This thesis investigates to what extent and under what conditions it is likely that the Netherlands will meet its national target of reducing the average use of household drinking water from 129 in 2021 to 100 litres per person per day [lpppd] in 2035, as described in the National Plan of Action for Drinking Water Conservation (2024). This plan, published by the Dutch Ministry of Infrastructure and Water Management, was formulated due to growing concerns about anticipated drinking water shortages by 2030. Along with other policy measures, it led the Dutch government to attempt to shift toward demand-management measures. However, the effectiveness of the recently introduced and planned conservation measures remains uncertain, especially in light of various future developments.

This research assesses the potential impact of the proposed household-level policy measures using a model with a bottom-up demand component combined with a higher-level supply component. It applies the methodology of Exploratory System Dynamics Modelling and Analysis. An approach to execute a scenario-based exploration under deep uncertainty, simulating the combined effects of demographic dynamics, increased periods of drought, and economic growth in twelve potential future scenarios. As each of the ten drinking water companies operates within their own demographic and geographical context, they all face their own challenges, and different results are generated.

These results show that in none of the simulated scenarios for any of the drinking water companies, household demand actually falls to the policy target of 100 lpppd by 2035. Instead, demand only decreases to around 120 lpppd in 2035, with slight variations between regions and exogenous factors.
However, that decrease persists and reaches 110 lpppd by 2050. Regarding the supply side of the drinking water distribution system, total household and industrial demand actually increases significantly in most scenarios up to 2030 due to population and economic growth. Regional variation further highlights that some water companies may encounter local shortages, even if national demand remains within its supply limits. A key outcome of this research is the demonstration of a policy-focused modelling framework that policy makers and researchers can reuse and extend.

These findings show that the current mix of policy interventions is unlikely to be sufficient to meet the policy objective set for the conservation of drinking water. Nevertheless, demand management is one element of several in drinking water management. The simulations also show that when drinking water companies are successful in developing additional fresh water sources the challenges of increasing drinking water demand could be met.

However, more impactful policy interventions could be made still if decisive action is taken in both the implementation and development of further demand management strategies. There remains a lot to gain by further exploring the limits and opportunities of the Dutch drinking water distribution system to support the implementation of more robust and future-proof policies.