Scenario for risk management in Glinščica catchment

Description

The Glinščica is a small peri-urban catchment on the edge of Ljubljana where several problems overlap: flooding, loss of biodiversity, poor water quality and a declining water table. This tool assembles the management scenarios that were developed with the catchment's stakeholders and tested against those problems.

The scenarios combine the measures under consideration — large retention areas, re-meandering of the channel, re-vegetation of the banks — into coherent strategies rather than a list of separate interventions, and they were built in the course of the participatory process so that the combinations reflect what the stakeholders considered feasible as well as what the models considered effective.

Each scenario was then assessed for its effect on the water-related risks, on the co-benefits that the stakeholders had identified as important, and on the distribution of those effects between the actors in the catchment. The comparison is presented as the basis for the catchment's risk management decision rather than as a recommendation.

Applications to decision making in the insurance sector

The Glinščica scenarios show what a small catchment can and cannot deliver. The retention and re-meandering measures reduce flood peaks modestly and co-benefits substantially, which is the configuration in which an insurance contribution to funding is most plausible: the avoided damage alone does not pay for the measure, but the reduction in expected loss is real and identifiable.

Added value of this modelling approach

It treats a set of measures as a strategy rather than as a series of projects. That is the unit at which a decision is actually taken, and it is also the unit at which the trade-offs between measures become visible.

What decision can be improved with this modelling approach

Selecting a combination of measures for a catchment; judging how the benefits and the burdens of a strategy are distributed between the actors; and deciding what to do first when the measures cannot all be implemented at once.