CHAPTER FOUR

ENVIRONMENTAL CONSEQUENCES Part 2

Cultural Environment

This impact analysis methodology applies to three primary types of cultural resources: archeological sites, ethnographic resources, and cultural landscape resources (including individually significant historic structures).

Section 106 of the National Historic Preservation Act requires a federal agency to consider the effects of its actions on properties included in, eligible for inclusion in, or potentially eligible for inclusion in the National Register of Historic Places, and provide the Advisory Council on Historic Preservation a reasonable opportunity to comment. A programmatic agreement was developed among the National Park Service at Yosemite, the California State Historic Preservation Officer, and the Advisory Council on Historic Preservation, in consultation with American Indian tribes and the public, to take into account the effects of park planning and operations on historic properties (NPS 1999c, also see Appendix 8, Cultural Resources, Programmatic Agreement).

Impact analysis follows established procedures and stipulations outlined in the programmatic agreement. These include: (1) identifying areas and types of resources that could be impacted; (2) assessing information regarding historic properties within this area and conducting additional inventories and resource evaluations as necessary; (3) comparing the location of the impact area with that of important cultural resources; (4) identifying the extent and type of effects; (5) assessing those effects according to procedures established in the Advisory Council on Historic Preservation’s regulations; and (6) considering ways to avoid, reduce, or mitigate adverse effects.

Site specific compliance, with project specific details will be completed for prescribed fire and fuel treatments, consistent with the cultural resources programmatic agreement.

Cultural resource impacts in this document are described in terminology consistent with the regulations of the Council on Environmental Quality, and in compliance with the requirements of both the National Environmental Policy Act (NEPA) and Section 106 of the National Historic Preservation Act. The Section 106 determination of effect for the undertaking (implementation of the alternative), required by the programmatic agreement, is included in the “Section 106 Summary” for each alternative, presented later in this chapter.

This methodology focuses on specific treatments discussed in Chapter 2, Alternatives, as well as areas containing cultural resource that, when burned, are most likely to be adversely affected. These areas are identified through the Fire Interval Return Departure (FRID) analysis. Using the median FRID analysis (Chapter 2, pages 2-5 to 2-7), areas with a FRID value of three or greater are more likely than those with a value less than three to burn at an intensity that would impact cultural resources. Burns in these areas would also be more difficult to control to the degree needed to protect known resources, unless mitigation measures were implemented prior to the burn (see Mitigations of Impact, below).

Type of Impact

Impacts are considered either adverse or beneficial to historic properties (cultural resources) when analyzed under NEPA. However, impact type is not viewed this way when conducting analysis under Section 106 of the National Historic Preservation Act. For the purposes of assessing effects to historic properties under the National Historic Preservation Act, effects are either adverse or not adverse. Effects under both NEPA and the National Historic Preservation Act are considered adverse when they diminish the significant characteristics of a historic property.

Duration of Impact

Impacts to historic properties (cultural resources) could be of short term, long term, or permanent duration. Analysis of the duration of impacts is required under NEPA, but is not required and is not usually considered in assessing effects in terms of National Historic Preservation Act.

Intensity of Impact

Negligible:       Impacts would be barely perceptible changes in significant characteristics of a historic property.

Minor:             Impacts would be perceptible and noticeable, but would remain localized and confined to a single element or significant characteristic of a historic property (such as a single archeological site containing low data potential within a larger archeological district or a single contributing element of a larger historic district).

Moderate:        Impacts would be sufficient to cause a noticeable but not substantial change in significant characteristics of a historic property.

Major:             Impacts would result in substantial and highly noticeable changes in significant characteristics of a historic property.

Impacts can be either direct or indirect. Direct impacts result from specific actions, such as biomass removal or fire line construction using a bulldozer. Indirect impacts generally occur after an action, and are a result of changes in the condition of the landscape (such as loss of vegetation and subsequent erosion).

Mitigation of Impacts to the Cultural Environment

NEPA calls for a discussion of the “appropriateness” of mitigation, and an analysis of the effectiveness of mitigation. A reduction in intensity of impact from mitigation is an estimate of the effectiveness of this mitigation under NEPA. It does not suggest that the level of effect, as defined by implementing regulations for Section 106 of the National Historic Preservation Act, is similarly reduced. Although adverse effects under Section 106 may be mitigated, the effects remain adverse.

Mitigation in this document is based on the cultural resources programmatic agreement and includes the avoidance of adverse effects or the application of one or more standard mitigation measures as described in stipulations VII (C) and VIII (Appendix 8). Avoidance strategies may include protecting historic resources from fire and fire-related impacts through onsite fuels reduction or use of portable sprinkler systems and protective shelters. Stipulation VIII requires the National Park Service to notify the State Historic Preservation Officer, American Indian tribes, and members of the public of its decision to implement standard mitigation measures for individual actions having an adverse effect on historic properties.

Outlined below are the mitigating measures that would be taken, under all alternatives, to reduce or avoid impacts to cultural resources:

Pre-Incident Planning

¨       Known cultural resources would be assessed for hazardous fuels, and these hazards would be reduced as part of ongoing fuel reduction programs.

¨       The National Park Service would continue to consult with park-associated American Indian tribes and groups about fire management planning and specific fire management actions in order to identify issues and resources of concern and implement the most appropriate treatments.

¨       In traditional use areas fire planning would consider the needs of cultural practitioners to access and use of traditional resources.

¨       In fire management units lacking cultural resource inventory data, background research and inventory would be conducted to identify resources that may be important and would be susceptible to adverse impacts from fire or fire management actions.

¨       Planning for fire management actions would include protection of known cultural resources.

¨       Cultural resources typical of those found at Yosemite would be included in long-term research and experimentation about the effects of fire on cultural resources.

Incident Response

¨       Archeologists or cultural resource specialists would be involved as resource advisors or technical specialists to advise fire management teams of cultural resource issues and concerns.

¨       Archeologists or cultural resource specialists would, wherever possible, aid in positioning crew camps, holding lines, spike camps, helispots, drop zones, and other fire suppression-related facilities to avoid damage to cultural resources.

¨       Archeologists or cultural resource specialists would advise fire management teams of known, significant cultural resources where potential impacts of fire could be reduced or avoided through emergency fuel reduction.

¨       Wherever possible, archeologists or cultural resource specialists would document significant cultural resources prior to a burn.

Post-Burn Measures

¨       Archeologists or cultural resource specialists would document the post-fire condition of known cultural resources.

¨       Where feasible, significant cultural resources would be stabilized to prevent post-fire damage.

¨       Archeologists or cultural resource specialists would, where necessary, conduct post-burn inventory at areas affected from construction of holding lines, spike camps, and other fire related facilities.

¨       Archeologists or cultural resource specialists would conduct post-burn inventories in unstable areas and recommend stabilization as noted above.

¨       Archeologists or cultural resource specialists would conduct inventories and prescribe any necessary resource protection measures in areas proposed for post-burn treatment where cultural resources might be affected.

¨       Archeologists or cultural resource specialists would perform post-fire monitoring surveys of portions of fires after ground visibility is improved.

Archeological Resources

The impact analysis provides a comparison of the FRID analysis with actions proposed for the management units under each alternative. For areas with more than three missed fire return intervals, fuel accumulation is unnaturally high and fires (prescribed burns and wildland fires) could generate soil and below-soil temperatures that damage archeological materials.

Type and Duration of Impact.  A change in the physical attributes of an archeological site that affects the information contained in that site is irreparable and considered adverse and of permanent duration. Adverse impacts to archeological resources can result from manual or mechanical fuels treatment, direct heating during fire, fire response and suppression, post-fire ecological processes, emergency rehabilitation, and fire damage restoration. The intensity of impacts to archeological resources can range from negligible to major, depending on the management actions taken and/or on the intensity of burning. The majority of these impacts are long-term in duration. Appendix 8 contains a list of fire-related effects.

Fire can also have beneficial impacts to archeological resources. Burning duff and forest litter exposes mineral soil not visible during inventories of unburned areas, allowing for greater accuracy in documenting site constituents and boundaries. Burning within a natural fire regime also reduces the threat of high-intensity fire and the need for suppression activities.

Intensity of Impact.  The intensity of impact to an archeological resource would depend on the potential of the resource to yield important information, as well as the extent of the physical disturbance and/or degradation. For example, moving earth at an archeological site with low data potential might result in a minor, adverse impact.

Negligible:       Barely perceptible and not measurable, and would usually be confined to archeological sites with low data potential.

Minor:             Perceptible and measurable, and would remain localized and confined to archeological site(s) with low to moderate data potential.

Moderate:        Sufficient to cause a noticeable change, and would generally involve one or more archeological sites with moderate to high data potential.

Major:             Substantial and highly noticeable changes, involving archeological site(s) with high data potential.

Mitigation of Impacts

For archeological resources, mitigation includes site avoidance during fire suppression activities, protection of flammable materials during burns, and reducing heavy fuel loads in a manner that preserves and protects the site. In some situations standard treatments such as complete site documentation (e.g. at some historic dumps) may be appropriate as a way to preserve site information and forego continued site management.

Ethnographic Resources

While developing this plan, the National Park Service consulted with culturally-associated American Indian tribes and groups. Both have expressed strong support for increasing the annual number of acres burned. They also have expressed support for the standard treatments for known ethnographic resources or traditionally used plant species (such as avoiding traditionally used plants or timing the burns to promote culturally-desired characteristics in plants). The National Park Service would continue to consult with culturally associated American Indian tribes about each year's prescribed fire program and on individual fires. This provides American Indian tribes and groups the opportunity to provide additional information or express concerns about ethnographic resources and discuss appropriate treatments.

Type of Impact 

Fire-related adverse impacts to ethnographic resources can occur as result of fuels treatment, burning, fire response and suppression, emergency fire rehabilitation, and fire damage restoration. For example, traditionally-used plants can be damaged or destroyed if they are exposed to fire at the wrong point in their annual life cycle. Wooden features can be destroyed if not protected from burning. Most ethnographic resources that are known can be protected from adverse impacts through protection or, in the case of plants that benefit from fire, prescribing appropriate burn times and intensities. Fire was used extensively by American Indians in managing and maintaining some plants for traditional use—continued burning is necessary to maintain the health, vigor, culturally-desirable characteristics, and extent of many traditionally-used plants.

Duration of Impact 

Short-term:      Causes a temporary change in important vegetation or temporarily restrict access to an important resource, yet do not disrupt the cultural traditions associated with that resource for a noticeable period.

Long-term:      A change in culturally important vegetation or a cultural feature for a noticeable period. This period would vary by resource type and traditional practitioners. Long-term changes would disrupt cultural traditions associated with the affected resource, but the disruption would not alter traditional activities to the extent that the important cultural traditions associated with the resource are lost.

Permanent:      Impacts to ethnographic resources would involve irreversible changes in important resources such that the ongoing cultural traditions associated with those resources are lost.

Intensity of Impact   

The intensity of impacts to an ethnographic resource would depend on the importance of the resource to an ongoing cultural tradition, as well as the extent of physical damage or change.

Cultural Landscape Resources, Including Individually Significant Historic Sites and Structures

Type of Impact 

Adverse:         Physical changes to significant characteristics of a resource or its setting, such as removal or burning of historically important vegetation or burning of historic structures.

Beneficial:       Restoration of a natural setting or reduction in heavy fuels adjacent to structures—measures that reduce risk of loss through burning.

Duration of Impact 

Short-term:      Activities such as temporary removal of vegetation or other contributing resources, road closures, or prescribed burns, where the impacts are noticeable for a period of from one to five years.

Long-term:      Reversible changes, lasting from five to twenty years, in a significant characteristic of a historic structure or landscape.

Permanent:      Irreversible changes such as complete removal or burning of important vegetation or structures.

Intensity of Impact

Negligible:       Barely perceptible and not measurable; would be confined to small areas or a single contributing element of a larger National Register district.

Minor:             Perceptible and measurable; remain localized and confined to a single contributing element of a larger National Register district.

Moderate:        Sufficient to cause a change in a significant characteristic of an individually significant historic structure; or would generally involve a single or small group of contributing elements in a larger National Register district.

Major:             Substantial and highly noticeable changes in significant characteristics of an individually significant historic structure; or would involve a large group of contributing elements in a National Register district.

Mitigation of Impacts 

Mitigation measures for historic structures and cultural landscape resources include measures to avoid impacts, such as removing heavy fuels in and adjacent to cultural landscape features and historic structures; protecting flammable historic structures from burning; and excluding fire from especially sensitive designed historic landscapes.

Social Environment

Recreation

Fire management activities and the potential for closures, restrictions and direct effects were evaluated for their potential to affect visitation and an aggregate of recreational activities in Yosemite National Park.

Type of Impact

Adverse:         Reduce visitor participation, quality of visitor experience, and/or service level.

Beneficial:       Enhance visitor participation, quality of visitor experience and/or service level.

Duration of Impact

Short-term:      Temporary in nature, during the period when a fire management activity would take place.

Long-term:      Permanent effect on the visitor experience.

Intensity of Impact

Negligible:       Imperceptible or undetectable effect upon visitors.

Minor:             Slightly detectable or localized effect on visitors.

Moderate:        Readily apparent localized effects on visitors.

Major:             Substantial, highly noticeable effects and/or effects that would result in major limits on activities.

Scenic Resources

Fire management activities and operations, catastrophic fire, and smoke from fires were evaluated for their potential to affect scenic quality of major scenic values or historically important views, such as in Yosemite Valley, along road corridors, and in Wilderness.

Type of Impact

Adverse:         Degrades visual quality.

Beneficial:       Improves visual quality.

Duration of Impact

Short-term:      Short-lived or temporary (less than five years) occurring primarily during or just after fire management activities (managed wildland fire, prescribed fire, biomass removal, etc.).

Long-term:      Effects are detectable for more than five years after fire treatment.

Intensity of Impact

Negligible:       Imperceptible or undetectable.

Minor:             Slightly detectable or limited to a relatively small area.

Moderate:        Readily apparent.

Major:             Substantial, highly noticeable and/or results in a change of character of the landscape.

Noise

In this analysis, the noises associated with fire management activities and operations were evaluated for their influence on the soundscape. Sound levels for various activities and pieces of equipment were compared to a reference sound level [40 dB(A), see table 3.12 and text in Chapter 3, Noise].

Type of Impact

Adverse:         Noise levels increase.

Beneficial:       Noise levels decrease.

Duration of Impact

Short-term:      Temporary and associated with transitional types of activities.

Long-term:      Permanent effect on the ambient noise environment.

Intensity of Impact

Negligible:       Imperceptible or undetectable.

Minor:             Slightly detectable near the source, but not expected to have an appreciable effect on ambient noise levels.

Moderate:        Clearly detectable, and could have an appreciable effect on ambient noise levels; moderate effects may include the introduction of a noise into an area with little or no ambient noise.

Major:             Clearly audible against ambient noise levels; or would have a substantial, highly noticeable effect on ambient noise levels.

Local Communities

Alternatives were evaluated for their socioeconomic effects on local communities. Socioeconomic effects include potential direct effects of property loss and potential indirect effects in economic terms, in the event of park closures.

Type of Impact

Adverse:         Degrades or otherwise negatively alters the characteristics of the existing environment, as it relates to local communities, visitor population, regional economies, and concessioners and contractors.

Beneficial:       Improves on characteristics of the existing social and economic environment, as it relates to local communities, visitor population, regional economies, and concessioners and contractors.

Duration of Impact

Short-term:      Temporary and typically transitional; associated with implementation of an action.

Long-term:      Permanent impacts on the social and economic environments.

Intensity of Impact

Negligible:       Undetectable and expected to have no discernible effect on the social and economic environment.

Minor:             Slightly detectable and not expected to have an overall effect on the character of the social and economic environment.

Moderate:        Detectable and could have the potential to initiate an increasing influence on the social and economic environment.

Major:             Substantial, highly noticeable influence on the social and economic environments, and could be expected to alter those environments permanently.

Environmental Justice

Alternatives were evaluated for their effects on minority and low-income populations and communities.

Type of Impact

Adverse:         Degrades or otherwise negatively alters the characteristics of the existing environment, as it relates to local communities of minority and low-income populations.

Beneficial:       Improves on the characteristics of the existing social and economic environment, as it relates to local communities of minority and low-income populations.

Duration of Impact

Short-term:      Temporary and typically transitional effects associated with implementation of an action.

Long-term:      Permanent effects on the social and economic environments.

Intensity of Impact

Negligible:       Not detectable and expected to have no discernible effect on the social and economic environment for minority and low-income populations

Minor:             Slightly detectable and expected to have no overall effect on the character of the social and economic environment for minority and low-income populations.

Moderate:        Detectable and could have the potential to initiate an increasing influence on the social and economic environment for minority and low-income populations.

Major:             Substantial, highly noticeable influence on the social and economic environments, and could be expected to alter those environments permanently for minority and low-income populations.

Special Designations

Wild and Scenic Rivers

See Chapter 5, Wild and Scenic Rivers.

Wilderness

The impacts of fire management activities and operations on Yosemite Wilderness were evaluated by assessing their effect on both the wilderness user and the wilderness setting.

Type of Impact

Adverse:         Degrades wilderness values or interferes with the public’s use and enjoyment of wilderness

Beneficial:       Improves wilderness values or enhances the public’s use and enjoyment of wilderness.

Duration of Impact

Short-term:      Occurs in the period concurrent with the implementation of individual actions or leaves evidence of human activity that lasts no more than five years after the action.

Long-term:      Continues after completion of the individual actions and can be expected to persist for longer than five years.

Intensity of Impact

Negligible:       Imperceptible or undetectable.

Minor:             Slightly perceptible and limited to a relatively small area.

Moderate:        Apparent.

Major:             Substantial or highly noticeable.

Energy Consumption

Fuel consumption was estimated for each alternative using the average annual amount of accomplishment for each activity, in acres, and an estimate of equipment fuel consumption, on a per acre basis. Assessments of effects are made using the following.

Type of Impact

Adverse :        Increase in energy consumption.

Beneficial:       Decrease in energy consumption.

Duration of Impact

Short-term:      A change in energy consumption that would last less than five years.

Long-term:      Change in energy consumption that would last five years or more.

Intensity of Impact

Negligible:       Increase or decrease by less than 5% annually.

Minor:             Increase or decrease by 5% to 20% annually.

Moderate:        Increase or decrease by 21% to 50% annually.

Major:             Increase or decrease by more than 50% annually.

< Chapter 4, Part 1  [ Alternative A | Alternative B | Alternative C | Alternative D ]