Slizza basin: studies for hydro-geological risk management in a small alpine basin and their consequences or applicability on trans-national planning

Giacomo Casagrande Autorità di bacino regionale del Friuli Venezia Giulia (Basin Regional Authority of Friuli Venezia Giulia, )

Methodologies and best practices for the participation of the stakeholders involved in flood risk prevention

Danube FLOODRISK – Trento, 3-4 october 2011 SUMMARY

1) Territory 2) Overview of actors and competences at regional level on soil-water defence 3) Activities of Regional basin authority FVG 4) Slizza river ( basin): studies and involvment in the transnational context

Danube FLOODRISK – Trento, 3-4 october 2011 INSTITUTION OF AUTHORITY

ƒNATIONAL LAW 183/89 (Basin Authorities, Basin Management Plans)

ƒ11 basins under national management

ƒ16 basins under interregional management

ƒAll other basins single region management

ƒREGIONAL LAW 16/2002 (Institution of Regional Basin Authority, ABR FVG)

ƒOperating from november 2004

ƒNATIONAL LAW 152/2006 (Basins Districts)

ƒTransition period, from 2009 ABR FVG under temporary commissary

Region Friuli Venezia Giulia has autonomous law conditions

Danube FLOODRISK – Trento, 3-4 october 2011 TERRITORY - Eastern Alpine District

Danube FLOODRISK – Trento, 3-4 october 2011 TERRITORY – Regional local basins

Austria Slizza

High plain Slovenia Veneto

Est Isonzo

Competence area 2176 Km2 Region FVG 7845 Km2 Regional proportion 28% Low plain - Lagoon Municipalities 75

Danube FLOODRISK – Trento, 3-4 october 2011 ORGANIZING STRUCTURE

ƒ 3 GOVERNANCE UNITS ƒ COMITATO ISTITUZIONALE ( dpr n. 0301/Pres. 8/10/02) ƒ COMITATO TECNICO (costituito in data 26/04/2005) ƒ SEGRETARIO GENERALE

ƒ OPERATING AGENCY (art. 10 LR 16/2002): ƒ SEGRETERIA TECNICO OPERATIVA (from 2004)

ƒ JOINING COMMITTEE (art. 11 LR 16/2002): ƒ CONSULTA DI BACINO

Danube FLOODRISK – Trento, 3-4 october 2011 REGIONAL ACTORS

4 ATO regionali 4 Comprensori di bonifica Occidentale Centrale Cellina - Meduna Orientale goriziano Ledra -Tagliamento Orientale triestino Pianura isontina 1 ATO interregionale: Bassa friulana Region del Lemene Provinces Municipalities

22 bacini di rilievo regionale 2 bacini di rilievo nazionale (ora Distretto Alpi orientali)

Danube FLOODRISK – Trento, 3-4 october 2011 REGIONAL ACTORS

Water/Soil: Coordination and competences

CONSORZI DI BONIFICA •Realizzazione/manutenzione opere idrauliche REGIONE: •Provvista/adduzione acque destinate ad usi agricoli Attribuzione di funzioni •Distribuzione irrigua LR 16/2002: Difesa del suolo e (LR 28/2002 •Bonifica idraulica demanio idrico •Servizio di piena e pronto intervento LR28/2002: Consorzi di bonifica •PIANO GENERALE DI BONIFICA COMPRENSORIALE LR 13/2005: Organizzazione del SII da coordinarsi con il Dlgs 152/2006: AUTORITA’ D’AMBITO Testo unico ambientale •Organizzazione e gestione del Servizio idrico integrato Controllo e •Ricognizione opere esistenti di adduzione, distribuzione, fognatura, •Programmazione ed indirizzo coordinamento depurazione nell’utilizzo delle risorse idriche (LR 13/2005) •Controllo gestione e qualità del SII •Vincolo idrogeologico •PIANO TERRITORIALE D’AMBITO •Elenco acque pubbliche •Concessione derivazioni da acque AUTORITA’ DI BACINO REGIONALE pubbliche •Safeguard and mantaining of water balance •Delimitazione bacini idrografici Collaborazione e (Respect of DMV; assessment on water supply) regionali, comprensori di bonifica, coordinamento •Hydrogeological balance ambiti territoriali ottimali (LR 16/2002) •Management on flood and landlslide hazard •Opere idrauliche e di difesa da •PIANI DI BACINO (hydraulic defence; PAI) inondazioni •Servizio di piena e pronto intervento idraulico COMUNI : tratte corsi d’acqua interne ai centri abitati •Pulizia idraulica e manutenzione Delega: •Pulizia idraulica (asporto di rifiuti, piante,arbusti ecc) •PIANO TUTELA ACQUE convenzione tra •Manutenzione ordinaria di argini, parapetti, opere idrauliche Comune e Regione •Pulizia argini e pertinenze fluviali (LR 16/2002) •Recepimento nei PIANI URBANISTICI COMUNALI di indirizzi vincoli imposti da piani o altri strumenti sovraordinati

Danube FLOODRISK – Trento, 3-4 october 2011 ACTIVITIES AND RESULTS

1. Piano stralcio per la difesa idraulica del torrente Cormor (approved, 2009). Definition of HYDRAULIC plans and actions 2. Piano stralcio per la difesa idraulica based on DEFENCE del torrente Corno (adottato, 2010) TR = 200 anni

3. Piano stralcio per la difesa idraulica del torrente Slizza (work in progress) • Hazard maps (H1-H4); HYDROGEOLOGICAL Progetto di Piano stralcio per l’assetto idrogeologico, PAI • achievement of RISK MANAGEMENT (in study) 2007/60/CE objectives

Progetto di Piano stralcio per • bathymetric map, TUTELA la difesa idraulica e la tutela circulation ECOLOGICA E ecologica ed ambientale della hydraulic model; Laguna di Marano e Grado AMBIENTALE • morphological (in study) and ecological protection of lagoon environment Danube FLOODRISK – Trento, 3-4 october 2011 HYDRAULIC DEFENCE – Cormor river case

Austria ƒFlood towards plain from hill territory of 80-90 km2; Tagliamento ƒHigh plain with riverbed large channel; Slovenia ƒLow plain riverbed completely between artificial levee (land reclamation 1930- Corno 1960); Cormor Isonzo ƒFew possibilietes for operating in low plain (urbanization, infrastructures)

Adriatic sea

Danube FLOODRISK – Trento, 3-4 october 2011 HYDRAULIC DEFENCE – Cormor river case

Reference flood for operations planning Tr=200 anni

Reference flood was calculated with Geomorphoclimatic Istantaneous Unit Hydrograph,

30 Max discharge m3/s 350 pioggia totale

Pioggia efficace 27,93 mm 288 m3/s 6 3 Volume = 15.3 x 10 m300 25

GIUH medio sul picco 26,18 mm GIUH medio 250 sul picco 20 19,48 mm ] 200 ] m /s q =0.250 3 p m [ a 15 [m ta

t =2.035 ta r p oggi 13,50 mm 150 o pi t =7.990 p b 10 100

intervallo considerato 5 per la determinazione 50 della pioggia media

0 0 06/ 06/ 07/ 07/ 07/ 07/ 07/ 07/ 07/ 07/ 07/ 07/ 05/ 05/ 05/ 06/ 06/ 06/ 06/ 06/ 06/ 06/ 06/ 06/ 06/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 10/ 98_22 98_24 98_2 98_4 98_6 98_8 98_10 98_12 98_14 98_16 98_18 98_20 98_20 98_21 98_23 98_2 98_4 98_6 98_8 98_10 98_12 98_14 98_16 98_18 98_20

data e ora

Danube FLOODRISK – Trento, 3-4 october 2011 HYDRAULIC DEFENCE – Cormor river case

Technical solutions and planned works

ƒDivertion tunnel towards Torre river (Isonzo basin), max discharge = 100 m3/s ƒRimodeling of flood detention area of Sant’Andrat ƒNew flood detention area near Zugliano ƒPlan management introduce also rule and constraints in land use, definition of “riverine zones”. Obligation for municipalities to develope actions following hydraulic invariance cocepts in urbanized areas.

Danube FLOODRISK – Trento, 3-4 october 2011 HYDRAULIC MODELING

Common instruments and methodologies

ƒGIUH and SCS-CN ƒMIKE FLOOD (MONO AND BI-DIMENSIONAL) ƒLIDAR DATA FOR DTM

23 km ƒDISCHARGE (ADCP instruments) AND LEVEL MONITORING (RECENT)

Danube FLOODRISK – Trento, 3-4 october 2011 EXPLOITATION FOR HYDROPOWER

KAPLAN TURBINE COCLEA (SCREW)

Danube FLOODRISK – Trento, 3-4 october 2011 MARANO AND GRADO LAGOON –Bathymetric map

ƒNew bathymetric map (after 1960) ƒHydraulic circulation model ƒSite of national interest (Hg) ƒFuture plan for morphological and ecological safeguarding

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – General context

ƒSlizza > Gailitz > > (Drau) > Danube ƒH max 2677m, H min 600m ƒ180 km2 ƒMain branch 30 km

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – Activities

TOPICS

1) PAI – Hazard mapping for landslides and floods 2) Transnational involvement – Cave Predil case 3) Transnational cooperation – Floodrisk: need of shared approaches/practices/informations 4) DMV and water withdrawal for hydropower

GENERAL CONSIDERATIONS FOR NE ALPINE BASINS 1) Major problems (es. victims) comes from Debris Flow phenomena 2) During last years episodes of flood due to rainfall and snowmelting (especially in december) 3) Need of specific hydraulic modeling (snowmelting, real time models, rapid alerting systems) 4) Increasing of water request for hydropower

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – PAI hazard mapping

+

… to be revisited (2007/60/CE, DLGS 49/2010)

Danube FLOODRISK – Trento, 3-4 october 2011 VAL CANALE – Event august 2003

29.08.2003 ƒVal Canale (Pontebba, Malborghetto, municipalities) ƒStrong rainfall event in 12 hours, tens of debris flow from small basins (< 1-2 Km2) ƒ400 landslides, 2 victims

Danube FLOODRISK – Trento, 3-4 october 2011 VAL CANALE – Evento agosto 2003

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – Cave Predil specific case

CAVE DEL PREDIL (Pb,Fe, Zn MINE) Residual waste sediments ~2M m3

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – Cave Predil specific case

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – Cave Predil specific case

Debris flow from hypotetycal dam break : ƒCollapse volume hypothesized (stability analisys partially made but difficult) ƒSlizza river runs next to waste storage basins – disponibilità di acqua per la formazione della colata detritica ƒDebris Flow modeling with FLO- 2D

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA - HYDRAULIC MODELING

3 APPROACHES on specific case

Different 1) GIUH and SCS-CN , ABR FVG results 2) TOPMODEL (TOPography based hydrological MODEL), UNITS Es. TR 200 years (250- 3) Conceptual model based on HEC-HMS approach, UNIUD 350 mc/s)

..TOWARDS A SOLUTION AFTER 20 YEARS FOR POLLUTION, FLOOD AND MUD FLOW RISK Important financing (5-6 M euro) will enable works for hydrogeological and pollution safeguarding: ƒby pass for waterflow from slopes ƒEnhancement and rise of riprap (pali secanti) ƒOverlay of deposits with clay layer

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – Need of transnational cooperation

Historical discharge series from Thorl station (start 1975) Transnational cooperation would be fundamental for: ƒMonitoring ƒModels calibration ITA SLO ƒReal time modeling ƒAlert/alarm thresholds and systems ƒRisk analysis and scenario (common strategies and approaches)

QUANTIFLOOD project (OJ C 49 of 16/2/2011, Projects on prevention and preparedness) MASSMOVE project, Minimal standards for compilation of danger maps like landslides and rock fall as a tool for disaster prevention (Interreg IV)

Danube FLOODRISK – Trento, 3-4 october 2011 SLIZZA BASIN – DMV

Increasing of request for small hydropower stations DMV (Deflusso minimo vitale): AUSTRIA ƒRegional Law 28/2001 – definition of DMV as 4 l/s/km2 (intention of temporary act); ƒFrom 2007 resolution of ABR – adoption of a modified swiss

method (Q347); ƒLegal action of private companies;

SLO

Danube FLOODRISK – Trento, 3-4 october 2011 THANK YOU FOR ATTENTION

Danube FLOODRISK – Trento, 3-4 october 2011