Il progetto HydroPeaking:

problematiche e prospettive

Bruno Maiolini, Fondazione E. Mach

FONDAZIONE EDMUND MACH

Istituto Agrario di San Michele all’Adige

variability

seasonalitypredictability

Principle 2 life history patterns- spawning- recruitment

stablebaseflows

reproductivetriggers

modified from: Basic Principles and Ecological Consequences of Altered Flow Regimes for AquaticBiodiversity. Bunn & Arthinghton, 2002

dis

char

ge

time

Principle 4 natural regime discourages invasions

Principle 3

lateral connectivity

Principle 1

channel formhabitat complexitypatch disturbance

bioticdiversity

spates

drought

max

mean

min

time scales are a major concern

Glaciers recede with warming climate: as glacier mass is lost, river basinhydrology will shift from being fed bymeltwater to precipitation supplydominated

A) initial increase in meltwater generation

B, C) followed by reduced runoff in the

long term

(1994)

But:

Hydropower plants

>10MW power output

Large dams (height >15 m

or capacity > 3x106 m3

Source: Alpine Convention, 2nd Report on the state of the Alps –“Water”

PRE-DAM CONSTRUCTION

POST-DAM CONSTRUCTION

Hydrological alterations on a temporal scale: the example of the Adige

G. Zolezzi, A. Bellin, M. C. Bruno, B. Maiolini, A. Siviglia. 2009. Assessing hydrological alterations at multiple temporal scales: Adige River, Italy. Water Resources and Research

Storage in reservoirs

Hydropeaking

Hydrological alterations on a spatial scale

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Precipitation

Discharge

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Upper course, moderately impacted (Noce stream at Malè, 695 m a.s.l. )

Downstream 1st hpp:

moderate hydropeaking

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Lower course, strongly impacted (Noce stream at Mezzolombardo, 205 m a.s.l.)

Downstream 2nd hpp:

severe hydropeaking

Headwaters: climate-driven

Adige Villalagarina 2007

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Adige Marco 2007

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Hydrological alterations on a spatial scale

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1 2 3 4 5 6 7 8 9 10 11n° sample

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m3

Total NB8 Total NB 13 Total NB15

M. C. Bruno, B. Maiolini, M. Carolli, L. Silver.

2010. Shrt time scale impacts of hydropeaking on

benthic invertebrates in an Alpine stream

(Trentino, Italy). Limnologica

The ecological consequences effects of hydropeaking is rather well known, in our contributes we quantified the effects on the different components of the benthic and hyporheic communities

M. C. Bruno, B. Maiolini, M. Carolli, L. Silveri.

2009. Impacts of hydropeaking on the hyporheic

invertebrates in an Alpine stream (Trentino,

Italy). Int. J. Lim

Effects of hydropeaking on the hyporheic community:

clogging of the interstices

Thermopeaking in Alpine streams: event characterization and time scales. G .Zolezzi, A. Siviglia, M. Toffolon, and B. Maiolini. Ecohydrology, 2010

Thermopeaking In storage HPP with hypolimnetic releases, hydropeaking is associated to abrupt changes in water temperature (thermopeaking), imposing sudden and repeated warmer conditions in winter and cooler in summer

discharge

Distance

from

source

Headwaters: abstraction

discharge

Natural Hydropower-impacted

Release from HPP

Hydropeaking-impacted

reachRelease from HPP

plants & abstraction

Storage in reservoirs

Minimum flow releases

È necessario attrezzarci a governare gli ambienti acquatici

Pier Francesco Ghetti

thus a very complex, in global changing scenario of Heavily

Modified Water Bodies, with a reduced capacity to deliver

appropriate ecosystem benefits & goods.

we need to face the challenge of meeting the expectations of

the WFD 2000/60, maintaining the strategic, renewable and

gas-free hydropower production

Remediation strategies may be

structural (retention basins, river morphology restoration,

river widening) or

operational (reduce rise and fall surges, reduce ∆Q e.g. <5).

Complex problems need complex, scientifically sound solutions: the Rhone-Thur example

A missed opportunity: multipurpose reuse of HPP released waters

possible advantages: •reduction of HP in HMWB•increased minimum flow•more ecosystem benefits obtainable•win win solutions (HP vs EB)

HPP

Possible re-use of turbinated waters: the Rotaliana plain

•maintain production

•reduce hydropeaking

•agricultural land vs agricultural ecosystem

•denitrification

•phytodepuration

•biodiversity

•adjacent biotopes

•groundwater recharge

•Noce river rehabilitation

•drainage boards (job creation)

CONCLUDING REMARKS

In Alpine regions, intermittent hydropower generation has high economical relevance, being the most important renewable electricity source, with no CO2 emission.

However:

•Hydropeaking and thermopeaking impose severe impacts on stream ecosystems. Reduction/changes in HPG in the Alps are not realistic for socio-economic reasons.

•Lessons learned from recent multidisciplinary stream ecology research and some European restoration experiences indicate possible win-win chances to meet environmental issues & HPG needs

•Compensation and restoration measures are site specific but should be planned at the water basin level, with a multidisciplinary approach (ecology, hydrology, economy, social sciences)

Thank you for your attention and very special thanks to my FEM colleagues and to those from the Department of Environmental

Engineering of the University of Trento