Integrated water management at the

regional scale in a context of climate

uncertainty. The project MontanAqua

Emmanuel REYNARD

Institute of Geography, University of Lausanne

Projektteam:

WP1: Karl Herweg, Martin Hölzle, Matthias Huss, Martina Kauzlaric, Hanspeter Liniger, Emmanuel

Rey, Bruno Schädler (Uni Bern, Uni Fribourg)

WP2: Mariano Bonrisposi, Emmanuel Reynard (Uni Lausanne)

WP3: Olivier Graefe, Christine Homewood (Uni Fribourg)

SP: Stephan Rist, Flurina Schneider (Uni Bern)

Gestion durable de l’eau

Programme nationale de recherche PNR61

The Alps = Water tower of Europe

Viviroli & Weingartner (2004), in Hydrology and Earth System Sciences

Dry areas in the Alps

Mean summer precipitations © Swiss Hydrological Atlas

socio-

economic and

political system

different

users water resources

water availability

in space and time

climate (change)

The project MontanAqua (2010-2013)

WP 3

WP 2

WP 1

Synthesis package

The project MontanAqua (2010-2013)

The study area

South-facing slopes in the Valais

500 m to 3000 m asl.

11 municipalities, 36‘500 inhabitants

760‘000 tourist nights per year

Pictures: E. Rey, 2011

Tseuzier dam and artificial lake Picture: E. Reynard, 2010

Capacity: 51 million cubic meters

High demographic dynamic

Bonriposi 2011

Conceptualisation of the water system

Water availability

today, 2050

Catchments (headwaters)

Clusters of communes

Icogne Montana

Lens Chermignon

Randogne Mollens

Venthône Miège

Veyras Sierre

Water consumption

today, 2050

Water management

today, 2050

St-

Léonard

Conceptualisation of the water system

Schneider, 2012

Preliminary results: the Plaine Morte glacier

Sierre (500 m asl.)

Montana (1500 m asl.)

Plaine Morte glacier (2800 m asl.)

Role of the glacier in a region approaching water stress?

Ru

no

ff (m

io m

3/y

r)

“Additional

” water to

the region?

Runoff from

Plaine-Morte region

© Schweizer Flugwaffe

BE

VS

Huess, 2012

UNIBE

Preliminary results: karstic system

Contribution: some mio. m3/yr, cf. water consumption approx. 10 mio. m3/yr

EO - Eosin

UR -Uranin

Tzeusier lake - Loquesse

Simme - Lenk

UNIBE

Preliminary results: hydrology

Contribution: some mio. m3/yr (cf. water consumption 10 mio m3/yr)

1. Annual precipitation is 3 to 4

times higher than at Montana

station

2. Significant contribution of glacial

melt-water (until 2060)

3. Tseuzier storage lake: key

element for the management of

the (abundant) water

Water tower of the

MontanAqua region!

Bonriposi, 2012

Preliminary results: water uses

Drinking water is partly used for irrigation

Irrigation: no data available Water need was modelled (however,

calculated volume is smaller than the effective water volume transported in

the bisses)

No common view at the regional scale and difficulty to obtain some data

P [mm] from March to October

Ag

ricu

ltu

ral

wate

r n

eed

[m

3]

2010 Tem

p

[°C

]

P [

cm

]

W

ate

r

u

se [

m3]

1 mio m3

Drinking water

Water need for

irrigation Artificial snow

Preliminary results: hydropower production

Filling of Tseuzier lake (Potential) competition between

different users particularly in time

of shortage

A

A

B Hydro power production has priority. Other water users have

to pay the market price for

electricity

when using water from the lake

B

In the future:

Potential for a multi

purpose storage

Wi Su

Bonriposi, 2012

Preliminary results: socio-political system

Homewood, 2012

- Hypothesis 1 ( past, today): The institutional and political

fragmentation has not been a problem because of the almost

unlimited availability of water (TRUE)

- Hypothesis 2 ( future): The system is changing from supply-

oriented management to demand management and from a

fragmented system to an integrated management system

(partly TRUE)

- The Tseuzier lake, the useful storage capacity of which exceeds

the present day water use by 5 times, offers as multi purpose

storage an interesting opportunity for the water management in

the future.

Scenarios for the future (2050)

Water availability

today, 2050

catchments

Icogne Montana

Lens Chermignon

Randogne Mollens

Venthône Miège

Veyras Sierre

Water consumption

today, 2050

Water management

today, 2050

3 Visions (scenarios)

- expansion

- optimisation

- Moderate development

by Group RegiEau

Emission scenario

A1B

- different realisations

Outlook

Tseuzier storage lake is situated in

the middle of the water tower;

concession until 2037

Key element to satisfy all needs:

• From single to multi purpose storage

• How?

• Process of negotiation between different stakeholders: water

users, communes, power company

• Management / priorities in times of shortages

Interesting case study for a quite frequent situation in the future (cf. also new

lakes)