Operation of PPL Montana’s eight-powerhouse Missouri-Madison hydro project involves management of prehistoric and historic cultural resources, including archaeological properties and historic buildings and structures. To effectively manage these resources, PPL Montana implements a detailed cultural resource management plan that includes cooperative partnerships with resource agencies and conservation groups.
By Jon H. Jourdonnais and James J. Shive
The 258-MW Missouri-Madison project consists of eight hydro facilities and one storage reservoir along the Missouri and Madison rivers in Montana. The oldest facility — 17-MW Black Eagle on the Missouri River — was built in 1898, and the newest facility — 55-MW Cochrane on the Missouri River — was built in 1955.
The construction of hydro facilities on the Madison and Missouri rivers was critical in the development and expansion of mining and minerals processing in the state during the late 19th and early 20th centuries. The Missouri River facilities near Great Falls, Mt., provided power for lighting and hoisting operations in the vast complex of copper mines operating in Butte, more than 150 miles away. They also provided the significant amounts of electrical power the minerals processing facilities needed. In addition, electrical power from the Great Falls facilities provided motive power to portions of the Old Milwaukee Road electric railroad system as it crossed Montana in the early 20th century. The 8-MW Madison, 18-MW Hauser, and 35.5-MW Holter developments also helped to power mining, ore processing, and copper smelting facilities in Butte and Anaconda.
The Missouri-Madison project features a variety of prehistoric and historic archaeological properties and historic architectural-engineering properties. These properties include some of the generating facilities at the project.
To manage these properties, PPL Montana implements a cultural resource management plan. The plan, developed as part of Federal Energy Regulatory Commission (FERC) project relicensing in the 1990s, covers management of both prehistoric and historic archaeological properties and historic architectural-engineering properties. In addition, the plan outlines how to manage general actions by PPL Montana that could affect these cultural properties.
Prehistoric and historic archaeological properties
In 1993, as part of its work on the FERC relicensing process, licensee Montana Power Company sponsored inventories of prehistoric and historic archaeological properties associated with the project. Prehistoric properties are those occupied before the arrival of Euro-Americans in Montana. A number of prehistoric properties were identified, including tool production sites and long-term encampments. Historic properties are those related to more recent occupation. Historic properties identified were primarily related to the construction and operation of the hydro plants. Some of these properties were being affected by project operation, so the licensee developed measures to mitigate these effects.
Some properties were in areas that, at the time, would not be affected by project operations. However, the licensee could not fully determine the areas that might be involved in future project actions. Therefore, the licensee developed a plan to actively manage these resources during future project operations and associated actions. This is done, in part, through review of proposed project-associated actions at or in the vicinity of any prehistoric and historic properties. Periodic inspections of these properties also are part of the management process.
The prehistoric and historic archaeological properties identified are set aside for resource conservation purposes, with avoidance of effects as the preferred alternative. Additional properties have been added since implementation of the new license began in 2000. (PPL Montana acquired the project from Montana Power Company in 1999.) Many of these properties have been identified in working with land management, fisheries and wildlife conservation and enhancement, or public recreation programs.
To avoid potential effects, PPL Montana relocates or redesigns actions so as to avoid ground-disturbing activities over the archaeological properties identified. For example, a trail proposed by the U.S. Forest Service near Great Falls was relocated to avoid affecting two historical archaeological properties. The plan calls for such avoidance, unless the proposed actions are essential to the continued electric generation operations or an emergency action is needed. Actions essential to continued generation would include adding a new powerhouse or other critical facilities where no alternative site is possible.
If potential effects cannot be avoided, PPL Montana sponsors archaeological data recovery, sufficient to mitigate the effects arising from actions considered essential to continued generating operations. In the case of emergency actions, the plan is waived for the duration of the emergency. The cultural resource management plan defines emergencies as actions that are essential responses for the immediate safety of plant personnel or the public, such as imminent danger of dam or other essential generating facility failure, fires, natural disasters, spill containment, health, or safety. PPL Montana is required to work with the State Historic Preservation Officer and any other involved parties to determine what effects may have occurred during the emergency, if the property is still eligible for listing in the National Register of Historic Places (NRHP), and what measures need to be taken to conserve whatever portion of the property remains intact.
During relicensing, the licensee determined that some adverse effects to certain prehistoric archaeological properties already were occurring. The effects were a result of the erosion of some properties, which were located either along the shoreline or in the fluctuation zone of two project reservoirs. The erosion resulted from operation of the projects.
To address these adverse effects, PPL Montana has sponsored data recovery operations at several prehistoric archaeological properties on the Missouri-Madison project. These operations have provided opportunities to work closely with federal land management agencies in situations where prehistoric archaeological properties are located on public lands under the administration of such agencies. For example, staff from PPL Montana and the Helena National Forest worked closely on implementing archaeological data recovery to mitigate project-related erosion effects at one prehistoric archaeological property on the project. Archaeological excavations and subsequent analyses documented multiple occupations, from about 2,400 years ago to about 175 years ago. Faunal materials recovered from the occupations included bison, small mammals, fish, and freshwater mussels.
In addition, PPL Montana and Helena National Forest entered into a partnership to preserve one prehistoric archaelogical property, which was being eroded as a result of operation of a project reservoir. Similarly, PPL Montana and Gallatin National Forest worked closely on archaeological data recovery as mitigation of project-related erosion effects at several other prehistoric archaeological properties on and adjacent to the project.
Historic architectural and engineering properties
During relicensing, the licensee performed inventories and evaluations of various plant operating buildings and structures for NRHP eligibility. Out of that work, the licensee identified NRHP-eligible historic operating facilities at eight of the nine developments in the project. The facilities at Hebgen Reservoir include the buildings and structures that constitute the operator camp. At the Madison development on the Madison River, these facilities include the 1900 and 1906 powerhouses and elements of the water-delivery system. At the Holter development on the Missouri River, these facilities include the 1918 dam, powerhouse, various operating buildings, and houses located in the operator camp.
The relicensing studies also identified a single historic district eligible for the NRHP on the Missouri River in the vicinity of Great Falls. Such districts typically include a variety of individual buildings, structures, and sites all related in theme, within a defined boundary or within the boundaries of one or more units of a larger, combined district. The Great Falls district includes separate land areas and facilities along the Missouri River. Such units were identified at the Black Eagle, 32-MW Rainbow, 59.5-MW Ryan, and 33-MW Morony developments. The Hauser operating facility on the Missouri River had been evaluated for NRHP eligibility in 1982 and includes the dam and powerhouse and a variety of historic buildings, structures, and sites that are the contributing elements of an NRHP-eligible district.
Several of these NRHP-eligible districts include historic archaeological properties. These properties are considered part of the NRHP district but also are independently eligible for NRHP listing. They relate to development of the historic hydro facilities and their earliest years of operation. These properties can yield significant information on the lives of the people who built and operated the hydro developments that were so important in the late 19th and early 20th century development of Montana.
To manage these historic architectural, engineering, and archaeological properties, PPL Montana reviews all actions proposed within and adjacent to the projects to determine if the actions would cause potential effects to any of the contributing elements of these districts. A contributing element can be any building, structure, or site that contributes to the NRHP significance of the district. Some elements may both contribute to the NRHP eligibility of a district and be independently eligible for NRHP listing. These reviews consider all actions involving any lands, waters, buildings, structures, major equipment, and general engineering systems.
As part of this management, PPL Montana uses a concept called “replacement-in-kind.” This concept, developed in the 1980s by Southern California Edison Company, recognizes that constant technology improvements will be needed and become available for hydro plants. Therefore, a system must be developed that makes it possible to maintain and update hydro facilities in a manner that conserves their historic architectural and engineering values.
Application of this principle for the Missouri-Madison project is stipulated in the cultural resource management plan. The NRHP studies performed during relicensing included a focus on those buildings, structures, and engineering systems that were essential to expressing the significance of the facilities and thus defined the contributing elements of the NRHP districts. In 2000, PPL Montana developed principles and guidance for the Missouri-Madison facilities, defining replacements-in-kind for important architectural and/or engineering elements.
The replacements-in-kind system has been successfully used at a number of facilities on the project. For example, in 2005, PPL Montana identified a window design to replicate some of the current plant windows at the Rainbow and Hauser powerhouses. The replacement windows matched the size of the historic window opening, as well as other elements of the historic window designs, while also providing for improved energy efficiency and the use of modern, lower-maintenance materials.
However, it is not always possible to use a replacement-in-kind. If potential adverse effects are unavoidable, PPL Montana’s management plan calls for completion of Historic American Engineering Record documentation of the affected element(s). Documentation to be provided may consist of sketch plan drawings of architectural-engineering elements; large-format photographs of specific resources; large-format photographic architectural data; and potentially reproductions of selected historic drawings and/or photographs. The collected data is processed and submitted to the National Park Service for archival management.
Many actions associated with license implementation could arise over the life of the license, and those actions could affect NRHP-eligible cultural resources. Therefore, PPL Montana reviews any specific actions — proposed by PPL Montana or other parties — to determine the potential for adverse effects to NRHP-eligible or -listed properties. The types of actions PPL Montana reviews include:
— Land disturbance associated with plant redevelopment and/or major maintenance activities;
— Land development, land management, or natural resource conservation actions (such as reservoir shoreline or riverine habitat improvements);
— Public recreation facility developments, such as day- or term-use recreation areas, trails and roads development, building construction, and boat ramps; and
— Permits, easements, agreements, rights-of-way, transfers or exchanges of lands, or the transfer, sale, or lease of such lands.
This review involves four basic steps:
- ) Scoping of the need for and extent of both a cultural resource inventory and NRHP evaluation study;
- ) Completion of an on-site resource inventory and NRHP evaluation study, if determined to be needed during step 1;
- ) Assessment of effects and development of a management plan for any properties identified as NRHP-eligible during step 2; and
- ) Implementation of management plan measures.
Implementing these steps has given PPL Montana opportunities to work collaboratively with many partners, especially federal and state lands and natural resource management agencies. For example, one of the most successful natural resource management programs for the project is a partnership among PPL Montana; federal, state, and local agencies; and private conservation groups to protect and enhance fisheries and wildlife on the Madison and Missouri rivers.
The program is directed by fisheries and wildlife technical advisory committees. PPL Montana reviews the committee proposals for fishery and wildlife conservation and enhancement measures, under the provisions of the cultural resource management plan. The proposals cover a broad range of fisheries, wildlife, habitat, and water quality areas. Many of these actions will not pose any potential effects to cultural resources and, in fact, may contribute to conservation of cultural resources. However, when land-disturbing activities are proposed, it often is necessary to implement the four steps mentioned above.
If cultural properties are identified and the work cannot be modified to avoid potential effects, additional steps may be required. These can include evaluation of the NRHP eligibility of the affected properties and instituting measures to mitigate adverse effects. PPL Montana has worked with both federal and state agencies involved in technical advisory committee proposals of this nature to successfully address cultural resource management and conservation and enhancements for fisheries or wildlife. For example, PPL Montana worked with the Montana Department of Fish, Wildlife and Parks on the placement of a needed building at a state-operated wildlife management area. The original proposal called for constructing the building on a previously identified cultural property. The Montana Department of Fish, Wildlife and Parks relocated the building to avoid any potential effects to that property.
Agencies are responsible for cultural resource management with regard to the actions they propose, so agencies sponsor or conduct the cultural resource management studies needed on these projects. PPL Montana supports such studies by providing information on known or potential cultural resources in the area of the proposed action. In some cases, PPL Montana also jointly sponsors these cultural resource management studies. The successes of the partnerships for fish and wildlife protection and enhancement have resulted in the development of similar partnerships in the area of public recreation.
The plan in action
Using the cultural resources management plan has resulted in some great successes. One example is preservation, in partnership with Helena National Forest, of a prehistoric archaelogical property at a project on the Missouri River.
Property 24LC237 is a prehistoric archaeological property on lands under the administration of the U.S. Forest Service. Artifacts and other cultural material left by American Indian hunter-gatherers are buried within river sediments. In 1992, the licensee determined that the property, located within the Helena National Forest, was eligible for the NRHP. Radiocarbon dating of some materials recovered from this property produced a date of 900 B.C.
Based on formal monitoring studies performed between 1993 and 1998, bank erosion was identified as adversely affecting this significant archaeological property. The objective of those studies was to determine the areas and extent of erosion. Erosion was documented but did not occur across the entire length of the shoreline. The areas with erosion were devoid of vegetation at the base of the bank.
The sometimes standard erosion remediation method — reshaping the nearly vertical banks back to a more gentle angle of repose, installing a network of rock and erosion-control fabric matting, seeding the reshaped bank, and installing a network of rock barbs at the base of the bank — would have had an extensive, adverse effect on the archaeological resources. To mitigate these effects would have required extensive archaeological excavations, with still a net loss of archaeological resources. Also, this area has important natural scenic value to visitors. PPL Montana needed to find a method for abating erosion while leaving the banks virtually intact.
PPL Montana engineers, along with cultural resource management professionals with the U.S. Forest Service and Legacy Consulting Services, developed a plan in 2003 to build soil-cement logs at the base of the embankment, then in-fill behind them with soils and nutrients. These structures would be built in areas of the bank where erosion was occurring. Natural regeneration of vegetation would follow and the system would be monitored for five years, with enhancements performed as needed.
In 2004, the Montana Conservation Corps constructed the soil-cement logs using a mixture of soils from the area and cement, reinforced with steel rebar. Workers placed the logs at the base of the embankment and added soil and nutrient (sterilized cow manure). Native vegetation (grasses, forbs, emergent wetland species, and one shrub species) was allowed to regenerate behind the logs. Monitoring by Legacy Consulting Services and the U.S. Forest Service since 2004 has shown that the installations have been mostly successful in giving native vegetation a chance to become established behind the soil-cement logs. Additional enhancements to these installations are planned for 2008.
The partnership between PPL Montana and Helena National Forest to manage property 24LC237 is a direct outgrowth of the overall partnership established as a result of the fisheries and wildlife enhancement efforts that were part of the cultural resources management plan. Such partnerships promote collegial relations among the participants while appropriately considering cultural resources. The partnerships have eliminated duplicative efforts on the parts of PPL Montana and government agencies to consider cultural resources on the same project. Overall, they have reduced costs for such considerations, by establishing a system in which cultural resource management performed by one party addresses the needs for all parties involved in the undertaking.
These partnerships have produced solid results. These include reductions in the cost to PPL Montana for addressing cultural resource management in implementing vital programs. Agency partners include these considerations in their planning and budgeting processes. PPL Montana assists by providing information to agency partners and coordination among partners for undertakings where multiple partners are involved.
The cultural resource management plan for the Missouri-Madison project results in conservation of vitally important, non-renewable cultural resources in a cost-effective manner. It also promotes positive relationships between PPL Montana and both public and private parties.
Jon Jourdonnais is director of hydro licensing and compliance with PPL Montana LLC. James Shive, president of Legacy Consulting Services, is the cultural resources manager for the Missouri-Madison project.