Chapter 7 - Built-Environment Cultural Resources

A building, such as a house, barn, church, hotel, or similar construction, is created principally to shelter any form of human activity. "Building" may also be used to refer to a historically and functionally related unit, such as a courthouse and jail or a house and barn. Buildings eligible for inclusion in the National Register must include all of their basic structural elements. Parts of buildings, such as interiors, facades, or wings, are not eligible independent of the rest of the existing building. The whole building must be considered, and its significant character-defining features must be identified. If a building has lost any of its basic structural elements, it is usually considered a ruin and categorized as a site.

The term structure is used to distinguish from buildings those functional constructions made usually for purposes other than creating human shelter. Structures include roads, railroads, trails, bridges, dams, canals, ditches, and retaining walls. If a structure has lost its historic configuration or pattern of organization through deterioration or demolition, it is usually considered a ruin and categorized as a site.

A district possesses a significant concentration, linkage, or continuity of sites, buildings, structures, or objects united historically or aesthetically by plan or physical development. A district derives its importance from being a unified entity, even though it is often composed of a wide variety of resources. The identity of a district results from the interrelationship of its resources, which can convey a visual sense of the overall historic environment or be an arrangement of historically or functionally related properties. For example, a district can reflect one principal activity, such as a mill or a ranch, or it can encompass several interrelated activities, such as an area that includes industrial, residential, or commercial buildings, sites, structures, or objects. A district can also be a grouping of archaeological sites related primarily by their common components; these types of districts often will not visually represent a specific historic environment.  Large-scale cultural landscapes are usually classified as districts.

A site is the location of a significant event, a prehistoric or historic occupation or activity, a small-scale cultural landscape, or a building or structure, whether standing, ruined, or vanished, where the location itself possesses historic, cultural, or archaeological value regardless of the value of any existing structure. A site can possess associative significance or information potential or both, and can be significant under any or all of the four criteria. While it is unusual, physical remains need not mark a site if it is the location of a prehistoric or historic event or pattern of events and if no buildings, structures, or objects marked it at the time of the events (see National Register Bulletin 15, Section IV). However, when the location of a prehistoric or historic event cannot conclusively be determined because no other cultural materials were present or survive, documentation must be carefully evaluated to determine whether the traditionally recognized or identified site is accurate.

A site may be a natural landmark strongly associated with significant prehistoric or historic events or patterns of events, if the significance of the natural feature is well documented through scholarly research. Generally, though, the National Register excludes from the definition of "site" natural waterways or bodies of water that served as determinants in the location of communities or were significant in the locality's subsequent economic development. While they may have been "avenues of exploration," the features most appropriate to document this significance are the properties built in association with the waterways.

In rare cases, if evaluation is warranted, the architectural historian may be requested to evaluate built-environment resources under Criterion D, for their potential to yield significant information about the historical past.

The term "object" is used to distinguish from buildings and structures those constructions that are primarily artistic in nature or are relatively small in scale and simply constructed. Although it may be movable by nature or design, an object is associated with a specific setting or environment. Small objects not designed for a specific location, or that have been moved from the original location for which they were designed, rarely require study. Such works include transportable sculpture, furniture, and other decorative arts, that unlike a fixed outdoor sculpture, do not possess association with a specific place. Examples of objects include boundary markers, monuments, fountains, sculptures, and statuary. 

The Section 106 PA among the FHWA, the Advisory Council on Historic Preservation (ACHP), the SHPO, and Caltrans governs all undertakings under the Federal-aid Highway Program in California. This means that all Caltrans projects with FHWA involvement now need to comply with the Section 106 PA instead of 36 CFR Part 800, except where the Section 106 PA itself directs otherwise. The attachments to the Section 106 PA also provide general guidance that Caltrans follows on non-federal projects. Chapter 2, particularly Section 2-3, discusses the Section 106 PA, provides a detailed discussion of this document and the procedures to follow.

While, the Section 106 PA streamlines the process for the majority of federal projects, the Seismic Retrofit Programmatic Agreement (Seismic Retrofit PA) may be used to streamline specific bridge projects.

The Seismic Retrofit PA applies only to seismic retrofit work on a bridge that is federally funded and that involves either structural modification of an existing bridge or the replacement of a bridge by a newly constructed structure, including any associated activities within the Area of Potential Effects (APE) of the project. Note that if a project involves any upgrades, enhancements or other activities that are not specified in the Seismic Retrofit PA, that document may not be used to streamline Section 106 compliance.

Under the Seismic Retrofit PA, seismic retrofit projects are exempt from review under Section 106 when the project’s activities are

• Restricted to the bridge itself
• Limited to one of the nine types of activities listed in Seismic Retrofit PA Appendix B.

Seismic retrofit work on bridges is exempt from CEQA because it is a statutory exemption. However, if the bridge is owned by Caltrans, PRC §5024 still applies and consultation with the SHPO is required if the bridge is National Register or California Historic Landmark listed or eligible.

There may be situations when, theoretically, both programmatic agreements may apply on a bridge retrofit project. Either—but only one of them—can be used, depending on which is more likely to be to Caltrans’ benefit. On a project involving only the seismic retrofit of a bridge, however, it is likely that the Seismic Retrofit PA would be most beneficial.

Documents used in historical research generally are classified as either primary or secondary sources. Secondary sources are those works that present or interpret historical information, that is, works that discuss the historic period but are not, themselves, of the period. They may include textbooks, journal articles, local histories, scholarly studies, reference works, and survey documents. Secondary sources usually are investigated first, and they are the main resource for preliminary research.

Primary sources are those works that are first-hand accounts of historic events or that are contemporaneous with the historic period. They may include letters, diaries, maps, public records, and newspapers of the time. Primary sources usually are investigated only after an examination of secondary sources and a field survey have narrowed the focus to specific properties and themes that warrant more intensive research.

Repositories for both primary and secondary sources include libraries, archives, government agencies, universities, historical societies, and private holdings. Exhibit 4.1 describes both primary and secondary documents and provides information on standard sources.

The National Register states, “The significance of a historic property can be judged and explained only when it is evaluated within its historic context.” It defines historic contexts as “those patterns or trends in history by which a specific occurrence, property, or site is understood and its meaning (and ultimately its significance) within history or prehistory is made clear.”

Developing a historical context generally begins with compiling information from secondary sources on relevant historical themes. National Register Bulletin 15 defines a theme as “a means of organizing properties into coherent patterns based on elements such as environment, social/ethnic groups, transportation networks, technology, or political developments that have influenced the development of an area during one or more periods of prehistory or history. A theme is considered significant if it can be demonstrated, through scholarly research, to be important in American history.”

Adequate historical research should be conducted to identify and develop the appropriate themes to determine whether those themes are significant and to establish the context within which to assess significance of the built environment. It is acceptable to use previously written historical contexts from other reports, so long as the excerpts are appropriately credited and cited. Understanding the connection between historical context and themes (or areas of significance) and the properties being evaluated is crucial in determining National Register eligibility. Also, it is essential to include the geographic and temporal extent of the relevant context (e.g., citrus growing in Riverside County 1880 to 1900; commercial development in Marysville’s central business district 1860-1890) to provide the context’s limits.

When a project covers a large area and there are numerous properties that might require evaluation, if time constraints and the travel budget allow, a quick reconnaissance (windshield) survey is advisable prior to a formal field survey. The windshield survey can reveal the quantity, quality, and distribution of resources that might require evaluation, allowing the architectural historian to be better prepared for the full field survey. When an early field visit is not feasible, preliminary information might be gathered through use of the Caltrans Photolog, satellite photography, existing aerial photographs and maps, previous studies, or contact with knowledgeable locals.

The Section 106 PA identifies certain categories of properties that inherently lack potential for historic significance, and following review by appropriately qualified PQS or by consultants meeting the same standards, typically do not warrant any further consideration. Section 106 PA Attachment 4 defines these categories of properties, specifies the level of professional qualifications needed to exempt them, and describes exceptions to the exemptions. Historical Property Types 4, 5, and 6 may only be exempt from evaluation after review by a Caltrans Architectural Historian or Principal Architectural Historian, or a consultant who meets the PQS standards for architectural history.

No written documentation or mapping of exempted resources is necessary. It is sufficient to state in the Historical Resources Evaluation Report (HRER) that, “Consistent with Section 106 Programmatic Agreement Attachment 4, no [other] properties in the APE required evaluation.” See Chapter 4 and Exhibit 2.8 for information on addressing exempted resources in the Historic Property Survey Report (HPSR) or the Historical Resources Compliance Report (HRCR) for state-only projects.

Consultants are not required to document their exempted properties for Caltrans PQS who are reviewing consultant-prepared documents. Caltrans PQS are responsible for ensuring only that the consultants are professionally qualified to exempt properties under Section 106 PA Attachment 4; they are not responsible for the consultants’ conclusions.

Exempting Properties When the Section 106 PA Does Not Apply

For undertakings wholly or partly on, or that could affect, tribal lands, and for other federal undertakings for which the Section 106 PA does not apply, Caltrans uses the Cultural Resources Letter Report (Letter Report) format to consider cultural resources that normally would be exempted under Section 106 PA Attachment 4. See Exhibit 6.2 for guidance when and how to use the Letter Report. District environmental staff may contact the Section 106/PA Coordination Branch (Section 106 Branch) Chief in CCSO regarding appropriate use of the Letter Report.

National Register and California Register criteria state that usually, a property must be at least 50 years old to be considered for historical significance, in order to ensure that sufficient time has passed to gain an adequate historical perspective for its evaluation. On the field survey, visual inspection generally will be adequate to sort out properties that may require evaluation based on their age. In order to conduct cultural resources surveys efficiently and not have to re-survey the same APE, it is Caltrans policy to treat as 50 years old all cultural resources that will become 50 years old by the time a project is scheduled to be completed.

If visual inspection alone does not clearly indicate a property’s age, the following resources may be useful in verifying the construction date:

• Caltrans Right-of-Way database
• Sanborn Fire Insurance Company maps
• United States Geological Survey (USGS) topographical maps
• Historical maps and photographs
• Reclamation district maps
• Aerial photographs
• Land ownership atlases
• Subdivision plat maps
• Tax assessment and appraiser’s records
• Building permit files
• Utility records (date of first water or sewer service)
• City or county directories

Each property evaluated must be considered as a whole; however, that does not necessarily require physical access to, or recordation of, private spaces, restricted areas, or distant elements. Most built-environment properties can be adequately surveyed from public sidewalks or other public right of way. When physical access is restricted, unsafe, or infeasible, properties can be evaluated based solely on information that is reasonably obtainable. In those circumstances the survey document should explain why the coverage was limited.

Built-environment surveys do not require consideration of residential interiors, suburban backyards, or similar spaces lacking public access. In rare cases, buildings may have accessible interior spaces with demonstrable potential for historical or architectural significance, e.g., an intact classic movie theatre interior, the ornate public lobby of a train station, or an early manufacturing plant with intact original equipment.

While large properties, such as ranches, military bases, irrigation systems, or industrial complexes, must be considered as a whole, the survey should focus on those elements that are subject to project effects, not on recording distant components that will not be affected.

When documenting properties within the right of way, it is necessary to pay special attention to safety. When recording properties, such as roads, railroads or bridges, in or near the traveled way, it is necessary to follow safe field practices. The Caltrans Safety Manual requires that protective clothing always be worn, and that one needs to have a “buddy” standing lookout for hazardous conditions. To avoid becoming distracted by potential traffic dangers, it is important to be particularly alert while taking photographs. If photographs of a property cannot safely be obtained, do not pursue the effort or attempt any unsafe behavior. Instead, explain the situation as described in Section 7-7.4 above.

When resources require evaluation, research must focus on whether those properties are eligible for inclusion in the National Register or are historical resources for purposes of CEQA. Research should be as efficient as possible, identifying only those areas of significance that apply to the resources in the APE. Unrelated areas or extraneous information should not be in the HRER, however interesting they may be.

Most properties encountered during survey work will lack significance. They will be ordinary or modest in character and will not be associated with important events, individuals, styles, or property types. It is always possible that such a property, unremarkable on the surface, could contain hidden values, but it is more likely that any potential significance will be known locally or will quickly be discovered through preliminary research. For the vast majority of properties, what appears to be ordinary, in fact is so, and it is not good public policy to expend major effort exploring unlikely avenues and pursuing diminishing returns. At the same time, experience has shown that researchers may need to do extensive research for properties on the borderline of eligibility, and as much effort may go into properties that ultimately prove to be not eligible as those that are found eligible.

It is not expected that every survey will uncover eligible properties, and the “best” property in a survey area does not equate to eligibility. The context for evaluation is the established historic context, not the project area.

National Register Bulletin 15: How to Apply the National Register Criteria for Evaluation

specifies that in order to qualify for the National Register, “a property must be significant; that is, it must represent a significant part of the history, architecture, archaeology, engineering, or culture of an area, and it must have the characteristics that make it a good representative of properties associated with that aspect of the past.”  The property must also possess the physical features necessary to convey that history.

In National Register evaluations, significance must be viewed within the local historical and architectural context, which is the interpretive and comparative framework composed of similar resources in an area. This framework provides the basis for assessing the historical or architectural significance of a property. For example, a property determined eligible for its architectural style in one community might not be eligible in another community that had a richer stock of similar historic properties.

The criteria for evaluation are as follows:

• Criterion A. Properties that are associated with events that have made a significant contribution to the broad patterns of our history. Criterion A recognizes single historic events or patterns of events, when both the event itself and the property’s association with it can be proven to be significant.
• Criterion B. Properties that are associated with the lives of persons significant in our past. Criterion B applies to the single property best associated with an important individual, such as the individual’s home, office, or studio. More than one property can be associated with an individual, however, when each property represents a different important aspect of that individual’s significance. Criterion B is often misapplied to a person’s works, which are more appropriately evaluated under Criterion C.
• Criterion C. Properties that embody the distinctive characteristics of a type, period, or method of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant and distinguishable entity whose components nay lack individual distinction. Criterion C addresses architectural, engineering, and artistic values, and it applies to historic districts, which may or may not contain individually eligible components.
• Criterion D. Properties that have yielded or may be likely to yield information important in prehistory or history. Criterion D generally applies to archaeological resources rather than to the built environment, but in extremely rare circumstances, built-environment properties can have Criterion D values, such as when an unusual rammed-earth building could possess important construction information that was otherwise unknown.

Of these four criteria, Criteria A and C are the ones that typically apply most frequently to built-environment properties.

For CEQA purposes, evaluate resources using the California Register of Historical Resources criteria codified in PRC §5024.1(c). See Exhibit 2.16 for a comparison of the National and California Registers and Exhibit 4.2 for National Register definitions and criteria.

Consult National Register Bulletin 15for additional guidance in applying the criteria. This bulletin also identifies several types of properties that are normally excluded from National Register eligibility (under Criteria Considerations; see Section 7-8.4 below).

In addition to significance under one or more of the criteria, a resource must retain historical integrity. National Register Bulletin 16A defines integrity as “authenticity of a property’s historic identity, evidenced by the survival of physical characteristics that existed during the property’s historic or prehistoric period.” It is through its integrity of physical character that a property conveys its history, and its sense of time and place. It is the physical manifestation of the historic themes and context.

National Register Bulletin 15 (Section VIII) characterizes historic integrity as “. . .the ability of a property to convey its significance. . . The evaluation of integrity is sometimes a subjective judgment, but it must always be grounded in an understanding of a property’s physical features and how they relate to its significance. . . Historic properties either retain their integrity or they do not.”

There are seven aspects of integrity (see box). All seven aspects of integrity and every essential physical feature from its period of significance do not need to be present, but the property must retain enough essential physical features to convey its past identity and, thus, its significance.

Essential physical features define:

1. Why a property is significant (the applicable National Register Criteria and Areas of Significance).
2. When it was significant (Period of Significance).
   
   

   The 7 aspects of integrity:
   - Location	- Workmanship
   - Design	- Feeling
   - Setting	- Association
   - Materials

The eligibility Criteria and areas/ periods of significance determine which aspects of integrity are most critical. For example, if a property is important because it exemplifies a particular engineering type (Criterion C), the integrity of the property’s design, materials, and workmanship are vital. Integrity of feeling and association may be more meaningful to properties eligible for their association with persons or an event, such as citrus growing the late 19^th century (Criterion A).

The steps necessary in assessing integrity are outlined in National Register Bulletin 15 Section VIII as

1. Define the essential physical features (also called character-defining features) that must be present to represent the property’s significance.
2. Determine if the essential physical features are visible enough to convey their significance.
3. Determine if the property needs to be compared to similar properties.
4. Determine which aspects of integrity are particularly important to the property and if they are present.

Historic setting is a factor in determining the boundaries of a historic property. It is mentioned here to emphasize its importance in determining historic integrity. Setting “refers to the character of the place in which the property played its historic role” (National Register Bulletin 15). Thus, if a property retains its integrity of setting along with other essential physical features, it would convey sense of time and place from its period of significance.

The National Register Criteria and the California Register both identify several types of properties that normally are excluded from eligibility or listing (see table below). However, there are National Register Criteria Considerations and California Register Special Considerations that specify the conditions under which these property types may be eligible for the National Register or considered historical resources under CEQA.

See Exhibit 2.16, for an explanation of the following considerations.

a.  These normally excluded properties do not need to go through formal evaluation, but they should be acknowledged in the HRER and their status explained. No further effort is needed for properties that meet the criteria considerations, unless they qualify as exceptions.

Linear resources such as trails, roads, railroads, and canals that cross or border a project area and may extend far beyond it can be challenging on a survey. The first step is to determine whether they are subject to potential effect by the project, and should be included within the APE. The second step is to consider whether they require evaluation, or if they are exempt under Section 106 PA Attachment 4.

Some types of projects have no potential to affect a linear resource, either directly or indirectly, and thus the resource does not need to be included in the APE. In such projects, the linear resource is typically either adjacent to the project area without direct contact, or it encounters the project area in a brief crossing at an already altered point. For example, if a project to replace a bridge over a canal does not involve any physical impacts to the canal, and the bridge has no historical associations with the canal (e.g. postdates the period of significance for the canal), the canal can be excluded from the APE. The HRER would specify that the canal was not included in the APE because the project has no potential to affect it.

Even linear resources within an APE may be found exempt from evaluation under Section 106 PA Attachment 4. Such exempt properties include contemporary canals, pipelines, ditches, and levees; converted railroad grades; segments of bypassed or abandoned roads; city streets and sidewalks; transmission lines; and fences and walls. Other linear structures, including roads, railroads, canals, and similar resources, also can be determined exempt in accordance with Section 106 PA Attachment 4, when it is appropriate to do so. For example, because such properties generally are subject to routine maintenance and improvement projects, they are often substantially altered and can thus be found exempt by appropriately qualified PQS or consultants.

If a project does have potential to affect a linear resource that is not exempt from evaluation, the resource as a whole must be considered. Formal recordation and evaluation of an entire long, linear property is rarely necessary, however. The level of effort will depend on the nature and scope of the project and its potential to affect the property as a whole. If a project has the potential to affect only a short segment of a large property, the property as a whole may be briefly examined, its potential eligibility described (e.g., National Register criteria, approximate boundaries, period of significance), and it can be considered eligible for the purposes of the project. The segment subject to effect then may be evaluated in the context of the larger property as to whether it would be a contributor to the larger property as a whole, and that segment would be considered eligible or ineligible for the purposes of the project only. The HRER would state that the segment(s) is/is not a contributor to the larger property should that property ever be determined eligible for inclusion in the National or California Register.

Trails

California contains traces of numerous nineteenth-century emigrant trails, such as the Stevens Trail and the California Overland Emigrant Trail, that have clear potential for historical significance in California history. If any traces of these early emigrant trails are located within the APE, the trail will require evaluation.

It cannot be expected that early trails will be clearly visible on the ground today. Indeed, many have vanished under subsequent roads or other development, or from the actions of natural processes. This loss of most early trails increases the likelihood that physical evidence supported by accurate documentation of an important early trail will lead to a finding that the trail is eligible, assuming there is some reasonable degree of integrity of setting.

Many historic trails in California have been designated under other federal laws that have their own criteria. Regardless of any such other designation a trail may possess, Caltrans evaluates trails in accordance with the National Register and California Register eligibility and integrity criteria.

Streets and Roads

For the most part, streets and roads and their associated features are part of our modern, ubiquitous infrastructure, and as such do not require study. City streets, isolated segments of bypassed or abandoned roads, sidewalks, retaining walls, and fragments of bypassed or demolished bridges are typically exempt from evaluation under Section 106 PA Attachment 4.

A short, isolated segment of abandoned or bypassed road normally would be exempt from recordation or evaluation, even when it is part of an old road that possesses historical associations. However, such a property is not exempt if it is long enough to convey a sense of the road’s potential significance, or if there are multiple segments that collectively could convey potential significance.

In most cases, if roads and related features are not associated with significant themes, or if their significance cannot be conveyed because of loss of integrity, neither recordation nor evaluation is warranted.

A number of California highways either have been listed in or determined eligible for inclusion in the National Register. The Old Ridge Route in Castaic, Los Angeles County, and the original route of the Old Redwood Highway (U.S. 101) in Del Norte County are listed on the National Register. Other sections of highway have been determined eligible for inclusion in the National Register as a result of Caltrans projects, including the Arroyo Seco Parkway (Pasadena Freeway) and segments of the Cahuenga Freeway in Los Angeles County, the Cabrillo Freeway in San Diego, Route 66 in San Bernardino County, Highway 50 over Echo Summit in El Dorado County, the Feather River Highway in Plumas and Butte counties, and a segment of Highway 101, the Redwood Highway, in Del Norte County.

The FHWA and ACHP have agreed that the Interstate Highway system, with few exceptions, is exempt from Section 106 regulations and from Section 4(f). Additionally, under federal law (SAFETEA-LU Section 6007), the bulk of Interstate Highway system is exempt from consideration as a historic property under Section 4(f). FHWA has developed a list of Nationally and Exceptionally Significant Features of the Interstate Highway System to which the Interstate Highway system exemption does not apply. Very few features on the Interstate system in California are on that list. Refer to Chapter 2 Section 2-2.7 for guidance on this exemption. It is important to remember that the Interstate Highway exemption does not apply to freeways and highways that are not officially part of the Interstate system.

While segments of the Interstate could be subject to review under state laws and regulations, the majority of the Interstate in California would meet the conditions outlined in Section 106 PA Attachment 4. This is the guidance Caltrans also uses to exempt resources from evaluation under CEQA and PRC §5024. See Chapter 2 Section 2-7 (State-only Projects) and Section 2-7.9 (State-owned Cultural Resources) for further guidance.

In recent years, the state and federal governments officially have recognized the historical significance of several twentieth-century highways. At the federal level, Congress has passed an Act to Preserve the Route 66 Corridor and the Lincoln Highway Study Act. At the state level, the California Legislature has recognized the historical significance of U.S.Highway 99, Historic U.S. Highway Route 101, U.S. Highway Route 40, and alternate U.S. Highway Route 40. Note, however, that legislative recognition is commemorative and does not equate to eligibility for the National Register. There are historic highway associations for a number of recognized routes and much popular interest in their recognition and preservation. While it does not translate directly into National Register or California Register eligibility, it is important to be sensitive to the public and legislative interest in these routes.

Railroads

Because railroads are almost invariably over 50 years old and have the potential to possess significance for their role in California’s history and economy, they generally require evaluation when a transportation project has the potential to affect them.

However, projects on a highway that merely parallels a railroad or that intersects it at an existing grade crossing, or construction of a new over- or undercrossing that does not physically touch the railroad, have limited potential to affect it. In such cases, the railroad need not be included in the APE.  Physical proximity of one transportation facility to another does not necessarily introduce an effect.

It is sufficient in such cases to state in the HRER that the railroad was not included in the APE because the project has no potential to affect it. No further discussion of the railroad is necessary; do not mention it in the HPSR.

When an evaluation is warranted, it is conducted in a focused manner that concentrates on the segment within the APE. If the railroad as a whole appears to possess significance, then that segment in the APE is assessed within the context of the property as a whole to determine whether the segment retains sufficient integrity to convey a sense of the railroad’s significance.

Loss of original rails, ties, and ballast does not necessarily indicate loss of integrity for a railroad, because those elements are subject to frequent replacement on working lines. Railroads in use for many years are no more likely to retain those original materials than are houses of the same age, for example, to possess an original roof.

When a railroad is abandoned, rails and ties are typically removed for reuse, thus an abandoned railroad cannot be expected to possess those elements of materials and workmanship. However, the property would then need to possess a high degree of the other aspects of integrity (location, setting, design, feeling, and association) in order to retain sufficient integrity for eligibility.

Railroad grades that have been converted to uses such as roads, levees, or bike paths, however, will have lost historic integrity, and therefore, would not meet National or California Register criteria; they will be exempt from evaluation, provided they are not part of a larger historic property requiring evaluation (see Section 106 PA Attachment 4).

Not all water conveyance properties encountered in the course of a project require study. No studies are needed when the project has no potential for effect on the property and it can be excluded from the APE, or when the property is exempt from evaluation.

It is sufficient in such cases to state in the HRER that the canal was not included in the APE because the project has no potential to affect it. No further discussion of the canal is necessary; do not mention it in the HPSR.

Even when the APE includes canals and related features, they will be exempt from evaluation. Section 106 PA Attachment 4 contains a list of water conveyance and control features that typically are exempt; additional water conveyance properties that are substantially altered also may be determined exempt by Caltrans PQS or consultants who are appropriately qualified to make this exemption.

However, a bridge that was constructed as part of a canal system could be a contributing element to that larger property. If the bridge may be a contributor to a larger system, or if a project does otherwise have the potential to affect a canal or other water conveyance feature, the property would be included in the APE. Unless exempt from evaluation, the canal, and possibly the system of which it is a part, will require evaluation.

Depending on the project’s potential for effect, and on the characteristics of the resource itself, the evaluation may concentrate on just the affected segment of the canal, but in any case, it will examine the segment within the context of the property as a whole.

Follow the guidance in Caltrans’ “Water Conveyance Systems in California, Historic Context Development and Evaluation Procedures” whenever there are water conveyance resources requiring evaluation. This document provides historical context for water conveyance systems in California, as well as guidance for recognizing, classifying, and describing these systems and their individual components, determining appropriate level of documentation, and determining significance and integrity. The guidelines also contain an extensive bibliography and suggestions on organizing the information in a report format.

California Historic Bridge Inventory

Unlike other types of resources, most bridges on both state highways and local roads already have been evaluated for National Register eligibility in the California Historic Bridge Inventory (first completed in 1986 and updated in 2006). Therefore, few highway or road bridges will require formal evaluation for Caltrans projects. The findings of the California Historic Bridge Inventory, or subsequent amendments to those findings, typically is the only documentation required, and is referenced the HRER and HPSR/HRCR, as appropriate. Exhibit 7.5 contains an explanation and listing of the five “Historical significance” categories assigned to bridges in the inventory.

Bridge Evaluations

While formal bridge re-evaluations rarely are necessary, new information, subsequent alterations, passage of time, changing perceptions of significance, or loss of similar properties may be cause for reconsideration. Caltrans projects also may involve railroad bridges, privately owned bridges, or other bridges that were not included in the Historic Bridge Inventory and that consequently must be evaluated. Caltrans has in place a Bridge Evaluation Memorandum of Understanding (MOU) and MOU short form for use in those instances where a bridge was not included in the Historic Bridge Inventory. See Exhibit 7.3 and Exhibit 7.4. Please contact the Historical Architectural and Community Studies (HACS) branch in CCSO for assistance and further guidance if it appears that a bridge evaluation is warranted.

Note that culverts not assigned a Caltrans bridge number are identified in Section 106 PA Attachment 4 as a property type typically exempt from evaluation.

For bridge projects that qualify under the Seismic Retrofit PA, there is a streamlined procedure for identification, evaluation, and treatment. This agreement also includes a Checklist designed to assist staff in following appropriate procedures under the Seismic Retrofit PA.

As defined by National Register Bulletin 15, a district “possesses a significant concentration, linkage, or continuity of sites, buildings, structures, or objects united historically or aesthetically by plan or physical development.”

Typically, significant historic districts are found eligible under Criterion C because they “represent a significant and distinguishable entity whose components may lack individual distinction.” Districts may also be found eligible under Criterion A should they also possess important historical associations with significant events. Criterion D also might be applicable if there is a historical archaeological component. Otherwise, Criteria B and D rarely apply to districts.

The buildings, sites, structures, or objects that compose a district form a significant and distinguishable entity, but they may lack sufficient integrity or significance to be eligible as individual properties. The interrelationship of resources create the character of a district and can project a visual sense of the historic environment, as well as represent “an arrangement of historically or functionally related properties.”

While a district may contain buildings, structures, objects and features that are not individually eligible for inclusion in the National Register, the resources that do make up the historic character of the district must have sufficient historic integrity to convey a sense of time and place from the period of significance. Contributing elements of the district must reflect its historic theme or area of significance, evoke a sense of that time and place, and retain a sufficient degree of integrity from the period of significance.

A historic district must have substantially more contributing elements than noncontributing elements. Numbers do not tell the whole story, however, as some features will have a more substantial presence than others or have a greater effect on the overall appearance of the district. Keep in mind that an eligible district should appear much the same as it did during its period of significance. This can be done only if the preponderance of resources, or their effect, within the district boundaries clearly reflects the physical appearance of the area during the period of significance.

A generally accepted rule of thumb: contributing elements should constitute roughly two-thirds or more of the total number of features of substance within the historic district boundaries

A formal evaluation of an entire large district on the periphery of a project area is not always necessary, depending on the nature and scope of the project and its potential to affect the property as a whole. If a project has the potential to affect only a small component of a large district, the district may be briefly examined, its potential eligibility described (e.g., National Register criteria, approximate boundaries, period of significance), and it can be considered eligible for the purposes of the project only. The individual properties subject to effect then may be evaluated as to whether they are contributors to that district.

Historic landscapes generally are categorized either as sites or districts, and specifically defined as either vernacular or designed landscapes.

Vernacular landscapes (sometimes called cultural landscapes) are the result of past human activities, land uses, and choices. They may display a particular arrangement of resources reflecting a significant land use, rather than a conscious design. These landscapes often are rural. An example could be an important dairy-farming region in which the farms display a consistent pattern and style from an earlier time.

Designed landscapes are conscious works in a recognized style or tradition. They may be associated with significant developments, persons, or events in landscape

architecture. Aesthetic values often play an important role. An example could be a park or the grounds of a college campus designed by an important landscape architect.

Generally, historic landscapes that are categorized as sites are recorded and evaluated in the same manner as other sites, while historic landscape districts are treated in accordance with the same basic principles as other historic districts.

As with other historic districts, formal evaluation of a large landscape district on the edge of a project area may not be necessary. If there is little potential to affect the landscape as a whole, it may be briefly discussed, outlining the qualities of its potential eligibility, and the landscape can be considered eligible for the purposes of the project only. Individual components subject to effect would then be evaluated to determine whether they are contributors to that historic landscape.

Caltrans has developed the “General Guidelines for Identifying and Evaluating Historic Landscapes,” which should be followed when potential landscapes are encountered. The guidelines include recognition, classification, and description of landscapes; determination of the appropriate levels of documentation; and determinations of significance and integrity. The guidelines also contain an extensive bibliography and suggestions for organizing the information in a report format.

Although Traditional Cultural Properties (TCPs) usually are associated with Native American values, on rare occasions built-environment resources also may qualify as TCPs. Consult National Register Bulletin 38National Register Bulletin 38: Guidelines for Evaluating and Documenting Traditional Cultural Properties, for guidance in evaluating any potential TCPs.

National Register Bulletin 38 states that a traditional cultural property can be “defined generally as one that is eligible for inclusion in the National Register because of its association with cultural practices or beliefs of a living community that (a) are rooted in that community's history, and (b) are important in maintaining the continuing cultural identity of the community.” Such associations must be traditional, important, and continuing, playing the same role in the community today as in the past. Just as with any other property, a TCP must meet National Register criteria for significance and integrity.

Developing a compelling argument for eligibility as TCPs of built-environment properties such as ethnic neighborhoods can be difficult and time-consuming. It should be pursued only after careful consideration. Sometimes properties that might appear to have potential TCP values could be better recognized and more easily and appropriately documented as National Register property types (buildings, structures, objects, historic districts, etc.) under the “area of significance” categories outlined in National Register Bulletins 15 Part V and 16A Part III.8. However, when built-environment properties do have values that best can be addressed as a TCP, they should be evaluated as such, following the guidance in National Register Bulletin 38.

It must be emphasized that eligibility of historic-era TCPs should be based on scholarly historical research and that the resource or traditional activities must be based in the past and, in continuing use for at least 50 years, and the TCP must have integrity. When supporting documentary evidence can be expected to exist, historical research must be conducted, and the findings examined with intellectual rigor. The associated community also must be clearly identified, and the full range of its members’ opinions noted, including opposing viewpoints.

Properties are determined to be not eligible for inclusion in the National Register when they either lack significance under any of the National Register criteria, or they lack the integrity necessary to convey any significance they might possess.

A reasonable level of effort must be made to identify possible significance, “reasonable” depending on the particular circumstances for each property. If research fails to reveal any potential for important associations under criteria A or B, and the property displays no apparent values under Criterion C, or if it lacks integrity because of substantial alterations, and there is no potential for archaeological deposits (see Chapter 6), the property can be determined to be not eligible for inclusion in the National Register.

An adequate argument has to be constructed for ineligibility, as well as for eligibility, and the determination must convey the rationale and present the evidence in support of the conclusion. Generally, the more obvious the conclusion, the less effort needs to go into the argument.

Properties are determined to be eligible for inclusion in the National Register when they possess significance under any of the National Register criteria, and they possess the integrity necessary to convey that significance.

A determination of eligibility must convey specific findings, the rationale for those findings, and supporting evidence. It is a professional obligation also to reveal any evidence or argument for a contrary conclusion, which should be discussed objectively, and the reason for the final judgment explained.

In order for the State Historic Preservation Officer to concur in a determination of eligibility, it is necessary to identify and provide justification for the following specifics the:

• Applicable National Register criteria. Only one criterion is needed for eligibility, but any others that may apply should also be mentioned.
• National Register property boundaries. (See Section 7-9.3, below.)
• Period of significance. More than one period can apply when a property has different phases of significance. A property significant for its architecture will generally have the date of construction as its period of significance, although the period can be extended to include the date of later alterations that have also acquired significance.
• Level of significance. National, state, or local.
• Contributing and noncontributing elements. Any substantial components that add to or detract from the property’s significance, such as buildings, fences, or vegetation.
  

Boundaries of a historic property must be delineated clearly and carefully, as they are a critical factor in the subsequent assessment of project effects on the property. The National Register Bulletin, Defining Boundaries for National Register Properties, provides substantial guidance on establishing boundaries, including the following summary: 

Selection of boundaries is a judgment based on the nature of the property's significance, integrity, and physical setting. . . . Select boundaries that define the limits of the eligible resources. Such resources usually include the immediate surroundings and encompass the appropriate setting. However, exclude additional, peripheral areas that do not directly contribute to the property's significance as buffer or as open space to separate the property from surrounding areas. Areas that have lost integrity because of changes in cultural features or setting should be excluded when they are at the periphery of the eligible resources.

The guidance is also useful for determining boundaries for historical resources under CEQA and compliance with PRC §5024.

Current property lines (assessor’s parcels) often are the appropriate boundaries for built-environment properties in urban or suburban areas, and sometimes for rural properties as well. When a historic property does not correspond with the current legal parcel, other kinds of boundaries may be used. Historic ownership maps may be used to show the original property lines from the period of significance; landscape features such as tree rows, stone walls, or roads may provide logical limits; or adjacent modern intrusions can represent appropriate boundaries for the limit of the eligible resource. Whatever boundaries are chosen, it is important that they be described in relation to other features in a manner that will clearly distinguish the eligible property from its surroundings.

Boundary lines need to be delineated on a map of appropriate scale and detail. For large properties, the boundaries may be drawn on a USGS quad sheet. If the boundaries are straight lines that form a polygon, Universal Transverse Mercator (UTM) coordinates can be used to designate the vertices of the property. If used, mark and label the UTM references on the map. See National Register Bulletin #28: Using the UTM Grid System to Record Historic Sites.

In unusual cases where the property is a historic district composed of discontinuous elements, boundaries for each of the separate parcels of land comprising the district should be selected according to the guidelines presented in National Register Bulletin 16A. This situation is limited to situations in which

• Visual continuity is not a factor of historic significance
• Resources are geographically separate
• Intervening space lacks significance.

A good example is a canal system, in which human-made elements are interconnected by natural components that are excluded from the National Register. Another example is where a portion of a historic district was separated from the rest of the district by intervening development or highway construction and the separated portion has sufficient significance and integrity on its own to meet the National Register criteria.

It is important to make careful, thoughtful judgments regarding boundaries, especially when including land outside the legal parcel within the historic property’s boundaries. Boundaries must be defensible in terms of the intrinsic historical or architectural values they contain. The boundary description needs to provide a clear rationale, particularly when the boundary does not correspond to the current legal parcel, based upon historical significance and historic integrity.

Essential physical features are those distinctive tangible elements and physical features that convey a property’s historic appearance and that are indispensable to conveying its historic significance. Essential physical features (also referred to as contributing elements or character-defining features) are directly related to the criteria under which a property qualifies for the National Register of Historic Places. Identifying a property’s essential physical features is critical in assessing its integrity for the evaluation, and in determining a project’s effects on that property. If the various materials, features and spaces that give a property its visual character are not recognized and preserved, then essential aspects of its character may be damaged through project effects, mitigation, rehabilitation, and other activities.

Essential physical features may include such elements as materials, craftsmanship, construction details, overall shape and size, spatial relationships, and contributing setting. In general, only exterior, publicly accessible features of built-environment properties require consideration on a survey. For most Caltrans projects, the exterior essential physical features of buildings, structures, objects, sites and districts are the most critical because they are the features that are most likely to be affected.

There are situations, however, when Caltrans projects have the potential to affect interior features, such as maintenance activities and repairs to Caltrans-owned historic buildings, or when appropriate mitigation measures include interior work on affected historic buildings or structures. Careful consideration needs to be given as to whether identifying interior character-defining features is necessary. Understanding what essential physical features a historic property possesses becomes critical in during the effects phase of the Section 106, CEQA and PRC §5024 processes, and guide the development of mitigation measures.

Character refers to the visual aspects and physical features that comprise the appearance of every historic built-environment resource. Essential physical features include overall shape and size of a resource, its materials, craftsmanship, decorative details, spatial relationships, various aspects of its site and environment, and, in limited circumstances, interior spaces and features.

When determining whether a property meets National Register criteria or is a historical resource under CEQA, discussion of these features in the evaluation tends to be generalized, a summary of the overall features the property possess that conveys its significance under the applicable eligibility criteria. If a historic property will be adversely affected, or the Secretary of the Interior’s Standards for the Treatment of Historic Properties (Standards) are used to achieve a finding of No Adverse Effect with Special Conditions, to develop mitigation measures, or to obtain a Categorical Exemption under CEQA, a more detailed and ranked list of specific character-defining features may be necessary. See Exhibit 7.2 for further guidance on describing and listing these features.

The discussion of essential physical features for individually eligible buildings, structures, objects and districts is fairly straightforward, as described previously. Contributing buildings and structures within historic districts, however, require more thought when considering effects and mitigation measures. If these contributing properties are not individually, eligible their features must be linked to the features of the historic district in which they are located and must convey the significance of the district.

With few exceptions, interior features rarely convey the essential physical features of the district. For each affected contributor, how it relates to the historic district’s essential physical features, the integrity of the contributor itself, and its own essential physical features also would need to be summarized and noted.

A property’s historic setting often is a factor in determining a project’s indirect effects.