Developing a Methodological Framework for Estimating Temporary Drainage Capacity to Inform Land Requirements for a Highway Construction Project in Scotland

Mandy Wallace,Sam Flint,Derwyn Lear,Iain Mcnee,Anita Meldrum,Slobodan Mickovski

doi:10.3390/su12145522

Mandy Wallace, Sam Flint + Show 4 more

Open Access

https://doi.org/10.3390/su12145522

Copy DOI

Abstract

Silt pollution generated during major highway construction projects can prove detrimental to the water environment and the aquatic species that depend on it. Construction activities can leave many kilometers 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, assurances need to be provided during scheme development to demonstrate that there is sufficient space to accommodate temporary drainage. In response, a methodological framework has been developed that can be applied before construction commences to estimate the required capacity of settlement ponds including runoff and soil loss volume estimation, which are estimated using the Rational Method and Revised Universal Soil Loss Equation (RUSLE). 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 the land required to accommodate temporary settlement ponds.

Highlights

Highways construction can be detrimental to the environment due to the level of ground disturbance, which can span many kilometers
Two reported areas of potential weakness in their application of the Revised Universal Soil Loss Equation (RUSLE) on forest road plots include RUSLE developed for natural soils, and the scale of application in the study was smaller than RUSLE was originally intended for
The methodological framework provides temporary drainage designers with a useful tool to estimate the size of construction drainage to ensure that sufficient land is available to accommodate construction drainage features

Summary

Introduction

Highways construction can be detrimental to the environment due to the level of ground disturbance, which can span many kilometers. Once vegetated surfaces are stripped and topsoil is removed, areas of exposed soil are left susceptible to water and wind erosion. When exposed surfaces are eroded, without adequate water management in place, suspended eroded materials can enter the water environment. Once in the water environment, they can be damaging to downstream receptors [1]. Providing suitable mitigation against elevated rates of suspended solids in the water environment prevents a number of ecologically detrimental effects. This can include reduced light penetration in the water column for aquatic plants and smothering of salmonid spawning areas [2]

Objectives

Methods

Results

Discussion

Conclusion