HomeMy WebLinkAbout08022016 Planning & Zoning Work Session Packet CI'Otyof e
wa r
All Hazard Mitigation Plan
Final Plan
April 12, 2010
Seward Hazard Mitigation Plan 1- March 23, 2004
Revised April 12,2010 ST
TABLE OF CONTENTS Page
1. Chapter 1 -Introduction............................................:................ 3
I. -Purpose of Plan........................................................ 3
II. -Methodology............................................................ 4
III. -Plan Organization..................................................... 5
IV. -City of Seward- background.......................................... 6
2. Chapter 2 -Hazard Identification................................................. 8
3. Chapter 3 -Historical Hazards in Seward....................................... 15
4. Chapter 4 -Hazards in Seward.................................................... 18
Annex A -Floods....................•..........s................................... 18
AnnexB -Earthquakes............................................................ 25
AnnexC - Tsunami................................................................ 28
Annex D - Coastal Erosion........................................................ 29
Annex F - Wildland Fire........................................................... 33
AnnexF - Weather.............................................................. ... 34
Annex G -Snow Avalanches/Landslides.......................................... 35
AnnexH -Volcano.................................................................. 36
AnnexI -Technical................................................................. 37
AnnexJ - Economic............................................................... 38
5. Chapter 5 -Public Participation on Plan.......................................... 42
6. Chapter 6 -Implementation......................................................... 43
6 A -Potential Project List.................................................. 44
7. Referenrces -References and addendums .......................................... 47
Seward All Hazard Mitigation Plan -2- March 23, 2004 ^�
Revised,Apri(12,2010
Chapter 1 - Introduction
I. Purpose of Plan
The purpose of this plan is to fulfill loran Hazard Mitigation Plan requirements. The plan will
identify hazards; establish community goals and objectives and select mitigation activities
that are appropriate for the City of Seward.
The Disaster Mitigation Act of 2000 (DMA 2000), Section 322 (a-d) requires that local
governments, as a condition of receiving federal disaster mitigation funds, have a mitigation
plan that describes the process for identifying hazards, risks and vulnerabilities, identify and
prioritize mitigation actions, encourage the development of local mitigation and provide
technical support for those efforts.
In addition, this plan has fulfilled the requirements of the National Flood insurance Reform
Act of 1994 (NFIRA). With this act, Congress authorized the establishment of a Federal
grant program to provide financial assistance to States and communities for flood mitigation
planning and activities. The Federal Emergency Management Agency (FEMA) has
designated this Flood Mitigation Assistance (FMA).
Under the FMA. FEMA Provides assistance to States and comm, unities for activities that will
reduce the risk of flood damages to structures insurable under the National Flood
Insurance Program (NFIP). FMA is a state-administered, cost-share prograrn through
which states and communities can receive grants for flood mitigation planning, technical
assistance and mitigation projects.
The purpose of this plan is to produce a program of activities that wiil best tackle Seward`s
hazard and flood problems and meet other community needs. Consistent with FEMA
planning process guidelines, the purpose of this plan is to accomplish the following
objectives:
Ensure that all possible activities are reviewed and implemented so that disaster related
hazards are addressed by the most appropriate and efficient solution;
Link hazard management policies to specific activities;
Educate residents about potential hazards that threaten the community, including but
not limited to flood and wildfire hazards, extreme weather conditions, earthquakes and
tsunami;
Build public and political support for projects that prevent ne?k problems from known
hazards and reduce; r"utUre losses;
Fulfill planning requirements for future hazard mitigation project grants; and,
Facilitate implementation of hazard mitigation, management activities through an i action
plan.
Seward Ali Hazard Mitigaticn Plar, 3- � March 23, 2,004��
Rev+sad,April 12,2010
ll. Methodology
The methodology used for the development and updating of the Seward Hazard Mitigation
Plan, consisted of the following tasks:
1. Public involvement
2. Coordination with other agencies or organizations
3. Hazard area inventory
4. Problem identification
5. Review and Analysis of possible mitigation activities
6. Local adoption following a public hearing
7. Periodic review and update
This hazard mitigation plan contains a list of potential projects and a brief rationale or
explanation of how each project or group of projects contributes to the overall mitigation
strategy outlined in the plan.
The Mitigation Plan will be evaluated and updated every five years. In addition, the plan
will be updated as appropriate when a disaster occurs that significantly affects Seward,
whether or not it receives a Presidential Declaration. The update will be completed as soon
as possible, but no later than the 12 months following the date the disaster occurs.
Routine maintenance of the plan will include adding projects, as new funding sources
become available or taking projects off the list when they are accomplished.
Seward M Hazard Mitigation Ran -4- � � v March 23, 2004
Revised,.Apri!12,2010
The Plan is organized as follows:
Chapter 9
Chapter i presents sections on the purpose and goals of the plan, methodology used, and
a background study of the City of Seward.
Chapter-2
Chapter 2 identifies known hazards in Seward, such as flooding, tsunami and earthquake
potential, and beach erosion, including probability of each event.
Chapter 3
Chapter 3 addresses historical floods and other hazards that have occurred within the City
of Seward,
Chapter_4
Chapter 4 includes annexes of hazards affecting the City of Seward with hazard
assessment vulnerability and potential mitigation measures.
Chaioter 5
Chapter 5 outlines the public participation process undertaken during the planning process
and for the purpose of prioritizing projects and updating the plan.
Chapter S
Chapter 6 addresses implementation procedures and a prooess for updating the plan.
References
References are included in this section.
-Seward All Heard Mitigation liar, 5- March
Mwrch 23, rCloQ
Revised, April 12.2010
IV. City of Seward — Background
General Location
Seward is situated on Resurrection Bay on the east coast of the Kenai Peninsula, 125
highway miles south of Anchorage. It lies at the foot of Mount Marathon, and is the gateway
to the Kenai Fjords National Park. The communities of Bear Creek and Lowell Point are
adjacent to Seward. The city lies at approximately 60.104170 North Latitude and
149,44222' West Longitude (Sec. 10, T001 S. R001 W, Seward Meridian;. The City of
Seward is located in the Seward Recording District. The incorporated area encompasses
14.4 sq. miles of land and 7.1 sq. miles of water.
Climate
Seward experiences a maritime climate. Winter temperatures average from 17 to 38
degrees F; summer temperatures average 49 to 63 degrees F. The average annual
precipitation includes 66 inches of rain and 80 inches of snowfall. Due to the proximity of
the Gulf of Alaska and the topography of the land, large low pressure systems often bring
heavy rains and strong winds during the fall storm season.
Histoly of Seward
Resurrection Bay was named in 1792 by Russian fur trader and explorer Alexander
Baranof. While sailing from Kodiak to Yakutat, he found unexpected shelter in this bay from
a storm. He named the bay Resurrection because it was the Russian Sunday of the
Resurrection. Seward was named for U.S. Secretary of State William Seward, who
negotiated the purchase of Alaska from Rlfssia during the Un4oln administration. In the
1890's, Capt. Frank Lowell an,ived with his family and established a settlement. In 1903
John and Frank Ballaine and a group of settlers arrived to begin construction of a railroad.
Later, this settlement became a town. Seward became an incorporated city in 1912. The
Alaska Railroad was constructed between: 1915 and 1923, and Seward was developed as
the ocean terminus and supply center for interior Alaska. By 1960, Seward was the largest
community on the Peninsula. Tsun:arnis generated after the 1964 earthquake destroyed the
railroad terminal and killed several residents. As an ice-free harbor, Seward has become an
important supply center for Interior Alaska. 2003 was the i 00'h anniversary of the founding
of Seward.
Culture
Seward is primarily a non-Native community, although the Outekcak Tribe is very active
within the community. Seward's annual Fourth of July c--Iebration and its grueling Mount
Marathon racie attract participants and visitors worldwide. Other annual events include the
Seward Silver Salmon derby in August and the Polar Bear Jump-Off Festival in ,January.
Seward All Hazard Mitigation Plan-`--Y -6 — -- � � March 23, 2004 —
Revise.l,Apri 12,20 10
Po ulafion and Econom
In 2009, the [department of Community and Economic Development certified Seward's
pops}lation at 2,619 people. Seward is incorporated as a home rule city.
As the southern terminus for the Alaska Railroad and road link to Anchorage and the
Interior, Seward has long been a transportation center. The economy has diversified with
tourism, commercial fishing and processing, ship services and repairs, oil and gas
development, a coal export facility for Usibelli Mine, Alaska Vocational Technical Center
(AVTFC), the Spring Creek Correctional Center, and the University of Alaska's Institute of
Marine Sciences. The Alaska SeaLife Center, the Kenai Fjords National Park and the Mt.
Marathon Race during the Fourth of July festivities attract visitors. Over 320,000 cruise ship
passengers visit Seward annually. Approximately seventy- five residents of Seward hold
commercial fishing permits.
Facilities
Water, is supplied by nine wells, is treated and distributed throughout Seward. Sewer is
collected via pipes to a secondary treatment lagoon. Almost all homes are connected to the
city systems. Refuse collection is provided by the city under contract; the Borough provides
solid waste disposal. The Kenai Peninsula Borough refuse transfer facility is located on
Dimond Boulevard.
Seward Public Utility purchases power from Chugach Elecaria Association for day to day
operations, and owns six emergency standby diesel generators.
Harbor facilities include approximately 4000 linear feet of moorage and space for up to 650
vessels.
Seward Providence Medical Care Center is licensed to admit and care for up to six in-
patients. The Long Term Care Facility, Seward Mountain Maven is licensed to admit and
care for up to forty patients.
Fire/rescue resources include Seward's primary facility, Seward Fire Department located at
316 0' Avenue in downtown Seward and one satellite station located at mile 6.5 Nash
Road in the Seward Marine Industrial Center basin; area.
Transportation
Seward is connected to the Alaska Highway system by the Seward Highway. Bus and
commercial trucking services to and from Anchorage are available daily. Air services and
charters are available at the State-owned airport. Two ;paved runways are utilized, at 4,240
and 2,300 feet. The port serves cruise ships, cargo barges and ocean freighters from
Seatfle and overseas. The small boat harbor has two launch ramps. slips for 650 vessels
and approximately 4,000 linear feet of moorage for transient vessels. The Alaska Railroad
provides aver -1.4 billion pounds of cargo transit each year, impotling cargo for the A-iaskan
Interior and exporting coal to the Pacific Rim. Seasonal passenger transportation is
available by rail and highway.
Seward A11 Hazard Mitigation Plan - -7- v-'-�-Y-Y-- ;March 23, 2004
Revised,April 12,2010
Chapter 2 -- Hazard Identification
The Alaska Division of Hotneland Security and Emergency Management is in the process
of preparing a Hazard Mitigation Plan for the state. The following hazard matrix was
modified from that plan for the Seward area.
Hazard Matrix — Seward Census Area
Earth- Snow Land-
Fleod�wildfire sake Volcano Avalanche Tsunami Weather Slides Erosion Drou ht Tech Economic
orohabi!it Y-H Y-L Y—H U Y I Y Y Y ! Y I N y
Extent L L T Z L L T L T f Z T T
Previous i---- --I----
i Occurrence Y Y Y Y I Y Y I Y Y
Y
Probabiiity-
Y= Hazard is present in jurisdiction but probability unknown
Y-L= Hazard is present with a low probability of occurrence
Y -H = Hazard is present with a high probability of occurrence
N = Hazard is not present
U = Unknown if the hazard occurs in the jurisdiction
Extent; Previous QCCUrrP!1Ct?
Z= Zero Y = Yes
L= Limited N = No
T=Total or extensive
Seward All Hazard Mitigation Plan ----- 8 - March 23, 2004
Revised,April 12,2010
The following sections are explanations of hazards that are present in the City of Seward.
Flood
Definition
Riverine: Periodic over bank flow of rivers and streams.
Flash: Quickly rising small streams after heavy rain or rapid snow melt.
Urban: Overflow of storm sewer system usually due to poor drainage following
heavy rain or rapid snowmelt.
Tidal/Storm: Surge and wave runup, higher than normal tidal range and higher
inshore wave run-up due to storm effects in coastal areas.
The Fast Zone of the Kenai Peninsula Borough is at risk to flooding from heavy rains;
spring ice jams and rapid snow melt; tidal storm surges and coastal wave run-up, glacial
damming and glacial outburst flooding, and special geologic conditions. high flows can
occur during any season, but are most common as a result of rapid snowmelt in the spring
or intense precipitation during the summer and fall. In the East Zone, flooding hazards are
compounded by steeply sloped, unstable mountain streams.
In Seward, development is occurring on alluvial fans and deltas which have been deposited
by these steep drainages. The hazards associated within the area were demonstrated in
major flood occurrences in October of 1986, August 1989, September 1995, October and
November 2001, October 2006 and December 2009. Flooding in Seward and the
surrounding area has resulted in repeated disruption of vital services such as water, sewer,
power, and transportation routes; damage to roadways, bridges, flood control structures
(dikes, weirs), buildings, port and harbor facilities, airport facilities, railroad facilities, utilities
and communications systems and in addition natural/environmental emergencies such as
landslides.
Seward Area Drainages:
Spruce Creek surge-releaseldebrs
Lowell Creek surge-release/debrls
Japanese Creek surge-release/debris
Resurrection River seasonal
Glacler/Salmon Creek seasonal
Sawmill Creek surge-release/debris
Godwin Greek surge-release/debris
4th of July Creek surge-release/debris
Lost Creek surge-releaseldebris
Debris and surge-release flooding will continue to be a problem, in the Seward area.
according to the 1994 Resurrection River Reconnaissance Report, the US Army Corps of
Engineers stated that the 1986 and 1995 storms lef, the steep drainages even less stable
and more prone to landslides and avalanches in future storms. In addition, stream channels
tend to migrate unpredictably across the alluvial fans as deposition ocCUrs. Consequently,
snapping flood hazard areas on these fans is difficult and unreliable,
Sew.drd All Hazard Mitigation Plan .9 _---March 23, 2004
Revised,April 12,20 10
In 2003, residents of Seward, Bear Creek and Lowell Point established a flood-service area
board, the Seward/Bear Creek Flood Service Area (SBCFA). This board's duties are to
provide flood protection, planning and mitigation services, as well as developing,
implementing and updating a development plan for furnishing flood protection services. The
board will develop criteria for determining service area involvement in future flood control
projects, and coordinate with the City of Seward to ensure there is neither duplication nor
contradiction in the flood control projects or services provided.
The SBCFSA Flood Hazard Mitigation Plan was originally published July 2005 and updated
November 2007.
The October 2006 flood event resulted in federal disaster declaration as residents were
evacuated, highways and roads flooded, levees damaged and critical infrastructure
damaged, The December 2009 high water event and storm surge resulted in a state
disaster declaration as critical waterfront infrastructure was damaged including the wave
barrier along Lowell Point Road, the Seward Green belt area and the seawall at the Alaska
SeaLife Center.
Earthquake
Definition: Sudden motion of the earth's surface, faulting, and ground failure.
Coastal Alaska is within the pacific subduction zone. Subduction zones are areas where
one tectonic plate plunges beneath another. Earthquakes cluster at the edge of the
plunging plate, and its path into the mantle can be traced by the location of the
earthquakes. The "ring of fire" around the Pacific is a giant earthquake zone, and coincides
with a ring of subduction zones that produces the world's deepest trenches, such as the
36,000 foot deep Marianas Trench. it is striking evidence for the existence of these zones.
An example of a subduction-zone plate bou^dart' is found along the northwest coast of the
United States, western Canada, and :southern Alaska and the Aleutian Islands. Subduction
zones are characterized by deep-ocean trenches, shallow to deep earthquakes,, and
mountain ranges containing active volcanoes. Seward is located on this subduction zone.
Seward's earthquake risk may be better explained by using the matrix prepared by the
Alaska Division of Homeland Security and Emergency Management
(ADHS&EM) designates Seward as a jurisdiction that has a high probability of an
earthquake. Seward is designated as having a zone 4 risk. Earthquakes can trigger
secondary hazards including fires, fuel spills, landslides, avalanches, tsunamis, uplift,
subsidence, infrastructure failures and soil liquefaction.
Tsunami Hazard
Tsunamis are ocean waves that are generally triggered by vertical motlor; !�,,f the sea floor
during major earthquakes. Near ocean or undersea landslides or volcanic eruptions can
also generate tsunamis. They can be generated locally or a great distance from where they
landfall. Tsunamis have historically caused significant damage to coastal Gummunitizs
Seward AN Hazard Mitigation Plan � T -10-_�� March 23, 2034
Revised,Apri! 12,2010
throughout the world. As the tsunami crosses the deep ocean, its length from crest to crest
may be a hundred miles or more, and its height from crest to trough will only be a few feet
or less. They can not be felt aboard ships nor can they be seen from the air in the open
ocean. In the deepest oceans, the waves will reach speeds exceeding 600 miles per hour
(970 krn/hr). When the tsunami enters the shoaling water of coastlines in its path, the
velocity of its waves diminishes and the wave height increases. It is in these shallow waters
that a large tsunami can crest to heights exceeding 100 feet (30 m) and strike with
devastating force.
As a tsunami leaves the deep water of the open sea and travels into the more shallow
waters near the coast, it undergoes a transformation. Since the speed of the tsunami is
related to the water depth, as the depth of the water decreases, the speed of the tsunami
diminishes. The change of total energy of the tsunami remains constant, Therefore, the
speed of the tsunami decreases as it enters shallower water, and the height of the wave
grows. Because of this "shoaling" effect, a tsunami that was imperceptible in deep water
may grow to be several feet or more in height. When a tsunami finally reaches the shore, it
may appear as a rapidly rising or falling tide, a series of breaking waves, or even a bore.
Reefs, bays, entrances to rivers, undersea features and the slope of the beach all help to
modify the tsunami as it approaches the shore.
Earthquake or other seismic activities near Seward can cause a tsunarn. i to occur in
Resurrection Bay as was the case In 1964. Due to the frequency of earthquakes within
Alaska and the ocean topography of Resurrection Bay, there is a significant threat that a
tsunami will occur again.
Shoreline Erosion
Definition: Storm 'induced waves and flooding cause the destructive erosion of the coastal
areas.
From the fall through the spring, large low pressure systems that develop in the Gulf of
Alaska and systems that are brought to the region by winds in the upper atmosphere steer
massive storms in the North pacific Ocean toward Alaska. When these storms impact the
shoreline, they often brng wide swathes of high winds and rain, occasionally causing
coastal flooding and erosion.
The intensity, location and the land's topography influence the storm's impact. Another
factor that influences the damage done to the shoreline by coastal storms is the amount of
rain associated with the system. Fierce storm conditions do not have to be present to cause
damage.
Coastal shoreline erosion is a continuing problem within the City of Seward along the
waterfront campground and near the Seward Marine Industrial Center. Weather conditions
.make shoreline erosion an ongoing threat to the city,
Savvwd All hazard Mitfgatron P'.an �----- i 1Wrch 23, 2004
Revised,Ap!il 12,?010
Erosion to the beaches caused by storms or high winds are an ongoing hazard in the City
of Seward. The December 2009 storm surge with high water event caused extensive
damage to the wave barrier along Lowell Point Road, the Seward v^reen belt area and the
seawall at the Alaska Seal_ife Center. Lowell Point Road is the only access for Kenai
Peninsula Borough Citizens living in that community, access for State and Federal Parks
and a key sewer and electric utility corridor for Seward. Other wave action and coastal
flooding also causes damage to the shoreline. Use of Resurrection Bay by recreational
boaters, is a source of wave action which will continue to be a problem even without
significant storms. City of Seward has taken steps to minimize the impacts of erosion on
the beaches with the addition of rock walls, culverts and channels; but additional measures
are necessary.
Coastal erosion regularly threatens significant assets including the City owned bike path,
Playgrounds, park, RV sights landmarks and the Alaska Sea Life Center,
Wildfire
Wildfires that were reviewed are:
Wildland fire
Urban Interface fire
Firestorms
Wildfires do not present a major threat to people or property because of the coastal
weather conditions in the Seward area. Urban Interface Fire risk changes, as more
development occurs, placing people and property at a higher risk due to accidental and
man made fires.
The fire risk has also been increasing in recent years due to the spruce bark beetle
infestation. The dead trees are very -dry and therefore highly combustible. This will
present an even bigger probiem in the coming years as the trees start to fall, littering the
forest floor with flammable material.
Volcanoes
Alaska is the home to more than 80 major volcanic centers. In general, there are one or two
eruptions a year. Over half of the state's population lives within 100 miles of an active
volcano.
The single greatest hazard from an explosive volcanic eruption is ash, fine fragments of
rock blown into the atmosphere during volcanic eruption.
Lahars, lava and tsunami generating landslides are also potential hazards during a volcanic
eruption.
Seward Ali Hazard Mitigation Plan -12- vJ March 23. 2004
Revisr,d.Api{i 12.2o!a
Avalanches
An avalanche is a slope failure consisting of a mass of fluidized snow sliding down a
hillside. The damage caused by an avalanche varies based on the avalanche type, the
consistency and composition of the avalanche flow, the flow's force and velocity, as well as
the avalanche path. Avalanches usually occur on slopes between 25 and 50 degrees, with
most starting between 30 and 40 degrees. They can be triggered by both natural and
human factors.
There is growing exposure to this hazard as development continues to occur in avalanche
prone areas and participation in winter recreational activities increases.
Winter Weather
Winter weather includes heavy snows such as blizzards, ice storms and extreme cold.
Heavy snows can bring she community to a standstill by inhibiting transportation, knocking
down trees and utility lines, and by causing structural collapses in buildings not designed to
withstand the weight of the snow. The cost of repairs and snow removal can be significant.
Ice buildup can bring down utility and communication lines as well as malting transportation
diffiCult.
Extreme cold causes fuel to congeal in storage tanks and supply lines stopping fuel flow to
residential furnaces. Without heat water and sewer pipes can freeze and pipes can
rupture. Alternate heating sources can cause their own set of problems, from accidental
fires and illness from carbon monoxide in the home. Extreme cold can also increase the
likelihood of ice Jams and flooding.
Landslide
Landslide refers to "the downward and outward movement of slope forming materials
reacting under the force of gravity." The materials are usually natural soil, rock, artificial fill
or a combination of those items. The term covers a range of events including mudflows,
mudslides, rock flows, rockslides, debris flows, debris avalanches, debris slides and earth
flows.
Geology, precipitation, topography and cut and fill construction practices all influence
landslide activity. They are often the result of heavy precipitation, coastal storms, flooding,
vc1canic eruption, construction work or seismic activity.
One of the costliest landslide events ever experienced in the United Stakes was associated
with the 1964 Good Friday earthquake. Approximately 60 percent of the total damage
caused by the earthquake was due to landslides. This was part of the equation for the
tsunami damage in Seward.
SeGvard A.I Hazard Mitigation Plan e -13- Mar& 23, 2004. .�
Revised.Aord 12, 2010
Drought
Droughts are fairly rare in Seward. A drought is commonly defined as a period of time of
very low precipitation. Drought severity depends on duration, intensity and geographic
extent as well as the demand on the water supply.
Seward experiences periods without rain, and the forests and grasslands become
extremely dry, increasing the probability of Urban Interface fires.
Economic
r omit
A large section of the Alaskan economy is resource based. When the resources generate
insufficient revenue, due to lack of the resource availability, poor prices or other conditions,
an economic disaster may be the result. Economic disaster consequences usually affect a
wide geographic area. Some of the resources that could lead to disasters if their
availability becomes limited include fish, lumber and coal. Seward is a tourist destination for-
cruise ships, road and rail. The visitor decline would have a major impact on the economic
wellbeing of Seward.
Interactive Ai y ure of Hazards
A hazard cannot be treated in isolation, as there are inter-relation between the hazard
agents. Frequently one hazard event triggers another. For example, a coastal storm will
often trigger food and landslides. Or a wildfire could increase erosions and flooding risks.
As a result, all possible consequences of a hazard need to be considered when deciding
the most appropriate mitigation actions. it is also important to consider all the hazards that
could occur in an area when decided which mitigation activities to undertake. Some
mitigation measures could worsen the effects from the hazards such as allov0ng economic
development in areas susceptible to tsunamis or landslides.
Seward All Hazard Kltigatbr, Plan � -14- March 23, 2004
Rovised,Apo: 12,2010
Chapter 3 -- historical Hazards in Seward
History of Flooding in Seward
In 1986, over 15 inches of rain fell in a 36 hour period; saturating the steep slopes and
causing severe erosion. In some areas, landslides and avalanches dammed stream
channels, eventually causing a "surge-release" of floodwaters and debris when the dam
failed. This material, which included boulders as large as 8-feet in diameter, caused
extensive damage to buildings and facilities located downstream on the alluvial fans.
In August 1989 and September 1995, only active channel work kept Japanese Creek from
changing course and charging through the western edge of Forest Acres Subdivision.
Workers kept it within the channel. Creek waters joined Resurrection River to flood
southerly along the Seward Highway embankment into the undeveloped Forest Acres and
Fort Raymond area. Water moved across the highway and moved toward the Port Avenue
section of the small boat Harbor. Part of the Seward Fisheries Meal Plant and the north
boat launch facility in the harbor were destroyed by the rapid water movement. The City of
Seward has worked with the Kenai Peninsula 8orOUgh to implement the Resurrection
River/Japanese Creek flood mitigation work. The work in the Resurrection River delta was
completed in 1999 and some maintenance work was done in July 2000. The construction
for the initial phase of the Japanese Creep Levee was completed during the summer of
2001.
Currently, the City of Seward has completed the permitting process for the second phase of
the project, has completed the Japanese Creek relocation and, by the time of this plan's
approval, will have completed all the property acquisitions. The second phase of the
project vAll extend the lever:/read to the Seward Highway. Construction of the levee and
relocation of utilities is planned to begin in 2010. (please see maps below and attached)
lr!a,Ye,�Istn
.fit t
TkOi Fowl Acru :lDffi1rs
IsvAS'-ikr.
usouo: aswla:
c. ux
l..e+trlroa+!Psotp:iol i ��tiaen�a9��nzn.
---' Appoxlrll3 I ca.yt&Ys ad I*A-(Olig FEMA) / 4
.•^•. Pru�nuldrroek,eol±pnleertf—'��fl) �
P�¢n�y Bulildbnc� r i
uc:-c
lfwvadlieiJi>w Propmd Noeth broil Acrt L*YoU'Rogd , l.sv"d0d.5to Reba hl jecc
iy.,aRl,AYaka I
USC$Crairl3ons,d(A•7) . _ S.'ix[V trF* r
01,4r3._A I:N v,aq,ak,�a tm Ifr
F�80. 1670U7
SiGli I`»SqQ' a. vO..A 4yidi Ww
Rir..}cn Ob�,n,Wx.mJ'�+w tlp.;r
Seward All F1a?B±C MitigationPlan °sar,.h 23, 2004
Revised,April�2,2010
A major area of flood concern in the city involves the Lowell Creek Flood Control Project.
This project, built in 1940, diverts Lowell Creek away fron the city through a tunnel in Bear
Mountain and into ResurreO,on Bay. During floods, Lowell Creek can reach high velocities
and carry boulders and debris weighing several tons. Blockage of the tunnel would cause
flood flow to go over the spillway and flow through the middle of the city. Due to the age of
the tunnel and the potential for catastrophic failure from debris blockage, the tunnel has
been determined to be inadequate and unsafe_ Many repairs of the tunnel have taken place
throughout the years beginning in 1945, with additional emergency repairs in 1984, 1988,
and 1991. More recently an overhaul of the tunnel occurred in the winter of 2002-2003.
The US Army Corps of Engineers and subcontractors were responsible for tunnel work
including a lining of high strength concrete on the floor and replacement of some railroad
ties at the entrance for protection. Voids were found beneath the tunnel and were filled
during this project period.
During the 1995 and 2001 flood event, sediment and rock that flowed out of Lowell Creek
washed away riprap and a portion of the bridge at the waterfall which eroded the water
main and sewer line.
The flooding event in October 2006 was caused by the combination of high tides, warm
temperatures and the remnants of a typhoon stalled over south central Alaska caused 9 to
15 inches of rain to fall on the Seward area. The heavy rains contributed to the closing of
the Seward Highway at Mile 4, portions of the airport were flooded and residents from
outlying areas were evacuated from their homes. The outflow from the Lowell Creek
diversion tunnel dumped a 25 foot pile of debris and gravel on the bridge, severed the only
road to residents living at Lowell Point and threatened water main and sewer lines. Several
levees were damaged and approximately 200,000 cubic yards of bed load was deposited in
Japanese Creek severely constraining the levee's ability to contain flood waters,
The Alaska District of the U-S_ Army Corns of Engineers assumed long-term maintenance
and repair responsibility of the tunnel, inlet and outlet structures, until completion of
construction of an alternative method of flood diversion or until November 8, 2022. The
City of Seward continues to work with our congressional delegation to insure this project iS
funded.
History of Earthquake and Tsunami Events in Seward
On Good Friday; March 27, 1964, North America's strongest recorded earthquake, with a
moment magnitude of 9.2, rocked central Alaska. Large areas were lifted up or dropped by
several feet, landslides were extensive, ground failure led to large fissures in the ground,
landslides into bays caused huge seiche waves locally and a tsunami caused damage
thousands of miles away. The result in Seward was disastrous to the town, waterfront,
boats and railroad. An estimated $14 million in damage occurred. An entire section of the
waterfront slid into Resurrection Bay.
Sewa,d Ail Hazard Mitigatiun Plan -16- ~March 23, 2004
Revised,April 12,2010
During the 1964 earthquake, landslides into bays near Valdez and Seward sent 35 foot
waves sloshing back and forth like water in a bathtub. In Seward, an oil tanker was
wrenched Loose from a pipeline, which erupted in flames, spreading to the nearby oil tanks.
Burning oil on the water washed inland. Ships were battered against piers and washed
ashore. Warning time can be limited when the tsunami is triggered close to the impacted
coastline. In Seward, a 1070 meter section of the waterfront slid into the Resurrection Bay
due to the earthquake shaking. This generated a local tsunami causing much damage. Oil
from storage tanks was spread on to the water and ignited. About 20 minutes later, the first
wave of the main tsunami hit. The 11-13 fatalities in Seward were due to the local and the
main tsunamis.
History of Erosion In Seward
Coastal erosion is an ongoing problem for the City of Seward. Areas most seriously
affected by shoreline erosion include Lowell Paint Road, Alaska SeaLife Center Lease site.
Waterfront Park south to the waterfall and the Seward Marine Industrial Center (SMIG).
Emeraency erosion control efforts by the City of Seward include the shoreline at the
waterfront camping area and within the Seward Marine Industrial Center. In recent years,
the city has replaced riprap along Lowell Point Road in a number of different locations to
maintain the protection of the city sewer line.
The December 2009 storm surge event with high water caused extensive erosion and
damage to the wave barrier alone Lowell Point Road, the Seward Green belt or water front
park area and the seawall at the Alaska Seal ife Center.
Seward Ai! Hazard Mi?iga;'ron Plan --�-�- March 23, 2044 —
RevIsedL APO 12,2010
Chapter 4 — Hazards in Seward
The goal of mitigation is to reduce the future impacts of a hazard including property
damage, disruption to local and regional economies, and the amount of public and private
funds spent to assist with recovery, However, mitigation should be based on risk
assessment.
A risk assessment predicts the potential loss from a hazard event by assessing the
vulnerability of buildings, infrastructure and people_ It identifies the characteristics and
Potential consequences of hazards, how much of the community could be affected by a
hazard, and the impact on community assets.
A risk assessment consists of three components: hazard identification, vulnerability
analysis and risk analysis. Hazard identification will attempt to identify known hazards
within the community. Vulnerability analysis will show how each hazard may have an
impact an the community. Risk analysis will show what frequency and what damage from
identified hazard may impact the community.
The following annexes descritpe hazards that may occur in the City of Seward. i he
hazards are broken into annex sections, which when appropriate, identify the hazard,
assess vulnerability, risk; mitigation goals and potential projects. Due to time constraints,
hazards that are not identified as a significant risk to the City of Seward are included but
given less comprehensive attention.
Annex A - Floods
A. Hazard Assessment
Step one is to identify the hazard. As outlined in Chapter 2 of this plan, flooding in the City
of Seward occurs primarily as a result of heavy rains and the effects of being built on the
alluvial fans of Resurrectinn River and Lowell Creek.
B. Vulnerability Assessment and Impacts
Step two is to identify the jurisdiction's vulnerability (the people and property that are likely
to be affected). Inventorying the jurisdiction's assets to determine the number of buildings,
their value, and population in hazard areas can also help determine vulnerability,
identifying hazard prone critical facilities is vital because they are necessary during the
response and recovery activities.
Major rain events in the past have shown that the Seward area is prone to flooding by
many factors, including swelling of water ways, surge-debris release and the damming
effects caused by erosion of the steep banks of the surrounding mountains, rapid snow
melt and to some degree, storm surge, The 'City of Seward remains vulnerable due to its
being built on an alluvial fan. The Lowell Greek Tunnel Project is an example of mitigation
Seward All Hazard Mitigation Flan �w~ -18- YY March 23, 2004
Revi3.-d,n.ardi 2,2NO
planning for the City of Seward_ In 1992, a report on flood damage reduction was created
by the US Army Corps of Engineers. In this report, the Corps determined that the tunnel
has deteriorated due to debris abrasion. The rails used to armor the tunnels floor had been
torn out and floor has eroded to the bedrock. The report: states the tunnel has been
determined to be vulnerable to blockage and possible collapse. They also determined that
the tunnel is deteriorating faster than it could be repaired. Blockage of the tunnel by lining
failure, debris and/or landslides would cause flood flow to go over the spillway. Water and
debris would flow through the heart of the city. Homes, senior citizen apartments, medical
and dental clinics, and the hospital are situated in the Lowell Creek Canyon just below the
diversion dike. According to the 1992 US Army Corps of Engineers report, the flood control
project is considered unsafe and inadequate. The most recent repair work was done during
the winter of 2002-2003, in which the Corps replaced the floor, rails and part of the eroded
bedrock voids. These repairs should control the erosion problem for a number of years but
this will be an ongoing project. The 2008 Water Resources and Development Act (WRDA)
returned the Lowell Creek diversion tunnel to the US Army Corps of Engineers
management and authorized a project to correct current deficiencies.
Resurrection River is another area prone to flood damage. In 1994, the US Army Corps of
Engineers did a reconnaissance report on prevention of flood damage for the Seward Area
Rivers, In this report, all the watersheds entering the upper Resurrection River were
examined and it was determined that rapid sedimentation in the Resurrection River channel
places much of the development adjacent to the river in danger of flood damage. A
significant concern of possible flood damage is the Seward Highway bridge crossings.
During the 1995 flood event, limter crossed the hlghway at or near these crossings. In
1999, 150,000 cubic yards of debris, woody material, gravel, sand and silt was removed
from Resurrection River approximately 2000 feet downstream from the center Seward
Highway Bridge. The desired effect of the work was to alleviate backwater conditions
eliminating potential flooding. Along with this project, the city replaced the culverts of the
lagoon outflow at 4tr. Avenue. Recent improvements to the Seward Highway and Alaska
Railroad bridges include the installation of clear span bridges across the Resurrection
River.
In 1996, the City of Seward developed a mitigation plan for flood hazards in the city.
Flooding mitigation and recommendations have been done for Spruce Creek, Lowell Greek,
Rudolph Crook, Japanese Creek, Resurrection River Basin, Sawmill Creek and Fourth of
July Creek. That plan is available at the City of Seward Community Development office.
The Kenai Peninsula Borough Flood Mitigation Flan also includes Seward and areas north
of the city and is available through the borough office. In 2003 the Kenai Borough adopted
Ordinance 2003-30 establishing the Seward/Bear Creek Flood Service Area (33BCFA),
Section 16.50.090 of the Kenai Peninsula Code defines the SBCFSA Board of Directors
powers and duties, which include responsibility for developing, implementing and updating
a plan for furnishing flood protection, planning and mitigation ser�fices. The SBCFSA Flood
Hazard Mitigation Plan was originally published July 2005 and updated November 2007.
Risk analysis is the final level of hazard assessment. It involves estimating the damage
and costs likely to be experienced in a geographic area over a period of tirne. Risk has two
measurable components.- (1) the magnitude of the harm that may result (defined through
Seward All Hazard Mitigation Play -1�_ Mlarwh 23, 2004
Revised,April 12,2010
the vulnerability assessment); and (2) the likelihood or probability of the harm occurring
tmultiple flooding scenarios).
The magnitude of the flooding in Seward has been historically high, Debi-is and surge-
release flooding will continue to be a problem due to the topography and traditional weather
patterns of the area. Risk depends on the degree of flooding and can include disruption of
services, transportation routes, and communication systems. According to the FEMA FIRM
maps, if there was a 100 year flood event, the estimated borough assessed values of
structures within the flood affected area is in excess of $21,000,000. These structures
include residential buildings, commercial buildings and public facilities. In 1986, estimated
recovery costs for the City of Seward were projected at $2.2 million. The 1995 flood had
estimated repairs to just city property was $147,700.
In Seward, there are flood warning systems which give community residents' an organized
notification of impending florid danger. The National Weather Service 'NWS) provides flood
I
orecast and warning data utilized by many communities that have local warning systems.
National Flood Insurance Pro rams rNFIK
The function of NFIP is to provide flood insurance to homes and businesses located in
floodpiains at a reasonable cost, and to encourage the location of new deveiopimfent away
from the floodplain. The program is based upon mapping areas of flood risk, and requiring
local implementation to reduce that risk, primarily through guidance of new development in
floodpiains.
The City of Seward uses Flood Insurance Rate Maps (FIRM), effective May 19, 1981, and
codified the Flood Plain Mitigation Plan in October 1999, to depict areas of flooding within
the city limits. The FIRM depicts the flood plain as determined by FEMA.
Detaiis of the NFIP can he found at http'/iw�% foma.Qov/dos/libraryfr�fpd2-scri.p.doc.
The 1981 Flood insurance Rate Maps are outdated and are in need of updating to address
the following items,
1981 reaps need to be reevaluated with the 29 years of additional data.
Corrections may need to be made for areas where fill or naturally high around is now
shown as flood prone but may not be in jeopardy of flooding.
In 2010, FEMA will update its FIRM maps for time City of Seward. The estimated date for
release of the draft maps is March 30, 2010. Draft hard copy reaps will be released for
public, review, and once public meetings are held by FEMA and public comment is
obtained, final maps and digital shapefiles will be available in 2011.
The City of Seward Community Development Office is available for estirriatf s of the
number and assessed values of structures located within the areas identifies; on the FIRM.
Seward All Hazard hrritigabon Piar, -20- March 233, 2004
Revised,AprA 12,20?0
To deal with problems of flooding at the Seward Airport, the State of Alaska Department of
Transportation and Public Facilities published the Seward Airport Master Plan and
environmental assessment in July 2008.
The City of Seward and the US Army Corps of Engineers have made substantial progress
in prevention of flooding in Seward. The Lowell Creek Tunnel Project completed in 1940,
diverts the waters of Lowell Creek away from the city through Bear Mountain and into
Resurrection Bay. The Japanese Creek Levee Project completed in 2001, keeps flood
waters from entering the Forest Acres Subdivision and crossing the highway. These
projects, as well as the Resurrection River dredging project, currently reduce the risk of
major flooding within the city.
C. Mitigation Measures
This section of Annex A addresses flood mitigation goals for the City of Seward with
potential projects to achieve these goals.
Goal 1: Identify hazard areas and select mitigation measures for those ;areas
Goa! 2: Increase public awareness of hazards
Goal 3: Enact mitigation measures
This first goal is to identify the flood hazard areas and mitigation measures that will better
protect individual and commercial property owners within the City of Seward. On going
mitigation measures include:
• Floodplain development permits to include elevation certificates and data
Request base sea level and flood elevations from builders on proposed projects
• Provide maps of flood hazard areas, in digital and hard copy
m Update as required city code floodplain management ordinance
a Update the Seward Flood Hazard Mitigation Flan, 1996, this was subsequently
replaced by the Seward/Bear Creek Flood Service Area Flood Hazard Mitigation
Plan, Originally published July 2005 and updated in November 2007.
• Update the Seward Flood Hazard Mitigation Plan, 1996
• integrating Flood Hazard Mitigation strategies into the Seward 2010 Comprehensive
Plan, 1990
• Include flood issues in the Seward Strategic Plan, 1999
• Provide FEMA Public Outreach Floodplain information booklets
• Staff coordination. with SBCFSA, KPB, State of Alaska, and Federal Floodplain
managers on flood issues within the City of Seward.
: Building Permits; insuring the adopted building codes address flood issues
• Continue working with the Seward Bear Creek Fiend Service Area Advisory Board to
update the working mitigation plan.
• Advising the US Army Corps of Engineers of conditions concerning the Lowell Creek
Tunnel Project including renovating the tunnel and developing a new outfall,
Maintain and extend the Japanese Creek Levee.
S,a°,yard Al! Hazard Mitigation f'iar,� — '-21, March 23, 1004
Revised,Aprit 12,2010
• Remove excess bed load accumulation in Seward's rivers and creeks.
• pitch, drainage, sea wall and culvert construction, coordinated to help ensure the
safe, flood free drainage even during potential storm events.
Potential Projects:
• Acquire land within the city to develop a usable secondary evacuation route that
bypasses the Seward lagoon and boat harbor areas. Provide barriers to this route
and designate it as a recreational trail for use outside of emergency access.
(Planning and Zoning Commission, May 6, 2004)
• Complete the Two Lakes Park Replat and the joint use access agreements providing
the secondary evacuation route.
• Update Flood Insurance Rate Maps: the 1981 maps need to be reevaluated with 29
years of additional data. Evaluate additional programs that address Seward`s unique
alluvial fare flood problem.
• The City of Seward should continue improving its NFIP Community Rating System,
under the Federal insurance Administration's Community Rating System (CRS) by
exceeding the required standards to obtain further flood insurance premium
reductions for poliwyholders within communities while simultaneously reducing flood
losses.
North Forest Acres Levee and Access Road Project. Phase 2 of this project has
begun to protect the North Forest Acres Subdivision and other areas of the City of
Seward from recurrent flood damage by constructing a levee along the lower portion
of Japanese Creek. Flood-proofing existing structures: Improving existing structures
to make them less susceptible to flood damage could be a viable project for many of
the historic buildinas or non-elevated structures.
• The below was completed in 2009 with the help of the Kenai Watershed Forum.
Dai,2Z Hill Drainage Improvements: Upsize culverts and improve haphazard
drainage in the Dairy Hill Area. During heavy rainfall events, the flows in tho
drainages can become severe and cause washouts of roadways, culverts and
building improvements. An HIVIGP grant application was submitted in 4010 in the
amount of$339,387.00,
• Replace the Dairy Hill Road/ Seward Lagoon culverts with larger culverts. During
flood events, the existing culverts cannot divert enough water to prevent flooding of
the road.
• Conduct a structural assessment of the 4rh of July Creek dike. A failure of the
existing dike would cause damage to infrastructure of the city water supply and
Spring Creek Correctional Center.
• Coordinate with the US Army Corps of Engineers as they develop a project to
upgrade, replace or find an alternative to the Lowell Creek diversion tunnel and it's
resulting out-flow sediment build up
Japp Creek Investigation to evaluate the flaw capacity of they existing flood control
corridor; to determine sedimentation trends/rates, and to utilize this information to
develop a long terrn maintenance strategy and funding plan io preserve the system.
Seward All Hazard Mitigation Piar. --- -22- ��_— Pasch 23, 2004
Revised,lApri!12,2010
• Fourth of July Creek investigation to evaluate the flow capacity of the existing flood
control corridor, to determine sedimentation trends/rates, and to utilize this
information to develop a long term maintenance strategy and funding plan to
preserve the system.
• Spruce Creek evaluate the flow capacity of the flood control corridor and determine
sedimentation rates. Use this information to develop a plan to preserve the flood
control corridor and to create a long term maintenance strategy and funding plan.
• A geomorphic investigation should be conducted of Scheffler Creek to determine the
size, frequency, and potential deposition characteristics of future debris flows.
• Consider lard use code regulation changes to more effectively guide development
and floodplain use. Evaluate certain areas for additional preventative measures. The
city subdivision regulations which govern the division of land for sale or development
should include floodplain regulations. The floodplain regulations should be
incorporated into the Alaska Coastal Management Program (ACMP) and the Seward
Comprehensive flan.
• Support a U.S. Army Engineer District, Alaska needs Assessment this fall to
consider needs throughout the greater Seward watershed area. Alternative, the City
could proceed ahead to request our Congressional delegation to establish earmarks
of$100K for our preliminary assessments.
Goal two is to increase public. awareness. This could be accomplished by the following
measures.
• Information Dissemination: The purpose of information dissemination is to provide
the community residents with knowledge about the flood hazards in their
neighborhoods and possible activities for mitigation. A variety of agencies can
participate in information dissemination. Manuals are available through the City of
Seward Clerks Office, Community Development Office and at the Seward
Community library.
Outreach Projects: The City continues to provide flood information and technicai assistance
to Current and prospective residents and business owners, The City will schedule
training/info sessions for local realtors, contactors and lending institutions. Real estate
disclosure: Alaska State Statute 34-70 requires a seller to disclose flood hazard on
residential properties.
• Risk Analysis: With advances made in Geographic Informatio+n System ('"'IS)
technology, it is becoming increasingly easy to analyze the risk of various flood
events. This analysis, of course, depends on the availability of data relating to
building location and value and flood recurrence. Performing multiple risk analyses
helps to increase public understanding of a coastal or river flood potential. Often,
risk is understood only at the "100-year" level, because this farms the basis for Flood
Insurance Rate Maps, The "100-year" flood means a flood level having a .i%
chance of being equaled or exceed annually. If information is collected and
reviewed, the possibility of predicting what areas may be impacted during a 5, -110, 15
year cycle.
Seward All Hazard Mitigation Piart � -23 ._------March 23, 2004
Revised.April 12,2010
Potential Projects:
• Continue distributing the brochure describing the City/ of Seward food dangers and
fioodpiain building regulations.
• Continue working with FEMA and other Federal and State Agencies as the Flood
Insurance Rate Maps (FIRMS) are updated and researching other tools for
accurately forecasting and mitigating Seward's complex alluvial fan flood problem,
• Continue working with FEMA to obtain the latest National Flood Insurance Program
information and scheduling workshops.
• Provide floodplain regulations information, updates or revisions to the citizens of
Seward.
Continue coordination with FEMA to conduct flood proofing or elevating workshops
for the City and public.
Continue the City's efforts working with potential partners or agencies while
capitalizing on multiple funding sources for mitigation projects, including erosion and
sediment control projects.
• Continue refining the education and outreach programs to notify current
homeowners and potential homebuyers about flood hazard risks in identified areas,
• Provide local realtors and lending institutions with GIS copies of FIRM as they are
updated.
• Complete North Forest Acres Levee and Access Road Proje..t.
Complete Dairy !-Till Road/ Seward Lagoon culvert replacement.
Conduct a structural assessment of the 4fr' of.July Creek dike.
• Obtain ongoing permits for the Lowell Creek outfall sediment and erosion control
program.
• Continue public education concentrating on the SAWS (Siren Aiert and Warning
System.), what it means and what to do in the event of an emergency. Educate the
public on the Emergency Alert Network. (Planning and Zoning Commission May 6,
2004)
• Continue providing new homeowners, builders or renovators a brochure detailing the
fuel tank stand codes helping to insure they're more floodlearthquake prepared
(Planning and Zoning Commission May 6, 2004)
The third goal in the process is to enact mitigation solutions. The City working closely with
the SBCFSA has identified flood mitigation problems and recommended solutions within
their capabilities, which have been through the public process and approved by the City
Council, with some funded and others competing for state or federal funding. Mitigation
problems exceeding the City and SBCFSA capabilities and expertise have been forwarded
to FEMA, US Army Corps of Engineers and other federal and state organizations for their
assistance. Tho City and SBCFSA have agreed or) those, projects that can be funded by
each and included in their budget. Grant requests and other financial sources are being
sought on those that exceed either's capacity, Completion of any project will depend on
the availability of funds and any changes of priority.
Seward All i-lazard Mitigation Plan -24- March 23, 20L14
Revisad,April 12.2010
Annex B - Earthquake
A. Hazard Assessment
Earthquakes are common occurrences in Seward. The threat of a tsunami is dependent on
the magnitude and location of the tectonic activity.
Most large earthquakes are caused by a sudden release of accumulated stresses between
crustal plates that move against each other on the earth's surface, Some earthquakes
occur along faults that lie within these plates. The dangers associated with earthquakes
include ground shaking; surface faulting, ground failures, snow avalanches, seiches and
tsunamis. The extent of damage s dependent on the magnitude of the quake, the geology
of the area, distance from the epicenter and structure design and construction. A main goal
of an earthquake hazard reduction program is to preserve lives through economical
rehabilitation of existing structures and constructing safe new structures.
Ground shaking is due to the three main classes of seismic waves generated by an
earthquake. P (primary) waves are the first ones felt, often as a sharp jolt. S (shear or
secondary) waves are slower and usually have a side to side movement, T hey can be very
damaging because structures are more vulnerable to horizontal than vertical motion.
Surface waves are the slowest, although they can carry the bulk of the energy in a large
earthquake. The damage to buildings depends on how the specific characteristics of each
incoming wave interact with the buildings' height, shape, and construction materials.
Earthquakes are usually measured in terms of their magnitude and intensity. Magnitude is
related to the amount of energy released during an event while intensity refers to the
effects on people and structures at a particular place. Earthquake magnitude is usually
reported according to the standard Richter scale for small to moderate earthquakes. Large
earthquakes, like those that commonly occur in Alaska are reported according to the
moment-magnitude scale because the standard Richter scale does not adequately
represent the energy released by large events.
Intensity is usually reported using the Modified Mercalli Intensity Scale. This scale has 12
categories ranging from not felt to total destruction. Different values can be recorded at
different locations for the same event depending on local circumstances such as distance
from the epicenter or building construction practices. Soil conditions are a major factor in
determining an earthquake's intensity, as unconsolidated fill areas will have more damage
than an area with shallow bedrock.
On the Richter scale, magnitude is expressed in whole numbers and decimals. A 5.0
earthquake is a moderate event, 6.0 characterize a strong event, 7.0 is a major earthquake
and a great earthquake; exceeds 8.0. The: scale is logarithmic and open-ended.
Su;-face faulting is the. differential rnovemerrt of the two sides of a fault. There are three
general types of faulting. Strike-slip faults are where each side of the fault rnoves
Seward All Hazard Mitigation Pian -25- Maroh 23, 2004
Revised,Apri'> 12,2010
horizontally. Normal faults have one side dropping down relative to the other side. Thrust
(reverse) faults have one side moving up and over the fault relative to the other side.
Earthquake-induced ground failure is often the result of liquefaction, which occurs when soil
{usually sand and course silt with high water content) loses strength as a result of the
shaking and acts like a viscous fluid. Liquefaction causes three types of ground failures:
lateral spreads, flow failures, and loss of bearing strength.
On Sunday, November 3, 2002 magnitude 7,9 Denali Fault Earthquake, one of the largest
ever recorded on U.S. soil according to the U.S. Geologic Survey, resulted in no damage in
Seward. On a global level, three of the ten strongest earthquakes ever recorded occurred
in Alaska.
B. Vulnerability Assessment and Impacts
Seward, Alaska is located in the Pacific Subduction Zone In which Oceanic-continental
convergence is taking place. This area is also known as the Ring of Fire or the Pacific Rim
of Fire. it is the place where two tectonic plates are in a very Slow collision. The buildup of
pressure between the tectonic plates determines the degree of earth movement. Such
destruction (recycling) of crust takes place along convergent boundaries where plates are
moving toward each other, and sometimes one plate sinks (is subducted) under another.
The location where sinking of a plate occurs is called a subduction zone (USGS). Volcanic
activity is also high along subduction zones.
The City of Seward is very vi-flne-rable to such earth movements. A risk analysis for the City
of Seward shows significant impact to priority infrastructures and the economy: If the right
conditions occur during an earthquake, a tsunami is also a potential hazard.
u This photo was taken after the 1964
earthquake. It shows the waterfront area where
major devastations occurred from both the
j-' earthquake and the resulting tsunamis.
Photos frog the Earth Science Photographs from the
U.S. [geological Survey Library, by ,Joseph K. McGregor
and earl Abston, U.S. Geological Survey Digital Data
Series DDS-21, 1995.
Impact to the city would be subatantiial if a major earthquake occurred. The history of
Seward during the 1964 earthquake shows that many major problems were eminent,
Depending on the magnitude of the quake; a number of different outcomes could tape
place, Transportation, infrastructure: emergency services, commerce and individual
Property as well as lives wouid be affected by a large quake. in the 2004 plan edition:,
mitigation measures Goal 1; had an objective to obtain land for a secondary evacf.tation
route that bypasses the Seward Lagoon and boat harbor areas.
Seward fill Hazard Mitigation Pian -2E- — March 23, 2004
Revised,Ann 12,2010
In January 2010, the Seward Planning & Zoning Commission approved a replat of land
owned by the City to designate it as a park. A sixty foot wide Right -of- Way was included
in the request to allow for access to a private landholder. The landholder agreed to allow for
a secondary access route across their property for consideration of the right of way. Details
on the exact location of the secondary route and its width will be determined in the spring of
2010. Construction of the route will not start until funds are available to complete it.
Goal 2 in the Plan mitigation measures had an objective to develop a brochure to educate
homeowners on fuel tank stands. That objective was included in the information packet
given to anyone applying for a Building Permit. During the plan review phase of a project
items that are of concern for earthquake mitigation are pointed out to the developer and
where possible required for the project.
C. Mitigation Measures
Goal 1: Identify hazard areas and select mitigation measures for those areas
• Update building codes to stay current with state requirements and industry
concerning earthquake protection.
• Identify non-buildable sites through the city's land use plan and city zoning maps.
o Earthquake proof priority structures (schools, city buildings, public safety offices,
etc.) This project requires the. involvement of many government entities and
assessments of various structures. Where possible employ Earthquake resistant
building technology to mitigate damage.
• Acquire land within the city to develop a secondary evacuation route that bypasses
the Seward lagoon and boat harbor areas. Provide barriers to this route and
designate it as a recreational trail for use outside of emergency access. (Planning
and Zoning Commission, May 6, 2004) (sand has been designated in January of
2010. The survey of the route is scheduled to be accomplished in the spring of
,010.)
Goal 2: Increase public awareness of hazards
R Conduct community mock emergency exercises and evaluate response.
• Develop public education to concentrate on the SAWS (Siren Alert and Warning
System), what it means and what to do in the event of an emergency. Educate the
public on EAN (Emergency Alert Network). (Planning and Zoning Commission May
6, 2004) Possibly make public announcements using the utility billing memo and the
scanner announcement page with GCI cable i V and radio.
Continue to update brochures and handouts to educate homeowners on fuel tank stand
codes and earthquake mitigation measures so they will be more flood/earthquake
prepared.
tieward All Hazard Mitigation Plan. -27- march 23, 2004
Revised,April 12,2010
Goal 1 Enact mitigation measures
The third goal in the process is to enact mitigation solutions. Once the potential problems
and solutions have been addressed along with input From the public process and approval
of the City Council, the mitigation can go forward, The process of funding each project can
be addressed during the normal budget process and/or with grant funding. Completion of
any project will depend on the availability of funds and any changes of priority.
Annex C -Tsunami
A. Hazard Assessment
Tsunamis are ocean waves that are generally triggered by vertical motion of the sea floor
during major earthquakes. bear ocean or undersea landslides or volcanic eruptions can
also generate tsunamis. They can be generated locally or a great distance from where they
landfall. darning time can be limited when the tsunami is triggered close to the impacted
coastline.
Seismically-generated local tsunamis
Seismically-generated local tsunamis were produced during the 1964 earthquake.
Earthquakes generate tsunamis when the sea floor abruptly deforms and displaces the
overlying water from its equilibrium position. Waves are formed as the displaced water
mass, which acts under the influence of gravity, attempts to regain its equilibrium. The main
factor which determines the initial size of a tsunami is the amount of vertical sea floor
deformation. This is controlled by the earthquake's magnitude, depth, fault characteristics
and coincident slumping of sediments or secondary faulting. Other features which influence
the size of a tsunami along the coast are the shoreline and bathymetric configuration, the
velocity of the sea floor deformation, the water depth near the earthquake source, and the
e`ficiancy which energy is transferred from the earth's crust to the wafter column.
Landslide-generated tsunaris
Submarine and sub-aerial landslides car: generate large tsunamis. Sub-aerial landslides
have more kinetic energy associated with therm so they trigger larger tsunamis. An
earthquake usually, but not always, triggers this type of landslide and they are usually
confined to the bay or lake of origin. During the 1964 earthquake, landslides into bays near
Valdez and Seward sent 35 foot waves sloshing back and forth like water in a bathtub.
Warning time can be limited when the tsunami is triggered close to the impacted coastline.
In Seward, a 1070 meter section of the waterfront slid into Resurrection Ray due to the
earthquake shaping. This created a local tsrinarni causing much damage. Landslides
usualiy occur in the heavily glaciated areas of Prince William Sound and farts of Southeast
Alaska. One earthquake can trigger multiple landslides and landslide-generated tsunamis.
Low tide is a factor for submarine landslides because low tide leaves part of the water-
saturated sediments exposed without the support of the water. Loading on the delta from
added weight such as trains or a warehouse or added rill can add to an area's instability.
Savvard All Hazard Mitigation Pian -28- --�-- March 23, 2004
Revised,April 12:20110
Resurrection Bay borders the Gulf of Alaska and it is vulnerable to tsunamis generated by
landslides, underwater landslides, crustal plate movement, and volcanic activity in the
North Pacific Ocean: The Gulf of Alaska could receive a tsunami from several possible
sources.
B. Vulnerability Assessment and Impacts
The map below is from the State of Alaska Hazard Mitigation Plan which designates
Seward as having a high tsunami hazard.
arrow
i TSUNAMI HAZARD r, .
BY CoMMUN".
(DISTANT SOURCES ONLY)
-:---,ALA , i ® "
41 Nigh
1
Q Modcrate
Low I Gme
1 None or negligible I 41Savoonga
� t
r .m
mar
Saint Paul Kodiak Sitka
5hemya
and Point
J , Arla nalsska Gulf of R;ask a
Q
0 _200 aao
_f.
$; This truck at Lowell Point,
2 miles from Seward, was
r
bent around a tree by the
surge waves generated by
the underwater landslides
alone the Seward
waterfront. i he truck was
J about 32 feet above water
" A level at the time of the
earthquake.
Source US Geological Survey.
Seward All Hazard Mitigation Plan; --- -29- March 23, 2004
Revised,April 12.2010
C. Mitigation Measures
Seward was one of the first cities in the U.S: to be considered Tsunami Ready. The city has
put together evacuation maps, pamphlets and signs designated to help people in our
community escape potential risk. Due to the history of tsunamis in Seward, the city has
cooperated with the State of Alaska and the Kenai Peninsula Borough in the development
of tsunami warning signals. The city has developed response plans to deal with the effects
of tsunamis. In the 2004 version of this plan, in Goal 1 we identified two potential projects
that benefit the community. With the assistance of The State of Alaska DHS/EM, USGS,
UAF Geological Department and NOAA we have finalized a new inundation map for the
community. This map shows the effects of different size waves and effects frorn waves
generated inside and outside of Resurrection Say, The final version of the map went to the
publishers in January 2010. The second project was to acquire land to develop a
secondary evacuation route. An agreement has been reached with the private landowner
who will allow for this route over their property. Survey of the route has been completed
and we are currently looking into any engineering studies that may be required-
Goal 9: identify earthquake and tsunami hazards within the City of Seward and evaluate
and prioritize potential mitigation measures.
Potential Projects:
• Revise tsunami inundation hazard prediction maps and-revise as needed after an
event or disaster.
• Develop a seccndary evacuation route that bypasses the Seward lagoon and boat
harbor areas. Provide barriers tc this route and designate it as a recreational trail for
use outside of emergency access. (Planning and Zoning Commission, May 6, 2004)
• Drill or dry run practice community evacuations of above and existing evacuation
ro utes,
• Place one electrical supply circuit underground across the Lagoon in an old
waterline.
• Complete an underground electrical supply circuit over Dairy Hill and through Two
Lakes Pa,k.
• Complete an unciergr ound circuit from the South Harbor expansion to Jefferson
along Ballaine Blvd.
• Complete the SMIC electrical loop along Sorrel Fed.
• Complete the electrical loop along Alemeda St. To Leirer Rd.
• Complete the underground electrical loop on Lowell Pt. from Beach Drive to Lowell
PL Rd., and the loop from Shady Ln. to Beach Dr.
Goal 2: Protect lives and proper de 3 in the event of a tsunami through public education and
emergency response exercises.
• Install AWS (Alaska Weather System) radios in public buildings. These radios will
also broadcast tsunami watches and warnings.
Install EMWIN (Emergency Managers Weather Information Netiotork), from the
National Weather Service into the police dispatch area.
Seward All Hazard Mitigation Plan -W- Maras 23, 2004 �~~
Revised,Aprd 12,2010
m Conduct community mock tsunami exercises and review responses to correct
deficiencies.
o Develop public education to concentrate on the SAWS (SirenAlert and Warning
System), what it means and what to do in the event of an emergency. Educate the
public on EAN (Emergency Alert Network),
Annex a — Coastal Erosion
A. Hazard Assessment
Erosion to the leaches caused from storms or high winds are an ongoing hazard in the City
of Seward. Other wave action and coastal flooding also causes damage to the shoreline.
South facing shorelines within the city are more susceptible to wave erosion. These
shorelines are mainly public property.
B. Vulnerability Assessment and Impacts
Erosion in the form of wave action in Resurrection Bay is caused by a number of different
scenarios. The most damaging wave action is the result of stoarn surge. These storm,-
induced waves cause the destructive erosion of coastal areas. Use of Resurrection Bay by
recreational boaters, is a source of wave action which will continue to be a problem even
without significant storms.
The City of Seward has taken steps to minimize the impacts of erosion on beaches with the
addition of rock wa!ls, culverts and channels. In 2002, the City of Seward did some
emergency erosion control work south of the ship lift located in Seward Marine Industrial
Center. The protect was designed to reduce the ongoing erosion; in that area. Over $38,000
was spent on that repair effort. The U.S. Army Corps of Engineers is looking into more
extensive erasion work at the SMIC.
After the 2006 food event, the City of Seward evaluated options for additions! erosion
control within the Seward Small Boat Harbor basin. A new Travelift dock was built in 2008,
connecting the existing sheet-piiing dock forming the foundation for the Best Western Hotel.
Additional rock was placed in the north-west corner to help alleviate the erosion problem in
this quadrant of the harbor.
The north-east corner of the harbor requires additional mitigation efforts to prevent future
damage from future flooding events. A stormwater drain is currently in place in this area;
however shore bank erosion will continue to be a problem unless rock, sheetpile or other
substrate is placed in the area to prevent further erasion. 4 his area of the harbor has been
subject to damage from wave action because the east breakwater was not originally
designed or built long enough to protect this area from wave averts originating from
Seward All Hazard Mitigation Plan �~ -31 Marti? 23, 2004
3evised,April 12, 2010
Resurrection Bay. In 2010 the US ARMY Corps of Engineers awarded a contract to extend
the east breakwater 215 feet to mitigate this problem.
An additional consequence of the flooding events in Seward is the accumulation of debris
(soil, rocks, vegetative matter, trash) that is deposited in the harbor basin, This requires
additional dredging to maintain proper depth in the harbor. The US Army Corps of
Engineers maintains responsibility for a portion of the harbor dredging, but most flood
prone areas are the City of Seward's responsibility, Dredging is scheduled to occur in 2011
based on funding availability.
Lowe!I Point Road on the south end of the City of Seward has suffered repetitive erosion
and flood damage problems from both weather and coastal erosion. Lowell Point Road
serves as the infrastructure access to the sewage treatment facility. This access must be
maintained. Erosion to the access road south of the waterfall has been a major economic
and safety concern. The city estimates it would cost approximately $5 million dollars to
replace and erosion proof the existing access, electric and sewer lines.
In December of 2009 a storm surge caused severe damage to Lowell Point Road, Alaska
SeaLife Center, the south camping area, camping area along Sailaine Bivd and the south
beach of SMiC. The State of Alaska made a declaration of disaster for this event.
C. Mitigation Measures
GOAL: Reduce the amount of shoreline erosion within allowable practices and monetary
constraints.
Potential Projects.
0 Build a protective barrier south of the Seward Marine Industrial Center (SMIC) for
erosion control-
0 Complete wave, barrier at the ship lift located in SMIC.
111 Maintain the rock barrier located in the Waterfront Park area.
• Create a baseline assessment on Lowell Point Road, existing infrastructures and the
feasibility of culvert/ditch line, installation.
0 Maintain or redesign rip-rap barriers along Lowell Point Road.
m Dredging operations to remove debris and fill at the head of Resurrection Bay near
the airport.
• Cover the underground electric line to Lowell Pt. with concrete
Current Mitigation measures required at Waterfront Park includes 1) repairing,
maintaining and redesigning the rock barrier located in the Waterfront Park area and
21 implementing a regenerative program of our native Beach Rye Grass (Elymus
arenarius) by aggressively replanting, relocating city campground fire pits,
implementing educational signage to redirect foot and recreational vehicle traffic and
installing boulders and other barriers to prohibit vphicles from damaging the coastal
vegetation.
Seward All Hazard M;tigation Flan -32- --- March 23, 2004
Revised,April 12, 2010
• install a protective "spit' near the waterfront in cooperation with the state, to protect
from coastal erosion, storm surge tides and tsunami inundation. Similar to the south
harbor upland, but smaller.
• Install sheet-piling or a rock barrier along the north-east edge of the harbor to
prevent further erosion,
• Dredging operations to remove debris and sediment accumulation within the harbor
from flooding events and to maintain necessary depth.
Annex E — Wildland Fire
A. Hazard Assessment
T he City of Seward has a low probability of direct wildland fire hazard but there have been
instances of wildland/urban interface fire situations in May of 2000 and 2001.
Seward is subject to the effects of a wildland fire in the East Zone of the Kenai Peninsula.
Primarily, transportation to the city would be disrupted if a major wildland fire event would
take place in the East Zone.
B. Vulnerability Assessment and Impacts
The City of Seward has a low risk of wildland fire and secondary effects of a fire from the
East Zone are covered in the KPE Hazard Mitigation Plan.
The communities of the East Zone have the potential to experience both large structural
and urban/wildland interface fires, urge wildland fires also have the potential to affect
Seward from secondary/ effects such as air space and road closures due to smoke. Fires
may arise as isolated incidents, or be caused by other emergencies such as earthquakes.
In addition, they may be complicated by the presence of hazardous materials, and extreme
weather conditions.
There is a history of large; wildland fires in the East Zone such as the Moose Pass fire of
1985 or the Crown Point fire of 2001. The increasing amount of spruce-bark beetle killed
forest couuled with the right mix of weather and fire behavior could result in a large wildfire
that would impact people, property, air quality and the transportation corridor. Under certain
conditions, the increased beetle kill forest may increase; the potential for the starts of
urban/wildland fires in formerly low risk areas. The potential risk to property and people can
be great given the correct mix of extreme fire weather and increased fuel loading.
Although the City of Seward has a low probability of wildland ire, the East Zone wildland
fire potential has been problematic for Seward and continues to pose a threat to the city. in
the ;rase of the wildland fire that affected the Kenai Lake/Trail River campground in 2001,
the City of Seward gavo mutual aid to the US Forest Service. The Seward Fire Department
crew was on the fire from June 26 through June 29, 2001.
Seward All Hazard Mitigation Plan -33- March 23, 2004
Rovl-;- ,April 12,7010
Pa ten(;a1 Projeois:
« Acquire permission to clear hazard, and potential hazard trees beyond the
permit area for the transmission line from Dave's Creek to Crouse Lake from
the State and the USFS.
• Clear the trees from the newly acquired permission areas and the brush within
the permitted area.
Urban Fires
As with many communities, the City of Seward has a greater probability of urban dire
situations than wiidiand fires. Urban fires continue to dominate the city's fire
prevention/protection efforts within the City of Seward. Structural, vehicle, marine and small
brush fires are common occurrences within the city.
C. Mitigation Measures
The Kenai Peninsula Borough offered a course on urban interface fire lighting in May of
2004 to better prepare firelighters for wildland/urban fire situations. The three day course
was sponsored by the Borough Office of Emergency Management and Central Emergency
Services in Soldotna. It was designed to address the issues of wildland/urban fires on the
peninsula. The City of Seward has participated in the Alaska Firewise program, which
identifies hazards to homeowners and offers solutions to protect residents in or near
forested areas. Relocating the Seward Building Department into the Fire Department has
helped streamline this part of the process for builders by consolidating review of potential
response to a structure, operational needs of the builder and City department's
requirements in one location. During this plan review structures that are in an area that has
risk/exposure to a wildland/urban fire, have been required to incorporate protective
measures,
KPB is tracking the spread of the spruce bark beetle; throughout the peninsula. The KP8
Spruce Bark Beetle Office offers assistance and advice to businesses and homeowners.
Annex F. Weather
A. Hazard Assessment
The City of Seward has a high probability of weather related hazards. Winter storms can
include heavy snowfall, ice storms, blizzards and extreme cold. Heavy spring or fall
precipitation can lead to flooding in the Seward area.
Seward Al! Hazard ivilitigation YI j;1 -34- March 23, 2004
Revised,April 12.7010
B. Vulnerability Assessments and Impacts
The probability of weather related hazards in Seward is high. Weather can disrupt
communications; power, transportation, emergency services, and can pose a risk to
individuals. Heavy snow has secondary effects as well, such as avalanches that ciose the
highway and rail access into the city. A major winter storm in 2000 caused numerous
avalanches that closed the Seward Highway in several places between Anchorage,
Girdwood and Seward. This storm also caused power outages that affected the city and
outlying areas. People rushed to the local grocery stores and most of the perishable foods
were cleaned out as soon as the town was notified that the road would be closed, Medical
supplies had to be flown in and the state ferry Tustumena was given deliveries from other
communities to bring into Seward. Many people were stranded for up to seven days in one
of the several communities that were affected.
Other major weather events include flooding, wind and extreme cold. Flooding of the past
was a direct result of major downpours and already saturated ground. Extended dry periods
and wind have affected the city by hampering efforts of controlling ire. In May 2000, a
wildland fire in the Japanese Creek region quickly spread due to high winds and dry
conditions, The City of Seward evacuated the Gateway Subdivision due to the speed at
which the fire was traveling.
C. Mitigation Measures
Goal: increase public awareness of hazards related to severe weather
• Coordinate responses of private contractors during a severe event as indicated in
the City's Emergency Plan.
e Public education on the effects of severe weather.
• Inform public of availability of AWS radios, in preparation of potential weather
advisories.
a Activate the City's EOCr to coordinate planning and logistical efforts in dealing with
the emergency.
Potential projects:
® Rebuild the old transmission line sections in L awing, Boulder Ck, and Lakeview to
current distribution standards (its current use) so that. it will withstand known weather
conditions,
6 Rebuild the double Circuit line from Dimond Blvd, to Dairy Hili Rd to withstand
known weather conditions.
Seward AN Hazard Mitigation Purl -35-~ March 23; 2004
Revised,April 12,2010
Annex G -- $now Avalanches/Landslides
A. Hazard Assessment
Both snow avalanches and landslides are common occurrences within the City of Seward.
Lowell Point Road is commonly closed during the winter from snow avalanches. Landslides
occur along that same road during heavy rains. Lowell Canyon is also prone to landslides
during heavy rain. If a landslide were to block the Lowell Creek Tunnel entrance, serious
flooding could affect homes, businesses, the hospital, and the senior center. Monitoring of
Lowell Creek during major weather events is a ;'sigh priority for the City of Seward.
B. Vulnerability Assessment and Impacts
There is a moderate probability of snow avalanches/lanndslides within the City of Seward.
Infrastructure disruption in Lowell Canyon can be a result of an avalanche or landslide
event. Many of the secondary effects of avalanche are road closures on the Seward
Highway which have greater impact to the community as a whole.
C. Mitigation Measures
Goal: increase public awareness of hazards of avalanche/landslides in the community
identify avalanche areas within the city and generate GIS Hazard Maps. Coordinate
with Community Development on locations of areas for any zoning issues.
Create safe parking areas along Lowell Point Road for vehicles.
Develop and install signs designating avalanche danger zone.
e Renovate Lowell Canyon Tunnel access.
• Establish a retaining structure in Lowell Canyon to prevent avalanches from
disrupting city water storage system.
Potential Projects:
• Design and develop a new generation of diversion structures and flexible
transmission poles to bend with the snow impact.
Underground more of the distribution lines in avalanche areas, ex. Mile 22.
Annex H — Volcano
A.: Hazard Assessment
The City of Seward, in the East Zone of the Kenai Peninsula Borough, would see
secondary effects from a volcanic eruption. Actions needed are to he able to cope with
;potential long term effects and continual activity from the volcanoes. InfrastructUre, facilities
and priority buildings will need to be secured from volcanic ash fallout. Citizens with
respiratory conditions would need to be protected or evacuated,
eward All Hazard Mitigattion Plan -36- March 23, 2004
Revised,April 12,2010
B. Vulnerability Assessment and Impacts
The vulnerability assessment is covered in the Kenai Peninsula Borough Hazard Mitigation
Plan for the East Zone. In the Borough's Emergency Plan is a checklist that covers volcanic
activity. The City has adopted the checklist for activities to be performed for warning,
response and recovery phases (Vol. 2 KPB Emergency Plan Hazard Specific Checklist).
C. Mitigation Measures
Goal: increase public awareness of hazards
• Defer to KPB Hazard Mitigation Plan for guidance on mitigation plans
• Identify critical facility risk and nee: from ash fallout.
Annex I — Technical
A. Hazard Assessment
There are various technical hazards within the City of Seward. One of the most prevalent is
the anhydrous ammonia that is used in chilling facilities at the local fish processing plants.
Facilities are located at the SMIC, the boat harbor and the south end of town. Other
potential technical hazards within the city include; fuel storage facilities, explosive storage
and hazardous materials shipped into she city by marine vessel and truck or train cargo.
8. Vulnerability Assessment and Impacts
The probability of a technical hazard incident in the City of Seward is low, although there
have been incidents in the past. Anhydrous ammonia is the most significant hazard that
affects the community. Anhydrous ammonia is a corrosive and toxic gas that is an eye,
nose and throat irritant. It is highly toxic if inhaled and may be an explosive hazard in a
confined space. An example of this is the anhydrous ammonia leak and explosion at the
Icicle Seafood's processing plant in Homer, Alaska, On July 1, 1993. The fire/explosion
destroyed the Homer Plant. A broken ammonia line, under repair at the plant, was the
source of the explosion. An estimated 34,000 lbs was in the system at the time of the
explosion. It is not clear how much anhydrous ammonia escaped out of the system before
the incidents. The plant was located on the Homer Spit, which is away from the heavily
populated portion of the city but within close proximity of many businesses, campgrounds
and the boat harbor. During the fire, the Spit had to be evacuated which took approximately
one hour to complete.
Sevti--rd All Hazard Mitigation Plan -37- Mi3rch 23, 2004
Revised,April 12.2010
Icicle Seafood's Seward Plant, located in trip Seward boat harbor and within 1 mile of
downtown Seward, holds 23,000 lbs. of anhydrous ammonia in their system with an
additional 300 lb external cylinder. Resurrection Bay Seafoods, located at the southern end
of town has 650 lbs. in the system. Polar Seafoods, located in the SMIC area has 4500
lbs. Due to the proximity of two of these processing plants to populated areas, the city has
a high risk from the effects of an anhydrous ammonia release.
Icicle Seafoods currently has an Emergency Response Plan in place for potential release of
anhydrous ammonia. In coordination with the Seward Eire Department, Icicle Seafoods
conducts a simulated leak exercises. Icicle also does an in-house monthly exercise as part
of their CRP. The plan is designed to meet the requirements of the Process Safety
Management of Highly Hazardous Chemicals, the Hazardous Waste Operations and
Emergency Response regulation, and Part 68 of Risk Management Plan regulations. The
plan is available at the Icicle Seafoods Seward Fisheries Plant.
Another potential technical hazard incident is the fuel storage tanks located north of the
small boat harbor. These include gasoline, heating oil, motor oil, and diesel and propane
storage facilities. All of which have the ability cause extreme environmental disasters
and/or fire/explosion incidents. In the event of a failure of any of these tank systems, the
risk to the City of Seward is high. The probability however of such failures is low. The
largest threat from a fuel spill would be environmental contamination. The petroleum tank
facility is located within a few hundred yards of the shoreline. A major spill or rupture of any
tank would have far reaching impacts.
All of these technical hazards can, also occur as secondary affects of other identified
hazards such as earthquakes, tsunamis and flooding. During the 1964 earthquake,
ruptured fuel lines and ignition of the fuel caused additional problems for the City of
Seward. Other technical hazards that could affect the City of Seward by secondary effects
are listed in the KPB Hazard Mitigation Plan.
C. Mitigation Measures
Coal: increase public awareness of hazards of potential spills/accidents
• Work with industry operators to educate the public on potential hazards and develop
strategies for response, evacuation, and containment.
• Develop spill/clean up plans with industry.
• Encourage sites to meet standards/regulations for all reportable quantity hazard
materials.
• During large renovation, repairs or after a disaster, encourage the use of utilidoors
for future pipelines.
SaYVard All Lazard Miligat;on Plan�� -38 Marc` 23, 2004 --
Revise:-,April 12,2010
Annex J Economic
A. Hazard Assessment
An economic hazard for the City of Seward would primarily result as a secondary effect of
other potential hazards such as earthquakes, tsunamis and flooding. Because of the
diversified economy of Seward, the probability of an economic hazard is low.
B. Vulnerability Assessment and Impacts
The economic impact of increased natural gas prices is currently being fait through the Fuel
Adjustment Charge in our electric bills. This increase is expected to increase dramatically
in the next few years.
The City of Seward has a low probability of other economic hazards. There are a number
of scenarios that could cause a hazard to the economy if they were to occur. A few of these
would be the closure of one or many of the government/private industry that has significant
influence to the local economy. A few of the local industries that could affect the City of
Seward would be the loss of the tourism industry or the closure of the Alaska Vocational
Technical Center.
Tourism in Seward is an industry that has far reaching impact on Seward businesses and
residents. There are many different industries that stem from the influx of the travel
Industry. There are approximately 28 hotels, motels, and bed and breakfasts, 27
restaurants, 4 seasonal water tour companies, 66 charter boats, 2 grocery stores, 22 art/gift
shops, the Alaska SeaLife Center, hardware businesses and charter booking agencies, 2
fuel companies, campgrounds, and other related industries throughout the area could all be
impacted by the reduction or elimination of tourism. A potential cause of reduction would be
a terrorist threat or action based in the city or within the US. if one cruise ;ship 'Vas
destroyed or taken by a terrorist organization in the US the reduction of tourist coming to
Seward could be 100%,
Another major industry that has far reaching impacts on the City of Seward is the Alaska
Vocational Technical Center (AVTEC), AVTEC is a state entity. AVTEC owns and operates
12 buildings, leases 1 building, has 69 full time employees with a payroll of $4.4 million,
and spend approximately $530,000 in local businesses. AVTEC offers its employees good
wages, benefits and a retirement system. The employees in return live in the community
using the various businesses and services. A possible scenario that could affect The role of
AVTEC in our community %could be the reduction of the State budget.
An impact to the commercial fishing industry could also affect the City of Seward by the
reduction of services, employment and the decrease in vessels and crews who suppo,-t
many businesses throughout the city. Theso include the 3 local fish processing facilities,
fuel companies, grocery stores, restaurants and hardware./fishing supply stores.
Seward Ali Hazard Mitigation; Plan -39- March 23, 2004
Revised,April 12.2010
Government agencies would also be impacted such as the City of Seward for port fees,
business license fees, and other research/enforcement agencies.
The probability of any of these events to occur is very low bUt the impact to the economy of
the community would be high.
C. Mitigation Measures
Goal 1: Increase public awareness of potential hazards
• Make concise information available to the public about local industry concerning any
government control.
• Make sure that accurate information is given to agencies that are responsible for
dissemination of information concerning the City of Seward or other government
agencies.
® Public groups (Chamber of Commerce, Lions, and Rotary Clubs, etc.) with business
interests have accurate and timely information available to dispel rurrors.
Goal 2: Support and encourage planned economic development that will he beneficial
to the City of Seward.
• Develop and find existing programs that insure that the City of Seward is a safe and
clean place for visitors to come.
Goa!3: Support and encourage the permitting and construction of an in state gas line
to the states vast gas reserves.
-Seward All Hazard Mitigation Plan -40- March 23, 2004
RpOsed,April 12,2010
Chapter 5 - Publiic Participation on Pian
In 2010 Fire Chief David Squires led the revision of the Hazard Mitigation Plan for the City
of Seward sunder the direction of the City Manager, Phillip dates.
Working with the following people within City of Seward departments Executive Liaison to
the City Manager, Suzi Towsiey collected information.
Departments from the City of Seward that assisted in compiling information include:
Fire Department — David Squires, Fire Chief
Engineering / Building Department— Stefan Nilsson
Public Works -- W.C. Casey and Kirsten Vesel
Community Development- Christy Terry and Donna Glenz
Electrical (Department- John Foutz and Jeff Estes
Small Boat Harbor- Kad Anderson
Seward Parks and Recreation- Karin Sturdy
Upon completion of the first draft, copies were distributed to the Fire Station, the Public
Library and the City Clerks office for public review.
The first public hearing for the draft proposal was held at the Planning and Zoning
Commission meeting of April 6, 2010.
Additional public hearings on The All Hazard Mitigation Plan were conducted at City
Council meetings on April 12, and April 26 2010.
Comments from the public from the meetings will be incorporated into the plan before
submission to the KPB, State of Alaska, and Federal Governments.
The Kenai Peninsula Borough has put toga ther a public notice bulletin with contacts for the
City of Seward as well as Borough contacts for individuals interested in the process of
hazard mitigation. This is available on the internet at
httI2://www.boro;ugh.kenai.ak,us;emergencythazmitpIan.htm
Public input into The All Hazard Mitigation Plan planning process was solicited in a Public
Notice published in the Seward Phoenix Log on April 1 and 8, and 15, 2010.
Interagency coordination was received from the following agencies:
Kenai Peninsula Borough
State of Alaska
US Army Corps of Engineers
Seward All (-Hazard Miticiati-in Plan -41- March 23, 2004
Revised,April 12. 2010
The State of Alaska gave direction on how to formulate the plan, identify the hazards and
mitigation measures. The State of Alaska reviews the plan for compliance and
completeness and recommends changes that need to be made.
The Carp of Engineers provided information can past mitigation efforts and estimations on
proposed mitigation measures and including the permitting process.
In the revision of this plan under the direction of City Manager, Phillip Oates, each of the
City departments were contacted for input for completed mitigation measures, new
proposed mitigation measures and other hazards that may effect the City of Seward. Any
agency contacted to review the original plan was given the opportunity to review the
revised document,
Seward Ali Hazard Mitigation.. Dian -42- March ''?.3, 2004
RevisF,d,Apd;12,2010
Chapter 6 — Implementation
The City of Seward will implement this plan by the methods outlined in this chapter. In
addition to a positive cost/benefit ratio, projects will be prioritized and selected for
implementation based on community goals, planning objectives, funding availability,
environmental concerns and public support. The City Manager is responsible for
implementing the plan as resources allow. Projects selected for funding will follow a public
process with the Planning Commission making recommendations to the Seward City
Council for further public input and approval of projects. Completion of any project will
depend on the availability of funds, changes in priority and will need to be individually
approved and adopted by the City Council prior to the start of that project.
The Planning and Zoning Commission will review the potential projects list for
recommendations to the Council can which projects should receive the highest priority. The
Council is responsible for making the final decision on which projects are submitted for
funding.
Because flooding from severe storms presents the greatest threat to Seward it is
anticipated that projects mitigating damage from floods will receive the highest priority. In
subsequent updates of the plan, continued evaluation of danger from other hazards will be
undertaken.
Determining which projects should be submitted for funding will be based on a FEMA
approved cost/benefit method. A publication by FEMA explains how to determine cost-
effectiveness of mltigation projects and how to calculate the benefit-cost ratio. In addition
to a positive cost/benefit ratio, projects will be prioritized and selected for Implementation
based on community goals, planning objectives, funding availability, environmental
concerns and public support.
The Plan will be monitored and it will be updated when a disaster occurs that significantly
affects Seward, whether or not it receives a Presidential Declaration, assuming funding is
available to update The Plan. The update will be completed as soon as passible, but by no
later than the 12 months following the date the disaster occurs. The normal review cycle
will ba five vears.
The City Manager will direct staff to start the updating of this Plan two years before the end
of the five-year cycle. Securing grant monies and developing a project plan will occur the
two years before the end of the five year requirement. Writing of the update will happen
one year before the end of the five year cycle, to allow for adequate time for public
participation. The public will be advised of the revision process through announcements
the paper for public review and comment at regular Planning and Zoning C;ornmission
meetings and City Council Meetings. Plans will be available at vaKous public sites
(example: Literary, City Nall). Advertisements will run in the Seward Phoenix Log, Our
weekly local newspaper, requesting public comment,
SaW-3rd All Hazard Mitigation Plan _ -43- �J V� March 23, 2004
Revised,April 12, 2010
The All Hazard iJiitigation Plan will be updated as necessary as required by State of Alaska
law, Title 29-40,030. At a minimum however The h Ian will be evaluated and updated every
five years.
6A— Potential Projects
The following list is based upon city staff analysis of vulnerabilities and mitigation measures
for known hazards in the Seward area. Prioritizing the list will depend on future disasters
and the needs of the community. Inclusion of short and long term projects is consistent
with the state hazard plan.
9 Short-term projects are those; which Could be accomplished within a two year time
period.
• Long-term projects will take longer than two years and/or depend on other projects
being accomplished first or substantial funding resources.
Project Listing: (not prioritized)
1. Identify additional hazards not covered previously and do a risk analysis within a two
year time period. (Short Term)
2. The current Flood Insurance Rate gaps are very outdated and are in need of
updating to address the following items. (Long Term)
➢ 10$1 maps need to be reevaluated with 23 years of additional data.
Corrections may need to be made for, areas where: fill or naturally high ground is
now shown as flood prone but may not be in jeopardy of flooding.
➢ U.S. Corps of Engineers needs to analyze new flood boundaries as part of the
harbor/port improvement project:
➢ Investigate better flood programs, especially ones specific to alluvial fan flooding.
3. City of Seward should evaluate the benefits of applyir'g to FEiVIA to join the
Community Rating System, (Short Term)
4. City staff should work with adjustors on the Community Rating System to reduce
interest rates. (Long Term)
5. Information on how to obtain insurance from the NFIP should be provided to private
property owners. (Short Term)
6. Publish a brochure containing information on the City of Seward flood dangers to be
distributed to the community_ (Short Term)
7, Require that realtors dis€;lose hazard risk in real estate transactions. (Short Term)
6. Bring a food-proofing workshop to Seward to assist the City and private property
owners. (Short Tel'n)
Seward Ali Hazard Mitigation Pian -44- March 23, 2004 —v
Revised,April 12,2010
9. Reevaluate land use codes and subdivision regulations that are specific to
development within the flood prone areas. (Short Term)
10. Mitigate damage to reads, drainage and utilities by requiring that reconstruction be
to a higher standard after a storm. (Long Term)
11. Revise the flood plain ordinance to include a provision for cumulative substantial
improvement or damage. (Short Term)
12. Properties should be identified that would be appropriate for protection because or
flood risks, and after public input, acquisition, conservation, or flood hazard
protection regulations by the government should be pursued. (Lang Terre)
13. Require buildings to be built with the lowest floor one foot above base flood
elevation. (Short Term)
14, Improve enforcement of floodplain regulations, including requiring certificates for all
structures within the flood plain. (Short Term)
15. Continued maintenance of the Resurrection River drainage. In conjunction with KPB;
conduct an engineering study to determine the Host effective use of the dredge
materials frorre the maintenance: dredging. (Lang Term)
16. Continue Lowell Creek Tunnel outflow maintenance. (Short Term)
17, Expand public awareness about NOAA Weather Radio for continuous weather
broadcasts and warning tone alert capability. (Short Term)
18. ldentify buildings or locations vital to the emergency response effort and buildings or
locations that, if damaged, would create secondary disasters. (Short Term)
19. Encourage real-time availability and use of satellite data to evaluate fire, spruce bark
beetle killed forest, and flood or tsunami potential. i.e. Eiv1WINS, KIPS Spruce Bark
Beetle. (Long Term)
20, Encourages KPB school mitigation efforts. This measure will increase help to protect
children and retain a school's functionality as an emergency shelter. (Long Term)
21. Encourage non-structural mitigation and preparedness activities. Encourage
activities at the household level. (Short Term)
22. Conduct city-;wide earthquake/tsunami driils. Citywide earthquakeAsuna,ni drills will
educate people on what to do when an earthquake/tsunami occurs and reinforce
interagency and individual expectations. (Long Term)
Seward All Hazard Mitigation Pion -41:- March 23, 2004
Revised, April 12,2010
23. Encourage the development of earthquake structural performance standards and
incorporate earthquake overlay zones in the community land use ordinances.
Encourage the development of citing requirements based or, soil type, slope, and
other considerations. Before this can happen, information about where the various
risks are located must be developed, (Long Terra)
24. Promote incorporation of new methods to improve building performance. New
materials and construction techniques might be more effective or feasible than what
is currently available. (Long Term)
25. Evaluate the need for development of large-scale earthquake-hazard maps of the
Seward areas. Seismic hazard area maps need to be created for the area. The
maps should depict site amplification, liquefaction susceptibility, and ground failure
at a minimum scale of 1 inch = 1 mile. (Long Term)
26. Publish Tsunami Inundation Maps. Revise reaps after a signir"Icant event or natural
disaster, (Long Term)
27. Improve the Lowell Creek diversion project by reassessing the best route for creek
diversion, renovation of the tunnel and development of a new outfall. (Long Term)
26. Identify and advise of avalanche/l and siide areas within the City of Seward for
potential community development. (Short Tear,)
23. Encourage the Kenai Peninsula Borough to include serAce areas outside of City of
Seward city limits in this plan.
S-3%vard All Hazard Mitigation Plaro � -45- _-� mare 23, 2004
R.evlsW,April 12, 2010
References and Addendum
1 City of Seward: Flood Hazards Mifi ation Plan. City of Seward Community Development
Department and Hensley Consulting Services, 1996.
2 graft State Hazard Mitigation Plan. Alaska Division of Emergency Services (ADES),
March 2002.
s Flood Damage Reduction Revised Reconnaissance Re ort Seward Alaska Lowell
Creek. United States Army Corps of Engineers (USCOE), August 1992.
4 Flood Miti ation Assistance Guidance. Federal Emergency Management agency
(FEMA) FEMA 299, August 1997.
e Kenai Peninsula Borough All- Hazard ;'y9itigatian Plan l irst_r�raft 2�103. Bechtol Planning
and Development, November 2003.
Kenai Peninsula Borough Flood Miti ation Plan. KPB, March 1996.
7 Seward Area Rivers; Flood Darner a Prevention. Interim reconnaissance Report. United
States Army Corps of Engineers, February 1994.
P, Subduction Zones. Alan Feuerbacher
httn:l/www eocities cc�n�-L- _ s/Acaden y/v(14OhLcodG9.htm
U.S. Geological Survey web sites; http://nei,,.usgs.goy,
httP:/ieubs.usasgav/nup?ications/text/understand; ..1itmi
io FEMA publications: How to Determine Cost-Effectiveness of Mitigation Projects and
Calculating the Benefit-Cost Ratio. htt ://www.fema.�okrlfima/ dm.shtm
The Water Resources Develo Trent Act t f -007, Section 5032 Lowell Creek Tunnel,
United States Army Corps of Engineers, 2007
12 Proposed North Forest Acres Levee/Road mac:, HDR, Wm. J. Nelson & Associates.
AeroMetric, April 20061
Addendum of Revisions/Updates
Sewarc A! Hazard tvlitga#icr? nlan♦..y�-� _47a�_�___� 14iarci! 23, 2004
Revisej,April 12,2310
DEPARTMENT OF THE ARMY
U.S.ARMY CORPS OF ENGINEEFIS
WASHINGTON,D.C.20314-1000
CEMP-POD JUN 2 9 20
MEMORANDUM FOR COMMANDER, Pacific Ocean Division(CEPOD-PDC)
SUBJECT: Implementation Guidance for Section 5032 of the Water Resources Development
Act of 2007(WRDA 2007)— Lowell Creek Tunnel, Seward, Alaska
1. Section 5032 directs the Secretary to assume responsibility for the long-term maintenance and
repair of the Lowell Creek tunnel,Seward, Alaska unfit an alternative method of flood diversion
is constructed and operational,or 15 years after the date of enactment of WRDA 2007 (8
November 2007), whichever is earlier. In addition, the Secretary is authorized to conduct a study
to determine whether an alternative method of flood diversion in Lowell Canyon is feasible.
Further, if the Secretary determines an alternative method of flood diversion in Lowell Canyon is
feasible,the alternative method shall be constructed and the Federal share of the cost of carrying
out such alternative method will be the same as the Federal share of the cost of the construction
of the Lowell Creek tunnel, A copy of Section 5032 is enclosed for information.
2. Construction was cornpicted in 1940 of the existing Lowell Creek project to protect the city of
Seward from the floodwaters of Lowell Creek. The project consists of a diversion dam and a
concrete lined tunnel 10 feet in diameter and 2,070 feet long through Bear Mountain. The
construction was perforniedat Federal expense and the City of Seward provided,at no cost to the
Government,all lands,easements, and rights-of-way necessary for construction. The City of
Seward assumed responsibility for operation and maintenance of the existing project upon
completion of construction.
3. The Alaska District will assume long-teen maintenance and repair responsibility of the
concrete lined tunnel (and tunnel inlet and outlet structures) until completion of construction of
an alternative method of flood diversion or until 8 November 2022(15 years a-fler the date of
enactment of WRDA 2007), whichever is earlier. Funding to accomplish the long-term
maintenance and repair will be budgeted in the O&M account in accordance with existing
budgetary policies and procedures. In advance of the budget request,a letter report that details
the extent and cost of the operations and maintenance must be submitted for review and approval
by the ASA(CW). Long-term maintenance and repair activities of the concrete lined tunnel (and
tunnel inlet and outlet structures)will be limited to those that meet the definitions for
"replacement"and "rehabilitation"in Section 12 of ER 1110-2-40 1,"Operation, Maintenance,
Repair, Replacement, and Rehabilitation Manual for Projects and Separable Elements Managed
by Project Sponsors" such as replacement of worn out portions of the concrete lined tunnel (and
CEMP-POD
SUBJECT: Implementation Guidance for Section 5032 of the Water Resources Development
Act of 2007—Lowell Creels Tunnel, Seward, Alaska
of-way necessary for the construction. Further, upon completion of construction the non-Federal
sponsor shall operate,maintain,repair, replace,and rehabilitate the new project. Contact the
POD RIT for direction on drafting the PPA.
FOR THE COMMANDER:
G�
Encl -C," Y. D IKE
Chief, Pacific Ocean Division
Regional Integration Team
Directorate of Military Programs
3
� _ a
NO�Yf"T�7
44.
., a
41S c '.