THE EVALUATION OF THE EVALUATION OF ECOLOGICALLY ACCEPTABLE ECOLOGICALLY ACCEPTABLE

FLOWSFLOWS

Dr. NataDr. Natašša SMOLARa SMOLAR--ŽŽVANUTVANUTDr. ALEKSANDRA KRIVOGRAD KLEMENDr. ALEKSANDRA KRIVOGRAD KLEMENČČIIČČ

Mag. ALIDA REJECMag. ALIDA REJEC

CLEAN ENERGY WITHOUT FRONTIERSCLEAN ENERGY WITHOUT FRONTIERS

19 September 200819 September 2008

1. INTRODUCTION1. INTRODUCTION2. EAF ASSESSMENT2. EAF ASSESSMENT3. REVIEW OF EAF3. REVIEW OF EAF4. CASE STUDIES4. CASE STUDIES5. CONCLUSIONS5. CONCLUSIONS

7500 freshwater springs in SloveniaThe permanent hydrographic network of streams and rivers measures over 26.000 km + 7.700 km of flash flood channels in Alps

1. INTRODUCTION1. INTRODUCTION

Ljubljana

HYDROLOGYHYDROLOGY

MORPHOLOGYMORPHOLOGY

BIOLOGYBIOLOGY

PHYSICOPHYSICO--CHEMICAL CHEMICAL PARAMETERSPARAMETERS

AQUATIC ECOSYSTEMAQUATIC ECOSYSTEMRIPARIAN ECOSYSTEMRIPARIAN ECOSYSTEM

Water management :Water management :

The objectiveThe objectiveecologicallly acceptable flow EAFecologicallly acceptable flow EAFquantity and quality of water ensuring the preservation quantity and quality of water ensuring the preservation the aquatic ecosystem: structure and functionthe aquatic ecosystem: structure and function

water body water body sections of water body sections of water body

Background: Water Act 2002Background: Water Act 2002

-- WFD WFD -- WFD and hydromorphological pressures, 2006WFD and hydromorphological pressures, 2006-- WFD and HPP, 2007 WFD and HPP, 2007 -- FAO Fisheries Report No.821 ...FAO Fisheries Report No.821 ...-- Brisbane declaration, 2007Brisbane declaration, 2007

The important part of RBMP and main contribution to The important part of RBMP and main contribution to river revitalisationriver revitalisation

ECOLOGY :ECOLOGY : ECONOMYECONOMY

There are complex effects between ecosystem parameters, There are complex effects between ecosystem parameters, these show that the ecosystem is able to adapt to relatively these show that the ecosystem is able to adapt to relatively small changessmall changes which occur in nature. If the balance is which occur in nature. If the balance is interrupted by big changes then the ecosystem is not stable interrupted by big changes then the ecosystem is not stable anymoreanymore. . →→ EF determination is a difficult task:EF determination is a difficult task: interdisciplinary interdisciplinary approachapproach for EF determination and for EF determination and each section of the each section of the riverrivershould be treated separatelyshould be treated separately

EAF EAF EAF

2. 2. EAF ASSESSMENTEAF ASSESSMENTProcessProcess•• definition the objectives: status of the riverdefinition the objectives: status of the river•• definition of starting points, instream values, water definition of starting points, instream values, water abstraction scenarios abstraction scenarios •• evaluation of critical parametersevaluation of critical parametersResultResultFlow regime which has to be ensure at the river section: Flow regime which has to be ensure at the river section: Morphology, habitats, aquatic and riparian flora and faunaMorphology, habitats, aquatic and riparian flora and fauna

Methods for EAF determination:Methods for EAF determination:

1.1. Hydrological methodsHydrological methodslook up tables, indiceslook up tables, indices

2.2. Hydraulic rating methodsHydraulic rating methodsfieldwork, rapid desk fieldwork, rapid desk -- top analysis, top analysis, combination hydrology, hydraulics, ecologycombination hydrology, hydraulics, ecology

3.3. Habitat simulationHabitat simulationrelation flow: habitatrelation flow: habitat

4.4. Holistic methodologiesHolistic methodologiesfunctional analysis, panels of expertsfunctional analysis, panels of experts

•• 1992 1992 -- 1994: Criteria for minimum flows1994: Criteria for minimum flows•• 1992 1992 -- 2007: EAF evaluation on more than 200 2007: EAF evaluation on more than 200

river sections with water abstraction/diversion river sections with water abstraction/diversion •• 2001 2001 –– 2005 EU projects2005 EU projects•• Development of new methods around the Development of new methods around the

worldworld

•• Results of fieldwork and experiences are Results of fieldwork and experiences are selected criteriaselected criteria

•• Gap between MOP and interdisciplinarity; Gap between MOP and interdisciplinarity; theory and practisetheory and practise

3. REVIEW OF EAF3. REVIEW OF EAF

The starting points for selecting the criteria:The starting points for selecting the criteria:

the importance of the importance of preservationpreservation and protectionand protectionrivers, their habitats with flora and fauna and rivers, their habitats with flora and fauna and diversity of organismsdiversity of organisms

EEAAF should be determined F should be determined before each impactbefore each impact in in the river or in the area, which could have an the river or in the area, which could have an influence on the structure and function of the river influence on the structure and function of the river as the ecosystem.as the ecosystem.

The necessary of The necessary of selectedselected hydraulic, hydrologicalhydraulic, hydrological, , morphologicalmorphological and ecological and ecological parametersparameters on the on the sections concerned should be checked.sections concerned should be checked.

For each For each change of quality and quantitychange of quality and quantity of water of water in the river a new in the river a new assessment assessment of Eof EAAF is required.F is required.

WATER ABSTRACTIONWATER ABSTRACTION

ECOLOGYECOLOGY

HYDROMORPHOLOGYHYDROMORPHOLOGY

HYDROLOGYHYDROLOGY

HYDROECOLOGICAL METHODHYDROECOLOGICAL METHOD ECOHYDROLOGICAL METHODECOHYDROLOGICAL METHOD

1992 1992 -- 2006: 1852006: 185Hydroecological:143

Ecohydrological:42

F >100 km2: 61 F <100 km2 : 124

Soca: the longest river flowing into the Adriatic (96 km in Slovenia)total: 136 kmF = 1612 km2, limestone

4. CASE STUDY: THE SOCA RIVER4. CASE STUDY: THE SOCA RIVER

PODSELA DAM

HPP DOBLAR

HPP PLAVE

0 5 km 10 km

S 5

S 6S 7

SLOVENIA

AJBA DAM

S 1

S 2

S 4

S 3

SOČA

SOČA

1939, (96) 180 1939, (96) 180 mm33ss--11

4320 m4320 m

1940, (75) 180 1940, (75) 180 mm33ss--11

7950 m7950 m

Zoobenthos, PhytobenthosZoobenthos, Phytobenthos, phytobenthos biomass , phytobenthos biomass Sampling in different hydrological habitatsSampling in different hydrological habitats

(up to 5 points at each sampling site)(up to 5 points at each sampling site)low flow, 1995 low flow, 1995 –– 2003 (2008)2003 (2008)

HydrologicalHydrological parameters: flow, current velocityparameters: flow, current velocitySedimentSediment analyses: analyses: Wolman Count Wolman Count -- numerical analysis numerical analysis PhysicoPhysico--chemicalchemical analyses: analyses: T, T, OO22 , saturation, conductivity, pH, COD, BOD5, , saturation, conductivity, pH, COD, BOD5, nitrite, nitrate, phosphorusnitrite, nitrate, phosphorusFlora and fauna in the riparian zoneFlora and fauna in the riparian zoneLandscape evaluation Landscape evaluation –– increasing flow downstream increasing flow downstream the dam (test)the dam (test)

METHODSMETHODS

RESULTSRESULTS

Hydrological parameters for the Soca River for the period 1961Hydrological parameters for the Soca River for the period 1961--1995 for 1995 for water regimes with and without water abstraction.water regimes with and without water abstraction.

Cross-section F (km2)

MDF(m3s-1)

MADF(m3s-1 )

MAMF(m3s-1)

Q82(m3s-1)

Q95(m3s-1)

Podsela Dam 1244 80 16 10 27.43 20.04SO2 - n 1254 80.6 16.1 10.0 27.47 20.08

SO2 - a 1254 22.5 0.13 0.12 0.64 0.25

SO4 - n 1345 86.2 17.8 10.5 29.70 21.22

SO4 - a 1345 33.1 1.0 1.0 1.41 1.12

changes in the changes in the hydrological regimehydrological regime (flow duration curve, (flow duration curve, current velocity, flow) current velocity, flow) and in and in sedimentsediment structurestructure

decrease in diversity of aquatic decrease in diversity of aquatic habitatshabitats

0

0,3

0,6

0,9

0 0,5 1 1,5 2

Q (m3/s)v

(m/s

)

S1.1S1.2S1.3S2.4S2.1S2.2S2.3

TEST: Increasing flow downstream the dam

→→ Due to abstractions, the physicoDue to abstractions, the physico--chemical composition chemical composition of water is defined by of water is defined by inflowsinflows downstream of the downstream of the catchmentcatchment→→ Water temperatureWater temperature, , Concentration of oxygenConcentration of oxygen

0

0,5

1

1,5

2

2,5

3

3,5

4

SO1 SO2 SO3 SO4 SO5 SO6 SO7

Sampling site

BOD

5 (m

g O

2/l)

20022003

BOD5 at sampling sitesBOD5 at sampling sites

PHYSICAL PHYSICAL ANDAND CHEMICAL PARAMETERSCHEMICAL PARAMETERS

00,10,20,30,40,50,60,70,80,91

2.3

3.3

2.2

6.3

7.3

5.2

5.1

5.3

6.1

6.2

3.1

4.2

2.1

3.2

4.1

4.3

1.2

1.3

1.1

7.1

7.2

SO2SO3SO4SO5SO6

SO1SO7

The Bray-Curtis coefficient of similarity, February 2003

Low flow, favourable light Low flow, favourable light conditions, nutrients and sediment conditions, nutrients and sediment structure were factors which made structure were factors which made proliferation of algae possibleproliferation of algae possible

High biomass of High biomass of phytobenthosphytobenthoscan develop only after an can develop only after an extended period of habitat stabilityextended period of habitat stability

AQUATIC FLORA AND FAUNAAQUATIC FLORA AND FAUNA

EAF ASSESSMENT FOR THE SOCA RIVEREAF ASSESSMENT FOR THE SOCA RIVER

The impact of abstraction, especially in the time of The impact of abstraction, especially in the time of low flows shows changes in low flows shows changes in hydrological,hydrological,physicophysico--chemicalchemical and and ecologicalecological parameters parameters downstream of the damsdownstream of the dams

Improve the habitats: the number and diversityImprove the habitats: the number and diversityTake into account: existing water abstraction Take into account: existing water abstraction (67 years)(67 years)According to analyses of parameters According to analyses of parameters

The EAF below the Podsela damThe EAF below the Podsela damThe EAF below the Ajba damThe EAF below the Ajba dam

EAF

EAF

KORITNICAKORITNICAHPP Možnica, 1911

F = 37,7 km2

sQs = 3,00 m3/ssQn = 1,07 m3/snQn = 0,65 m3/sQ300 = 1,35 m3/sQ347 = 0,85 m3/s

EAF = 0,20 m3/s• river bed (55 %,13 %)• physico-chemical parameters

0,417 m3/s

L = 380 mQi = 2,8 m3/s

0,030 m3/s

VIPAVAVIPAVA

HPP Gradišče, 1922

F = 482,7 km2

sQs = 14,24 m3/ssQn = 1,92 m3/snQn = 0,98 m3/s

EAF = 0,40 – 0,60 m3/s

Water abstraction for HPP

HPP

Inflow of used water to Vipava

L = 200 m

Qi = 12 m3/s

5. CONCLUSIONS5. CONCLUSIONS

Water use: ecology and economyWater use: ecology and economyValues of EAF: Values of EAF: hydrological parameters are the basishydrological parameters are the basisAssessment of EAF : Assessment of EAF :

interdisciplinarityinterdisciplinaritytimetimedata (measurments, sampling, analyses)data (measurments, sampling, analyses)

Sistematical evaluation of EAF, every Sistematical evaluation of EAF, every section of the river is treated separatellysection of the river is treated separatellyMonitoring of EAF and other mitigation Monitoring of EAF and other mitigation measuresmeasures

Thank you for the attention!Thank you for the attention!