protect the natural dune seawall, our first line of defense against hurricanes

17
Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes Richard L. Watson, Ph.D. TexasCoastGeology.co m (361) 749-4152

Upload: lahela

Post on 09-Jan-2016

26 views

Category:

Documents


1 download

DESCRIPTION

Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes. Richard L. Watson, Ph.D. TexasCoastGeology.com (361) 749-4152. Protect the Dune Seawall, 1970. TexasCoastGeology.com. Poor Beach Management, 2005. TexasCoastGeology.com. Pure Sand Graded from Road. - PowerPoint PPT Presentation

TRANSCRIPT

Page 1: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Protect The Natural Dune

Seawall, Our First Line of

Defense Against

Hurricanes

Richard L. Watson, Ph.D.

TexasCoastGeology.com

(361) 749-4152

Page 2: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Protect the Dune Seawall, 1970Protect the Dune Seawall, 1970

TexasCoastGeology.com

Page 3: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Poor Beach Management, 2005Poor Beach Management, 2005

TexasCoastGeology.com

Page 4: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Pure Sand Graded from RoadPure Sand Graded from Road

TexasCoastGeology.com

Page 5: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Removing Dune SandRemoving Dune Sand

TexasCoastGeology.com

Page 6: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Lost to the Natural Dune SeawallLost to the Natural Dune Seawall

TexasCoastGeology.com

Page 7: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Port Aransas Beach Regulations

Port Aransas Beach Regulations

The City of Port Aransas shall prohibit The City of Port Aransas shall prohibit beach maintenance activities which will beach maintenance activities which will

result in the SIGNIFICANT result in the SIGNIFICANT REDISTRIBUTION of sand or which will REDISTRIBUTION of sand or which will

SIGNIFICANTLY ALTER THE BEACH SIGNIFICANTLY ALTER THE BEACH PROFILE.PROFILE.

TexasCoastGeology.com

Page 8: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Port Aransas Beach Regulations

Port Aransas Beach Regulations

The City of Port Aransas shall prohibit The City of Port Aransas shall prohibit beach maintenance activities unless beach maintenance activities unless

maintenance activities will not maintenance activities will not materially weaken dunes or dune materially weaken dunes or dune

vegetation or reduce the protective vegetation or reduce the protective functions of the dunes.functions of the dunes.

TexasCoastGeology.com

Page 9: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

State Beach Regulations Add Further LimitationsState Beach Regulations Add Further Limitations

All sand moved or redistributed due to All sand moved or redistributed due to beach maintenance activities shall be beach maintenance activities shall be

returned to the area between the line of returned to the area between the line of vegetation and mean high tide.vegetation and mean high tide.

TexasCoastGeology.com

Page 10: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

State Beach Regulations Add Further LimitationsState Beach Regulations Add Further Limitations

The General Land Office encourages The General Land Office encourages the removal of litter and other debris the removal of litter and other debris by handpicking or raking and strongly by handpicking or raking and strongly discourages the use of machines discourages the use of machines (except during peak visitation periods) (except during peak visitation periods) which disturb the natural balance of which disturb the natural balance of gains and losses in the sand budget gains and losses in the sand budget and the natural cycle of nutrients.and the natural cycle of nutrients.

TexasCoastGeology.com

Page 11: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Violation of Federal Regulations

Violation of Federal Regulations

The U.S. Army Corps of Engineers has The U.S. Army Corps of Engineers has requested that the City of Port Aransas requested that the City of Port Aransas cease dumping sand below the Mean cease dumping sand below the Mean High Water line. To do so, the City High Water line. To do so, the City needs a federal permit or it is in needs a federal permit or it is in violation of the Clean Water Act (CWA).violation of the Clean Water Act (CWA).

TexasCoastGeology.com

Page 12: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

New Dune Ridge in 8 Years, 2005New Dune Ridge in 8 Years, 2005

Page 13: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

High Dune, Wide Beach Best?High Dune, Wide Beach Best?High Dune, Wide Beach Best?High Dune, Wide Beach Best?

• Is a high dune and a wide beach the best protection?

• The most important part is the maximum volume, height and width of dunes.

• Hurricane surge will quickly cross any width beach and begin eroding the dunes.

• We MUST have the largest possible vegetated dune system to buy time for the storm to pass.

• Is a high dune and a wide beach the best protection?

• The most important part is the maximum volume, height and width of dunes.

• Hurricane surge will quickly cross any width beach and begin eroding the dunes.

• We MUST have the largest possible vegetated dune system to buy time for the storm to pass.

Page 14: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

How Should We Manage the Beach?

How Should We Manage the Beach?

• Put a row of bollards in the center of the present road where the trash cans are now.

• Narrow the driving lane or move the present bollards seaward.

• This will maintain a pedestrian beach, a driving roadway, parking, and allow the dunes to grow.

• There is no downside. We maintain the full utility of the beach and get additional hurricane protection at no cost to the City

• Put a row of bollards in the center of the present road where the trash cans are now.

• Narrow the driving lane or move the present bollards seaward.

• This will maintain a pedestrian beach, a driving roadway, parking, and allow the dunes to grow.

• There is no downside. We maintain the full utility of the beach and get additional hurricane protection at no cost to the City

TexasCoastGeology.com

Page 15: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

What about the future?What about the future?• Create a procedure to evaluate future needs,

including after a hurricane as well as after further dune growth.

• Require that the dunes be allowed to grow.• Create a permanent beach and dune

protection board staffed by local citizens and local scientists.

• Recognize that our beach is our most important tourist attraction and our dunes are our most important hurricane protection.

• Create a procedure to evaluate future needs, including after a hurricane as well as after further dune growth.

• Require that the dunes be allowed to grow.• Create a permanent beach and dune

protection board staffed by local citizens and local scientists.

• Recognize that our beach is our most important tourist attraction and our dunes are our most important hurricane protection.

TexasCoastGeology.com

Page 16: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Vegetated Coppice DuneVegetated Coppice Dune

TexasCoastGeology.com

Page 17: Protect The Natural Dune Seawall, Our First Line of Defense Against Hurricanes

Protect The Natural Dune Seawall, Our First Line of

Defense Against

Hurricanes

Richard L. Watson, Ph.D.

TexasCoastGeology.com

(361) 749-4152

•Our best storm Our best storm protection is a protection is a high and wide high and wide natural dune natural dune system.system.

•Let nature build it Let nature build it for us, it is free.for us, it is free.

•Our best storm Our best storm protection is a protection is a high and wide high and wide natural dune natural dune system.system.

•Let nature build it Let nature build it for us, it is free.for us, it is free.