Developing a methodological framework for estimating temporary drainage capacity to inform land requirements for a highway construction project in Scotland

Major highway construction projects can prove detrimental to the water environment. Construction activities can leave many kilometres of exposed soil susceptible to erosion from surface water runoff which can result in silt pollution and degradation of ecologically sensitive watercourses if appropriate mitigation is not in place. In Scotland, the environmental regulator now requires assurance that there is sufficient space to accommodate temporary construction drainage. In response, Jacobs has developed a methodological framework that can be applied before construction commences to estimate the required capacity of settlement ponds which includes runoff and soil loss volume estimation. The application of the framework as a case-study has demonstrated the potential applicability of the approach and highlighted where further refinements can be made to increase the robustness for future applications by improving the accuracy of input parameters to address site-specific conditions. Furthermore, it demonstrates how adopting erosion control measures can reduce required to accommodate temporary settlement ponds.