Riobra to Optimise Key Flemish Wastewater Networks

Riobra is an inter-municipal company responsible for the sewer systems of 24 Flemish municipalities. The company's main tasks include creating new house connections and maintaining networks to ensure they function well. Operations also encompass combined, storm and foul water sewers, pumping stations, small-scale wastewater treatment works and stormwater retention basins.

Leveraging the data from the sources, in combination with InfoNet, the company has developed an investment and renovation plan to determine where new sewers are needed and existing sewers must be renovated.

The first step in the process is determining the physical location of new sewers and the location of new house connections. The sewer database is being updated with information from this survey, and the data will in turn shape maintenance plans going forward.

An inventory of a proportion of pipes and nodes across the 24 municipalities produced a great deal of information to be input into the GIS database and iSeries. The work began with zoning plans, which show whether houses are connected to the public sewer system (zones depicted in green) and which of them have individual wastewater systems (zones depicted in red).

The company surveyed all pipes and nodes in the green zones with high flow rates and lower flow areas with pipe lengths greater than 50m. Where the total length of pipe was under 50m but over 10m, a simple visualisation of the infrastructure was deemed sufficient. Pipes with low flows and shorter than 10m were not included.

In the red zones, the reverse applied: where the total pipe length was greater than 50m, the company created a visualisation, and where the length was less, the pipes were not registered.
For the inventory, Riobra undertook a GPS survey of a third of the manholes and associated pipes across its areas, underground surveys of all nodes (equating to around a third of the manholes) and a survey of all hydraulic structures.

InfoNet is also used to develop the investment and renovation plan, allowing Riobra to indicate project areas and identify investment programs. Again, themes are used to simplify this process- for instance, projects due to be constructed in 2011 are colored brown. It is therefore easy to find the location of the various projects and their due build dates on a city plan.

For all projects, as-built data and images - critical elements in undertaking new house connection work - are connected to the project areas as hyperlinks. Riobra uses both InfoNet and iSeries for this work, because it needs to collect administrative data and know the geographical location of the house connection.

Data can be imported and exported between InfoNet to iSeries, so that both databases hold relevant administrative and geographical information. New house connections are created in InfoNet using two connection nodes and a length of sewerage. Some of the data fields draw information from iSeries, and the quality of the data is checked before importing it into InfoNet and flagged according to its quality. The new connection request application form for householders is connected as an ancillary hyperlink, along with photographs of the finished work.
Riobra devises maintenance plans in InfoNet, by creating thematic maps. For example, pipes where debris depth is greater than six inches (150mm) are highlighted. These maps can then be used to plan how often a particular subset of pipes is cleaned. This data is imported from the operational MWH Soft InfoWorks CS model.

Riobra undertakes preventative maintenance such as sewer cleaning and surveying as well as reactive maintenance - resolving incidents such as collapses and pipe blockages. By adding data on such incidents to the InfoNet database, the company can determine if a pattern of collapses is occurring on a particular pipe run and consider renovation or replacement of a failing section.