# Presentation: 524087

## Annual Interagency Water Resources MeetingSouthwestern Division

*March 28, 2007*

## Overview of Water Resources Planning StudiesGalveston District

## Overview of Water Resources Planning Studies

*Galveston District  - FY07 Overview*
*GI  Studies ------ 8*
*CG Studies ------- 1*
*CAP Studies ----  0  *
*O&M Rehab -----2  *

## Overview of Water Resources Planning Studies

*GI Studies and FY07 Fed Funding:*
*     *_*Deep-draft navigation   (deepening and widening)*_
*Brazos Island Harbor Feasibility          $500,000*
*Sabine-Neches Waterway Feasibility   $400,000*
* **Freeport Harbor Feasibility                   $500,000*
_*Shallow draft navigation   (realignments)*_
*GIWW – Port O’Connor to Corpus Christi Feas.  $400,000*
*GIWW –Vicinity of Port Isabel Feasibility            $500,000*
*GIWW –High Island to Brazos                                 $400,000*
_*Shore erosion / ecosystem restoration*_
*Sabine Pass to Galveston Bay Feasibility    $270,000*
*Brownsville Resacas Feasibility                     $150,000*

**Notes:**
The Brazos Island Harbor study, which began in June 2006, will investigate the feasibility of deepening the entrance channel to 50 feet (currently 44 feet) and the main channel to 48 feet (currently 42 feet)  and widening to 400 feet.

Sabine Neches Feasibility is nearing completion and a feasible plan has been identified.   The plan will increase channel depth from 40 to 48 feet.

Freeport Harbor is scheduled to be completed in 2008.  The channel is currently 45-foot and the study is considering depths of 55 and 60 feet.

The Brownsville Resacas study is considering ecosystem restoration ideas for the natural lake features in Brownsville known as resacas.

## Overview of Water Resources Planning Studies

*CG -----------Clear Creek GRR                      $1,000,000*
*                        *
*O&M Rehab ----- Sabine Jetties Rehab*
*                            **---Matagorda Jetties Rehab*

**Notes:**
Clear Creek GRR is a flood damage reduction study for the Clear Creek basin located just south of Houston, Texas.  A feasible plan has been identified and the study is nearing completion.

## Salinity Impacts
Navigability 
               Hydrodynamic modeling of currents
               Ship/Tow Simulator 
Shoreline erosion (due to higher vessel speeds)
Maintenance dredging projections

*Navigability *
*               **Hydrodynamic modeling of currents*
*               **Ship/Tow Simulator** *
*Shoreline erosion (due to higher vessel speeds)*
*Maintenance dredging projections*

*H&H Modeling Issues for Navigation Studies*

**Notes:**
The majority of the FY07 Planning Studies in SWG are navigation studies which can involve complex H&H modeling tasks.  Most of our coastal and navigation related modeling is conducted at ERDC in Vicksburg, MS.
Our District H&H office has wanted to build a capability to handle this work, but this has proven difficult.
Complex hydrodynamic modeling needs super computers not desktop pc’s..  
Project managers want the most best available experts rather than risking time and project funds to grow in-house capability.

ERDC business model is very competitive (with our District H&H).
        Higher salaries structure.
        Constantly developing new tools.
        Not as concerned with creating standard software applications for generalized use in the private sector  (like HEC does).
        They court project managers and operations managers, and work with them directly.

Other competition:  Aggressive sponsors
Section 211(f)of WRDA 96. This authorizes non-Federal interests to plan, design, and construct Federal flood control projects, and upon approval of the project by the Assistant Secretary of the Army (CW), be reimbursed the Federal share of costs of work accomplished.

## Overview of Water Resources Planning Studies

*Questions?*

## Ship / Tow Simulator at ERDC

*Ship / Tow Simulator at ERDC*

**Notes:**
Ship / Tow simulator at ERDC  (photo from ERDC web site)

Corps regulations require simulations for all significant navigation projects and modifications.

## Slide 9

**Notes:**
Example of one of the deep draft navigation studies.  (This is the Brownsville Ship Channel.)

## Slide 10

**Notes:**
Sabine Neches Waterway
Note how far the channel must extend offshore to reach project depth.

## Slide 11

## Clear Creek GRR

**Notes:**
The Clear Creek GRR study is a general re-evaluation study funded through the CG funding.  The basin is just south of Houston.  

## Clear Creek GRR

*Clear Creek GRR*

**Notes:**
On the bottom half, this slide shows flood profiles superimposed with home elevations.  

The top half shows corresponding expected annual flood damages for each economic reach.

## Clear Creek GRR

**Notes:**
H&H modeling effort for the Clear Creek GRR was very large (>$1,000,000).  There were about 30 different first-added flood reduction alternatives.  These were each modeled in multiple sizes on a stand-alone basis.  

This slide shows net benefits for each measure.  Only a few (green ones on the right) had positive net benefits.

After the best were identified the H&H modeling then considered various combination plans so that a optimum plan could be identified.)

## Clear Creek GRR

*Clear Creek GRR*

**Notes:**
This map shows the preliminary NED plan.  There are four conveyance components and four detention components.  This plan was optimized from hundreds of individual and combined measures.

## Clear Creek GRR

**Notes:**
This is the modern template concept proposed for the Clear Creek GRR conveyance components on the creek.  

The idea is to preserve restore the low flow channel to a natural state with shading riparian vegetation.  This promotes good water quality and natural sediment transport regimes.  Capacity is provided by high flow benches which will be mowed.

All the conveyance measures are in portions of the creek that have been previously channelized.  From an environmental perspective, the proposed templates are better than what is is currently in place in many reaches.

## Bolivar Marsh

**Notes:**
This is an example of 1-D, networked, unsteady flow modeling with HEC-RAS for Bolivar Marsh.  

Bolivar Marsh is a beneficial use placement area for dredge material for the Houston Galveston Ship Channel.  

This modeling was performed in-house.  

This 8 day simulation takes about 2 minutes to run on a desktop pc.

## Bolivar Marsh

**Notes:**
This depicts the same scene as the previous slide except the analysis is 2-D RMA2 modeling.  

The 2-D model takes 16 hours to run on a PC.

This modeling was also performed in-house, with ERDC assistance.

## Matagorda Ship Channel Jetties

- Recent Aerial

*Matagorda Ship Channel Jetties*

**Notes:**
The Matagorda Jetties Rehab Study will address a scour problem at the end of the south jetty.  

## Matagorda Ship Channel Jetties

*Matagorda Ship Channel Jetties*

**Notes:**
The scour hole at the end of the South Jetty is over 75 feet deep and is threatening the stability of the jetty.

## Matagorda Ship Channel Jetties

**Notes:**
Here is an interesting simple flow table model that was put together at ERDC.  This test was run with different jetty lengths to see if that was a factor in flow distribution.

## Matagorda Ship Channel Jetties

- Peak Flood – occurred at 4 days 22.5 hrs

*Matagorda Ship Channel Jetties*

**Notes:**
ERDC (Nick Krause and others) also performed 2-D modeling.  This shows current vectors for partial failure of the jetty.  The objective of this analysis was to determine if jetty failure would cause cross currents that would be hazardous for navigation.

## Atkinson Island Mooring Basin

**Notes:**
This is another example of an O&M funded modeling study.  iAtkinson Island Mooring Basin is a shallow draft mooring basin on the Houston Ship Channel located where the channel emerges into Galveston Bay.  Steve Maynord and John Hite at ERDC conducted HIVEL vessel effect modeling for SWG to test different breakwater alternatives.  The basin is currently not used due to excessive wave action from deep draft vessel traffic. This study was completed in 2006.