River restoration of the lower Aurino in Italy

National Id
Italy_01
Site name
Restoration interventions in four different sites in the lower course of the Aurino stream: Molini di Tures/ Gais; Gatzaue/ Gais; gatzaue downstream; S. Giorgio- Brunico
Summary
This case study focuses on the restoration of the Aurino stream. River restoration measures were implemented along the Aurino stream as part of the Aurino management plan. Interventions were implemented in different moments within the years 2003-2011. The objectives were flood protection and, secondarily, the improvement of the natural environment. Different interventions were implemented to widen the river bed, such as for example: (i) forests were cleared in the relevant areas, to add space to the river bed; (ii) (artificial) river banks were lowered and enlarged; (iii) re-activation or creation of lateral river branches; (iv) measures to raise the river bed’s level. The Autonomous Province of Bozen – Hydraulic engineering department was in charge of funding, planning, designing and implementing the measures.
Before implementation, all measures were extensively presented to, and discussed with, municipalities, farmers, fishermen associations and local communities; informing and involving local communities and key stakeholders was the key to successful implementation. The availability of land was the main constraining factor: most of the measures were implemented on public land (state or municipal land). Only in the case of Gatzauer/ Gais Lot III measures were implemented mostly on private land, but this required compensation.
When implementing these NWRM, interventions had to seek a balance between the desired outcome and the economic activities in the area of intervention. In this case, for example, bringing back the ground water level back to the original level would not have been a desirable outcome for farmers. Negotiations with farmers led, on the one hand, to a reduced ambition of the interventions, but on the other hand it also led to acceptance of the measures and, ultimately, contributed to the success of implementation.
The in-depth description of the case study
NUTS Code
Provincia Autonoma di Bolzano/Bozen
RBD code
ITA
Transboundary
0
Data provider
Gloria De Paoli, ACTeon
Longitude
11.9562
Latitude
46.8488
Climate zone
cool temperate moist
Mean annual rainfall
600 - 900 mm
Mean rainfall unit
mm/year
Average temperature
8,2
Type
Case Study Info
Light or indepth?
In-depth
Average slope range
1-2%
Vegetation class
Grassland/ Riparian woodland
Monitoring impacts effects
1
Monitoring parameters
No specific monitoring plan was developed.
Overall, the Special Enterprise of the Autonomous Province of Bozen is not undertaking any monitoring, because they only have funds to implement the measures - they do not have the legal status of research institution. The Special Enterprise is collaborating with some Universities (Bozen, Trento and Innsbruck) which are undertaking some monitoring/research activities on their own, using their own budget.
The only monitoring they are undertaking is the measurement of the groundwater level, as this is a major concerns of local farmers: prior to implementing the measures, the Province and the farmers agreed upon a maximum ground water level. If the aquifer gets higher than this threshold, then the Special Enterprise committed to implement additional measure to bring down groundwater level below this threshold. However, information on this was not available.
In addition, some (little) monitoring activities took place (monitoring data not available).
Monitoring changed slightly from one site to the other. Please find below a summary of monitoring activities carried out in the three sites:
- Channel pattern/ Planform (more often only after measure implementation - both quantitative and qualitative monitoring
- Connection to groundwaters: monitoring in one site, before and after measure implementation †“ quantitative monitoring
- Structure and condition of riparian shore zones: after measure implementation, quantitative monitoring
- Regular check of piezometer levels
- Monitoring of invertebrates populations (quantitative monitoring after measure implementation
- Monitoring of fish and bird populations
Performance impact estimation information
Piezometers - Other measures: unknown
Application scale
River
Installation date
2014-04
Age
11
Performance timescale
> 20 years
Area (ha)
4,3
Area subject to Land use change or Management/Practice change (ha)
4,3
Size
4,3
Size unit
ha
Design capacity description
The preliminary study (1999) identified the maximum flow rates of the river with respect to different return times (10, 30, 100 and 150 years). The hydraulic model allowed for the identification of areas more vulnerable to floods up to a return time of 150 years.
Basis of design
The preliminary study (1999) identified the maximum flow rates of the river with respect to different return times (10, 30, 100 and 150 years). The hydraulic model allowed for the identification of areas more vulnerable to floods up to a return time of 150 years.
Constraints
The Aurino is an alpine stream, and thus it flows in a very narrow valley with high competition over land use by the different sectors (agriculture, industry, residential). As a consequence, land prices are amongst the highest in Italy. This means that these interventions, which reclaim land to the river bed, are necessarily confronted with these limiting issues: (i) interventions are limited in the sense that they cannot bring the ground water level back to its original level, as this would imply a loss of agricultural land; and (ii) due to land prices, interventions were mostly implemented on public land.
Favourable preconditions
Although the river bed is incised, the lower Aurino course still kept its meanders, and even before interventions it could have been considered one of the best conserved river stretches in the Bozen province.
Peak flow rate
464
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Other
Agreement with local farmers: if the groundwater table exceeds the threshold agreed upon, the Province committed to intervene to bring the level below the threshold
Negotiation with local farmers
Design consultation activity
Activity stage Key issues Name Comments
Screening phase
informing and involving local communities and key stakeholders was the key to successful implementation (see e.g; negotiations with farmers);
Design phase
informing and involving local communities and key stakeholders was the key to successful implementation (see e.g; negotiations with farmers);
Implementation phase
informing and involving local communities and key stakeholders was the key to successful implementation (see e.g; negotiations with farmers);
Screening phase
Several activities targeting local communities and stakeholders (e.g. negotiations with farmers, educational activities in schools)
informing and involving local communities and key stakeholders was the key to successful implementation (see e.g; negotiations with farmers);
Design phase
Several activities targeting local communities and stakeholders (e.g. negotiations with farmers, educational activities in schools)
informing and involving local communities and key stakeholders was the key to successful implementation (see e.g; negotiations with farmers);
Implementation phase
Several activities targeting local communities and stakeholders (e.g. negotiations with farmers, educational activities in schools)
informing and involving local communities and key stakeholders was the key to successful implementation (see e.g; negotiations with farmers);
Design land use change
Land use change type
Design authority
Authority type Role Responsibility Name Comments
Other
Initiation of the measure
Autonomous Province of Bozen
Autonomous Province of Bozen
Other
Determination of design details of the measure
Autonomous Province of Bozen
Autonomous Province of Bozen
Other
Implementation
Autonomous Province of Bozen
Autonomous Province of Bozen
Other
Financing
Autonomous Province of Bozen
Autonomous Province of Bozen
Key lessons
Participatory planning and communication activities are the key to successful implementation (see e.g. negotiations with farmers).
Success factor(s)
Success factor type Success factor role Comments
Public participation
main factor

Participatory planning and communication activities: informing and involving local communities and key stakeholders was the key to successful implementation (see e.g. negotiations with farmers).

Communication activities
main factor

Participatory planning and communication activities: informing and involving local communities and key stakeholders was the key to successful implementation (see e.g. negotiations with farmers).

Existing institutional framework
main factor

The Autonomous Province of Bozen has, as its name suggests, almost full autonomy when it comes to land and river management. This means that it has full responsibility and control over its territory and water bodies, so it can autonomously plan and implement interventions. In addition, it is one of the richest local administrations in Italy, and thus it has funds available. The measures were fully implemented by the Province, which has all the necessary equipment, and nothing was externally contracted or subcontracted: this allowed for keeping the costs down. Interventions were managed by a "strong" coordinator, who had everything under control.

Financing possibilities
main factor

The Autonomous Province of Bozen has, as its name suggests, almost full autonomy when it comes to land and river management. This means that it has full responsibility and control over its territory and water bodies, so it can autonomously plan and implement interventions. In addition, it is one of the richest local administrations in Italy, and thus it has funds available. The measures were fully implemented by the Province, which has all the necessary equipment, and nothing was externally contracted or subcontracted: this allowed for keeping the costs down. Interventions were managed by a "strong" coordinator, who had everything under control.

Attitude of decision makers
main factor

The Autonomous Province of Bozen has, as its name suggests, almost full autonomy when it comes to land and river management. This means that it has full responsibility and control over its territory and water bodies, so it can autonomously plan and implement interventions. In addition, it is one of the richest local administrations in Italy, and thus it has funds available. The measures were fully implemented by the Province, which has all the necessary equipment, and nothing was externally contracted or subcontracted: this allowed for keeping the costs down. Interventions were managed by a "strong" coordinator, who had everything under control.

Financing
Financing type Comments
Sub-national funds
The application was initiated, financed and implemented by the Special Enterprise for River Regulation and Land Protection, which is a body of the Autonomous Province of Bozen. The Province allocates funds to the Special Enterprise for the protection and safety of residential areas, and in turn the Special enterprise allocates part of these funds to restoration interventions.
Barrier
Barrier type Barrier role Comments
Other
main barrier
The availability of land was the main constraining factor: most of the measures were implemented on public land (state or municipal land). Only in the case of Gatzauer/ Gais Lot III measures were implemented mostly on private land, but this required compensation (see dedicated cell).
Attitude of relevant stakeholders
secondary barrier
Due to human modifications to the water body and consequent riverbed incision, in the previous decades the ground water table had lowered. However, a lower groundwater table allowed the expansion of agricultural areas, and this had to be taken into account when designing and implementing the measures - i.e. bringing back the ground water level back to the original level would not have been a desirable outcome for farmers. Therefore the capacity of the applications were constrained by negotiations with local farmers.
Attitude of the public
secondary barrier
In one case, the original plan had to be modified for acceptability issues. In the S. Giorgio/ Brunico site, the original project included a larger intervention (widening of the river bed + reactivation of an old branch of the Aurino stream). This would have implied clearing a large area of riparian forest (0.5 ha, 1/3 of the total forest area). Despite the fact that the riparian forest was classified as irreversibly degraded, such a massive forest clearing in a sensitive and densely populated area would not have been accepted. Therefore the reactivation of the old branch was substituted with the creation of a smaller dead branch, which is only 100 m long.
Driver
Driver type Driver role Comments
main driver
The main objective of the interventions is the improvement of riparian natural environments, coupled with protection against floods. More in detail, the interventions were aimed at tackling: (i) almost total disappearance of islands and gravel areas; (ii) dramatic reduction of flooding areas. Another major objective is to raise the groundwater level, which has significantly reduced over time. As a result of the former (i) the river has damaged longitudinal hydraulic works, especially near bridges; (ii) riparian forests are now rarely flooded, and this disturbs ecological dynamics. However, a lower groundwater table allowed the expansion of agricultural areas, and this had to be taken into account when designing and implementing the measures - i.e. bringing back the ground water level back to the original level would not have been a desirable outcome for farmers.
The issue described above are due to (i) hydromorphological interventions on Aurino's effluents, and on 40% of the Aurino stream: this led to the reduction of solid transport; and (ii) intense gravel mining along the lower stream course (in the 70's).
Financing share
Financing share type Share Comments
Policy description
The main objective of the interventions is the improvement of riparian natural environments, coupled with protection against floods. More in detail, the interventions were aimed at tackling: (i) almost total disappearance of islands and gravel areas; (ii) dramatic reduction of flooding areas. Another major objective is to raise the groundwater level, which has significantly reduced over time. As a result of the former (i) the river has damaged longitudinal hydraulic works, especially near bridges; (ii) riparian forests are now rarely flooded, and this disturbs ecological dynamics. However, a lower groundwater table allowed the expansion of agricultural areas, and this had to be taken into account when designing and implementing the measures - i.e. bringing back the ground water level back to the original level would not have been a desirable outcome for farmers.
The issue described above are due to (i) hydromorphological interventions on Aurino's effluents, and on 40% of the Aurino stream: this led to the reduction of solid transport; and (ii) intense gravel mining along the lower stream course (in the 70's).
Policy target
Target purpose
Peak-flow reduction
Groundwater Recharge
Improved Biodiversity
Policy pressure
Pressure directive Relevant pressure
Policy area
Policy area type Policy area focus Name Comments
Policy impact
Impact directive Relevant impact
Policy wider plan
Wider plan type Wider plan focus Name Comments
Regional
Water
Lower Aurino Management Plan
Management Plan for the Aurino river developed by the Autonomous Province of Bozen
Project-based
Water
River Basin Agenda
All interventions are part of the Lower Aurino Management Plan, and they are also included in the project "River Basin Agenda" (Alpine Space - Interreg IIIB) aimed at addressing common challenges of alpine river basins.
Essential functions and use of river basins are flood protection und flood retention, extensive agriculture and forestry, recreational use, groundwater protection and nature conservation. Modern river basin management therefore means conciliating these requirements at the best possible way.
River basin management as it is understood within the project group of the RBA, deals with coordination of procedures regarding flood protection and land use planning in Alpine valley floors.
The river basin management plays particularly a crucial role in the spatial development of endangered, intensively used valley sites. In the frame of the planning process it is important to integrate as many participants as possible, e.g. municipalities, departments, interested and concerned people, etc.
At the regional level, the interventions aimed at addressing both flood control and the enhancement of riparian environments.
Policy requirement directive
Requirement directive Specification
Direct benefits information
No info
Ancillary benefits information
No info
Costs investment information
No cost breakdown was available
Costs operation maintenance
No cost breakdown was available
Costs total
427000
Costs total information
Costs per site:
Molini di Tures: 100,000 €
Gatzaue/ Gais (all three lots): 195,000 €
S. Giorgio/ Brunico: 132,000 €
As the Province was fully in charge of implementation, and no activity was contracted or sub-contracted to external enterprises, these costs include all components (design, actual implementation, communication activities, a few monitoring activities)
Compensations basis information
In most cases, the measures were implemented on public land (property of the state or the municipality).
In Gatzaue/ Gais Lot III most of the land (0.6 ha) was privately owned. Once the measures were implemented, the landowner received in exchange other parcels. Some parcels on the old Aurino river bed were in fact still inventorized as "demanio idraulico" (state hydraulic property), but they cannot be considered anymore as part of the hydraulic private property as they are completely covered by woodland. These parcels were given to the private landowner as an exchange, whereas the formerly private parcels used for implementing the measures passed onto the hydraulic public property as they are now occupied by the river.
Information on Ecosystem improved biodiversity
The measures improved the river bed structure, created differentiated habitats and created areas with different flow speed. As a result, the fish population improved considerably, both in terms of size and ratios among main species.
Information on Ecosystem provisioning services
The measures improved the river bed structure, created differentiated habitats and created areas with different flow speed. As a result, the fish population improved considerably, both in terms of size and ratios among main species.
Information on Ecosystem water supply
Not relevant for the specific application
Ecosystem impact climate regulation
Not relevant for the specific application
Information on Ecosystem impact climate regulation
Not relevant
Information on retained water
no info
Information on increased water storage
no info
Information on runoff reduction
no info
Water quality overall improvements
N/A info
Information on Water quality overall improvements
The first RBMP for the Eastern Alps RBD classifies the Aurino stream in good (2003) and high (2004) ecological status (NWRM implementation in the period 2003-2004). Water quality after measure implementation was not measured
Soil quality overall soil improvements
N/A info
Information on Soil quality overall soil improvements
No info

Partners

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