Unalaska Deep Draft Navigation Channel_Industry Day Presentation.pdf

“The views, opinions and findings contained in this report are those of the authors(s) and should not be construed as an official Department of the Army position, policy or decision, unless so designated by other official documentation.”

UNALASKA DEEP DRAFT NAVIGATION CHANNEL

USACE Alaska District

Industry Day

Date: 16 March 2023

PROJECT PURPOSE

GEOTECHNICAL CONDITIONS

3/16/2023

PROJECT CONSTRUCTION PLANS

3/16/2023

PROJECT CONSTRUCTION PLANS

3/16/2023

Minimum Depth: -58 ft. MLLW with 1.5H:1V side slopes

Max Pay Line: -60 ft. MLLW with 2H:1V side slopes

Dredge Depths:

-42 ft. to -60 ft. MLLW

Placement Depths:

-60 ft. to -115 ft. MLLW No placed material allowed over -60’ MLLW

QUESTIONS?

ADDITIONAL INFO

WATER LEVELS DECEMBER 18 – 27, 2023

3/16/2023

Datum Value Description

MHHW 3.60 Mean Higher- High Water

MLLW 0.00 Mean Lower- Low Water

Max Tide 6.70 Highest Observed Tide

Max Tide Date & Time

01/27/1960 22:36

Highest Observed Tide Date & Time

December 25, 2022 Predicted Tide: +4.8 ft.

Observed Water Level: +6.1 ft.

“Storm Surge” 1.3 ft.

https://tidesandcurrents.noaa.gov/datum_options.html#MHHW https://tidesandcurrents.noaa.gov/datum_options.html#MLLW https://tidesandcurrents.noaa.gov/datum_options.html#MAXTIDE https://tidesandcurrents.noaa.gov/datum_options.html#MAXTIDEDT

DEPTH LIMITED WAVE – WAVES OVER THE SPIT

3/16/2023

ᵧb = 0.78 db1 = 48 ft. current depth db2 = 66 ft. dredged depth

Hb1 = 37.4 ft.

Hb2 = 51.5 ft.

Breaking Index (0.78)

Breaking Wave Height

Breaking Depth