IUAV Corso di perfezionamento in tutela e
gestione del suolo e delle acque
Venezia 13 Aprile 2012
The Environmental Impact
assessment in the urban
planning:
the prevention of the hydraulic hazard,
the Hydraulic Compatibility Assessment
Ing. Alessandro Pattaro
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Development plan presentation
1
The Hydraulic Compatibility Assessment
in Veneto
2
Hydraulic Compatibility Assessment of Meolo’s
PAT
3
Hydraulic Compatibility Assessment of
Maserada’s PAT
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1
The Hydraulic Compatibility
Assessment
in Veneto
(VCI di PAT, PI, Piani attuativi)
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Legal context of the Hydraulic Compatibility
Through the DGRV 3637/02 the Veneto Region requires that
the planning is subjected to Hydraulic compatibility
assessment.
Article 3, LR 11/2004 Rules for the Government of the territory
(known as new urbanism law)
4. The planning includes:
a) plan land use district (PAT), plan of action by
municipalities (IP), implementing urban development plans
(PUA);
b) Provincial Territorial Coordination Plan (PTCP);
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Objectives of the Hydraulic Compatibility
The adoption of new planning projects is subjected to
compliance with the opinion expressed by the competent
hydraulic authorities, identified by the Veneto Region in the
unit of the Regional Civil Engineers.
The VCI hydraulic calculations aim to define the design
interventions that have compensatory function to ensure the
“hydraulic invariance”.
The principle of invariance is defined: hydraulic invariance
means that the transformation of an area does not cause a
worsening of the discharge of the river receiving the runoff
originated from the same.
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Goals of the Hydraulic Compatibility
The fundamental purpose of the study is to support
compatibility hydraulic evaluation, from the stage of
conception:
• to ascertain the suitability of sites to accommodate the
new building;
• to consider the interference of the new settlements with
present and potential hydraulic disruptions;
• to determine possible changes in the hydraulic system
caused by new locations or changes of land use.
In summary: the hydraulic study aims to verify the eligibility of
the provisions contained in the planning projects, suggesting
good solutions in terms of good managment of the territory.
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Scheme of the Hydraulic Compatibility
1 – Collection and analysis of data
2 – Analysis of precipitation
3 – waterproofing evaluation in areas of urban expansion
4 – Application of a hydrological model (comparison between
different methods)
Hydrological assessment
of flow outgoing from
the basin study
Parameters suggested
from the local
managment authority
5 – Comparison of scenarios and evaluation of prevention,
containment and mitigation of hydraulic risk
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2
Hydraulic Compatibility
Assessment
Meolo’s PAT
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First case: the Compatibility Hydraulic
Assessment of Meolo’s PAT
Customer: Tepco srl
Project: Valutazione di Compatibilità Idraulica del PAT del
Comune di Meolo (VE)
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Geographical context
Monastier di TV
Roncade
F. Piave
Musile di P.
F. Sile
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Geographical context
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The areas potentially transformable
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The Piave ‘s PAI constraints, hazard mapping
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The Sile ‘s PAI constraints, hazard mapping
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The mathematical modeling 1d - 2d
The calculation
grid
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The flooding simulation in Meolo
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The new hydraulic hazard map
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The hydraulic assessment
N
W
E
Before urbanization
S
_EDIFICIO
_PAVIMENTAZIONI
_VERDE
90
0
90
180 Meters
_EDIFICIO
_PAVIMENTAZIONI
_VERDE
After the
waterproofing
N
E
W
S
90
0
90
180 Meters
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Which effects does the waterproofing area
cause on the existing hydraulic system?
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Which effects does the waterproofing area
cause on the existing hydraulic system?
Valutazione del volume di compensazione
0.14
0.12
portata [m³/s]
0.10
portata prima
dell'urbanizzazione
0.08
0.06
0.04
0.02
0.00
0
1
2
3
4
5
6
7
8
Tempo [h]
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The surface runoff increases and the stream
becomes faster
Valutazione del volume di compensazione
0.14
0.12
portata prima
dell'urbanizzazione
portata dopo
l'urbanizzazione
portata [m³/s]
0.10
0.08
0.06
0.04
0.02
0.00
0
1
2
3
4
5
6
7
8
Tempo [h]
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The surface runoff increases and the stream
becomes faster
Valutazione del volume di compensazione
0.14
To ensure the
hydraulic
invariance is
necessary to
create a
compensation
0.12
portata [m³/s]
0.10
0.08
0.06
portata prima
dell'urbanizzazione
portata dopo
l'urbanizzazione
0.04
0.02
0.00
0
1
2
3
4
5
6
7
8
Tempo [h]
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How to achive the mitigation
and compensation measures
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How to achive the mitigation
and compensation measures
1 – to insert a reducing flow
device in the upstream
section ahead the final
delivery
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How to achive the mitigation
and compensation measures
1 – to insert a reducing flow
device in the upstream
section ahead the final
delivery (ditch, river)
2 – to achieve a
compensation upstream
volume
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How to connect the
hydraulic network to
final delivery (ditch,
river)
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How to design the reducing discharge device
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VCI conclusions
The Hydraulic Compatibility Assessment ends with the
requirements that are incorporated in the Technical Rules of
PAT
Constraints, requirements and guidelines prescribe the
necessary measures to ensure the hydraulic invariance of
the urban development
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3
Hydraulic Compatibility
Assessment
Maserada’s PAT
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Second case: the Compatibility Hydraulic
Assessment of Maserada’s PAT
Customer : Comune di Maserada sul Piave
Project : Valutazione di Compatibilità Idraulica del PAT del
Comune di Maserada sul Piave (TV)
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Geographical context
Cimadolmo
LEGENDA
Idrografica principale
Argine S. Marco
Confini Comunali
Spresiano
F. Piave
Villorba
3
Breda di Piave
0
3
N
W
E
6 Kilometers
S
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The Piave ‘s PAI constraints, hazard mapping
N
W
E
S
Confini amministrativi
Pericolosità idraulica PAI Piave
F
P1
P2
P3
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The soil permeability (hydraulic conductivity)
LEGENDA - Permeabilità
Bassa (Argilla)
Elevata (Ghiaia)
Media (Sabbia)
N
E
W
S
3
0
3
6 Kilometers
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The groundwater depth
LEGENDA - Profondità falda freatica
0-2 m
2-5 m
5-10 m
Limite fascia risorgive
N
E
W
S
2
0
2
4 Kilometers
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Hydraulic runoff through infiltration device
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