [°C] and mean precipitation amounts [%] in comparison to 1971-2000 wet (WETTREG) dry(CLM) 2021-2050 2071-2100 2021-2050 2071-2100 ΔN ΔT ΔN ΔT ΔN ΔT ΔN ΔT Winter 20 1,5 55 3,8 -5 1,5 15 3,8 Spring 10 0,0 5 1,0 5 0,5 5 2,0 Summer -5 0,5 -10 2,0 -5 1,5 -25 3,8 Autumn 0 0,5 0 2,0 5 1,5 -5 3,5 climate scenarios

2021-2050

2071-2100

dry wet climate scenarios 2071-2100

Δ N

Δ T

MaasPrudence - gemittelt NRW

Simulation für Maas-Mittelwerte und NRW-Faktoren rainfall runoff models

discharge at Obermaubach necessary

simulation with TALSIM

TALSIM requires a.o. inflows to reservoirs

rainfall runoff models not area- wide available

assumption: discharge developing of river Inde transferable

Open pit filling begins 2030- 2050 for mining area “Inden” goodness of fit - Rur (d)

mmA

HQ

AM7 goodness of fit - Rur (h)

mmA

HQ results Rur - mmd

Mean monthly discharges Change factors for mean monthly discharges Gauge Stah, daily timestep (NASIM) Gauge Stah, daily timestep (NASIM)

observed (1961-1990) (2021-2050 dry) / simulated (1961-1990) simulated (1961-1990) (2021-2050 wet) / simulated (1961-1990) simulated (2021-2050 dry) (2071-2100 dry) / simulated (1961-1990) simulated (2021-2050 wet) (2071-2100 wet) / simulated (1961-1990) simulated (2071-2100 dry) simulated (2071-2100 wet) [-]

NASIM (d) Q [m³/s] 10 20 30 40 50 AB 0.00.51.01.52.0

JFMAMJJASOND JFMAMJJASOND

Month Month

Mean monthly discharges Change factors for mean monthly discharges Gauge Stah, daily timestep (GR4J) Gauge Stah, daily timestep (GR4J)

observed (1961-1990) (2021-2050 dry) / simulated (1961-1990) simulated (1961-1990) (2021-2050 wet) / simulated (1961-1990) Maximum rise: 13% simulated (2021-2050 dry) (2071-2100 dry) / simulated (1961-1990) simulated (2021-2050 wet) (2071-2100 wet) / simulated (1961-1990) simulated (2071-2100 dry) (February, wet scenario for simulated (2071-2100 wet) 2071-2100, NASIM (1h)) [-]

GR4J (d) Q [m³/s] 10 20 30 40 50 CDMaximum lowering: 63% 0.0 0.5 1.0 1.5 2.0

JFMAMJJASOND JFMAMJJASOND (September, dry scenario for Month Month

Mean monthly discharges Change factors for mean monthly discharges 2071-2100, GR4J (1d)) Gauge Stah, hourly timestep (NASIM) Gauge Stah, hourly timestep (NASIM)

observed (1971-2000) (2021-2050 dry) / simulated (1971-2000) simulated (1971-2000) (2021-2050 wet) / simulated (1971-2000) simulated (2021-2050 dry) (2071-2100 dry) / simulated (1971-2000) simulated (2021-2050 wet) (2071-2100 wet) / simulated (1971-2000) simulated (2071-2100 dry) simulated (2071-2100 wet) [-]

NASIM (h) Q [m³/s] 10 20 30 40 50 AB 0.0 0.5 1.0 1.5 2.0

JFMAMJJASOND JFMAMJJASOND

Month Month results Rur - HQ(Tn) Winter maximum discharges (1961-1990) Winter maximum discharges (1961-1990) Winter maximum discharges (1971-2000) Gauge Stah, daily timestep (NASIM) Gauge Stah, daily timestep (GR4J) Gauge Stah, hourly timestep

observed (1961-1990) observed (1961-1990) observed (1971-2000) simulated (1961-1990) simulated (1961-1990) simulated (1971-2000) simulated (2021-2050 dry) simulated (2021-2050 dry) simulated (2021-2050 dry) simulated (2021-2050 wet) simulated (2021-2050 wet) simulated (2021-2050 wet) simulated (2071-2100 dry) simulated (2071-2100 dry) simulated (2071-2100 dry) simulated (2071-2100 wet) simulated (2071-2100 wet) simulated (2071-2100 wet) Q [m³/s] Q [m³/s] Q [m³/s] 50 100 150 200 250 50 100 150 200 250 50 100 150 200 250 A B

2 5 10 20 50 100 2 5 10 20 50 100 2 5 10 20 50 100

Recurrence interval T[years] Recurrence interval T[years] Recurrence interval T[years] NASIM (d) GR4J (d) NASIM (h)

HQ100 Maximum rise: 10% (wet scenario for 2071-2100, NASIM (1h)) Maximum lowering: 57% (dry scenario for 2071-2100, GR4J (1d)) results Rur - AM7(Tn) Summer AM7-values (1961-1990) Gauge Stah, daily timestep (GR4J)

simulated (1961-1990) simulated (2021-2050 dry) simulated (2021-2050 wet) simulated (2071-2100 dry) simulated (2071-2100 wet)

GR4J (d) Q [m³/s] 0 5 10 15

2 5 10 20 50

Recurrence interval T[years]

AM7 (Tn=50 a) Minimum lowering : 20% (wet scenario for 2071-2100) Maximum lowering: 91% (dry scenario for 2071-2100) comparison of changes (Rur)

2021-2050 2071-2100 Climate scenarios national

• Input for szenarios based on variations with delta-method • Variations of inflows to reservoirs are devolved from changes in rainfall-runoff model Inde/Vicht for climate szenarios • Variation of signals from project ZWEK (DWD 2007)

Table 1: Variation of the mean temperature [°C] and the mean precipitation [%] in comparison to 1971-2000 wet (WETTREG) dry (CLM) 2021-2050 2071-2100 2021-2050 2071-2100 ΔN ΔT ΔN ΔT ΔN ΔT ΔN ΔT winter 20 1,5 55 3,8 -5 1,5 15 3,8 spring 10 0,0 5 1,0 5 0,5 5 2,0 summer -5 0,5 -10 2,0 -5 1,5 -25 3,8 autumn 0 0,5 0 2,0 5 1,5 -5 3,5 Hauptsee Rurtalsperre Schwammenauel

Maximum water level 181.500 Tm³ 281,50 mNN Maximum water level winter 175.680 Tm³ 280,50 mNN Normal water level 149.300 Tm³ 276,00 mNN Minimum operating water level 530 Tm³ 221,00 mNN Bottom of valley 0 Tm³ 214,00 mNN

OLEF reservoir WEHEBACH reservoir

URFT reservoir

HAUPTSEE

a a a a Hauptsee Rurtalsperre Schwammenauel

Dauerlinieduration - Hauptsee curve – HauptseeSchwammenauel comparisonVergleich of climate Szenarien szenarios

200000

160000

120000

80000 Vol [Tsd.m³]

40000

0 0 0,2 0,4 0,6 0,8 1 Pu [-]

Referenz Szenario 1 Szenario 2 Szenario 3 Normal Szenario 4 Stauzielwater level AbsenkzielMin. operating water level Hauptsee Rurtalsperre Schwammenauel

Hauptsee Schwammenauel (NW-Auswertung Mittel, Szenarien) Hauptsee – mean low water analysis

120000

100000

80000

60000 Vol [Tsd.m³]

40000

20000

0 0 102030405060

UndershootingUnterschreitung [days] [Tage]

meanMittel Referenz meanMittel Szenario 1 Mittelmean Szenario 2 Min. operating meanMittel Szenario 3] meanMittel Szenario 4 Absenkzielwater level Hauptsee Rurtalsperre Schwammenauel

Hauptsee SchwammenauelHauptsee (NW-Auswertung – minimal low Minimal, water analysi Szenarien)s

60000

50000

40000

30000 Vol [Tsd.m³]

20000

10000

0 0 102030405060

UndershootingUnterschreitung [days] [Tage]

Min Referenz Min Szenario 1 Min Szenario 2 Min. operating Min Szenario 3 Min Szenario 4 waterAbsenkziel level AMICE

General Objectives of Action Plan • 1.08./1.09 Measures in water management • 3.23. Rur reservoirs, models − Model implementation, calculation of current and ¨ future situation − Operational rainfall-runoff models for the whole Rur catchment area − Operational 1D-2D hydraulic models of the river Rur • 3.24. Rur reservoirs, risk assessment • 5.08. Site visits Rainfall-runoff models

lower Rur NASIM

Wurm NASIM middle Rur NASIM

Rur/Kall Inde/Vicht NASIM → in calibration NASIM

upper Rur Urft/Olef → in calibration NASIM → in calibration Linking the models

Basis: • 7 rainfall-runoff models (NASIM) • model of the reservoir system (Talsim-NG)

Approach: • Integration of the „simple“ systems in NASIM: ▫ Staubecken Heimbach ▫ Staubecken Obermaubach ▫ Wehebachtalsperre ▫ Dreilägerbachtalsperre ▫ Kalltalsperre ▫ Perlenbachtalsperre • Modelling the sophisticated parts of the reservoir-control with the Talsim model • Linking the parts of the System with runoff-time-series • Serial calculation of the model chain in 5 steps Linking the models „Sophisticated“ parts of the reservoir system modeled with Talsim T1

OLEF dam 465 mNN

RUR T2 URFT dam URFT 322,50 mNN WEHEBACH reservoir PAULUSHOF dam 251,80 mNN

RURTALSPERRE OBERSEE HAUPTSEE 281,50 mNN SCHWAMMENAUEL 281,50 mNN

Storage basin HEIMBACH 214,00 mNN Storage basin OBERMAUBACH 165,00 mNN powerstation HEIMBACH RUR

KERMETER - gallery Linking the models

Rur/Kall

T2 upper Rur

T1¨

Urft/Olef Linking the models

N1 k Catchment area of the Olef reservoir (part of the NASIM-model Urft/Olef)

T1 k Olef reservoir (part of TALSIM-model)

N2 k Catchment areas of Urft und Rur (2 NASIM-models) T2 k Urft reservoir, Obersee and Hauptsee (part of TALSIM-model) N3 k Rur catchment area downstream Schwammenauel (5 NASIM-models) AMICE AMICE General Objectives of Action Plan • 1.08./1.09 Measures in water management • 3.23. Rur reservoirs, models − Model implementation, calculation of current and future situation − Operational rainfall-runoff models for the whole Rur catchment area − Operational 1D-2D hydraulic models of the river Rur • 3.24. Rur reservoirs, risk assessment • 5.08. Site visits The northern Eifel Reservoir-System

Thank you for your attention