Severe rainfall can have an adverse impact on the network, resulting in cancelled and delayed train services. The speed restrictions that are imposed in response to such heavy rainfall were defined as emergency measures and lacked system level detail. We describe how a systematic approach that leverages existing data can be used to calculate the baseline risk, in addition to the network effect of imposing a speed restriction. We also look at how the deployment of these models into a digital tool delivers the capability to support decisions on the application of speed restrictions in an informed way, ensuring the network risk can be reduced to as low as reasonably practicable.