THE LEVEES OF DALLAS COUNTY · 2018. 4. 14. · THE LEVEES OF DALLAS COUNTY Jessica Baker, EIT, CFM...
Transcript of THE LEVEES OF DALLAS COUNTY · 2018. 4. 14. · THE LEVEES OF DALLAS COUNTY Jessica Baker, EIT, CFM...
THE LEVEES OF
DALLAS COUNTY
Jessica Baker, EIT, CFM
Walter Skipwith, P.E.
Steve Parker, P.E., CFM
TFMA 2008 Spring Conference
League City, TX
May 1, 2008
Introduction
• Map Modernization Program
• Certification
• Dallas County Levees
• Future Changes
MapMod
• $1 Billion
• 5 Years
• Began in 2004
• Requirement – Certify Levees or Else
• Dallas County
– Also began in 2004
– 2-Year Effort
Source: Region VI RMC
FEMA Levee Certification
Requirements
• Design Criteria– Levee Height and Freeboard
– Closures
– Embankment Erosion Protection
– Embankment and Foundation Stability
– Settlement
– Interior Drainage
– Other
• Operation Plans and Criteria
• Maintenance Plans and Criteria
Dallas County LeveesDallas County Levees
• History
– Ag Levees
– Federal Levees
– Municipal Levees
– State Created Levee Improvement Districts
• Inventory
• Process
InventoryInventory
NoUnknownUnknownVarious- Trinity/Tenmile Creek
NoUnknownUnknownVarious- Bois D’Arc
Various� Ag. Levee Districts
Yes4.3Dallas Sanitation DeptDallas� McCommas Bluff Landfill
Yes2.7Dallas/USACEDallas� Rochester Park
Yes6.7DallasDallas� Southside WWTP
Yes2.6Dallas Water
Utilities/USACEDallas� Central WWTP
Yes22.3Dallas/USACEDallas� Dallas Floodway
Trinity River
CERTIFIEDLENGTHOWNER/OPERATORCITYLEVEE DISTRICT
InventoryInventory
NoIrvingIrving� Running Bear Park Levee
Yes1.4DCFCD #1Irving� Dallas County FCD #1
(Bear Creek)
NoGrand PrairieGrand Prairie
� Grand Prairie Gun Club
Yes0.9Grand PrairieGrand Prairie
� Dorchester Levee
Yes1.9GPMURDGrand Prairie
� GPMURD
N/AGrand PrairieGrand Prairie
� City of Grand Prairie Landfill
Yes2.7TRAGrand Prairie
� TRA WWTP
YesInc.
aboveDallas/USACEDallas� Dallas Floodway
West Fork-Trinity River
CERTIFIEDLENGTHOWNER/OPERATORCITYLEVEE DISTRICT
InventoryInventory
Yes3.4DCURDIrving� DCURD (Las Colinas)
Yes8.9VIAFarmers Branch /
Carrollton
� Valwood Improvement Authority
Yes3.5IFCD#3Irving� IFCD #3 (Valley Ranch)
Yes, by PAL2.8IFCD#1/USACEIrving� IFCD #1 (Northwest Levee)
YesInc.
aboveDallas/USACEDallas� Dallas Floodway
Elm Fork-Trinity River
CERTIFIEDLENGTHOWNER/OPERATORCITYLEVEE DISTRICT
ProcessProcess
• FEMA Guidance
– FEMA Does Not Certify Levees
– FEMA Study Contractors Do Not Certify Levees
– Guidance is Forthcoming
– PM 34 (August 2005)
– PM 43
• October 2006, revised in March 2007
• PAL
– FEMA Region VI Levee Certification Process (Dec 2006)
• Letters to the Mayors (September 2006)
Certification ResultsCertification Results
• August 2006 - Preliminary DFIRMs
Submitted, 5 Levee Systems Certified
• June 2007 – Preliminary DFIRMs Published,
14 Levees Certified by Owners and Accredited
by FEMA
• One Levee granted PAL Status
• Two Levees (Ag) Insufficient in Height
• One Levee Insufficient Freeboard
Certification ResultsCertification Results
Case Study: Dallas FloodwayCase Study: Dallas Floodway
• Design Certified by the Corps in July 2006
• O&M Certified By City of Dallas
– Streets - River Levee Division
– Other COD Levees
• Dallas Water Utilities
• Sanitation
• Coordinated by
PW/T
Case Study: IFCD Case Study: IFCD -- 11
• Federal – part of Dallas Floodway Project
– USACE Inspects
• IFCD - 1– Created in 1971
– Constructed Flood Control Facilities in 1974
– Board has Taxing Authority
• City – Irving appoints Board Members
• PAL– Initially Rated Fair by USACE Not Qualifying
– District and City Undertook Emergency Repairs
– Rating Upgraded to Good
– PAL gives District 2 Years to get Certified
Case Study: IFCD Case Study: IFCD -- 11
Levee Slide at IFCD-1
Parallel Levee Channel
Wall Failure
Case Study: IFCD Case Study: IFCD -- 11
During repair of parallel
levee drainage channel
Parallel Levee Channel
in Better Days
Case Study: IFCD Case Study: IFCD -- 11
IFCD-1 Levee at Loop 12 During High Flow
Sheet Pile Wall had to
be replaced to get in to PAL program
Case Study: IFCD Case Study: IFCD -- 11
Drill Rig on Levee
Sampling for Geotechnical Studies
South Levee Tree
Clearing Rehab Construction
Levee Levee
MappingMapping
PAL Note
Levee MappingLevee Mapping
PAL Note
Levee MappingLevee Mapping• Floodway
Mapping to
landside toe of
levee
Future Changes?Future Changes?
• FEMA – Interagency Levee Policy Review Committee– New Flood Zone: XL
– Inventory
– 500-Year Flood Design
– Failure-Resistant Design
– Mandatory Flood Insurance Purchase at some Level
• ASFPM White Paper – Levees: the Double-edged Sword
• ASCE – Policy Statement 511: National Levee Safety Program
THE LEVEES OF
DALLAS COUNTY
Jessica Baker, EIT, CFM
Walter Skipwith, P.E.
Steve Parker, P.E., CFM
TFMA 2008 Spring Conference
League City, TX
May 1, 2008