HURRICANE ISAAC Discussion Thread #19

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE, LA
240 PM CDT TUE SEP 11 2012

...NWS RIVER FLOOD SURVEYS FOR HURRICANE ISAAC - WOLF RIVER...

.OVERVIEW...
VERY HEAVY RAINFALL FROM SLOW-MOVING HURRICANE ISAAC CAUSED
SUBSTANTIAL FLOODING IMPACTS ACROSS THE MISSISSIPPI AND LOUISIANA
GULF COAST REGION. THE NATIONAL WEATHER SERVICE CREATED TEAMS TO
SURVEY THE FLOOD DAMAGE AND ESTIMATE FLOOD SEVERITY IN THE IMPACTED
AREAS. HYDROLOGISTS FROM THE LOWER MISSISSIPPI RIVER FORECAST
CENTER, WFO NEW ORLEANS/BATON ROUGE, WFO JACKSON, AND WFO BIRMINGHAM
CONTRIBUTED TO THESE SURVEYS.

A BAND OF HEAVY RAINFALL FOLLOWED THE ENTIRE WOLF RIVER WATERSHED
FROM THE GULF COAST TO NEAR POPLARVILLE, MS. ESTIMATED RAINFALL
AMOUNTS OF 15 TO 20 INCHES WERE WIDESPREAD ACROSS THE WATERSHED. AT
THE SAME TIME, A SWATH OF RAINFALL TOTALS MEASURING GREATER THAN 20
INCHES FOLLOWED THE GENERAL COURSE OF THE RIVER. FLOOD DAMAGE
CONSISTENT WITH FLOODING OF MAJOR SEVERITY WAS SURVEYED ALONG THE
WOLF RIVER.

.WOLF RIVER AT MS26 EAST OF POPLARVILLE
FLOOD CATEGORY: MAJOR FLOODING, *NEW RECORD STAGE*
RIVER GAUGE: USGS CREST ONLY
PERIOD OF RECORD: 1952-1971, 1998-PRESENT
CREST: 34.5 FT SOMETIME BEFORE 12:05 PM CDT 08/30/2012
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN.
WATER APPEARED TO HAVE KNOCKED OVER FENCING AND A LARGE METAL GATE.

.WOLF RIVER AT SILVER RUN RD EAST OF POPLARVILLE
FLOOD CATEGORY: MAJOR FLOODING
RIVER GAUGE: N/A
CREST: POSSIBLY HIGHEST SINCE AT LEAST 1934
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN,
UP TO ELEVATION ABOUT 1 FT HIGHER THAN DECK OF BRIDGE. EVIDENCE OF
SCOURING AT BRIDGE APPROACH GUARDRAILS. ANECDOTAL EVIDENCE FROM
INDIVIDUAL RESIDING IN THE AREA SUGGESTS THAT FLOOD ELEVATION MAY
HAVE BEEN HIGHER THAN ANY PREVIOUS FLOOD SINCE 1934.

.WOLF RIVER AT MCNEILL-MCHENRY RD NEAR SILVER RUN
FLOOD CATEGORY: MAJOR FLOODING
RIVER GAUGE: N/A
CREST: N/A
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN,
UP TO ELEVATION ABOUT 1 FT HIGHER THAN APPROACHES TO BRIDGE. BRIDGE
WAS ARCH DESIGN THAT DID NOT OVERTOP. LARGE BRANCHES AND OTHER TREE
DEBRIS WAS NOTED ON TOP OF BRIDGE SUPPORT PILINGS. FLOODING WAS ALSO
SURVEYED ALONG GO GO RD JUST UPSTREAM OF SILVER RUN. WATER
ELEVATION IN SMALL DEVELOPED AREA ALONG THE RIVER APPEARED TO REACH
8 T0 10 FT ABOVE GROUND LEVEL IN PLACES. SOME LARGE FLOOD DEBRIS
APPEARED TO HAVE BEEN MOVED ABOUT 100 YDS UNTIL CAUGHT BY THICK
TREES/BRUSH.

.CRANE CREEK AT CRANE CREEK RD NORTHEAST OF NECAISE
FLOOD CATEGORY: MAJOR FLASH FLOODING
RIVER GAUGE: N/A
CREST: N/A
WIDESPREAD BENT TREES/BRUSH IN THE FLOODPLAIN AND MUD MARKS
SUGGESTED FLASH FLOODING REACHING ELEVATIONS OF 1 TO 3 FT OVER
BRIDGE DECK.

.WOLF RIVER AT US53 NORTHWEST OF LYMAN
FLOOD CATEGORY: MODERATE FLOODING
RIVER GAUGE: N/A
CREST: N/A
WIDESPREAD BENT TREES/BRUSH IN THE FLOODPLAIN SUGGESTED FLOODING
COVERING THE FLOODPLAIN REACHING ELEVATION 1 TO 3 FT OVER BRIDGE
DECK.

.WOLF RIVER AT CABLE BRIDGE RD WEST OF LYMAN
FLOOD CATEGORY: MAJOR FLOODING, *NEW RECORD STAGE*
RIVER GAUGE: USGS AUTOMATED GAUGE
PERIOD OF RECORD: 1971-PRESENT
CREST: 31.4 FT ABOUT 3:00PM CDT 08/31/2012
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN.
WATER APPEARED TO HAVE REACHED ELEVATION WITHIN 1 TO 3 FT OF BRIDGE
DECK. FLOODING WAS ALSO SURVEYED NEAR I-10 JUST DOWNSTREAM.
INFORMATION FROM HARRISON COUNTY EM OFFICE AND EVIDENCE FROM SURVEY
SUGGESTS WATER REACHED ELEVATION OF SHOULDER OF BRIDGE APPROACHES,
BUT DID NOT REACH ROAD OR BRIDGE DECK.

.WOLF RIVER AT BELLS FERRY RD NORTHWEST OF LONG BEACH
FLOOD CATEGORY: MAJOR FLOODING, *NEW RECORD STAGE*
RIVER GAUGE: COUNTY STAFF GAUGE
PERIOD OF RECORD: 1981-PRESENT
CREST: 16.0FT ABOUT 12:00PM CDT 09/01/2012
SUMMARY: WIDESPREAD BENT BRUSH AND TREES WITH MUD MARKS. WATER
COVERED BELLS FERRY RD FOR ABOUT 0.8 MI, TO ESTIMATED DEPTH OF 3 TO
4 FT IN MOST PLACES. NUMEROUS PROPERTIES WERE AFFECTED IN THE
TUCKER RD AND MAGNOLIA DR AREAS, WITH STRUCTURES RECEIVING WATER
DAMAGE. CREST STAGE WAS ESTIMATED BY NWS HYDROLOGISTS BY SURVEYING
HIGH WATER MARKS TO THE STAFF GAUGE AND BY ACCUMULATING ANECDOTAL
INFORMATION FROM NUMEROUS RESIDENTS IN THE AREA.

NOTE: SOME INFORMATION IN THIS STATEMENT REMAINS PRELIMINARY AND IS
SUBJECT TO REVIEW/UPDATE BY THE NATIONAL WEATHER SERVICE AND THE US
GEOLOGICAL SURVEY.



893
NOUS44 KLIX 112007
PNSLIX
LAZ034>037-039-040-046>050-056>072-MSZ068>071-077-080>082-012215-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE, LA
240 PM CDT TUE SEP 11 2012

...NWS RIVER FLOOD SURVEYS FOR HURRICANE ISAAC - WOLF RIVER...

.OVERVIEW...
VERY HEAVY RAINFALL FROM SLOW-MOVING HURRICANE ISAAC CAUSED
SUBSTANTIAL FLOODING IMPACTS ACROSS THE MISSISSIPPI AND LOUISIANA
GULF COAST REGION. THE NATIONAL WEATHER SERVICE CREATED TEAMS TO
SURVEY THE FLOOD DAMAGE AND ESTIMATE FLOOD SEVERITY IN THE IMPACTED
AREAS. HYDROLOGISTS FROM THE LOWER MISSISSIPPI RIVER FORECAST
CENTER, WFO NEW ORLEANS/BATON ROUGE, WFO JACKSON, AND WFO BIRMINGHAM
CONTRIBUTED TO THESE SURVEYS.

A BAND OF HEAVY RAINFALL FOLLOWED THE ENTIRE WOLF RIVER WATERSHED
FROM THE GULF COAST TO NEAR POPLARVILLE, MS. ESTIMATED RAINFALL
AMOUNTS OF 15 TO 20 INCHES WERE WIDESPREAD ACROSS THE WATERSHED. AT
THE SAME TIME, A SWATH OF RAINFALL TOTALS MEASURING GREATER THAN 20
INCHES FOLLOWED THE GENERAL COURSE OF THE RIVER. FLOOD DAMAGE
CONSISTENT WITH FLOODING OF MAJOR SEVERITY WAS SURVEYED ALONG THE
WOLF RIVER.

.WOLF RIVER AT MS26 EAST OF POPLARVILLE
FLOOD CATEGORY: MAJOR FLOODING, *NEW RECORD STAGE*
RIVER GAUGE: USGS CREST ONLY
PERIOD OF RECORD: 1952-1971, 1998-PRESENT
CREST: 34.5 FT SOMETIME BEFORE 12:05 PM CDT 08/30/2012
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN.
WATER APPEARED TO HAVE KNOCKED OVER FENCING AND A LARGE METAL GATE.

.WOLF RIVER AT SILVER RUN RD EAST OF POPLARVILLE
FLOOD CATEGORY: MAJOR FLOODING
RIVER GAUGE: N/A
CREST: POSSIBLY HIGHEST SINCE AT LEAST 1934
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN,
UP TO ELEVATION ABOUT 1 FT HIGHER THAN DECK OF BRIDGE. EVIDENCE OF
SCOURING AT BRIDGE APPROACH GUARDRAILS. ANECDOTAL EVIDENCE FROM
INDIVIDUAL RESIDING IN THE AREA SUGGESTS THAT FLOOD ELEVATION MAY
HAVE BEEN HIGHER THAN ANY PREVIOUS FLOOD SINCE 1934.

.WOLF RIVER AT MCNEILL-MCHENRY RD NEAR SILVER RUN
FLOOD CATEGORY: MAJOR FLOODING
RIVER GAUGE: N/A
CREST: N/A
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN,
UP TO ELEVATION ABOUT 1 FT HIGHER THAN APPROACHES TO BRIDGE. BRIDGE
WAS ARCH DESIGN THAT DID NOT OVERTOP. LARGE BRANCHES AND OTHER TREE
DEBRIS WAS NOTED ON TOP OF BRIDGE SUPPORT PILINGS. FLOODING WAS ALSO
SURVEYED ALONG GO GO RD JUST UPSTREAM OF SILVER RUN. WATER
ELEVATION IN SMALL DEVELOPED AREA ALONG THE RIVER APPEARED TO REACH
8 T0 10 FT ABOVE GROUND LEVEL IN PLACES. SOME LARGE FLOOD DEBRIS
APPEARED TO HAVE BEEN MOVED ABOUT 100 YDS UNTIL CAUGHT BY THICK
TREES/BRUSH.

.CRANE CREEK AT CRANE CREEK RD NORTHEAST OF NECAISE
FLOOD CATEGORY: MAJOR FLASH FLOODING
RIVER GAUGE: N/A
CREST: N/A
WIDESPREAD BENT TREES/BRUSH IN THE FLOODPLAIN AND MUD MARKS
SUGGESTED FLASH FLOODING REACHING ELEVATIONS OF 1 TO 3 FT OVER
BRIDGE DECK.

.WOLF RIVER AT US53 NORTHWEST OF LYMAN
FLOOD CATEGORY: MODERATE FLOODING
RIVER GAUGE: N/A
CREST: N/A
WIDESPREAD BENT TREES/BRUSH IN THE FLOODPLAIN SUGGESTED FLOODING
COVERING THE FLOODPLAIN REACHING ELEVATION 1 TO 3 FT OVER BRIDGE
DECK.

.WOLF RIVER AT CABLE BRIDGE RD WEST OF LYMAN
FLOOD CATEGORY: MAJOR FLOODING, *NEW RECORD STAGE*
RIVER GAUGE: USGS AUTOMATED GAUGE
PERIOD OF RECORD: 1971-PRESENT
CREST: 31.4 FT ABOUT 3:00PM CDT 08/31/2012
SUMMARY: WIDESPREAD BENT AND SNAPPED TREES/BRUSH IN THE FLOODPLAIN.
WATER APPEARED TO HAVE REACHED ELEVATION WITHIN 1 TO 3 FT OF BRIDGE
DECK. FLOODING WAS ALSO SURVEYED NEAR I-10 JUST DOWNSTREAM.
INFORMATION FROM HARRISON COUNTY EM OFFICE AND EVIDENCE FROM SURVEY
SUGGESTS WATER REACHED ELEVATION OF SHOULDER OF BRIDGE APPROACHES,
BUT DID NOT REACH ROAD OR BRIDGE DECK.

.WOLF RIVER AT BELLS FERRY RD NORTHWEST OF LONG BEACH
FLOOD CATEGORY: MAJOR FLOODING, *NEW RECORD STAGE*
RIVER GAUGE: COUNTY STAFF GAUGE
PERIOD OF RECORD: 1981-PRESENT
CREST: 16.0FT ABOUT 12:00PM CDT 09/01/2012
SUMMARY: WIDESPREAD BENT BRUSH AND TREES WITH MUD MARKS. WATER
COVERED BELLS FERRY RD FOR ABOUT 0.8 MI, TO ESTIMATED DEPTH OF 3 TO
4 FT IN MOST PLACES. NUMEROUS PROPERTIES WERE AFFECTED IN THE
TUCKER RD AND MAGNOLIA DR AREAS, WITH STRUCTURES RECEIVING WATER
DAMAGE. CREST STAGE WAS ESTIMATED BY NWS HYDROLOGISTS BY SURVEYING
HIGH WATER MARKS TO THE STAFF GAUGE AND BY ACCUMULATING ANECDOTAL
INFORMATION FROM NUMEROUS RESIDENTS IN THE AREA.

NOTE: SOME INFORMATION IN THIS STATEMENT REMAINS PRELIMINARY AND IS
SUBJECT TO REVIEW/UPDATE BY THE NATIONAL WEATHER SERVICE AND THE US
GEOLOGICAL SURVEY.