Exhibit 7 - ISR 2021-071Date: September 10, 2021 Report No. 2021-071
INFORMAL STAFF REPORT
TO MAYOR AND CITY COUNCIL
SUBJECT: Updates on archeological findings excavated at the Hickory Creek Interceptor Phases 1 and 2.
EXECUTIVE SUMMARY: March 5, 2021, Staff provided Informal Staff Report (ISR) 2021-013 in response to requested information on details associated with the archeological findings at the project site for the Hickory Creek Interceptor Project Phases 1 and 2. The first two phases of the Hickory Creek Interceptor include a 2.46-mile wastewater interceptor along the Hickory Creek Basin. On August 2, 2021, the City issued Mountain Cascade, the selected construction contractor for the project, a notice to proceed to begin project construction. Archeological findings discovered at the site have since been analyzed
and resulted in the need for additional data recovery, as required by the Texas Historical Commission (THC). A team consisting of City of Denton staff, design consultants, and the construction contractor, have been in ongoing communication to confirm how the data recovery will impact the project budget and schedule. The exact impacts are currently unknown and will become clearer upon THC approval
of the proposed data recovery scope of processes and procedures, which will be submitted to THC on September 10, 2021. This report provides a brief update on the recent findings and the proposed data recovery processes. Upon THC approval of the scope, which is anticipated by the close of September 2021, staff will identify and provide an update on the Hickory Creek Interceptor Phases 1 and 2 Project
scope, schedule, and budget.
BACKGROUND: The site is a pre-contact period Native American campsite on the shallow floodplain that lies south and west of a bend in Hickory Creek. The site was previously recorded in 2014 during an archeological survey conducted for the Bonnie Brae Street re-alignment and associated detention
pond. Based on their findings, archeologists in 2014 defined the site more narrowly, placing its
boundaries just outside the limits of the current interceptor easement, Bonnie Brae Street, and a detention basin that has since been constructed. However, the archeological survey of the Hickory Creek Interceptor easement in October 2020 found that elements of the site extend into the current Hickory Creek Interceptor project area.
The archeological findings are characterized by multiple rock hearths and a small quantity of associated tool and food debris that archeologists believe represent repeated, short term visits by mobile hunter gatherers over a period of about 1,200 years, and possibly more. Investigations within the interceptor easement to-date have uncovered eight new burned rock features with
associated burned organic remains, two dart points, mussel shell, and a small contingent of lithic
tool debris. The oldest features found so far appear to be about 5,000 years old, placing them in a period known as the Middle Archaic. As only two known sites of this time period have been found in the North Central Texas region, the site found in the Hickory Creek Interceptor area is relatively unique by virtue of age alone. The fact that there are multiple intact and well-defined overlapping
features elevates the site’s importance even further. Based on these preliminary data from testing,
the THC has determined that site is eligible for listing as a State Antiquities Landmark (SAL).
47
Date: September 10, 2021 Report No. 2021-071
Data recovery investigations to comply with the Antiquities Code of Texas (ACT) will be required before the interceptor can be constructed.
Data recovery will not stop the Hickory Creek Interceptor Project from moving forward. Data recovery is generally undertaken for archeological sites that have exceptional significance based on age, features, or potential to provide unique or new data about the past. Data recovery of an archeological site often happens when avoidance or preservation in place is not a viable option.
During data recovery, archeologists excavate a site or sites to essentially retrieve the irreplaceable
information out of the ground before it is lost forever due to project impacts. In compliance terms, this is also known as mitigation of effects for cultural resources. For the Hickory Creek Interceptor, archeologists, project engineers, and project managers with the
City have worked diligently to explore a variety of avoidance options for both sites. To-date, all
feasible options identified are either costlier and/or are more time consuming than simply conducting excavations to mitigate effects to the archeological sites in the current easement alignment.
ATTACHMENTS:
ISR 2021-013
STAFF CONTACTS: Rachel Wood
Deputy Director of Capital Projects
(940) 349-7718 Rachel.Wood@cityofdenton.com
Tracy Beck
Construction Project Manager
(940) 349-8925 tracy.beck@cityofdenton.com
REQUESTOR: Staff Initiated
PARTICIPATING DEPARTMENTS: Capital Projects/Engineering
STAFF TIME TO COMPLETE REPORT:
One hour
48
Date: March 5, 2021 Report No. 2021-013
INFORMAL STAFF REPORT
TO MAYOR AND CITY COUNCIL
SUBJECT:
Provide details on the archeological findings at the Hickory Creek Interceptor project site.
EXECUTIVE SUMMARY:
During the March 2, 2021 Capital Projects Update work session, Mayor Pro Tem Davis requested
information on details associated with the archeological findings at the project site for the Hickory
Creek Interceptor Project.
BACKGROUND:
As part of the Hickory Creek Interceptor project design, an archeological survey was conducted
in October 2020 covering 2.46 miles of the proposed wastewater interceptor easement along
Hickory Creek.
The survey consisted of visual inspection and backhoe trenching of 24 trenches spaced
approximately 476 feet apart and approx. 6.5-8.5 feet deep. Two archeological sites were
recorded, one formerly known near Bonnie Brae but the area has expanded with this survey. The
second is a newly found site near US 377. Both sites had similar characteristics. Specifically,
they are deeply buried under
more than a meter of
alluvium (clay or silt left by
flowing water) and both sites
exhibit burned sandstone rock
concentrations and mussel
shell debris in a thick cultural
sediment zone marked by
calcium carbonate filaments.
Both sites are of unknown
eligibility as State Antiquities
Landmarks until further
testing is completed.
To-date, one artifact has been
collected, a Kent-like dart
point (arrowhead). All
remaining material at the sites
has been field recorded
instead of collected.
41DTN580
41DTN624
Site locations are depicted above
49
Date: March 5, 2021 Report No. 2021-013
Conclusion/Next Steps:
An archeological survey found that the two sites contain indigenous pre-contact period features.
As avoidance of the sites is not feasible for completion of the Hickory Creek Interceptor Project,
formal eligibility testing for them has been recommended by the Texas Historical Commission
(THC), the state board which oversees review and compliance for Section 106 of the National
Historic Preservation Act (NRHP) and the Antiquities Code of Texas (ACT). Staff is currently
working with a consultant to ensure necessary site protections and archeological discovery can
occur while also proceeding with the selection of a contractor to construct the first two phases of
the Hickory Creek Interceptor project.
NORTHERN SITE SUMMARY
A) Late Archaic/Woodland Period dart point
on the surface of the exposed detention pond bank.
A
B
C
50
Date: March 5, 2021 Report No. 2021-013
B) Mussel shell fragments and burned
sandstone from Trench 2
C) Burned sandstone feature in floor of Trench 3
at a depth of 8.75 feet below surface.
51
Date: March 5, 2021 Report No. 2021-013
SOUTHERN SITE SUMMARY
Four (4) trenches were tested positive (Trenches 12, 13, 14, 15). The main concentration of
material at Site 41DN624 is located on the north site of the BNSF Railroad and US 377.
Although the limits of the site are drawn to extend around Trench 15 on the south side of the
roadway, investigators noted just two tabular burned sandstone rocks and just three mussel shell
fragments in trench walls.
D) Burned sandstone cluster Trench 12,
buried 4.25 feet below surface.
(14)
D (12)
E (13)
(15)
52
Date: March 5, 2021 Report No. 2021-013
STAFF CONTACTS:
Rachel Wood
Deputy Director of Capital Projects
(940) 349-7718
Rachel.Wood@cityofdenton.com
Tracy Beck
Construction Project Manager
(940) 349-8925
Tracy.Beck@cityofdenton.com
REQUESTOR: Mayor Pro Tem Davis
STAFF TIME TO COMPLETE REPORT:
One hour
53