Environmental Impacts of Transmission Lines on Water Resources

Overview

Detailed environmental studies indicate that transmission lines can negatively affect water resources, especially through construction impacts, soil disturbance, and changes in hydrology. and pollution runoff.

Documented Negative Impacts on Water

Water Pollution and Hydrology Changes

• Transmission line construction in wetland or riparian areas disrupts hydrological cycles, causing altered flows and degraded water quality in streams, rivers, and lakes.

• Tower placement and clearing corridor often change local drainage patterns, which may increase flooding risk and alter natural water movement underground and across the land.

Soil Erosion, Sediment, and Agricultural Harm

• Removing vegetation and windbreaks to install power lines greatly increases soil erosion.

• Increased sediment runoff lowers water quality, fills in wetlands, and harms aquatic habitats. This effect persists for years after construction, especially where erosion controls fail.

• Compacted soils and soil mixing can increase surface runoff and reduce water infiltration, making aquifers and groundwater recharge less effective and reducing agricultural yields.

Direct Contamination Risks

• Heavy equipment and soil excavation may expose buried contaminants or introduce new pollutants like oil, lubricants, and concrete washouts, which can leach into groundwater and nearby water bodies.

• Improper management during and after construction can result in pesticide, herbicide, and disease risk spreading through runoff to field drains and watercourses.

Other Ecosystems and Water Quality Effects

• Loss of vegetation cover can raise water temperature and negatively impact aquatic life.

• Construction and operation of power lines routinely fragment wetlands, disrupt wildlife migration, and threaten rare aquatic species.

• In some cases, runoff and atmospheric deposition of pollutants linked with power infrastructure contribute to lake and stream contamination, algal blooms, and loss of oxygen in water, harming fish and other organisms.

Summary Table

Negative Impact Description

Erosion, sediment runoff Lower water quality, harm aquatic ecosystems

Hydrological cycle disruption Alters water flows, & drainage patters; flooding risk

Pollution, contamination runoff Chemicals from soil, machinery, & vegetation kill aquatic life

Wetland loss, fragmentation Habitat loss; higher extinction risk for rare species

Thermal pollution Alters temperatures, harms fish & oxygen levels

Compacted soils, poor recharge Reduces aquifer recharge, increases field runoff

Conclusion

Research consistently shows that transmission lines pose real risks to water quality, aquatic habitats, and hydrology, especially during and after construction and when large corridors are cleared or wetlands disturbed.

Articles & Blogs

• StopMPRP.com: "Environmental Impact of High-Voltage Transmission Lines"

  • This advocacy site reports on how water pollution, erosion, sediment runoff, and hydrological disruption from transmission line construction and operation can harm streams, rivers, lakes, and wetlands. It highlights altered flows and degraded water quality as direct impacts of these projects, alongside effects on aquatic ecosystems.

    • https://stopmprp.com/what-is-at-stake/f/environmental-impact-of-high-voltage-transmission-lines

• Wisconsin Public Service Commission: "Environmental Impacts of Transmission Lines" (PDF)

  • This government brochure provides details on high-voltage transmission lines can contribute to surface water pollution, as well as the regulatory protections for high-quality water sources. It discusses how construction practices may alter hydrology and increase contamination risk via point source pollution.

    • https://psc.wi.gov/Documents/Brochures/Enviromental%20Impacts%20TL.pdf

• Nautilus Institute: "International Best Practices for Assessing and Reducing the Environmental Impacts of High Voltage Transmission Lines" (PDF)

  • The report covers toxic pollution, including contamination from pesticides and leaks of equipment fluids (such as PCBs), as well as water pollution from construction and maintenance camps, soil compaction, and hydrologic changes in wetlands and riparian zones.

    • https://www.nautilus.org/wp-content/uploads/2015/06/Env_Best_Practices_Williams_final.pdf

• Scenic America: "The Environmental Impact of Power Lines"

  • This blog examines landscape and waterway impacts, highlighting how corridor clearance leads to erosion and runoff, disturbance of natural waterways, and change in wetland hydrology, which results in loss aquatic habitat and increased water pollution.

    • https://www.scenic.org/2023/09/20/the-environmental-impact-of-power-lines/

• US EPA: "Electricity Delivery and its Environmental Impacts"

  • EPA resources document how high-voltage transmission line corridors can disrupt forest, wetlands, and other natural ecosystems, specifically noting disturbance to water features, pollution, and aquatic habitat fragmentation from tower and access road construction.

    • https://www.epa.gov/energy/electricity-delivery-and-its-environmental-impacts

• Sediver: "Pollution mitigation solutions for overhead line insulators" (PDF)

  • The article discusses how pollution-both atmospheric and waterborne-can accumulate on transmission line hardware and insulators, leading to further contamination issues, especially in rain events and humid climates.

    • https://www.sediver.com/wp-content/uploads/SEDOC18322-_Pollution-mitigation-solutions-for-overhead-line-insulators-1.pdf

Key Issues Covered

• Water Pollution from construction runoff and corridor clearing

• Changes in hydrology, stream flows, and wetland function

• Contaminants leaks (pesticides, PCBs, lubricants) and point source water pollution

• Soil erosion and sediment transportation into waterways

• Wetland and riparian loss, aquatic ecosystem fragmentation

These sources provide first-hand accounts, scientific analysis, and advocacy perspectives on direct and indirect water-related harms caused by high voltage transmission lines.