Utilizing FEMA’s National Flood Hazard Layer Web Mapping ......NJ AHPS points with FEMA layers . As of 10/7/2014: • FEMA NFHLs were added to 136 of 191 possible AHPS locations

1

Laurie G. Hogan Ray Kruzdlo Eastern Region Headquarters Mount Holly Weather Forecast Office National Weather Service National Weather Service National Oceanic and Atmospheric Administration National Oceanic and Atmospheric Administration

Utilizing FEMA’s National Flood Hazard Layer Web Mapping Service and Flood Insurance Studies

in the National Weather Service’s Advanced Hydrologic Prediction Services

New Steps in Flood Risk Communication and Decision Support Services

Weather-Ready Nation Be a Force of Nature

2

Flood Risk Communication to the public and state/local partners remains a significant

challenge for Federal Agencies.

Challenge: How do you effectively communicate flood risks?

Desired Results: Improved Awareness, Action


Weather-Ready Nation Motto Be a Force of Nature by knowing your risk, taking action

and being an example in your community.

Why Are We Doing This?

3

2011 NWS Strategic Plan Challenged us to rethink NWS services.

Impact-Focused Services: - Impact-based forecast - Redefine warnings to focus on a broad range of impacts, risks - Develop methods working with partners, to evaluate impacts

and apply results to improve services Decision Support: - Increase direct, interpretive support to the public sector officials

and emergency responders for incidents of national, regional, local significance

- Improve and expand the use of new technologies to communicate with partners, users and employees across NOAA. Examples include advanced visualization tools.


4

Floods are Dangerous and Costly


5

Floods are Dangerous and Costly


85 Total Fatalities

53% of the fatalities were vehicle related.

6

Project Background Facts:

• The National Weather Service’s Advanced Hydrologic Prediction Service (AHPS) is an authoritative source of flood forecasting/warning information

• FEMA is an authoritative source of flood risk information. - Defines the regulatory floodplain for the US. - 92% of the US population is covered.

• In June 2013, FEMA Mapping Information Platform, came online with a National Flood Hazard Layer Web Mapping Service (WMS). https://msc.fema.gov/portal

Approach: Combines the information – where possible.


7

Here’s What We’re Doing

Adding the FEMA National Flood Hazard Layer WMS to the AHPS stream gage locations maps


8

https://hazards.fema.gov/femaportal/wps/portal/NFHLWMS

Adding the Spatial Context of the Floodplain


9

Where are the FEMA layers available in New Jersey?

Not available: •Morris (portions) •Mercer •Burlington •Atlantic (portions) •Salem •Cumberland •Cape May


10

AHPS Locations in New Jersey http://water.weather.gov/ahps/region.php?state=nj


• 191 Gauges

11

NJ AHPS points with FEMA layers

As of 10/7/2014:

• FEMA NFHLs were added to 136 of 191 possible AHPS locations in the state of NJ

• 55 AHPS points in NJ did not have FEMA NFHLs available.

• 70% coverage


12

Further exploration of the FEMA layers


15

16

What Else Can Be Done? Impact-based DSS! Possible Inclusion of the FEMA Flood Insurance

Study Information into AHPS What: • Provide the stage estimates at the stream gage for 1%

exceedance levels (and other levels) • Provide stage estimates at the stream gage for

transportation infrastructure impacts (bridges) Multi-purpose objective: • Allow NWS staff to know the critical thresholds at a very

local level • Resource to local decision makers, industry, public


17

Inclusion of the FEMA Flood Insurance Study Information into AHPS

Methods: • Determine gage locations in FIS flood profiles • Complete spreadsheet of information from the

FIS/AHPS/USGS gage information • Verify a common vertical datum (NGVD29 vs.

NAVD88) for gage information and FIS information • Document Base Flood Elevation (1% exceedance at

the gage) • Translate structure impact information to the gage

elevations • Verify impacts locally with EM’s, add to AHPS


18

Getting Started at msc.fema.gov Example: Hershey, PA Dauphin County


19

Circled locations of interest relative to the FIS cross sections Examples: 1) Hershey stream gage - BZ 2) Sand Beach Rd. - CB,CC 3) Hershey Rd. - BX, BY 4) South Hanover St. – BR, BS (not shown)

Example: Hershey, PA Dauphin County


20

Collection of details from the FIS

Read Volume 1 – FIS study methods, modeling discussion , effective dates, floodway data, map history etc.


21

1% Annual exceedance - Highlighted

Gage “0” ~326’ NGVD 29

From USGS


Hershey Stream Gauge

22

1% Annual exceedance - Highlighted

Sand Beach Rd


23

1% Annual exceedance - Highlighted Hershey Rd (Rte. 39)

South Hanover St.


Shiny and New

24

Note: Bridges can be newer than the structures in the FIS (e.g.. South Hanover St.)

25

The Result

• By subtracting the gauge datum from the 1% exceedance value at a structure (bridge), we will be able to pass on the water level or stage that will affect that structure.

26

Examples of some possible AHPS impacts statements

• Consistent wording for floodplain impacts: 20 - FEMA flood insurance maps indicate that at 20 ft., if you are located in the 1% (100 year) floodplain, your property is at a high risk for flooding. A 1 percent flood is a flood that has a 1 percent chance of occurring in any year.

• Consistent wording for transportation impacts:

18 – Around 18 ft., flood waters begin to reach the bottom edge of the Route 39 Bridge (Hershey Rd) located northwest of Hershey.

• AHPS Impacts will be coordinated with local EMs.


27

FIS-Related Impacts Implementation Strategy

Labor-intensive. Implementation will progress on time-available basis.

Implementation will need coordination with the local EMs, county officials, and USGS.

Supports the NWS strategic plan goals - to

educate and inform the public about flood risk and provided impact-based forecast services to decision makers.


28

Sampling of References/Links

• AHPS: http://water.weather.gov/ahps/region.php?state=nj • FEMA: https://msc.fema.gov/portal • Imagery/map backgrounds • http://nationalbridges.com/ • http://www.ngs.noaa.gov/cgi-bin/VERTCON/vert_con.prl • http://waterdata.usgs.gov/nwis/rt


29

• Raymond Kruzdlo – WFO Mt. Holly, NJ • Northwest through southern NJ

• Nancy Furbush – WFO New York, NY • Northeast NJ

NWS Contacts for PA


30

Questions?

http://water.weather.gov

[email protected] [email protected] [email protected]


Documents

Utilizing FEMA’s National Flood Hazard Layer Web Mapping ......NJ AHPS points with FEMA layers . As of 10/7/2014: • FEMA NFHLs were added to 136 of 191 possible AHPS locations