Geothermal/Access and Transportation

From Open Energy Information

Geothermal Access and Transportation

Access and Transportation
Present, Potentially Affected

To access the geothermal site and to transport construction materials, the developer must comply with current federal, state, county and city road regulations. The preference is for existing roads to become access roads to eliminate or reduce the number of new roads that need to be constructed for the plant’s operation. All roads must be a part of the plant’s initial design to prevent conflicts with visual resource management teams. Roads must be monitored and maintained under a management plan developed by the developer.

Access and Transportation Impacts & Mitigation

During the construction phase of the plant, surrounding areas will experience an increase of industrial traffic on public roads. Nearby residents or businesses could notice an increase in noise as well as a potential increase in accidents involving industrial and passenger vehicles.

Traffic mitigation

Strategies include:

  • Schedule industrial traffic to arrive and depart during non-peak local traffic times;
  • To decrease accidents, post signs before the site to warn of oncoming trucks, and signs after the site thanking patrons for their compliance;
  • Know what kind of road alterations need to take place to withstand overweight and oversized industrial vehicles (i.e. widening roads and reinforcing bridges); and
  • Create a timeline to predict how long traffic patterns will be effected.


To mitigate noise impacts effecting patrons:

  • Notify nearby residents or businesses of the daytime hours the noise will be in effect.
  • Coordinate schedules with nearby businesses to diminish the disturbance during their operating hours.

Factors Affecting Access and Transportation

To follow current regulations, several factors need to be considered in the construction phase. The factors listed below will guide the developer in long-term access throughout the plant’s site.

Erosion and Water Diversion

Erosion is the gradual degradation of a natural feature over time due to wind or water. Human impacts can speed up this natural process if mitigation or land ethics are not observed. For example, if a road needs to be constructed into a hillside, the slopes cannot be steeper than 3:1 and cannot be filled more than 2:1. This mitigation measure decreases the likelihood of mudslides, avalanches, and flooding.

Runoff water needs to be diverted into a sediment-trapping mechanism to prevent flow into intermittent or perennial waterways. Mitigation structures include: water bars, berms, drainage ditches, and sediment ponds. These structures allow the water to flow at a slower constant rate to places that can retain a large volume of water. This is especially important in the event of a flood or heavy precipitation.

Soil Types

Sand, silt and clay are the 3 common types of soil. Most often, the soil type is a hybrid of 2 or 3 categories. Sand has the largest particles, while clay has the smallest. These 3 categories are consequently broken up into 12 different soil types that are classified by their physical, chemical or biological properties. Soil types are measured by how much water they can hold, therefore, knowing the soil type of the site is important because it can reveal how well the roads will be supported.