1. Risk MAP & the Little River Basin
Bob Hanger, City of Norman Dan Cary, Cleveland County
Ron Wanhanen, FEMA Region 6 Vikram Shrivastava, RAMPP
Oklahoma Floodplain Managers Association Annual Conference
Norman, OK
September 19-21, 2011
Ron / FEMA

2. Presentation Overview
Map MOD to Risk MAP
Why Little River Basin?
Project Scope
Revised Analysis and Mapping
Cleveland County, City of Moore, & FEMA Collaboration
Project Study Overview & Results - Preliminary Issuance
Schedule
Information Resources
Discovery - Lower North Canadian Watershed
Questions
Ron / FEMA 2

3. Map MOD to Risk MAP
FY2009 transition from Map Modernization (Map MOD) to FEMA Risk MAP
Three focus areas
Coastal
Levees
Other engineering needs
Ron / FEMA

4. Map MOD to Risk MAP
FEMA Risk Mapping Assessment Planning
Map Modernization used increasingly- available technology to increase the quality, reliability and availability of flood hazard maps and data
It focused on creating digital maps to provide timely, accurate information to community planners
Risk MAP further enhances the maps, involves communities during the assessment and planning stages, and guides and encourages them to communicate risk to their constituents
Ron / FEMA 4 4

5. Map MOD to Risk MAP
Through collaboration with State, Local, and Tribal entities, Risk MAP will deliver quality data that increases public awareness and leads to action that reduces risk to life and property.
Ron / FEMA 5

6. Why Little River Basin? Concerns with Zone A’s on 2008 Effective FIRM
New 2007 LiDAR and Imagery for City of Norman
New development is moving into this area
Bob Hanger

7. Why Little River Basin? City of Norman Stormwater Master Plan (SWMP)
SWMP Basin and Sub Basin data used for FEMA Study
Bob Hanger

8. Why Little River Basin? Project prioritization (FEMA’s Trifecta): Risk
Risk Deciles
Need
Zone As
New Development
Elevation data
2007 LiDAR
Vikram (RAMPP to present)

9. Source: http://www.clevelandcountycourtclerk.com/
Project Scope
Initial Coordination Meeting - October 27, 2009
Communities affected by project
City of Norman
Town of Noble
Oklahoma City
City of Moore
Cleveland County
Over the Shoulder
Meeting – March 15,
2011
Vikram / RAMPP
Source:

10. Project Scope Overview of Scope 14.2 miles to be studied
Detailed (Zone AE) with Floodway
6 Panels to be revised
0025, 0135, 0160, 0180, 0190, 0195, and 0295
Vikram / RAMPP

11. Project Scope – Selected Streams
Community
Stream Name
Study Type
From and To
Total Miles
Town of Noble and City of Norman
Dave Blue Creek
Detailed
From the current upstream limit of detailed study (at N. Main St.) to a point approx. 1 mile upstream of N. Main St.
1.0
City of Moore and City of Norman
Little River
From 12th Ave. NE to the current downstream limit of detailed study (approx. 4,500 feet downstream of SW 34th St.)
7.4
Vikram / RAMPP

12. Project Scope – Selected Streams
Community
Stream Name
Study Type
From and To
Total Miles
City of Moore
Stream E
Detailed
From the current upstream limit of detailed study (approximately 2,200 feet upstream of the confluence of Unnamed Tributary to Stream E) to a point approximately 1.9 miles upstream of the current
1.9
City of Oklahoma City
Tributary 3 of Canadian River Tributary 1
From SW 119th St. to a point approximately 0.9 mile upstream of SW 119th St.
0.9
Vikram / RAMPP

13. Project Scope – Selected Streams
Community
Stream Name
Study Type
From and To
Total Miles
City of Oklahoma City
Unnamed Tributary to Cow Creek Tributary 2 North Branch
Detailed
From the confluence with Cow Creek Tributary 2 North Branch to a point approximately 0.8 mile upstream of the confluence
0.8
City of Moore and City of Norman
Unnamed Tributary to Little River
From the confluence with Little River to a point approximately 1.7 miles upstream of the confluence
1.7
City of Moore and Cleveland County Unincorporated Areas
Stream A
LOMR P incorporation
n/a
Vikram / RAMPP

14. Revised Analysis and Mapping
Topo sources
City of Oklahoma City DEM
City of Norman 2007 LIDAR
National Elevation Dataset (NED)
Updated Imagery - City of Norman for panels 0190, 0195, 0295
Roads – Communities
County Boundary/City Limits: University of Oklahoma Center for Spatial Analysis
Vikram / RAMPP 14

15. Revised Analysis and Mapping
Enhanced Product - Riverine
Hydrology
Regional Regression Equation used for all streams
Vikram / RAMPP 15

16. Revised Analysis and Mapping
Key Areas of Change - Hydrology
Discharge Comparison Table
(effective FIS in parentheses vs. regression equations)
Flooding Source
Location
Drainage Area / sq. miles
Q10yr / cfs
Q50yr / cfs
Q100yr / cfs
Q500yr / cfs
Little River
Increase from Effective
Downstream of the confluence of Stream E
9.12
(8.70)
3,307
(2,590)
6,786
(4,355)
8,175
(5,320)
11,435
(7,680)
Stream E
Increase from Effective
At a point approximately 2,985 ft upstream of Southwest 34th Street
1.24
(1.33)
786
(792)
1,560
(1,320)
1,972
(1,590)
3,172
(2,263)
Trib 3 to Canadian River Trib 1
At Southwest 119th Street
1.21
(0.48)
954
(377)
1,786
(681)
2,147
(836)
3,019
(1,228)
Vikram / RAMPP
Discharge Increases potentially due to drainage area change and urbanization

17. Revised Analysis and Mapping
Enhanced Product - Riverine
Hydraulics
Recreate effective model
HEC-RAS 4.0 / HEC-GeoRAS 4.3
Step-backwater models with normal depth start
Multiple frequencies
Floodway determination
Tie-In to effective BFEs
Review with LOMRs
Redelineation for Tie-ins
Updated Manning’s “n”s
Vikram / RAMPP 17

18. Revised Analysis and Mapping
Key Areas of Change - Hydraulics
Comparison of Roughness Coefficients
Stream Name
revised “n” values
effective “n” values
Channel
Overbanks
Dave Blue Creek
0.045
0.100
Little River
0.020 – 0.090
0.035 – 0.100
Stream E
0.030 – 0.065
0.040 – 0.055
Trib 3 of Canadian River Trib 1
0.015 – 0.065
0.030 – 0.100
Unnamed Trib to Cow Creek Trib 2 North Branch
n/a
Unnamed Trib to Little River
Vikram / RAMPP

19. Revised Analysis and Mapping - Key Areas of Change
Dave Blue Creek:
Panel 295
New Zone AE with Floodway
Potential Development
Vikram / RAMPP
Red lines – effective
Shaded Areas – New or Revised Floodplain

20. Revised Analysis and Mapping - Key Areas of Change
Little River:
Panel 190
Change from Zone A to AE with Floodway
Tie – in
Vikram / RAMPP
Red lines – effective
Shaded Areas – New or Revised Floodplain

21. Revised Analysis and Mapping - Key Areas of Change
Stream E:
Panel 160
Change from Zone A to AE with Floodway
Reduce Zone A area from previous effective
Vikram / RAMPP
Red lines – effective
Shaded Areas – New or Revised Floodplain

22. Revised Analysis and Mapping - Key Areas of Change
Trib 3 of Canadian River Trib 1:
Panel 190
Change from Zone A to AE with Floodway
Vikram / RAMPP
Red lines – effective
Shaded Areas – New or Revised Floodplain

23. Revised Analysis and Mapping - Key Areas of Change
Unnamed Trib to Cow Creek Trib 2 North Branch:
Panels 25 & 135
Change from Zone A to AE with Floodway
Vikram / RAMPP

24. Cleveland County, City of Moore, & FEMA Collaboration
Stream A
FEMA Scoped Study Reach
LOMR ( P) submitted by developed in Cleveland County and City of Moore
Same extents for FEMA Study and LOMR
Data from LOMR used to maximize leverage by community
Dan Cary (Cleveland County) Presents. FEMA worked with County to use LOMR data as opposed to a new analysis. Leveraging local data.

25. Incorporated and superseding RAMPP’s draft analysis
LOMR Incorporation
LOMR P
Incorporated and superseding RAMPP’s draft analysis
Other LOMRs on revised panels will be reviewed for the Preliminary Maps: P P P P P P P
Dan Cary (Cleveland County) Presents. FEMA worked with County to use LOMR data as opposed to a new analysis. Leveraging local data.

26. Revised Analysis and Mapping – Products
Flood Insurance Study
Preliminary DFIRM GIS database
Mapping Panels
Hardcopy & Digital
Ron / FEMA 26

27. Project Study Overview and Results Preliminary Issuance
Tools to assist you in Review of FIRMs
Changes Since Last Map
Available on-line at RiskMAP6.com
Indicate State
Indicate County
Tool allows
Review by panel
Address look ups
Ron / FEMA

28. Schedule Project Task Completed by Issue Preliminary 09/30/2011
Final CCO Meeting
October 2011
90-Day Statutory Appeal Period for new BFEs
Spring 2012
Ron / FEMA 28

29. Information Resources
Ron / FEMA 29 29

30. Discovery - Lower North Canadian Watershed
Ron / FEMA 30

31. Questions?
Ron / FEMA 31