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Cultural Resources and Structural Rehabilitation Your NRCS Responsibilities
Rehab and NRCS l NRCS has responded to the national need to rehabilitate dams to ensure public safety and extend the useful life of valuable public works. l NRCS must also take cultural resources into account. l A cultural resources specialist is available for oversight.
Rehab Differs from New Construction for Cultural Resources l l The structure itself may be an historic property Much of the area is disturbed Much of the APE (area of potential effect) is on disturbed ground PSA (posts settlement alluvium) is usually abundant l l The structure itself is not an historic property Often, most of the area has little disturbance Usually the APE has little disturbance. PSA is often less of a factor
Is the Structure More than 50 Years Old? To be taken into account under Federal cultural resource law, the cultural resource usually must be more than 50 years of age. l Structures less than 50 years old, need not be considered (although there may be other cultural resources present that need to be considered). l
Only significant sites need to be taken into account Associated with important events l Associated with important people l Is distinctive in design or construction l Potentially contains important data l
Is an old structure significant? Common reasons old structures are significant involve associations with important events or the distinctiveness of design or construction. l For example, the first watershed in a conservation program, or an early example of employing a new technology. l
The structure must have integrity to be significant l The structure must have integrity of location, setting, design, materials, workmanship, and feelings and association.
Common reasons old structures lack integrity The setting may have radically changed, e. g. from rural to urban. l The structure may have been updated with repairs or new construction. l The structure may have been breached or filled with sediment. l
If the structure to be rehabilitated is a significant cultural resource: l And you do not have an effect on those attributes that make it significant, you do not have a cultural resource problem. l If you do have an effect, the agency will have to take it into account. This means weighing the cultural resource against other values of the undertaking and going through a consultation process.
Rehabilitation may have an effect on nearby cultural resources l l l New borrow areas Dam enlargement Constructing access roads Altering auxiliary spillways Removing existing houses Disposal of sediment
Areas that don’t need surveying l Areas covered by post settlement alluvium (PSA) l Recently disturbed ground l Areas already archeologically surveyed l Steep areas
Post Settlement Alluvium (PSA) l l l PSA is recent over wash PSA can accumulate rapidly PSA fills in structures The structure itself may have been built on PSA is normally excluded from cultural resource survey
Recently disturbed ground At rehab sites, ground is present that was disturbed by previous construction l Under normal circumstances, any cultural resources that might have been present, have been destroyed in those areas. l Consequently, disturbed areas are of little or no cultural resource interest. l
Determine where disturbance occurred during construction l Check old plans. l Ask older members of the community who might know. l Check aerial photos. l Get a soil scientist to probe the area. The soil scientist can tell you where the soil has been truncated, and by observing chaotic bedding can tell where soil has been disturbed.
Areas already archeologically surveyed Some areas have already been archeologically surveyed. l Don’t under ordinary circumstances resurvey areas that have a good survey already done. l
Steep Areas Slopes 10% or greater are unlikely to have structures or campsites l except for special resource areas such as flint outcrops, springs, and rock shelters. l Some archeological sites on summits may have eroded down slope, but this would be an area of the site that would lack integrity. l
Tips for borrow areas There is no cultural resources problem if you use PSA (e. g. sediment that is filling up the structure). l Nor is there a problem if you use a commercial borrow area, or borrow from previously disturbed areas. l
Tips for dam enlargement Enlarging (raising and lengthening) a dam usually causes ground disturbance. l You needn’t survey areas that are already disturbed. l Areas of existing disturbance include the dam itself, the original shaping of the valley walls, existing roads (especially if it is a road structure), and existing borrow pits and spill ways. l
Tips for access roads Heavy equipment needs to get to the project area, which in itself can damage cultural resources. l Use existing roads (including field roads) when possible and you avoid problems. l Use areas that have a history of being driven over by tractors. Tractors exert more pressure per square inch on the ground, than heavy construction equipment. l Bulldozing a road normally requires a survey. l
Tips for altering auxiliary spillways When dams are raised during rehab, usually the auxiliary spillway is moved upslope. l You want to know whether the new position has been previously disturbed or whether it has a slope of 10% or greater. If either or both of these conditions apply, you have little or no cultural resources problems. l
Tips on removing existing housing l l l Houses may be moved or demolished during rehab. If the house is over 50 years of age, its significance needs to be determined. Even a non-significant house that is moved may damage a cultural resource when it is taken to its new site. Ensure that the new site will not damage a significant resource. Remaining basements can be grubbed out by a backhoe, without damaging undisturbed deposits. This is because of the surrounding disturbed area that was needed for the concrete forms. Basements can be filled with PSA (e. g. ditch clean out).
Tips for disposal of sediment l l Dredging or breaching of a dam can produce large amounts of sediment. Burying significant cultural resources with its disposal can deny access to researchers. When possible, sediment should be disposed over disturbed ground, PSA, or very thinly “topsoiled” over cultivated fields. If used to fill side gullies, the gullies should be surveyed.