Texas’ Coastal Levees

Jefferson County Drainage District 7

TWCA Fall 2016 ConferenceOctober 13, 2016

TEXAS COASTAL LEVEES

HOW IS AN COASTAL LEVEE DIFFERENT THAN A RIVER LEVEE?

.....TWO WAYS

HOW IS A COASTAL LEVEE DIFFERENT THAN A RIVER LEVEE?

HOW IS A COASTAL LEVEE DIFFERENT THAN A RIVER LEVEE?

Jefferson County DD7

Port Arthur & Vicinity Hurricane Flood Protection Levee 107.42 Sq. Miles in

District Watershed. Two-thirds of District is

below 5 feet above mean sea level.

One-third of District is below 3 feet above mean sea level.

There are 36 miles of levee and floodwall in the District.

There are 276 miles of outfall ditches – 70 are concrete lined.

20 Pump Stations (8.2 million gallons per minutes capacity)

60 % to 70 % Drains to Taylor’s Bayou.

DD7Alligator Bayou Annex ~ Pump Station No.16A

Pumping Capacity 1.5 Million GPM

DD7Hurricane Levee ~ Closure Structures

• There are 54 sites containing 111 Closure Structures located within the 36mile levee.

DD7Hurricane Ike • September 13/14,

2008Hurricane Levee Closure Structure Hwy. 365 Water Elevation Approximately +14.2 Deep

Crane Bayou Pump Station No. 7

Levee system held (no breaches) Minimal damage to levees Supported request for accreditation

Compiled Certification Report 2012-2014 Submitted Certification Report in May 2014 FEMA comments in August 2014

Clarify Levee closures Include Max wave run-up

FEMA comments in July 2015 Provide Information on Levee Penetrations Provide Community Agreements for RR Xings

DD7 FEMA CERTIFICATION PROCESS

PROBLEM TRANSECT J36

PROBLEM TRANSECT J36

Proactive communications with FEMA Acceptable Rating from USACE inspections Keep good records of penetrations and crossings Review of FEMA’s Wave Analysis Important DD7 Accredited by FEMA September 2015

DD7SUCCESSES AND

LESSONS LEARNED

QUESTIONS?

Hurricane Ike in DD7 – Barge aground at HWY 73