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Harris County Flood Control District Model and Map Maintenance Program

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Presentation on theme: "Harris County Flood Control District Model and Map Maintenance Program"— Presentation transcript:

1 Harris County Flood Control District Model and Map Maintenance Program
Ataul Hannan, P.E., CFM Harris County Flood Control District National Flood Workshop Houston, TX, October 24-26, 2010

2 Overview Harris County Overview Model Management
Mapping Activity Statement No. 14 (HCFCD Agreement with FEMA) LOMR Delegation

3 Harris County

4 Tropical Storm Allison

HCFCD becomes Cooperative Technical Partner (CTP) – 2000 Tropical Storm Allison Recovery Project (TSARP) – June 18, 2007 New LiDAR topo, new models and maps Total Project Cost = $32 Million ($16M – HCFCD and $16M – FEMA) Stats 144 FIRM panels 1300 miles studied 22 watersheds New Network of Benchmarks New Topo HMS RAS DFIRMs We must protect the investment

6 LiDAR Elevation

7 Identified Flood Plains
The Scale of Our Work Identified Flood Plains


9 Why Model Management? Protect the investment
Current and accurate Information to local community & FEMA

10 Model Management Objectives
Continually manage and maintain the integrity of the effective model set Foster a partnership between HCFCD and the Floodplain Administrators Facilitate and expedite model and data distribution Coordinate concurrent development activities in watersheds

11 Standards

12 Why Do We Need Standards?
Purpose Maintain the integrity of the models and supporting data Ensure model modifications are made in a consistent manor so others can easily understand changes

13 Model & Map Standards Channel Cross Sections tied to LiDAR HEC-HMS

14 Standards

15 Modeling Standards Highlights
Model Version (HEC-HMS/HEC-RAS) HEC-HMS (v3.3.0) HEC-RAS (v3.0.1) No model truncation (Section 4.3.3) Use current model set (Section 5.2) Tracking number (Section 5.2) New/modified cross sections (Section 3.4.4) Nomenclature change (Section 3.2) Version: The versions of HEC-HMS and HEC-RAS can always be found on the home page of the M3 website. Truncation: Not a problem any more, look at the entire channel reach – Section 4.3.3 Current Model/Tracking Number: Ensures the user has the most current model – Section 5.2 Cross Section: New Cross Sections (Survey TOB to TOB / Lidar Overbanks) – Section 3.4.2 Nomenclature Change: The effective models are different than the Preliminary Models on the DVD. Preliminary Models are no longer valid. Must use effective models, Grand Father period is quickly approach (Work with HCFCD). – Section 3.2

16 Watershed Wide Updates
Model Management How ? Model Management Continuous Updates Watershed Wide Updates M3 is the Support System

17 Continuous Updates Objective:
Continually update the models and associated data sets due to changes in Floodplain and Floodways which require a LOMR Challenges: Many LOMRs throughout Harris County Multiple LOMR projects – one stream When FEMA approves the first LOMC project, they will issue a LOMC that will re-establish the model. However, FEMA may inadvertently supersede that model by approving the resultant second model. This issue above can be addressed through better coordination. FEMA does not update model data set and the models quickly become out to date and there is no one model which represents all of the approved LOMCs for the stream. FEMA’s model maintenance procedures work for the flood insurance program, but fall short of HCFCD goal. If the project has “no rise”, FEMA is generally satisfied but does not update the model set.

18 Our Agreement with FEMA
Mapping Activity Statement (MAS) Continuous Update Process (MAS No. 14 HCFCD Custodian models MAS = MOA with FEMA

19 Continuous Update LOMR

20 HCFCD and Local Community Agreement and Partnership
Continuous Update HCFCD and Local Community Agreement and Partnership

21 Continuous Update Local Floodplain Administrators
35 Different Floodplain Administrators within Harris County Our Agreement with FPM (Memorandum of Understanding) –mailed on Dec 17, 2009 Cursory review Follow standards Technical resource for communities Yearly workshops 34 Floodplain Administrators, HCFCD would like to conduct a “concurrence review” of all CLOMRs and LOMRs. HCFCD job is not to complete a through technical review. Ensure the standards are followed No model truncation Correct program version Electronic submittal of models and report MOA has been developed and distributed to the 34 Floodplain Administrators Open communication with regard to submitted LOMRs and CLOMRs HCFCD would like to review these LOMRs and CLOMRs Adopt our standards

22 Continuous Update Proposed LOMR FEMA Approval Model to FEMA
Update Master Model Set Local Review

23 Memorandum of Understanding
HCFCD Responsibilities: Provide current/accurate models from web Provide technical resource Provide training (yearly workshops) Local Community Responsibilities: Obtain models from HCFCD Follow Standards Provide HCFCD a copy of map revision submittal for review prior to signing Community Acknowledgement Form

24 What is M3?

25 M3 Functionality Model and Map Management (M3) System
Distribute models and supporting data Track changes to models Facilitate communication between projects Assist HCFCD in the review process

26 M3 Workbench

27 M3 Model Check-Out Benefits
Receive the most current and accurate model Current model versions Modeling standards Notifications of model changes

28 Average 30 to 40 LOMRs per year
Notifications Average 30 to 40 LOMRs per year

29 Notifications Various stages throughout the LOMR or CLOMR acceptance process Regular updates of model and supporting data Large projects in the same location Watershed-wide public projects Information will be available both on the website and through

30 M3 Checker


32 Continuous Updates with LOMR Delegation
Proposed LOMR LOMR Delegation FEMA Approval Model to FEMA Update Master Model Set Local Review

33 Advantages Most current and accurate models and supporting data come directly from HCFCD – one source HCFCD, FEMA and local communities are all in the same datum Knowledge of local area and issues Accessible during review process Technical resource Cut down review time





38 Reduce the risk and rediscover the beauty
QUESTIONS???? Reduce the risk and rediscover the beauty

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