Routing power lines: Towards an environmental and engineering friendly framework for avoiding impacts and conflicts in the planning phase

Abstract

Building new power lines is fundamental to supply the growing energy demand worldwide. Transmission Lines (TLs) impact assessments focus less on the first level (avoidance) of the mitigation hierarchy (MH) and more on the inferior levels (minimization, restoration, and compensation). Thus, designing TLs routes that avoid adverse environmental effects becomes an important challenge. Unfortunately, the environmental perspective is still poorly considered and incorporated too late into the projects, causing conflicts in the assessments due to divergent stakeholders' opinions. Identifying conflicting areas early is essential to avoid adding cost and delay to the project. Here, we proposed a decision workflow of route design which includes: i) the proposal of alternative routes using Geographic Information System and Least Cost Path Analysis based on two sets of fuzzy criteria – engineering and environmental; ii) an experimental approach with gradual variation among five scenarios that integrate engineering and environmental perspectives, based on Spatial Multi-criteria Analysis and Analytic Hierarchy Process; and iii) identification of route segments characterized by consensus between engineering and environmental perspectives, using a moving window analysis. Our findings show that the scenarios with the higher influence of environmental criteria achieved better performances in all environmental metrics. The spatial convergence among segments of all five modeled alternatives represents less conflict between environmental and engineering perspectives. We recommend that impact assessment of power lines should start taking advantage of the first level of the mitigation hierarchy (impact avoidance). This will represent a gain in the effectiveness of the impact assessment outcomes, a better focus on residual impacts during the following MH phases, a decrease in conflict level during the licensing process, and a potential reduction in project implementation time.