Texas Historical Commission




Horizon Environmental Services, Inc. (Horizon) was selected by the City of Dripping Springs to conduct an intensive cultural resources inventory survey and assessment of the proposed Dripping Springs Wastewater System Improvements Project (EID 1) in Dripping Springs, Hays County, Texas (USACE Project No. SWF-2020-00075). This survey represents the first phase of a larger project involving the proposed construction of wastewater system improvements in Dripping Springs. The current phase of the project would involve three separate components—the West Interceptor segment, which extends approximately 3.7 kilometers (2.3 miles) in length along Onion Creek west of Farm-to-Market Road (FM) 12; the Reclaimed Water Line segment, which extends approximately 1.3 kilometers (0.8 mile) in length between Needham Road and the intersection of FM 12 and FM 150; an approximately 2.3-hectare (5.7-acre) effluent pond located south of an existing water reclamation facility south of FM 150; and the proposed expansion of the existing water reclamation facility adjacent to the proposed effluent pond, which together cover 3.3 hectares (8.0 acres). The linear rights-of-way (ROW) of proposed pipeline segments would measure a maximum of 30.5 meters (100.0 feet) in width, and the proposed project components would cover a combined area of approximately 18.5 hectares (45.6 acres).

The proposed undertaking would be sponsored by the City of Dripping Springs, a public subdivision of the state of Texas. As a political subdivision of the state of Texas, the project would fall under the jurisdiction of the Antiquities Code of Texas (Natural Resources Code, Title 9, Chapter 191). In addition, the project would utilize funding provided by the Clean Water State Revolving Fund (CWSRF) program, which is a federal-state partnership between the US Environmental Protection Agency (US EPA) and the state of Texas. As the US EPA is a federal agency, the project would also fall under the jurisdiction of Section 106 of the National Historic Preservation Act (NHPA) of 1966, as amended. As the proposed project represents a publicly sponsored undertaking, the project sponsor is required to provide the Texas Historical Commission (THC), which serves as the State Historic Preservation Office (SHPO) for the state of Texas, with an opportunity to review and comment on the project’s potential to adversely affect historic properties listed on or considered eligible for listing on the National Register of Historic Places (NRHP) under the NHPA and for designation as State Antiquities Landmarks (SAL) under the Antiquities Code of Texas.

From October 1 to 3, on November 4, and on November 22, 2019, Horizon archeologists Jesse Dalton, McKinzie Froese, Amy Goldstein, Elizabeth Sefton, and Jared Wiersema conducted an intensive cultural resources survey of the project area, including pedestrian walkover with shovel testing and backhoe trenching. The survey was performed under the supervision of Jeffrey D. Owens, who served as Principal Investigator, under Texas Antiquities Permit No. 9114. The purpose of the survey was to locate any significant cultural resources that potentially would be impacted by the proposed undertaking. Horizon’s archeologists traversed the project area on foot and thoroughly inspected the modern ground surface for aboriginal and historic-age cultural resources.

Overall, vegetation across the entire project area generally consisted of short- to medium-length grasses interspersed with mature live oak and cedar trees, which afforded fair to good ground surface visibility (30 to 60%). Within the riparian zone of Onion Creek, vegetation consisted of tall, dense grass and mature honey mesquite, cedar, live oak, and hackberry trees, which provided poor ground surface visibility (<30%).

The West Interceptor segment runs along the gravelly terraces of Onion Creek. Topographically, this segment of the project area consists of steep limestone steps and rocky outcrops that give way to flat, open fields. The proposed interceptor crosses Onion Creek at three locations, and the lower stream terraces of the creek have extensive gravel bars and debris associated with high-energy flooding. Soil profiles typically consist of a shallow A horizon of hard, calcareous clay loam underlain by dense gravelly deposits; however, in the southeastern portion of the West Interceptor, deeper clayey loam alluvium underlain by limestone bedrock was encountered.

The Reclaimed Water Line segment traverses the west-facing hillslopes of upland ridges east of Onion Creek. Approximately the southeastern half of this segment of the project area would be constructed within the existing ROW of FM 12 west of the roadway, and construction, use, and ongoing maintenance of the roadway and associated facilities has resulted in extensive prior disturbances. Evidence of ground disturbance resulting from land clearing for housing developments and a transmission line were also noted within the northwestern portion of the proposed Reclaimed Water Line segment. The far northwestern end of the proposed Reclaimed Water Line segment skims the edge of the floodplain associated with a tributary of Onion Creek. Sediments on the terraces of this stream channel consist of calcareous loamy alluvial deposits, while soils across the upland portions of the segment consist of shallow deposits of gravelly clay and clay loam underlain by naturally degrading limestone bedrock.

The water reclamation facility expansion and effluent pond segment are located on the upper terraces northeast of Onion Creek. The water reclamation facility is an existing industrial facility surrounded by septic fields, and prior disturbances from construction, use, and ongoing maintenance of the facility are extensive. The proposed expansion area to the north of the existing facility is currently utilized as a septic field. Sediments within this segment of the project area consist of shallow, gravelly, calcareous loamy to clayey loam alluvium underlain by naturally degrading limestone bedrock.

In addition to a pedestrian walkover, the Texas State Minimum Archeological Survey Standards (TSMASS) require a minimum of 16 subsurface shovel tests per 1.6 kilometers (1.0 mile) for each 30.5-meter- (100.0-foot-) wide transect (or fraction thereof) for linear surveys unless field conditions warrant more shovel tests (e.g., in cultural high-probability areas) or fewer shovel tests (e.g., on steep slopes, in areas with excellent ground surface visibility). For block-area surveys, the TSMASS require two shovel tests per 0.4 hectare (1.0 acre) for project areas between 1.2 and 4.0 hectares (3.0 and 10.0 acres) in size. As such, a minimum of 37 shovel tests would be required within the West Interceptor segment, 13 shovel tests would be required within the Reclaimed Water Line segment, and 16 shovel tests would be required within the proposed water reclamation facility expansion and effluent pond area, for a total of 66 shovel tests for the project area as a whole. Horizon excavated a total of 106 shovel tests during the survey, including 82 shovel tests within the West Interceptor segment, 13 shovel tests within the Reclaimed Water Line segment, and 11 shovel tests within the facility expansion and effluent pond area. The shovel tests within the proposed facility expansion and effluent pond area were not all excavated directly within the final proposed construction footprint as the boundaries of this portion of the project area had not been firmly determined at the time of the survey, and no shovel tests were excavated within the existing water reclamation facility due to the extent of observable prior disturbances within this area. Overall, Horizon exceeded the minimum number of shovel tests required for the project area as a whole, and it is Horizon’s opinion that shovel testing was capable of fully penetrating sediments with the potential to contain subsurface archeological deposits (with the exception noted below where backhoe trenches were excavated along a portion of the West Interceptor segment).

In addition to shovel testing, Horizon excavated four backhoe trenches within the southeastern portion of the proposed West Interceptor segment. The trenches were excavated at roughly 100.0-meter (328.0-foot) intervals along the proposed centerline to depths ranging from 105.0 to 350.0 centimeters (41.3 to 137.8 inches) below surface. Sediments observed within trench profiles typically consisted of moderately deep deposits of grayish-brown fine clay loam over yellowish-brown fine sandy loam. Dense deposits of river cobbles and/or naturally degrading limestone bedrock were observed at the base of three of the four trenches, and it is Horizon’s opinion that backhoe trenching was capable of fully penetrating sediments with the potential to contain archeological deposits.

One chert flake was recorded in a shovel test (ST AG30) at a depth of 0.0 to 30.0 centimeters (0.0 to 11.8 inches) below surface at the far northwestern end of the West Interceptor project segment. Supplemental delineation shovel tests excavated around this initial discovery failed to produce any additional evidence of prehistoric cultural activity at this location, so the chert flake was recorded as an isolated artifact occurrence but was not documented as an archeological site. No other cultural resources of prehistoric or historic age were recorded within the project area during the pedestrian survey, shovel testing, or backhoe trenching.

Based on the results of the survey-level investigations documented in this report, no cultural resources would be affected by the proposed undertaking. In accordance with 36 CFR 800.4, Horizon has made a reasonable and good-faith effort to identify historic properties within the project area. No cultural resources were identified within the project area that meet the criteria for designation as SALs according to 13 TAC 26 or for inclusion in the NRHP according to 36 CFR 60.4. Horizon recommends a finding of “no historic properties affected,” and no further archeological work is recommended in connection with the proposed undertaking. However, human burials, both prehistoric and historic, are protected under the Texas Health and Safety Code. In the event that any human remains or burial objects are inadvertently discovered at any point during construction, use, or ongoing maintenance in the project area, even in previously surveyed areas, all work should cease immediately in the vicinity of the inadvertent discovery, and the THC should be notified immediately. Following completion of the project, all project records will be prepared for permanent curation at the Texas Archeological Research Laboratory (TARL).

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Creative Commons Attribution 4.0 License
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