This presentation was given to the ALDOT Research Advisory Committee on July 2, 2012 in consideration for funding a two-year monitoring project at Little Lagoon Pass, Alabama.
DSD-INT 2015 - The future of computer modeling of coastal wetland, estuarine,...
Monitoring the Coastal Processes in the Vicinity of Little Lagoon Pass
1. Monitoring the
Coastal Processes
in the Vicinity of
Little Lagoon Pass
A Presentation and Proposal to
the Alabama Department of
Transportation’s Research
Advisory Committee
Scott L. Douglass, PhD, PE, DCE & Bret M. Webb, PhD
University of South Alabama
Department of Civil Engineering
2. Monitoring the Coastal Processes of Little Lagoon Pass Outline
Presentation Outline
• Overview
• History & Motivation
• Relevance
• Monitoring Plan
• Modeling Analysis
• Summary & Conclusions
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
3. Monitoring the Coastal Processes of Little Lagoon Pass Overview
Overview
• Located in Gulf Shores, AL $%&&%&&%''%
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• 2480-acre coastal lake $480-9 #,-./012345167 (")*%+!
• 1 of 5 fresh water coastal lakes
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• Supports abundant marine life
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and wildlife
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• Constricted tidal connection
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• Major impacts by Hurricanes
Frederick (79) and Ivan (04)
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
4. Monitoring the Coastal Processes of Little Lagoon Pass History
History & Motivation
• Tidal inlet moved naturally
• Extension of West Beach Blvd.
necessitated stable inlet
• Tidal inlet “fixed” in place in
1980 with jetties
• Significant blockage of littoral
drift negatively impacts downdrift
(west) shoreline
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
5. Monitoring the Coastal Processes of Little Lagoon Pass History
History & Motivation
• Series of modifications to jetties
exacerbates littoral blockage
• 1991, ALDOT shortens jetties
(court ruling)
• Natural sand bypassing of jetties
is reestablished
• Required dredging frequency
increases (> 90 sq.ft.)
• $10M in 1990s
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
6. Monitoring the Coastal Processes of Little Lagoon Pass Motivation
History & Motivation
• To date, there has been no specific
annual monitoring of the ebb/
flood tidal shoals and littoral
processes at the pass (ruling)
• Any modification to the jetties will
impact coastal processes
• An appropriate monitoring plan
and subsequent analysis will
provide the technical justification
for ALDOT to defend itself against
future litigation
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
7. Monitoring the Coastal Processes of Little Lagoon Pass Relevance
Relevance
• ALDOT has unnecessarily spent
millions of dollars on litigation
• Proposed monitoring and analysis
will:
‣ document response of
shorelines to jetty modifications
‣ provide ALDOT with
defensible technical justification
‣ save ALDOT and AL taxpayer
millions of $ in future legal
expenses
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
8. Monitoring the Coastal Processes of Little Lagoon Pass Monitoring
Monitoring Plan
• 3x per year plus one post-storm
event survey
• Will document and describe
changes to beaches, ebb/flood
tidal shoals, and littoral system
through...
‣ Cross-shore beach profile
surveying (land and water)
‣ Surveying of ebb tidal shoal !
‣ Surveying of flood tidal shoal
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
9. Monitoring the Coastal Processes of Little Lagoon Pass Monitoring
Monitoring Plan
• ~2 miles on east/west of pass !
• Spacing of transects more dense
near pass, less dense with
increasing distance from pass
• Surveys of ebb/flood tidal shoals
• Along-channel surveys
• Comprehensive water quality
mapping of the lagoon for
graduate studies (no cost)
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
10. Monitoring the Coastal Processes of Little Lagoon Pass Modeling
Modeling Analysis
• Application of physics- and process-
based numerical models to evaluate
impacts of jetty modifications
• Pre- and post-project evaluations
(alternatives)
• Will use surveyed bathymetry
• USACE Coastal Modeling System
‣ Tides, Waves, & Currents
‣ Sediment Transport
‣ Structures
‣ Inlet Processes
‣ Morphologic Changes
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb
11. Monitoring the Coastal Processes of Little Lagoon Pass Summary
Summary & Conclusions
• ALDOT has unnecessarily spent
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IN THE UNITED STATES DISTRICT COURT
FOR THE SOUTHERN DISTRICT OF ALABAMA
SOUTHERN DIVISION
$millions on Little Lagoon Pass
LITTLE LAGOON PRESERVATION :
SOCIETY, INC., :
:
Plaintiff, :
:
v. : CIVIL ACTION 06-0120-M
:
litigation
UNITED STATES ARMY CORPS :
OF ENGINEERS, et al., :
:
Defendants. :
MEMORANDUM OPINION AND ORDER
This action comes before the Court on Defendants’ Motion to
• ALDOT does not have any
Dismiss (Docs. 17-18). The parties filed written consent and
this action has been referred to the undersigned Magistrate Judge
to conduct all proceedings and order the entry of judgment in
accordance with 28 U.S.C. § 636(c) and Fed.R.Civ.P. 73 (see Doc.
technical justification to defend
26). After consideration, Defendants’ motion is GRANTED.
The facts of this case, very briefly, are as follows. On
May 8, 2000,1 the predecessor to Sea Mist, Inc. (hereinafter Sea
2
Mist) applied to the Defendant U.S. Army Corps of Engineers
t h e m s e l ve s a g a i n s t f u t u r e
(hereinafter Corps) and the State of Alabama under Section 404 of
litigation
1
Though the application is dated February 8, 2000, it was not
signed until May 8, 2000 (Doc. 27, Exhibit A).
2
Sea Mist is not a party to this action.
• The proposed monitoring plan
and modeling analysis will save
ALDOT and the AL taxpayer
$millions more
University of South Alabama bwebb@usouthal.edu
Department of Civil Engineering http://usacoe.org/bwebb