Notice2024-01410
Notice of Intent To Prepare an Environmental Impact Statement for the Scoggins Dam Safety Modifications Project
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
January 25, 2024
Issuing agencies
Interior DepartmentReclamation Bureau
Abstract
The Bureau of Reclamation (Reclamation) intends to prepare an environmental impact statement (EIS) for the Scoggins Dam Safety Modifications Project in the Tualatin Basin, Oregon. The purpose of the project is to improve public safety by reducing risk associated with severe seismic loadings while continuing to meet authorized project purposes. Reclamation is seeking public comments to identify significant issues or other alternatives to be addressed in the EIS.
Full Text
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<title>Federal Register, Volume 89 Issue 17 (Thursday, January 25, 2024)</title>
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[Federal Register Volume 89, Number 17 (Thursday, January 25, 2024)]
[Notices]
[Pages 4989-4991]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-01410]
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DEPARTMENT OF THE INTERIOR
Bureau of Reclamation
[RR01021200; 23XR0680A5; RX.15470004.00118T0]
Notice of Intent To Prepare an Environmental Impact Statement for
the Scoggins Dam Safety Modifications Project
AGENCY: Bureau of Reclamation, Interior.
ACTION: Notice of intent; request for comments.
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SUMMARY: The Bureau of Reclamation (Reclamation) intends to prepare an
environmental impact statement (EIS) for the Scoggins Dam Safety
Modifications Project in the Tualatin Basin, Oregon. The purpose of the
project is to improve public safety by reducing risk associated with
severe seismic loadings while continuing to meet authorized project
purposes. Reclamation is seeking public comments to identify
significant issues or other alternatives to be addressed in the EIS.
DATES: Submit written comments on the scope of the EIS on or before
February 26, 2024.
Reclamation will hold two in-person and two web-based virtual
public scoping meetings on the following dates:
1. February 8, 2024, 5 p.m. to 6:30 p.m. (PST), Forest Grove, OR.
2. February 8, 2024, 6:30 p.m. to 8 p.m. (PST), Forest Grove, OR.
3. February 13, 2024, 11 a.m. to 1 p.m. (PST), Virtual (Zoom
webinar).
4. February 13, 2024, 4 p.m. to 6 p.m. (PST), Virtual (Zoom
webinar).
ADDRESSES: Send written scoping comments, requests to be added to the
project mailing list, or requests for other special assistance needs
via email to <a href="/cdn-cgi/l/email-protection#db999489f688939af68898959e8b9a9baea8b9a9f5bcb4ad"><span class="__cf_email__" data-cfemail="f7b5b8a5daa4bfb6daa4b4b9b2a7b6b782849585d9909881">[email protected]</span></a>.
The in-person meetings will be held at the Community Auditorium,
1915 Main Street, Forest Grove, OR 97116.
The web-based virtual meetings will be accessible at: <a href="https://www.virtualpublicmeeting.com/scoggins-sod-eis">https://www.virtualpublicmeeting.com/scoggins-sod-eis</a>.
To view more information regarding this project, go to: <a href="https://www.usbr.gov/pn/programs/sod/scoggins/index.html">https://www.usbr.gov/pn/programs/sod/scoggins/index.html</a>.
[[Page 4990]]
FOR FURTHER INFORMATION CONTACT: Rebecca Thompson, Bureau of
Reclamation, Columbia-Pacific Northwest Regional Office, 1150 Curtis
Road, Suite 100, Boise, Idaho 83706-1234; telephone (208) 600-2134;
email <a href="/cdn-cgi/l/email-protection#71333e235c2239305c22323f34213031040213035f161e07"><span class="__cf_email__" data-cfemail="6d2f223f403e252c403e2e23283d2c2d181e0f1f430a021b">[email protected]</span></a>.
Individuals who are deaf, deafblind, hard of hearing, or have a
speech disability may dial 711 (TTY, TDD, or TeleBraille) to access
telecommunications relay services to contact the above individual
during normal business hours or to leave a message or question after
hours. You will receive a reply during normal business hours.
SUPPLEMENTARY INFORMATION: This Federal Register notice provides the
public with information regarding Reclamation's intent to prepare an
EIS pursuant to the National Environmental Policy Act (NEPA) of 1969,
as amended. Reclamation will hold public scoping meetings to solicit
comments on the scope of the EIS and the issues and alternatives that
should be analyzed. Additionally, this notice serves to provide notice
and request public input on potential effects on historic properties
from this project in accordance with the Section 106 process as defined
in the National Historic Preservation Act (36 CFR 800.2(d)(3)).
Background
Scoggins Dam is an earthfill embankment dam located on Scoggins
Creek, a tributary of the Tualatin River, about 25 miles west of
Portland, Oregon. Construction of this 151-foot-high, 2,700-foot-long
dam was completed in 1975. The dam's reservoir, Henry Hagg Lake, is the
primary source of water for the Tualatin Basin, storing nearly 60,000
acre-feet (active 53,600 acre-feet), providing water for municipal and
industrial uses, irrigation, water quality, fish and wildlife habitat,
recreation, and flood control. The facility is operated and maintained
by the Tualatin Valley Irrigation District. There are roughly 11 miles
of shoreline around the lake at full pool; recreation facilities and
trails in this area are managed by Washington County as Scoggins Valley
Park.
The area of Scoggins Dam and its reservoir have high potential for
severe loading initiated by an extreme seismic event from identified
active faults, primarily the Cascadia Subduction Zone (CSZ), a 600-mile
fault stretching from northern California to northern Vancouver Island
in Canada. At its closest, the CSZ is 118 miles to the west of the dam.
The principal concerns for Scoggins Dam are uncontrolled releases or
dam breaches (dam failure) caused by severe loading from a CSZ seismic
event. The dam could also experience less severe loading from local
crustal fault earthquakes, the closest being the Gales Creek fault
zone.
Around 2007, after completing general investigations of potential
seismic hazards at the dam, Reclamation recognized the potential
impacts of a CSZ seismic event to Scoggins Dam. Reclamation continued
field data collection and evaluation and risk analyses updates through
2011 to improve the understanding of seismic risk to the dam. Since
2011, Reclamation has looked at various structural and non-structural
options to reduce seismic risk, including options that would increase
reservoir storage. In 2022, following completion of a Dam Safety
Advisory Team review, Reclamation began furthering design of a dam-
safety only structural option that would reduce risk in accordance with
Reclamation's public protection guidelines. This alternative will be
evaluated in the EIS.
Proposed Action
Reclamation proposes to reduce the risk to Scoggins Dam in the
occurrence of a CSZ seismic event by improving the loadings response
performance of the facility. This would be accomplished by raising the
dam crest, constructing a downstream shear key, creating a new
spillway, and placing additional berm material over the existing dam.
This project would not create additional reservoir storage in Henry
Hagg Lake.
Proposed dam structure modifications include:
<bullet> Excavate and backfill portions of the crest and existing
embankment.
<bullet> Construct a downstream shear key.
<bullet> Install a downstream rock filter and drain.
<bullet> Install a stability berm over the shear key and downstream
slope of dam.
<bullet> Raise the dam crest by ~7 feet.
<bullet> Demolish the existing spillway, bridge, and ancillary
features.
<bullet> Construct a new spillway, bridge, and ancillary features
and extend outlet works.
<bullet> Construct a new two-lane road across the dam.
The existing road across the dam would be closed during
construction. An alternative road would be constructed to provide safe
public transport. The project may also require permanently rerouting a
portion of the Stimson Mainline Road to accommodate the expanded
stability berm.
In addition to work on the dam, the project would include
modification to structures around the reservoir such as culverts and
recreation trails. Materials for construction would be excavated at one
or more borrow sites on the east side of the reservoir, requiring the
removal of large trees. Alternatives for accessing and transporting
materials from the borrow sites will be investigated in the EIS and may
include a combination of constructing a temporary haul route and using
the existing Scoggins Valley Road.
Previous Water Supply Studies
In 2001, the Tualatin Basin Water Supply Feasibility Study was
initiated to evaluate a range of water supply options in the basin,
including raising Scoggins Dam (publication in the Federal Register on
December 13, 2001, 66 FR 64454). A draft EIS was prepared in 2007, but
never published, due to the need to further evaluate the seismic risk
of the CSZ to the dam. During 2013, some of the partners in the
feasibility study began separately pursuing other water supply options
that did not include Scoggins Dam or Reclamation participation. In
2017, following receipt of a Joint Project Authority secured in
amendments to the Safety of Dams Act in 2015, Reclamation began working
jointly with Clean Water Services, analyzing the feasibility of three
options (dam safety only modification, dam raise, and new downstream
dam); all options would have reduced seismic risk at the dam, and two
would have increased water supply in the basin. In 2021, a
determination was made to forego further development of increasing
reservoir storage and to support development of a dam safety only
modification.
Statutory Authority and Anticipated Permits
NEPA [42 U.S.C. 4321 et seq.] requires Federal agencies to conduct
an environmental analysis of their proposed actions to determine
whether the actions may significantly affect the human environment. The
EIS will analyze the environmental effects of implementing the proposed
action and alternatives, and a no action alternative. The U.S. Army
Corps of Engineers, Tualatin Valley Irrigation District, Washington
County, Joint Water Commission, Clean Water Services, and Confederated
Tribes of the Grand Ronde Community of Oregon have accepted invitations
to participate as cooperating agencies for the EIS. Other entities will
be considered, as necessary, during the EIS process. In addition to
NEPA, various other Federal, state, and local authorizations may be
required for the proposed action. Applicable Federal laws include, but
are not limited to, the Endangered Species Act, National
[[Page 4991]]
Historic Preservation Act, and Clean Water Act.
Public Disclosure
Before including your address, phone number, email address, or
other personal, identifying information in your comment submission,
please be advised that the entire submission, including your personal
identifying information, may be made publicly available at any time.
While a commenter may request that Reclamation withhold personal
identifying information from public review, Reclamation cannot
guarantee that it will be able to do so.
How To Request Reasonable Accommodation
For special assistance at one of the scoping meetings, please
contact Rebecca Thompson or the TDD line (see FOR FURTHER INFORMATION
CONTACT section of this notice) at least 5 working days before the
meetings. All meeting facilities are physically accessible to people
with disabilities. Information regarding this project is available in
alternate formats upon request.
Jennifer Carrington,
Regional Director, Columbia-Pacific Northwest Region, Bureau of
Reclamation.
[FR Doc. 2024-01410 Filed 1-24-24; 8:45 am]
BILLING CODE 4332-90-P
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