US Army Corps of Engineers
Northwestern Division

CRSO: Introducing the affected environment

Columbia River System Operations EIS
Published Nov. 22, 2019
The CRSO EIS analysis considers the impacts of the five alternatives across a spectrum of resource categories, including recreation, wetlands and wildlife.

The CRSO EIS analysis considers the impacts of the five alternatives across a spectrum of resource categories, including recreation, wetlands and wildlife.

The U.S. Army Corps of Engineers, Bureau of Reclamation and Bonneville Power Administration have made significant progress on the development of the Columbia River System Operations environmental impact statement. Essential to the National Environmental Policy Act process and the comparison of the alternatives under consideration is the development of the Affected Environment and Environmental Consequences sections of the environmental impact statement. These sections define current conditions of the resources in the area or region in which an alternative would be implemented.

Comparing alternatives, both their potential to achieve project objectives and their impacts, requires detailed information about the existing conditions of a resource. Any areas or resources potentially impacted by the implementation of an alternative under evaluation are considered the affected environment. These areas are introduced in this CRSO EIS Update and will be detailed in the draft EIS.

The EIS then documents the expected impacts-the environmental consequences-of implementing an alternative. The Environmental Consequences section also includes the significance of these effects and documents how agencies evaluated these impacts. This section will be introduced in more detail in the next update.

Resources evaluated for this EIS

The role of scoping input

Public input received during the scoping phase early in the NEPA process contributes to identifying

  1. significant resources in the affected environment
  2. potential impacts to those resources
  3. appropriate mitigation measures.

This input also helps agencies set appropriate boundaries for the analysis of potential effects. For example, if the boundaries are defined too broadly, the analysis becomes unwieldy; if they are defined too narrowly, significant issues may be missed. A Scoping Summary Report that summarizes the comments received during this phase is available on the project website at www.nwd.usace.army.mil/CRSO/SSR.

The NEPA analysis considers the impacts of the five alternatives across a spectrum of resource categories. The five alternatives are outlined in the September 2019 Update and presented in a webcast. Both are available on www.crso.info.

The analyses for many of these resource categories are introduced below.

Navigation
The Affected Environment section will document conditions of the navigation and transportation system and associated shipping movements and costs. Analysis includes the location of the navigable waterway and the shippers and producers that use the waterway, and the navigation locks and reservoirs at eight of the 14 federal Columbia River System projects: Bonneville, The Dalles, John Day, McNary, Ice Harbor, Lower Monumental, Little Goose and Lower Granite. The analysis also considers the road and rail transportation systems within the region that would serve as alternate shipping modes if portions of the waterway were unavailable.

The Environmental Consequences section will document, for example, if an alternative would change river flow and timing, potentially reducing the depth of the navigation channel and altering barge configurations or capacities and impacting the transportation costs associated with river movements.

Flood Risk Management
The Affected Environment section will document flood risk conditions relative to the six Columbia River System storage reservoirs that provide water storage to regulate flood hazards downstream and the flood risk management provided by system operations and associated infrastructure, such as levee systems. The six projects are Libby, Hungry Horse, Albeni Falls, Grand Coulee, Dworshak and John Day. The area of analysis includes all urban and rural areas and populations potentially affected by changes in exposure to flood hazards. The areas are either downstream of one of the six storage projects or upstream within the reservoir of a project.

The Environmental Consequences section will document flood hazard conditions for the alternatives. Flood hazard conditions will be evaluated by assessing defined annual exceedance probabilities or, in simpler terms, the likelihood that specific water conditions measured by water elevations or flows, or both, would occur.

Power Generation and Transmission
The Affected Environment section will describe the elements of the power and transmission systems that could be affected by alternatives and the factors influencing regional electricity rates.

The Environmental Consequences section will document impacts of the alternatives to generation and transmission of power across the larger context of Pacific Northwest regional power resources of which the 14 federal Columbia River System projects are a subset. For example, this evaluation will determine if an alternative modifies the operations of hydroelectric or other generation facilities and any impacts on the Bonneville Power Administration’s ability to meet its power supply obligations.

Cultural Resources
The Affected Environment section will group cultural resources into three property-based categories: archaeological sites, traditional cultural properties, and historic built resources and objects within the study area that are more than 50 years old. The general area of analysis includes the 14 project locations and the area extending one mile in all directions from the reservoirs’ full pool elevations.

The Environmental Consequences section will document, for example, the impact to archaeological sites from water erosion based on the changes in reservoir water levels as defined in the different alternatives. It also will document any proposed long-term or permanent changes to historic built resources proposed in the different alternatives.

Recreation
The Affected Environment section will describe reservoir and river conditions relative to the recreation opportunities provided. It will detail water-based recreation activities such as boating, fishing and paddling, along with adjacent park and public space recreation conditions.  The general study area is the Columbia and Snake river systems, including reservoir and river reaches. The recreation analysis also focuses on recreational lands and activities located adjacent to mainstem rivers because these lands and activities may be impacted by the EIS alternatives. The analysis also includes impacts associated with potential changes to visitation to other areas that may result from the alternatives.

The Environmental Consequences section will document, for example, how recreation conditions may change under alternatives that would affect reservoir water elevations and the accessibility of recreational boat ramps.

Water Supply
The Affected Environment section will document the physical aspects of existing conditions. This includes the quantification of water needed for irrigation, municipal and industrial supply; the locations where water is diverted from surface water and from groundwater wells within one mile of the river; and the lands that use that water for irrigation. The area of analysis for the physical and socioeconomic aspects of water supply will be detailed in this section.

The Environmental Consequences section will document, for example, if an alternative that results in a change in reservoir elevation impacts the capacity of irrigation and municipal pumps to remain in service.

Environmental Justice
An environmental justice analysis under NEPA generally evaluates how each alternative is expected to impact the unique conditions of identified environmental justice populations, which include minority populations, low-income populations and Indian tribes. The U.S. Environmental Protection Agency defines a community with potential environmental justice populations as one that has a greater percentage of minority and/or low-income populations than does an identified reference area. For additional information, visit www.epa.gov/environmentaljustice.

The Affected Environment section will document the locations of environmental justice populations using information from U.S. Census Bureau.

The Environmental Consequences section will document, for example, if alternatives heighten these populations’ vulnerability and whether any adverse impacts fall disproportionately on and adversely affect environmental justice populations in these communities compared to the larger community and, if so, whether they meet the threshold of “disproportionately high and adverse.”

Anadromous and Resident Fish
The Affected Environment section will document existing conditions, including water quantity and water quality (temperature, total dissolved gas and turbidity) and habitat connectivity. Several metrics or measurements used to track conditions include survival of juvenile fish, return rates of adult salmon and mortality from gas bubble trauma. The area of analysis covers the Columbia River from the United States-Canada border to the lower Columbia River estuary downstream of Bonneville Dam and portions of the Columbia’s major tributaries and tributaries to the Libby and Hungry Horse projects. Other rivers in the study area may be included as appropriate and the EIS will document the study area in further detail.

The Environmental Consequences section will document, for example, if an alternative that result in changes in flow from a project impacts downstream survival of juvenile salmon.

Vegetation, Wetlands and Wildlife
The NEPA evaluation will determine how each alternative is expected to impact the aquatic, wetland and riparian vegetation that provides habitat for wildlife. Wildlife species are grouped into the broad categories of birds, mammals, reptiles and amphibians, and invertebrates. The Affected Environment section will describe the existing vegetation and wildlife that may be affected by the alternatives. The area of analysis consists of vegetation communities and habitats of the Columbia River Basin currently influenced by the operations of the 14 federal Columbia River System projects. Wildlife and plant species listed under the Endangered Species Act and their designated critical habitat also will be described and the EIS will further detail vegetation and wildlife communities.

The Environmental Consequences section will document, for example, if changes in flow from operational changes or dam breaching could hinder the establishment or change the composition of wetland vegetation and its role as feeding, sheltering and breeding habitat for wildlife.

Hydrology and Hydraulics
The NEPA evaluation will determine how each alternative is expected to change reservoir elevations, water releases from the dams, including spill, flow and stages (water levels) in the river channel downstream of the 14 federal Columbia River System projects. The Affected Environment section will describe the climate and hydrology of the Columbia River and its sub-basins, within the United States to downstream of Bonneville Dam, the reservoirs and reservoir operations of the basin (focusing on these 14 dams) and summary descriptions of the river reaches between dams.

The Environmental Consequences section will document, for example, the daily simulated effect of changed operations on reservoir elevation, discharge and spill, and any hydrologically connected reservoir or river downstream.

Geomorphology and Sediment Transport
The Affected Environment section will describe the baseline geology, geomorphology and sediment transport characteristics within Columbia River System reservoirs, and the downstream river reaches within the United States.

The Environmental Consequences section will document, for example, where operational changes to river flow and stage could alter a river’s capacity to move sediment. 

Water Quality
The NEPA evaluation will determine how each alternative is expected to impact

  • water temperature;
  • total dissolved gas and other physical, chemical and biological conditions; and
  • sediment quality.

The Affected Environment section will describe existing water and sediment quality conditions in order to compare them to state, tribal and federal standards. The general area of analysis includes the Columbia River and tributaries from the United States-Canada border, including the tributaries to the Libby and Hungry Horse projects and the Snake and Clearwater rivers, to just downstream of Bonneville Dam.

The Environmental Consequences section will document, for example, results from simulations of water temperature and total dissolved gas conditions under various weather, flow and dam operations of each alternative.

Air Quality
The NEPA evaluation will determine how each alternative is expected to impact regional air quality and greenhouse gas emissions in the Columbia River Basin region. Additionally, the analysis will relate the effects of the alternatives on power generation, navigation and transportation, and construction activities to the consequent effects on air pollutant and greenhouse gas emissions. The analysis will measure the effects of the emissions changes in terms of the potential for adverse effects on regional air quality (and associated health and ecological effects) and the social cost of carbon in the atmosphere.

The Affected Environment section will describe air pollutant and greenhouse gas emissions sources across the region and the current management of air quality and greenhouse gas emissions. The area of analysis for air quality and greenhouse gas emissions reflects the area over which air pollutant and emissions are generated from power generation, navigation and transportation, and construction activities and other emissions sources. Generally, this area is within the project area, although some potentially affected point sources occur outside of the regions (e.g., power plants in eastern Montana and Wyoming).

The Environmental Consequences section will document, for example, how shifts in power generation (e.g., from hydropower to fossil fuels or renewable resources) would affect energy-sector greenhouse gas emissions by modeling the total volume of carbon dioxide emissions for each action alternative relative to No Action.

Defining the Environment under NEPA
The National Environmental Policy Act requires federal agencies to evaluate each of the alternatives thoroughly to support comparisons about their implementation and their impacts on resources in natural and physical environments. Alternatives also are evaluated and compared in terms of their social and economic impacts. Under NEPA, “effects” and “impacts” may be used interchangeably and mean the same thing.

"Environment" under NEPA is defined as the natural and physical environment and the relationship of people with that environment. This means the environment considered in a NEPA process includes land, water, air, structures, living organisms, environmental values at the site or sites, and the social, cultural and economic aspects of the action.

The list of potentially impacted resources evaluated under NEPA is not identical for each study. Rather, resources are defined early in a specific NEPA study that considers conditions specific to the study area. Resources also are determined based on input from an interdisciplinary project team, stakeholders and the public.