To provide the best possible service this site uses cookies technicians . Continuing browsing the site you consent to their use in accordance with our Cookies Policy    

we plan the world of tomorrow.

EN FR IT ES

Olona-1

Expansion Basin of Olona river (Italy)

THE PROJECT CONCERNS THE DESIGN OF LAMINATION AND CONTROL WORKS OF THE FLOODS OF THE OLONA RIVER.


Project Manager

Alessandro Cacciatori

Alessandro Cacciatori
Hydraulic Engineer

Key Expert

Alessandro Paris

Alessandro Paris
Environmental Engineer

Project: Flood control works on the Olona river, Lombardy- Italy


Location: Lombardy Region, Italy


Client: Agenzia Regionale per il Fiume Po (A.I.P.O.) – (interregional Authority for the Po River)


Cost of total Works: €10,883,200


Services: Topographic and Geotechnical Surveys and Studies; Concept, Preliminary and Detailed Designs; Construction Supervision


Period: 2004-2008



The river Olona represents the main artery of a group of water courses in the north of Italy, most of which flow through built-up areas causing enormous damage to the population. The aim of the project was to make the river safe from flooding. The main problem in these areas is the total impermeability of the soil, so that normal water infiltration through the ground is virtually non-existent. All the water flows are confined to the river, increasing the water head especially during the rainy seasons (normally spring or autumn).This problem has been solved by designing two separate and artificial flooding areas, in order to allow the expansion of the river during the flood event, thereby avoiding the increase of the river level and consequently the risk of flooding for the neighbouring fields. The two areas are located on the hydrographic left and right sides of the river Olona.

 
The left bank flooding area consists in three descending small basins: the primary stage, which occurs in the upper basin, concerns the collecting of the surplus water coming from the main artery of the river Olona. The left bank in this stretch of the river has been re-shaped, in order to separate the river from the built-up area of S. Vittore Olona. In the middle basin it has been necessary to continue the re-shaping of the left levee, thus separating the new flood zone from the original riverbed. The lower basin is located near Parabiago town, and once again the left levee of the river was reinforced and raised to protect the town from flooding.
 
The right bank flooding area, like the left bank flooding area, is composed of three small descending basins. The river banks of all these basins were reinforced and raised to separate the new flood zone from the original riverbed and to protect the surrounding towns.
The left basins will be used for the more frequent floods, while the right basins will handle the extraordinary floods.
The realization of these two new artificial flooding areas along the river bank avoids the risk of floods in the nearby town, saving the population and removing the costs of the huge damages.
 
Further specific information
 
The main hydraulic characteristics of the left flooding area are:
  • The water intake is a trapezoidal channel with two mechanical flat gates which regulates the inflow
  • The restitution work is a special device consisting of two openings 4x4 m controlled by two gates and connected to the Olona river by two box-shaped structures that pass under the embankment of the flood areas
  • The intermediate discharge work is controlled by flat gates which, normally open, close when the maximum flood level is reached in the downstream sector
  • A safety overflow, 12 m long, is located in the levee of the third basin
The main hydraulic characteristics of the right flooding area are:
  • The water intake is a trapezoidal channel with two mechanical flat gates which regulate the inflow
  • The restitution work is a special device consisting of two openings 2x2 m controlled by one gate and connected to the Olona river by two box-shaped structures that pass under the embankment of the flood areas
  • The intermediate discharge work is controlled by flat gates which, normally open, close when the maximum flood level is reached in the downstream sector
  • A safety overflow, 12 m long, is located in the levee of the third basin
The whole system was studied by the application of a mono- and bi-dimensional mathematical model of the Olona river in which the following inputs were considered: rainfall runoff, channel flow, sewerage flow, real time control, water quality, emission and overall flow. The river Olona was schematized using a mono-dimensional grid, while the flooding areas were schematized using a bi-dimensional grid.
The model was calibrated and validated on the basis of the available data for the river Olona.

Technical Drawings & Renderings
pag. 1/5
Photo
  • Olona-1 Olona-1