Free Motion to Dismiss - Rule 12(b)(1) - District Court of Federal Claims - federal

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 1 of 21

Note on the Influence of the Mississippi River Gulf Outlet on Hurricane Induced Storm Surge in New Orleans and Vicinity
Joannes Westerink Civil Engineering and Geological Sciences Notre Dame, Notre Dame IN 46556

Department of University of

Bruce Ebersole Coastal and Hydraulics Laboratory, U.S. Army Engineering Research and Development Center Vicksburg, MS 39180
Harley Winer
New Orleans District, U.S. Army Corps of

Engineers

New Orleans, LA 70160
February 21, 2006

Concerns have been raised regarding the role of the Mississippi River Gulf Outlet (MGO) on storm surge propagation into metropolitan New Orleans and vicinity. This note discusses hydrodynamic model simulations that evaluate the influence of the MRGO on flooding during major hurricane events.
The physical system here is very complex, one comprised of a network of estuaries, lakes, rivers, channels, and low lying wetlands, with topographic major relief defined by river banks and an extensive system oflevees and raised roads. Water surface elevation response is driven by storm surge, tides, and wind-waves. Both storm surge and tides are characterized as forced very long wavelength inertial gravity waves, while wind-waves are gravity waves defined waves propagate and experience various levels of local by their short period. All three types of forcing which can further build amplitudes. In metropolitan New Orleans and vicinity, the amplitude of the tides is small; the maximum tide range is on the order of one half foot in Lake Pontchartrain and two feet in Chandeleur Sound. The amplitude of a storm surge can be much higher; for Hurricane Katrina, the peak storm surge along the MRGO adjacent to the S1. Bernard ParishlChalmette hurricane protection levee was computed to be as much as 18 ft. This note focuses on the relevant long period motion that dominates the circulation patterns in the area. In particular, the impact of the MRGO on large scale catastrophic storm surge development and propagation is examined.

The MRGO is a dredged channel that extends southeast to northwest from the Gulf of Mexico to a point where it first merges with the GulfIntracoastal Waterway (GIWW), and then continues westward until it intersects the Inner Harbor Navigation Canal (IHNC) as shown in Figure i. The first 9 miles, the bar channel, are in the open Gulf. The next 23 miles of the channel lie in the shallow open waters of Breton Sound. From there, the inland cut extends 14 miles to the northwest with open marsh on the northeast and a 4,000-ft wide dredged material placement bank on the southwest side. At this point the channel cuts across the ridge of a relict

i

Defendant's Exhibit C

.

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 2 of 21

the Mississippi River, Bayou La Loutre. For nearly the next 24 miles, there is a the hurricane protection levee atop a dredged material placement bank on the southwest side of channel and Lake Borgne and open marsh lie to the northeast. A portion of the levee protecting S1. Bernard ParishlChalmette and the portion of the hurricane protection levee along the south side of Orleans East Parish, north of the GIWW, form the "funnel" that is often referenced. The point where the MRGO and GIWW channels merge is just to the east of the Paris Road Bridge (see Figure I). From this point, the merged GIWW/MGO channel continues west for about 6 miles to the point where it intersects the IHNC; this portion has hurricane protection levees on both banks. The IHNC extends from Lake Pontchartrain, to the north, to the Mississippi River to the south. The IHNC has levees or floodwalls along both banks. The IHNC Lock, which the IHNC. The connects the IHNC to the Mississippi River, is located at the southern limit of MRGO bar channel authorized depth is 38 ft; the authorized bottom width is 600 ft. The remainder of the channel has an authorized depth of 36 ft and an authorized bottom width of 400 the channel has or 450 ft, depending on location. Due to ship wave erosion, the surface width of increased since its construction at a rate of up to 15 ft per year. The additional eroded open water typically has a depth of six feet or less. Therefore, even an additional 1000 feet of open water
distributary of

adds no more than 6000 square feet of conveyance, about a 21 % increase over the authorized

channel (assuming the channel is 40 feet deep, has a 600 ft wide dredged bottom and a I to 3
side slope).

It is importnt to distinguish between two sections of the MRGO and the role each plays in tide and storm surge propagation. One is the east-west oriented section that runs between the IHNC and the confluence of the GIWW/MGO near the Paris Road Bridge, labeled as the GIWW/MGO in Figure I, and hereafter referred to as Reach 1. The other is the much longer southeast-northwest section designated as the MRGO in Figure I, and hereafter referred to as the
Reach 2.

the MRGO is Reach i, the combined GIWW/MGO. It is through this section of channel that Lake Pontchartrain and Lake Borgne are hydraulically connected to
The critical section of

the this connectivity, the local storm surge and astronomical tide in the IHNC and in the section designated GIWW/MRGO is influenced by the tide and storm surge in both Lake Pontchartrain and Lake Borgne. The two Menteur Pass; the IHNC is the Lakes are also connected to each other via the Rigolets and Chef smallest of the three connections. The Reach I GIWW /MGO section of channel is very importnt in determining the magnitude of storm surge that reaches the IHNC from Lake Borgne
one another via the IHNC. Reach I existed as the GIWW prior to the construction of MRGO, although the maintained depth was lower. Because of

and Breton Sound. Ifthe hydraulic connectivity between Lake Pontchartrain and Lake Borgne is

this point will become primarily influenced by conditions at the IHNC entrance to Lake Pontchartrain; and tide or storm surge to the east of this point wil become primarily influenced by conditions in Lake Borgne.
eliminated at a point within this section of channel, tide or surge to the west of

Much concern seems to be focused on MRGOlReach 2 that runs from the GIWW/MRGO confluence, just east of the Paris Road Bridge, to the southeast. Past work, McAnally and Berger the (1997), Carillo et al. (2001), and Tate et al. (2002) for example, has shown that this section of MRGO channel, along with the critical section, the GIWW/MGOlReach I, plays an important

2

,

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 3 of 21

the astronomical tide wave and in the flux of more saline water from Lake Borgne/Breton Sound into Lake Pontchartrain via the IHNC. The significant role of the the low-amplitude tide has been established. MRGO in the propagation of
role in the propagation of

Three previous studies have been performed to examine the influence of MRGOlReach 2 these studies, Bretschneider and Collins Engineers, New Orleans District (USACE(1966), was performed for the U.S. Army Corps of the jlRGO channel, MV). The primary objective of the study was to determine the effects of and dredged material placement banks, and associated works, on the hurricane surge environment of an area to the east of the Mississippi River from the southern end of the MRGO to the IHNC. The study looked at Hurricane Betsy and six synthetic storms. Based on simplified one-dimensional numerical computations and estimates of channel conveyance effects, the report concluded that Betsy would have produced essentially the same surge elevations with or without the MRGO.
on flooding in New Orleans and vicinity. The first of

The second study was also commissioned by the USACE-MVN and involved "closing" the MRGOlReach 2 with a barrier placed across the MRGO extending out from state road 624 Engineers, New Orleans District, 2003). That and the La Loutre Ridge (U.S. Army Corps of closure was located just to the southeast of Shell Beach in Figure i. The study examined 9 synthetic storms with a track to the west of the Mississippi River running parallel to the MRGO with input strengths varying from 65 to 124 knots and forward speeds ranging from 5 to 20
knots. In addition, Hurricane Betsy input winds were examined. Each of

the 10 storms was

simulated with and without the MRGO closure along the La Loutre Ridge. The study applied the
S08 high resolution unstructured finite element grid with detailed refinement of GIWW, IHNC, the Rigolets Inlet and Chef

the MRGO,

Menteur Pass (Feyen et al. 2005, Westerink et al. 2006). Resolution and domain definition requirements have been verified for the S08 grid and the resulting model has been validated (Blain et al. 1994, Blain et al. 1998, Westerink et al. 2000, Feyen et al. 2002, Feyen et al. 2005, Westerink et al. 2006). The S08 grid applies a larger approximation for the width of the MRGOlReach 2 channel, thus leading to conservative estimates of the influence of the channeL. A two dimensional depth integrated version of the ADCIRC model (Luettich et al. 1992, Luettich and Westerink 2004, Luettich and Westerink, 2005, Westerink et al. 2006), a finite element based shallow water equation code that is accurate, stable and robust, was used to perform the computations.

Results from this study showed that for low-amplitude storm surges (peak surge having a magnitude of 4 feet or less), the presence ofMRGOlReach 2 increased the storm surge by up to the following amounts: 0.5 ft at Shell Beach and Bayou Dupre, and 0.3 ft at Paris Road Bridge and the IHNC Lock. For nearly all situations that were examined (results for all ten storms at the four locations shown in Figure i), the presence of the MRGOlReach 2 either did not cause a significant change or the increase was less than 0.3 ft. Ina few situations, notably a slow
moving weak storm, the presence of

the MRGOlReach 2 channel actually led to a very small

decrease in peak surge level at the four locations. For higher amplitude storm surges, peak
surges on the order of7 to 12 feet (which included Hurricane Betsy), changes induced by

MRGOlReach 2 were 0.3 ft or less for all situations. The MRGO did however considerably enhance drainage from Lake Pontchartrain through the IHNCIGIWW out to Breton Sound
following passage of

the storms.

3

,

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 4 of 21

Natural A follow up study was commissioned by the State of Louisiana, Departent of Resources and implemented by URS Corporation (2006). This study applied the same unstructured S08 grid but filled in the MRGOlReach 2 channel to surrounding topographic/bathymetric levels. This study also applied the ADCIRC code and the results were the MRGO had a very limited impact on similar to the USACE-MV study. Reach 2 of increasing storm surge for large storms, including Hurricanes Betsy and Katrina. All changes New Orleans. were less than 0.6 ft and most changes were less than 0.3 ft, in the vicinity of Results also indicated that the MRGO enhanced post storm drainage from portions of the system.

In general, the studies cited above reached consistent conclusions. The change in storm surge induced by MRGOlReach 2 (computed as a percentage of the peak surge magnitude) is greatest when the amplitude of the storm surge is low, on the order of a few feet or less. In these situations, changes induced by the MRGO are rather small, 0.5 ft or less, but this amount is as much as 25% of the peak surge amplitude. When the long wave amplitude is very low, the surge is more limited to propagation via the channels. Once the surge amplitude increases to the
point where the wetlands become inundated, this section of

the MRGO plays a diminishing role

in influencing the amplitude of storm surge that reaches the vicinity of metropolitan New Orleans. For storm surges of the magnitude produced by Hurricanes Betsy and Katrina, which overwhelmed the wetland system, the influence ofMRGOlReach 2 on storm surge propagation is rather small. When the expansive wetland is inundated, the storm surge propagates primarily through the water column over this much larger flooded area, and the channels become a much smaller contributor to water conveyance. The results of these studies can be readily understood by considering in more detail the
evolution of storm surge for critical hurricane tracks passing to the west of

the Mississippi River.

These storms blow wind across the region first from the norteast, then from the east, then from the southeast and south and finally from the west. The sustained northeasterly and especially easterly winds push water onto the wide and shallow Mississippi-Alabama Shelf into Breton and Chandeleur Sounds, and Lake Borgne. These winds build surge up regionally on the shelf and in particular against the Mississippi River and hurricane protection levees in Plaquemines Parish, against the St. Bernard ParishlChalmette hurricane protection levee system and into the so called funnel defined by the levees protecting St. Bernard ParishlChalmette and New Orleans East along the confluence of the GIWW/MRGO. As winds become southerly, the significant surge that has built up along the Mississippi River levees in southern Plaquemines Parish starts to propagate north as a constrained wave up the Mississippi River and as an unconstrained wave through Breton Sound; both influenced by the strength and direction of the winds. Finally, westerly winds blow surge away from these levees.
We note that the surge driven by the sustained northeasterly and easterly winds is not influenced by the MRGO, since the direction of water movement is from east to west across Breton and Chandeleur Sounds and Lake Borgne. The brief southeasterly and southerly winds do guide the substantial surge wave that has built up in Plaquemines Parish north across Breton Sound. In the case of Hurricane Betsy, the surge propagated in a northerly direction along the Mississippi River levees and was stopped by river levees at English Turn. In the case of Hurricane Katrina, the surge propagated in a northeasterly direction perpendicular to the MRGO

4

,

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 5 of 21

towards Gulfport, Mississippi. In either case, the northerly movement of

water is not

significantly influenced by the MRGO since the size of the surge is substantially larger than the increased cross sectional area for flow, or conveyance, offered by the MRGO. Furthermore the alignment of the MRGO does not coincide with the direction of propagation of the massive surge as it heads north and only briefly coincides with southeasterly winds which locally force flow.

We have simulated Hurricane Katrina both with the MRGOlReach 2 in place as well as with the MRGOlReach 2 filled to surrounding bathymetric and topographic levels. The hydrodynamic computations were performed with the TFO I ADCIRC model of Southern Louisiana which is a refinement of the earlier S08 model with added details and resolution for the coastal floodplains of the north shore of Lake Pontchartrain, Mississippi and Alabama (Interagency Performance Evaluation Task Force, 2006). We applied identical wind and pressure fields derived from a Planetary Boundary Layer (PBL) model to simulate the atmospheric forcing functions during the Katrina event (Thompson and Cardone, 1996). A sequence of hourly snapshots of water surface elevations with super-imposed winds (Figure 2) shows the evolution of storm surge with the MRGO in place. More detailed elevation values are given in corresponding labeled water elevation contour plots in Figure 3. Surge buildup starts with easterly winds blowing water from east to west against the Mississippi River levees in Plaquemines Parish as well against the hurricane protection levees of S1. Bernard ParishlChalmette in addition to driving water into the funnel defined by the levees protecting St. Bernard ParishlChalmette and New Orleans East. When winds become southerly, the massive surge that has built up in Breton Sound propagates north. We note that the northeasterly propagating storm surge has a crown of more than 16 ft above NGVD 29 extending out more
than 12 miles and water levels in the entire Mississippi-Alabama Shelf

exceed 10 ft above

NGVD 29.

The simulation without the MRGOlReach 2 results in very similar water levels in most of the domain for the Katrina event. Differences in the maximum Katrina event water levels with and without the MRGO in place are shown in Figures 4a and 4b. Notable differences with the MRGO Reach 2 channel in place are as follows: there is a reduction of water level of up to 0.2 ft at the entrance to the MRGO's inland cut; there is an increase of 0.3 to 0.4 ft in the marshes west of the MRGO in the region delineated by Pointe a la Hache, Carlisle, Stella, Caernarvon and Verret; a maximum increase of approximately 1.1 ft locally east of English Turn; in Lake Borgne along the MRGO there is a 0.1 to 0.2 ft increase; there is a 0.1 to 0.2 ft decrease along the St. Bernard ParishlChalmette protection levee; and finally there is a 0.1 to 0.2 ft increase in a portion of the GIWW/MGOlReach 1. In all other regions, including in the IHNC, differences are less than 0.1 ft. In addition, the New Orleans and vicinity protection system is not impacted more than 0.2 ft. These results coincide with those from the earlier studies. We note that the small increases in surge due to the presence of MRGOlReach 2 can be traced to the alignent of the local southeasterly winds that briefly occur later in the storm and that do in fact drive more water up the MRGOlReach 2. These waters then feed into the northward-propagating surge wave and spread laterally relative to the propagation direction. However due to fact that the alignment between the wind and the MRGOlReach 2 is brief and in light of the shelf-wide high water levels
at this stage of the storm, the impact on channel conveyance is smalL. The largest difference and

its associated pattern seen at English Turn is related to this mechanism as well as small differences in the northward propagating waves' phasing properties coupled with the winds

5

-

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 6 of 21

turning at this point as the eye of the storm moves across this area. The small decreases in maximum water elevations occur due to a small reduction in the local resistance to water being pushed by local winds in a northwesterly direction at the entrance to the MRGO/Reach 2 inland
cut and due to increased water depths reducing local set-up against the S1. Bernard Parish! Chalmette protection levee (local wind driven set-up is inversely proportional to the depth ofthe

water). .
The reasons for the very limited influence of

New Orleans for strong storm events are clear. First, the MRGO does not influence the importnt preliminary east-west movement of water that drives the significant build up of surge in the later stages ofthe early parts of the storm. Second, the northerly propagation of surge during the storm are only minimally influenced by the MRGO because the increased hydraulic conveyance associated with the channel is very limited for large storms due to the large surge magnitude and especially due to the very large lateral extent of the high waters on the Mississippi-Alabama shelf that build up early on from the east. In addition, the propagation direction of this surge wave does not typically align with the MRGO and furthermore the southeasterly winds which
the MRGOlReach 2 in the vicinity of

align with the MRGO occur only very briefly.

The fact that all studies show a larger proportional influence of the presence of the MRGOlReach 2 for low intensity (low peak surge magnitude) events is related to the fact that the proportional increase in conveyance due to Reach 2 is greater when the surge is small and the water levels in Breton Sound and Lake Borgne are generally low. This also explains why we see a more rapid drop in post-storm Lake Pontchartain levels for large-scale events with the MRGO in place. Waters typically withdraw relatively rapidly from Breton Sound and Lake Borgne due to the direct connection to open waters. The total combined conveyance of the Rigolets, Chef Menteur Pass and the IHC/GIWW/MGO system is increased with the MRGO in place under
the lower post-storm levels on the Mississippi-Alabama shelf.

While the simulations clearly show that the Reach 2 of the MRGO does not significantly influence the development of surge in the region for large storm events, the presence of the critical Reach i combined GIWW/MGO and IHNC connection between Lake Borgne and Lake Pontchartrain as well as the funnel defined by the hurricane protection levees along the banks of the MRGO and GIWW locally collect and focus surge in the region, influencing all hydraulically-connected regions as well as New Orleans proper. The degree offocusing by the levees which form the funnel is a function of the wind speed and direction. Strong winds from the east tend to maximize the local funneling effect.

6

,

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 7 of 21

References

Blain, C.A., U. Westerink and R.A. Luettich, 1994: The Influence of Domain Size on the Response Characteristics of a Hurricane Storm Surge ModeL. Journal of Geophysical
Research - Oceans, 99, C9, 18467-18479.

Blain, c.A., U. Westerink and R.A. Luettich, 1998: Grid Convergence Studies for the Prediction of Hurricane Storm Surge. International Journal for Numerical Methods in Fluids, 26, 369401.
Bretschneider, C. L., and J.r. Collins, 1966: Storm Surge Effects of

the Mississippi River-Gulf Outlet, Study A. NESCO Report SN-326-A, National Engineering Science Company, Pasadena, CA.

Carillo, A. R., R.C. Berger, M.S. Sarruff, and 8.J. Thibodeaux, 2001: Salinity Changes in Pontchartrain Basin Estuary, Louisiana, Resulting from Mississippi River-Gulf Outlet Partial Closure Plans. ERDC/CHL TR-OI-04, U.S. Ary Corps of Engineers, Engineer Research and Development Center, Vicksburg, MS.
Feyen, J.C., J.H. Atkinson and J.1. Westerink, 2002: GWCE-Based Shallow Water Equation Simulations of the Lake Pontchartrain - Lake Borgne Tidal System. Computational Methods in Water Resources XIV, S.M. Hassanizadeh et al. Eds., Volume 2, Developments in Water
Science, 47, Elsevier, Amsterdam, 1581-1588.

Feyen, J.C., U. Westerink, R.A. Luettich, J.H. Atkinson, C.N. Dawson, M.D. Powell, J.P. Dunion, H.1. Roberts, E. J. Kubatko, H. Pourtheri, 2005: A New Generation Hurricane Storm Surge Model for Southem Louisiana. Bulletin of the American Meteorological Society, In Review.
Interagency Performance Evaluation Task Force, 2006: Performance Evaluation Plan and Interim Status, Report I of a Series; Performance Evaluation of the New Orleans and Southeast Louisiana Hurricane Protection System. Report MMTF 00038-06, U.S. Army
Corps of

Engineers, Washington D.C.

Luettich, R.A., J.J. Westerink, and N.W. Scheffner, 1992: ADCIRC: An Advanced ThreeDimensional Circulation Model for Shelves, Coasts and Estuaries, Report I: Theory and Methodology of ADCIRC-2DDI and ADCIRC-3DL. Technical Report DRP-92-6,
Departent of the Army, U.S. Ary Corps of

Engineers, Washington D.C.

Luettich, R.A. and U. Westerink, 2004: Formulation and Numerical Implementation ofthe 2D/3D ADCIRC Finite Element Model Version 44.XX.
htt://ww.marine.unc.edu/C CATS/adcirc/adcirc theorv 2004 12 08.pdf

Luettich, R.A. and U. Westerink, 2005: ADCIRC: A Parallel Advanced Circulation Model for

Oceanic, Coastal and Estuarine Waters; Users Manual for Version 45.08. htt://ww.marine.unc.edu/C CATS/adcirc/documentlADCIRC title page.html

7

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 8 of 21

McAnally, W. H., and R.C. Berger, 1997: Salinity Changes in Pontchartrain Basin Estuary Resulting from Bonnet Carre Freshwater Diversion. Technical Report CHL-97-2, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS.

Tate, J. N., A.R. Carilo, R.C. Berger, and B.1. Thibodeaux, 2002: Salinity Changes in
Pontchartain Estuary, Louisiana, Resulting from Mississippi River-Gulf Outlet Partial
Closure Plans and Width Reduction. ERDCICHL TR-02-12, U.S. Army Corps of

Engineers,

Engineer Research and Development Center, Vicksburg, MS.
Thompson, E.F., and V.1. Cardone, 1996: Practical Modeling of Journal of

Hurricane Surface Wind Fields.

Waterway, Port, and Coastal Engineering., 122,4,195-205.
Engineers, New Orleans District, 2003: Numerical Modeling of

U.S. Army Corps of

Storm

Surge Effect ofMRGO Closure. New Orleans, LA.
URS Corporation, 2006: The Direct Impact of the Mississippi River Gulf

Storm Surge. Performed under contract 2503-05-39, Prepared for State of Department of

Outlet on Hurricane Louisiana

Natural Resources, Baton Rouge, LA.

Westerink, U., R.A. Luettich, H. Pourtheri, 2000: Preliminary Sensitivity Studies of Tidal
Response in the Lake Ponchartain-Lake Borgne System. Contractors report prepared for the Engineers, New Orleans District, New Orleans, LA. U.S. Army Corps of
Westerink, J.J., R.A. Luettich, J.C. Feyen, J.H. Atkinson, C. Dawson, M.D. Powell, J.P. Dunion, H.1. Roberts, E. J. Kubatko, H. Pourtheri, 2006: A Basin to Channel Scale Unstructured Grid Hurricane Storm Surge Model for Southern Louisiana. Monthly Weather Review, To
be submitted.

8

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 9 of 21

Figure la. Satellte image of Southeastern Louisiana.

Figure I b. Satellite image of metropolita New Orleans and vicinity.

9

-

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 10 of 21

-::---iai-..
.. ".
.. ..
... ,.. '"

-::.-

..

...aI.....-

Figure 2a. Water surface elevation with respect to the NGVD29 (ft) with boundar layer adjusted
wind velocity vectors (knots) during Hurricane Katrina on August 29, 2005 at 0700UTC.

-----..:~_.. ~ ..
.. .. ,..
...

--...
'''.-

.. .. :::

..

Figure 2b. Water surface elevation with respect to the NGVD 29 (ft) with boundary layer adjusted wind velocity vectors (knots) during Hurricane Katrina on August 29, 2005 at 1000UTC.
10

,

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 11 of 21

-::---..,ii.,
., ."
., " ..
.., '"

-...::' .,

Figure 2c. Water surface elevation with respect to the NGVD 29 (ft) with boundary layer adjusted
wind velocity vectors (knots) during Hurricane Katrina on August 29, 2005 at Ii OOUTC.

-::---in,.... .'
." ". ,..
..,

--::'

.. ..

..

~

,"'..-

Figure 2d. Water surface elevation with respect to the NGVD 29 (ft) with boundary layer adjusted wind velocity vectors (knots) during Hurricane Katrina on August 29,2005 at 1200UTC.

II

.-

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 12 of 21

-::---in:ii-.'
., ".
,"
'"

-.~::'

.. ..

..

..

.....-

Figure 2e. Water surface elevation with respect to the NGVD 29 (ft) with boundary layer adjusted
wind velocity vectors (knots) during Hurricane Katrina on August 29,2005 at 1300UTC.

Figure 2f. Water surface elevation with respect to the NGVD 29 (ft) with boundary layer adjusted
wind velocity vectors (knots) during Hurricane Katrina on August 29,2005 at 1400UTC.

12

-

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 13 of 21

Figure 2g. Water surface elevation with respect to the NGVD 29 (ft) with boundar layer adjusted wind velocity vectors (knots) during Hurricane Katrina on August 29,2005 at 1500UTC.

-..---IU'-_. .'
., u '"
..,

,"....-

-.._-

.., " .. i:, .,

Figure 2h. Water surface elevation with respect to the NGVD 29 (ft) with boundar layer adjusted
wind velocity vectors (knots) during Hurricane Katrina on August 29,2005 at 1600UTC.

13

,

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 14 of 21

-----in,-~ ..
.' ."
," .., .. ..
'"

~, -.._~

Figure 2i. Water surface elevation with respect to the NGVD 29 (ft) with boundary layer adjusted
wind velocity vectors (knots) during Hurricane Katrina on August 29,2005 at l700UTC.

"":t---q,-., ..
". ...
..,

.. ..

..

Figure 2j. Water surface elevation with respect to the NGVD 29 (ft) with boundar layer adjusted wind velocity vectors (knots) during Hurricane Katrina on August 29,2005 at 2000UTC.
14

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 15 of 21

-=--_-..,.,iaø
., ."
'"

--.,

'..

" ..

'" .., '"

Figure 2k. Water surface elevation with respect to the NGVD 29 (ft) with boundar layer adjusted wind velocity vectors (knots) during Hurricane Katrina on August 29, 2005 at 2300UTC.

-~---..,_ø ..
.' '"

.,

" .. " ..

'" .., ,,,

~

Figure 3a. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane Katrina on August 29,2005 at 0700UTC.

15

,

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 16 of 21

-----ia,-"" ~ ..
., ",
.. .. .. ..
... .., ..,

~

Figure 3b. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane Katrina on August 29,2005 at 1000UTC.

-::---II'''-., ",
'" '"

.. .. " ..

.., ..,

.'

Figure 3c. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane Katrina on August 29,2005 at IIOOUTC.

16

~

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 17 of 21

------..,-"" ..
.. ,.. .. ..
.. ~ ..

.' ."

.,

. Figure 3d. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane Katrina on August 29, 2005 at 1200UTC.

"":o-_---:io,,,,, .. .,
'"

.. " ~ " .,
..

,..

...

Figure 3e. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during Hurricane Katrina on August 29, 2005 at l300UTC.

17

-

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 18 of 21

-----ia,-~ ..
., ."
"' ..
,.. ..,

.. u u

.,

Figure 3f. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane KatrIna on August 29, 2005 at 1400UTC.

-;:---iA:_..
., '"
.., ...
,,, ..

.. u ..

..

Figure 3g. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane Katrina on August 29, 2005 at 1500UTC.

18

-

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 19 of 21

-.:---""'-..
., ."
...
..,

" " " .,

., ..

Figure 3h. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane Katrina on August 29,2005 at 1600UTC.

-:0---II:-.' .,
.. '"
'"

" .. " .,

..

..

Figure 3i. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during
Hurricane Katrina on August 29, 2005 at 1700UTC.

19

~

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 20 of 21

-----....,-.. .,
~

.. .. .. ~ ..

." ,..
,"

Figure 3j. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during Hurricane Katrina on August 29, 2005 at 2000UTC.

-----ii:"-"" _. .'
.,
'"

.. " " ~ " .,

...

'"

Figure 3k. Water surface elevation with respect to the NGVD 29 (ft) with labeled contours during Hurricane Katrina on August 29, 2005 at 2300UTC.
20

-

Case 1:05-cv-01119-SGB

Document 27-4

Filed 10/04/2006

Page 21 of 21

""--ut_""'8-'" .. .. .. .. ..
.. ..

-~
--¿-, ."¡'!;
r~ -:"'.' 'Po

: .~

-I

~

8

./

/

"

Figure 4a. Maximum Hurricane Katrina event differences in ft, for simulations with and without the MRGO in place. Positive differences indicate increased elevations with the MRGO in place while negative differences indicate decreased water levels with the MRGO in place.

--_-~ ~ 1.1 ..
,. .. .. .. .. ..

-.
./

--

.. .. .. ., ..
4'

.. .. ..

~-. ~~.: \ '

._,~~ ) ) ~l- I.,
Figure 4b. Maximum Hurricane Katrina event differences in ft in metropolitan New Orleans and vicinity, for simulations with and without the MRGO in place. Positive differences indicate increased elevations with the MRGO in place while negative differences indicate decreased water levels with
the MRGO in place.

21

--