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Susitna-Watana Hydroelectric Project Document
ARLIS Uniform Cover Page
Title:
Project safety resources, Study plan Section 16 Introduction : Final study
plan SuWa 200
Author(s) – Personal:
Author(s) – Corporate:
Alaska Energy Authority
AEA-identified category, if specified:
Final study plan
AEA-identified series, if specified:
Series (ARLIS-assigned report number):
Susitna-Watana Hydroelectric Project document number 200
Existing numbers on document:
Published by:
[Anchorage : Alaska Energy Authority, 2013]
Date published:
July 2013
Published for:
Date or date range of report:
Volume and/or Part numbers:
Study plan Section 16
Final or Draft status, as indicated:
Document type:
Pagination:
2 p.
Related work(s):
Pages added/changed by ARLIS:
Notes:
All reports in the Susitna-Watana Hydroelectric Project Document series include an ARLIS-
produced cover page and an ARLIS-assigned number for uniformity and citability. All reports
are posted online at http://www.arlis.org/resources/susitna-watana/
Susitna-Watana Hydroelectric Project
(FERC No. 14241)
Project Safety Resources
Study Plan Section 16 Introduction
Final Study Plan
Alaska Energy Authority
July 2013
Final Study Plan Project Safety Resources Introduction
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 16-1 July 2013
16. PROJECT SAFETY
16.1 Introduction
The Project, as currently envisioned, is anticipated to include a dam constructed using roller
compacted concrete (RCC) construction methods. The Project works will also include a large
reservoir, a spillway, cofferdams, diversion tunnels, integrated penstocks and powerhouse,
railhead improvements, temporary construction housing and maintenance facilities, borrow and
quarry areas, transmission lines, access roads, staging and stockpile areas, etc. The Project
safety studies will provide information and analysis to demonstrate that proposed structures are
safe and adequate to fulfill their stated functions.
16.2 Nexus Between Project Construction / Existence / Operations
and Effects on Resources to be Studied
Among the basic studies required to verify the design criteria for and the design of a large dam
are the seismic hazard evaluation and the Probable Maximum Flood (PMF) studies.
Project construction, operation, and maintenance activities have the potential to be affected by,
and to affect, seismic activity in the Project area, and extreme floods can also affect Project
operations. Thus, the ability to safely pass extreme floods and safely survive a regional or local
seismic event is of paramount importance in dam development. These studies will verify the
design criteria to be used for the PMF inflow and the routing of the PMF and also verify the
condition or nature of the seismic hazard such that appropriate design criteria are formulated.
16.3 Resource Management Goals and Objectives
The capability of Watana Dam to safely pass the most extreme floods, a FERC requirement, and
the ability of the dam to survive a seismic event are basic elements of a comprehensive dam
safety program under FERC’s 18 CFR Part 12 regulations. Dam safety is a fundamental design
criterion for the Watana Dam.
Additionally, The DNR’s Alaska Division of Geological and Geophysical Surveys (DGGS)
evaluates potential geologic hazards to buildings, roads, bridges, and other installations and
structures as part of its mission statement.
16.4 Summary of Consultation with Agencies, Alaska Native Entities
and Other Licensing Participants Regarding Revised Study
Plan Development
Many residents of the upper Susitna Valley expressed concerns about the stability of the
proposed dam during and after a seismic event. They have also expressed concern about the
dam’s ability to withstand extreme flood events.
AEA has informally consulted with the Alaska Division of Geological and Geophysical Surveys.
A conference call was held among FERC, AEA, and MWH representatives on August 20, 2012
Final Study Plan Project Safety Resources Introduction
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 16-2 July 2013
to discuss the structure of the Board of Consultants. An initial Board of Consultants meeting
was held on November 1-2, 2012 in Bellevue, Washington.
Consultation subsequent to the filing of the Revised Study Plan (RSP) is described within each
Final Study Plan (FSP).