Extra maintenance costs for roads and sewers associated with land subsidence in the Netherlands have been estimated at 250 million euro a year. This is a major burden on council budgets. In some places, costs are so high that the local authorities lack the financial resources to complete all the maintenance work that piles up. Municipal authorities and their advisers need a better understanding of the opportunities afforded by technical solutions and new developments to mitigate the high maintenance costs associated with land subsidence.
Copyright foto, Guus Schoonewille
In 2014, Deltares teamed up with CROW to conduct an exploratory study so that municipal authorities can make better decisions about planning maintenance work associated with land subsidence. The main obstacles to the optimisation of the maintenance and management strategy were mapped out in consultation with civil servants, infrastructure managers, contractors and consultancies. It emerged from the study that existing technical knowledge can be used better and that innovative solutions are required to save on the maintenance costs for infrastructure. It was also found that newly-developed and existing knowledge is not tested adequately in field conditions.
We then set out a number of lines for resolving difficulties, such as the definition of measurement objectives for subsidence and the quantification of the measurement data. Even the scheduling of maintenance and reconstruction on the basis of measurements of subsidence can lead to savings. Targeted measurements also give us a better picture of the alternative solutions used. Innovative solutions should help to save on maintenance. It is important here to have a clear picture of the interests of all those involved: they are the people who determine the potential range of policy and technical options. The exploratory study is the first step towards an improved maintenance strategy. The plan is to elaborate the broad solutions in a multi-year programme in 2015. We are currently looking for financing for this process.
By working together and exchanging knowledge, municipal authorities can make considerable savings in infrastructure maintenance. Deltares and CROW are eager to help.
Investing now in subsidence-free building methods saves on maintenance costs in the future.
John Lambert (left), Hans van Meerten (right)