This document summarizes work to update the local hazard mitigation plan for Seward Bear Creek Flood Service Area near Seward, Alaska. A team evaluated natural hazards in the area like flooding, earthquakes, and tsunamis using Hazus software. They encountered challenges with data collection during heavy rain and flooding. Field work was conducted during a flood event. The team modeled climate change impacts and developed mitigation approaches.

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Adventures in the
“Last Frontier”:
Hazard Planning Alaskan Style
Rich Chamberlain, GISP

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The Project
– Update the Local Hazard Mitigation Plan
Annex for the Seward Bear Creek
Flood Service Area (SBCFSA) near
Seward, Alaska
– Evaluate all natural hazards
– Estimate potential damages (Hazus)
– Include scenarios for climate change and
land use change
– Develop mitigation approaches

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The Team
– Dan Mahalak: Client with SBCFSA
– Scott Simmons: PM (Anchorage)
– Rich Chamberlain: GIS/Hazus Riverine
(Denver)
– Kim Pirri: Hydrology and Hydraulics (Denver)
– Jon Philipsborn: Climate Change (Atlanta)
– Shane Parson: Hazus UDF, Tsunami, EQ
(Maryland/Virginia)

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Challenges
– Data collection
– Using existing data
– Modeling hazards
– Modeling climate change

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What is Hazus?
ƒ Hazards U.S. – Multi Hazard
ƒ Earthquake, flood, and
hurricane wind/surge modules
ƒ FEMA software developed in conjunction
with the National Institute of Building
Sciences
ƒ Over 200 data layers – all open source
ƒ Runs as an FREE extension to ArcGIS

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Hazus Features
Earthquake Flood Hurricane

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Hazus Questions
1. How do you conduct Hazus field data collection
during a flood event?
2. What is the best way to model an Alaskan log cabin
with Hazus User-Defined Facilities (UDF)?
3. How do you account for glacial till deposition when
developing Hazus user-defined flood depth grids?
4. What process should be used with Hazus to model
climate change impacts for glacially-fed rivers and
streams?
5. What are the best ways to adapt 2D alluvial fan flood
and debris modeling output for use in Hazus?
6. How do you use tsunami model mapping and LIDAR
data to conduct Hazus tsunami risk assessments?

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Hazus Questions
1. How do you conduct Hazus field data collection
during a flood event?
2. What is the best way to model an Alaskan log cabin
with Hazus User-Defined Facilities (UDF)?
3. How do you account for glacial till deposition when
developing Hazus user-defined flood depth grids?
4. What process should be used with Hazus to model
climate change impacts for glacially-fed rivers and
streams?
5. What are the best ways to adapt 2D alluvial fan flood
and debris modeling output for use in Hazus?
6. How do you use tsunami model mapping and LIDAR
data to conduct Hazus tsunami risk assessments?

17. Let’s go to Seward…
Original Plan…
„ Field Tour w/ client
„ Kick-off Meeting
„ Field Measure Hydraulic
Structures (bridges,
culverts)
„ Building Stock Evaluation
(for structure type & 1st
floor elevation)
What really happened…
„ Raining…
„ Field Tour w/ Client
„ More Rain… Flooding…
„ Most locals bail on kickoff
meeting to respond to
flooding
„ More Rain… More Flooding…
„ See flooding and flood
response in action…
„ Building Stock Evaluation
„ Get the out before the road
is closed…

18. Field Data Collection…in the Rain!
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19. Rainfall
Seward
„ Annual Average
Precipitation = 69
inches
„ Week of 9/17-9/21
Rainfall Total ~15
inches
„ Month of September
Rainfall Total >30
inches* (it’s a record!)
*Source: AlaskaDispatch.com, 9/26/2012

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Hazus Questions
1. How do you conduct Hazus field data collection
during a flood event?
2. What is the best way to model an Alaskan log cabin
with Hazus User-Defined Facilities (UDF)?
3. How do you account for glacial till deposition when
developing Hazus user-defined flood depth grids?
4. What process should be used with Hazus to model
climate change impacts for glacially-fed rivers and
streams?
5. What are the best ways to adapt 2D alluvial fan flood
and debris modeling output for use in Hazus?
6. How do you use tsunami model mapping and LIDAR
data to conduct Hazus tsunami risk assessments?

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Hazus Questions
1. How do you conduct Hazus field data collection
during a flood event?
2. What is the best way to model an Alaskan log cabin
with Hazus User-Defined Facilities (UDF)?
3. How do you account for glacial till deposition when
developing Hazus user-defined flood depth grids?
4. What process should be used with Hazus to model
climate change impacts for glacially-fed rivers and
streams?
5. What are the best ways to adapt 2D alluvial fan flood
and debris modeling output for use in Hazus?
6. How do you use tsunami model mapping and LIDAR
data to conduct Hazus tsunami risk assessments?

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48. LiDAR-based
Modeling:
100-Year
Floodplains
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Hazus UDF Analysis
with User-Defined Depth Grids

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Hazus Questions
1. How do you conduct Hazus field data collection
during a flood event?
2. What is the best way to model an Alaskan log cabin
with Hazus User-Defined Facilities (UDF)?
3. How do you account for glacial till deposition when
developing Hazus user-defined flood depth grids?
4. What process should be used with Hazus to model
climate change impacts for glacially-fed rivers and
streams?
5. What are the best ways to adapt 2D alluvial fan flood
and debris modeling output for use in Hazus?
6. How do you use tsunami model mapping and LIDAR
data to conduct Hazus tsunami risk assessments?

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54. IPCC emissions scenarios 54

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USGS Regression Equation with
Temp. and Precip. Factors

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Hazus Questions
1. How do you conduct Hazus field data collection
during a flood event?
2. What is the best way to model an Alaskan log cabin
with Hazus User-Defined Facilities (UDF)?
3. How do you account for glacial till deposition when
developing Hazus user-defined flood depth grids?
4. What process should be used with Hazus to model
climate change impacts for glacially-fed rivers and
streams?
5. What are the best ways to adapt 2D alluvial fan flood
and debris modeling output for use in Hazus?
6. How do you use tsunami model mapping and LIDAR
data to conduct Hazus tsunami risk assessments?

62. Lowell Creek Flood Control
„ Built by USACE
in 1945
„ Diverts Lowell
Creek from
historic path
„ Eliminated
annual flooding
of Downtown
Seward
„ No bridge when
the waterfall
was built!

63. USACE 2D model for
alluvial fan
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64. Lowell Creek Waterfall -
Tuesday

65. Lowell Creek - Thursday
Diversion Dam
Tunnel Entrance

66. Lowell Creek Waterfall
Wednesday
Thursday

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Hazus Questions
1. How do you conduct Hazus field data collection
during a flood event?
2. What is the best way to model an Alaskan log cabin
with Hazus User-Defined Facilities (UDF)?
3. How do you account for glacial till deposition when
developing Hazus user-defined flood depth grids?
4. What process should be used with Hazus to model
climate change impacts for glacially-fed rivers and
streams?
5. What are the best ways to adapt 2D alluvial fan flood
and debris modeling output for use in Hazus?
6. How do you use tsunami model mapping and LIDAR
data to conduct Hazus tsunami risk assessments?

69. 2010 Tsunami Study of
1964 Good Friday EQ
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Recap
1. Field data collection: Prepare to get wet, use
technology
2. Hazus UDF: Photos, use existing data from
community
3. Glacial till: LIDAR, LIDAR, LIDAR
4. Climate change: Downscaled climate change data,
regression equations with temp and precip factors,
run Hazus for range of flows only
5. 2D alluvial fan model: Depth grid (think Plinko)
6. Tsunami: Modeling extent and LIDAR to make depth
grid

76. Seward Highway
Milepost 3.5 Overflow
~18” Deep on
Thursday
Eventually,
ADOT&PF did
close the
road…

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Questions?
Rich Chamberlain
Rich.chamberlain@urs.com