BRAZOS RIVER FLOOD GATES FEASIBILITY STUDY

Transcription

1 BRAZOS RIVER FLOOD GATES FEASIBILITY STUDY Stakeholder Involvement August 4, 2015

2 Texas Department of Transportation MISSION STATEMENT Work with others to provide safe and reliable transportation solutions for Texas. GOALS Maintain a safe system Address congestion Connect Texas communities Become best-in-class state agency 2

3 Maritime Division The Maritime Division promotes the development and intermodal connectivity of Texas ports, waterways and marine infrastructure and operations. In 1975 TxDOT was named the official non-federal sponsor for the Gulf Intracoastal Waterway (GIWW) in the Texas Coastal Waterway Act Maritime recently developed a GIWW Master Plan and the Master Plan stakeholders group determined that the Brazos River Floodgates represent the greatest challenge in terms of safety and efficiency anywhere on the entire GIWW TxDOT has initiated the federally required feasibility study on the Floodgates to determine what action needs to be taken to address the safety and efficiency concerns at the structure. 3

4 Brazos River Floodgates Antiquated structure of the gates is not adequate to accommodate modern waterway operations, causing inefficiencies and safety concerns Cost of tripping/impacts: Over $12 million per year 4

5 Stakeholders Group In a Civil Works planning study such as the Brazos River Floodgates (BRFG) Feasibility Study, public involvement, coordination, and collaboration is crucial to successfully conducting a study. TxDOT Maritime is forming a stakeholders group for the BRFG feasibility study to solicit input from users of the floodgates as to operation concerns and solutions to existing problems. TxDOT will open and maintain channels of communication with the public in order to give full consideration to user views and insight in the planning process. 5

6 Stakeholders Group Objectives of Public Involvement: Provide information about proposed activities to the public. Make the public's desires, needs, and concerns known to decision-makers. Provide for consultation with the public before decisions are reached. Consider the public's views in reaching decisions. 6

7 Stakeholders Group Be a Part of the Solution We will be meeting with stakeholders immediately following this presentation. We will also meet directly after the close of the GICA Seminar tomorrow at noon for those who can not meet with us today. Interested parties may also contact Matthew Mahoney at matthew.mahoney@txdot.gov or (512) to be involved with the stakeholders group. 7

8 Brazos River Floodgates Feasibility Study Goals Identify an engineering solution to improve navigation safety and efficiency at the intersection of the GIWW and Brazos River The solution will be evaluated and selected based on following criteria: Improvements to navigation safety and efficiency Impacts to flooding and sedimentation of GIWW from the Brazos River Impacts on the environment Capital and maintenance costs and economic benefit 8

9 Project Delivery Team (PDT) Organization TxDOT Project Manager Matthew Mahoney Independent Technical Review TBD Project Delivery Team Hatch Mott MacDonald (HMM) Project Manager Hugo Bermudez, PE, D.CE USACE Liaison Chris Salles, PMP Environmental Blanton & Associates Task Leader Kim Jenkins-Johnson Assistant Task Leader Jason Schindler Engineering Tetra Tech / HMM Task Leader for H&H Analysis Josh Carter, PE, D.CE Task Leader for Gate/Lock Design Greg Katzenberger, PE Economic Analysis Martin Associates Task Leader John Martin, PhD 9

10 Elements of Study Engineering Analysis and Design Data Collection Development of Alternatives Hydrologic and Hydraulic Analysis/Modeling Coastal Engineering Analysis Gate/Lock Engineering Design Alternatives Analysis and Evaluation Environmental Analysis and Documentation Environmental Impact Statement (EIS) Preparation Economic Analysis Existing Conditions Project Costs Project Benefits Benefit-to-Cost Ratio 10

11 Critical Path Schedule 11

12 Approach to Identify Preferred Engineering Solution Understanding of the problem Types of Engineering solutions Navigation Modifications Hydraulic Modifications Structural Modifications Analysis of alternatives 12

13 One Problem Multiple Factors Barges are larger now current configuration of the flood gates was designed during a time when barges were smaller and pulled rather than pushed by tugs. Collisions and damages 45 degree turn at the Brazos River crossing and the short distance between the gates makes it very difficult for tug captains to make the necessary alignment corrections especially when the Brazos River is at flood stage. Lack of efficiency when the river is at flood stage, barge tows must be broken and tripped one by one across the river for safety. The tripping activity is inefficient, causes congestion and diminishes the economic value of the entire waterway. Hydraulics and Sedimentation along GIWW and Freeport Ship Channel 13

14 Structural Measures Move the gates back away from the river. Increase the width of the channel through the gates. Reconfigure the guide wall to lessen its angle to the GIWW. Create a guide to pivot against. Straighten the crossing at the river, aligning the GIWW at a near- 90-degree angle with the Brazos River. The old bypass channel might be used for this purpose, or the new channel could be routed between the old bypass channel and the existing channel. Construct a true lock on the west end of the Brazos River Floodgates. Establish a more direct outlet for the San Bernard River. Remove the floodgates and dredge to maintain the crossing. 14

15 Complex Hydrodynamics & Sedimentation 15

16 Innovative Engineering Solutions in 3 Categories 1. Navigation Modifications 2. Hydraulic Modifications 3. Structural Modifications 16

17 Challenging Navigation: Narrow Gates Possible Solutions: Structural Modification Channel Realignment Change Gate Location 17

18 Challenging Navigation: Tight Maneuver Possible Solutions: Modify (straighten) alignment [Navigation] Space gates further from river [Navigation] 18

19 Challenging Navigation: tight maneuver with flow gradients Possible Solutions: Stilling basin [Hydraulic] Modify (straighten) alignment [Navigation] Space gates further from river [Navigation] 19

20 Current Locations Existing 20

21 Current Locations New Alignment Concept 1 21

22 Current Locations Proposed Locations New Alignment Concept 1 22

23 Current Locations Proposed Locations New Alignment Concept 2 23

24 Current Locations Concept 3 24

25 Proposed Locations Concept 3 25

26 deepen Proposed Locations New Cut Concept 3 26

27 Comprehensive Modeling Hydrodynamics Hydraulics / Structure Interaction Salinity intrusion Sediment Transport Pathways Sedimentation Sediment Transport Hydraulics & Structure Interaction Brazos River area Hydrodynamics Brazos Locks Hydrodynamics 27

28 Comprehensive Modeling Vessel hydrodynamics Desktop maneuverability and navigation simulation Full-bridge navigation simulation All coupled with custom hydrodynamic models of the site and alternatives Desktop Barge Navigation Simulation Complex Vessel Hydrodynamics Direct interface with Full-Bridge Navigation Simulation (photo courtesy of MITAGS-PMI) 28

29 Structural Innovation Innovation in the Floodgates Minimizing the operating weight of the floodgate Minimizing the surface area of the structural components Minimizing down-time for the floodgates is achieved with innovative structural design. Innovation in other Structures Constructing a true lock West Brazos River Floodgate (with both upstream and downstream gates) Constructing a Guide Pivot Structure or Guide Wall 29

30 Floodgate Design 30

31 Alternatives Matrix Identifying the Best Solution We have used this approach: 1. Savannah Harbor Expansion 6 mitigation plans 2. IHNC Surge Barrier 12 Different Barrier Options 7 Different Gate Options 3. Calcasieu Ship Channel 3 concepts, 28 alternatives Calcasieu Ship Channel 31

32 BRAZOS RIVER FLOOD GATES FEASIBILITY STUDY Stakeholder Involvement August 4, 2015