Three 500 Year Plus Rain Events

THREE 500 YEAR (PLUS) RAIN EVENTS

IN FOUR YEARS NWS WILMINGTON HYDROLOGIC SERVICE AREA

• 6 COUNTIES IN SE NORTH CAROLINA AND 8 COUNTIES IN NE SOUTH CAROLINA • 11 RIVER FORECAST POINTS, 4 TIDE LOCATIONS, AND ABOUT 30 DATA POINTS • RELATIVELY FLAT COASTAL PLAIN • ELEVATION SEA-LEVEL TO ABOUT 400 FT. BUT MOST RELIEF WEST OF INTERSTATE 95 • US GEOLOGICAL SURVEY “RAPID DEPLOYMENT” GAGES ADDED FOR EXTREME EVENTS LIKE SURGE AND MAJOR FLOODING “HURRICANE JOAQUIN” 2015 THU OCTOBER 1 TO MON OCTOBER 5

Hurricane Joaquin had no direct effect on the area but an upper level low pressure pumped deep tropical moisture into the area including a tap off of Joaquin. Antecedent conditions were dry but resulting rainfall caused a 1 to 3 category improvement in drought conditions on the next week’s US Drought Monitor. “HURRICANE JOAQUIN” 2015 THU OCTOBER 1 TO MON OCTOBER 5

Highest rainfall measurements were in the 20 to 25 inch range over 4 days which is at or above a 1000 year rain event in the NOAA Precipitation Frequency Atlas. Many ground truth reports were in the 200 to 500 year range coming in at 13 to 19 inches of rain for the event. “HURRICANE JOAQUIN” 2015 FLOODING

rd Flooding in Kingstree SC eclipsed record Major flooding in Effingham SC with 3 Major flooding in Conway SC with 3rd set in 1973 by 3 feet (late 1800s) highest level since late 1800s highest level since late 1800s Minor to moderate flooding was experienced in other parts of the ILM service area. Flooding was more widespread in areas served by Charleston and Columbia. HURRICANE MATTHEW OCTOBER 7 AND 8 2016 • MADE LANDFALL AS A CATEGORY 1 STORM NEAR CAPE Matthew ROMAIN ABOUT 11 AM OCTOBER 8 2016 BEFORE HEADING EAST-NORTHEAST OUT TO SEA. • FIRST HURRICANE TO MAKE LANDFALL NORTH OF FLORIDA IN OCTOBER SINCE HAZEL IN 1954 (OCTOBER 15). • PEAK WIND GUSTS WERE GENERALLY IN THE 70 TO 90 Hazel MPH RANGE NEARER THE COAST AND 40 TO 60 MPH INLAND. • MATTHEW RESULTED IN MODERATE TO MAJOR BEACH EROSION AND DAMAGE DUE TO STORM SURGE, PARTICULARLY IN GEORGETOWN AND HORRY COUNTIES. • SEVERAL PIERS WERE PARTIALLY OR COMPLETELY DESTROYED INCLUDING SPRINGMAID PIER IN MYRTLE BEACH RESULTING IN THE LOSS OF A NATIONAL OCEAN SERVICE TIDE GAGE.

NWS Wilmington Hurricane Matthew Information HURRICANE MATTHEW RAINFALL OCTOBER 7 AND 8 2016

When Hurricane Matthew struck our Peak observed 12 to 18 hour rainfall amounts area, antecedent conditions were very wet. In fact, the Lumber river at of 14 to 18 inches fall at or above the 1000 Lumberton was already in minor year return interval. Widespread 8 to 12 flood as the rain began and other inch amounts fall into the 100 to 500 year rivers around the area were on the return interval. high end of the normal range for the Sept 2016 % of time of year. normal rainfall HURRICANE MATTHEW FLOODING THE FLOOD OF A LIFETIME?

• LITTLE PEE DEE RIVER AT GALIVANTS FERRY – RECORD FLOOD, CREST OF 17.1 FEET EXCEEDED PREVIOUS RECORD BY OVER A FOOT (RECORDS BACK TO 1920S) • WACCAMAW RIVER AT CONWAY – RECORD FLOOD, CREST OF 17.9 FEET EXCEEDED RECORD FROM 1928 BY ABOUT AN INCH (RECORDS BACK TO LATE 1800S) • LUMBER RIVER AT LUMBERTON – RECORD FLOOD, CREST OF 28 FEET WAS THE HIGHEST EVER RECORDED AT LUMBERTON THOUGH RECORDS ONLY GO BACK TO THE LATE 1960S. • CAPE FEAR RIVER AT WILLIAM O HUSKE – MAJOR FLOOD, CREST OF 68.46 FEET WAS SECOND HIGHEST EVER AND HIGHEST SINCE 1945 • CAPE FEAR RIVER AT ELIZABETHTOWN – MODERATE FLOOD, CREST OF 36.44 FEET WAS FIFTH HIGHEST EVER (RECORDS SINCE 1915) • CAPE FEAR RIVER AT LOCK 1 NEAR KELLY – MAJOR FLOOD, CREST OF 28.58 FEET SECOND HIGHEST EVER AND HIGEST SINCE 1945. • NE CAPE FEAR NEAR BURGAW – MAJOR FLOOD, CREST OF 17.81 FEET HIGHEST SINCE RECORDS BEGAN IN 1999, NEXT UPSTREAM GAGE AT CHINQUAPIN EXPERIENCED SIXTH HIGHEST CREST SINCE THE 1950S. • BLACK RIVER AT KINGSTREE – MAJOR FLOOD BUT CREST OF 16.41 FEET OVER 6 FEET LOWER THAN 2015 FLOOD. • CAPE FEAR RIVER AT WILMINGTON EXCEEDED THE LEVEL FROM HURRICANE HAZEL BY A FRACTION OF AN INCH. HURRICANE MATTHEW FLOODING THE FLOOD OF A LIFETIME?

Lumberton Lumberton

Matthew resulted in the worst flooding most residents ever experienced in many locations around the area including along the Cape Fear River, Waccamaw River, Little Pee Dee River, Nichols, SC Lumber River, and many of their tributaries including the ICWW at Socastee. Wilmington – US 421 at USS NC HURRICANE FLORENCE SEPTEMBER 13 THROUGH 17 2018 • MADE LANDFALL AS A CATEGORY 1 STORM SOUTH OF WRIGHTSVILLE BEACH ABOUT 7 AM SEPTEMBER 14 2018 BEFORE MOVING SLOWLY TO THE WEST AND THEN NORTHEAST UP THE APPALACHIANS. RAIN BANDS AFFECTED THE AREA THE 13TH THROUGH THE 17TH.

• FIRST HURRICANE TO MAKE US LANDFALL FROM A POSITION SO FAR NORTH WHEN SO FAR EAST (25 DEG NORTH, 50 DEG WEST).

• OVERALL, STORM SURGE AND BEACH EROSION WERE LESS SEVERE FOR THE AREA SERVED BY NWS WILMINGTON THAN WAS EXPERIENCED DURING MATTHEW. HOWEVER, STORM SURGE PRODUCED SIGNIFICANT FLOODING TO THE NORTH.

• 106 MPH WIND GUST AT NWS WILMINGTON WAS THE HIGHEST WIND SPEED RECORDED AT THE OFFICIAL OBSERVATION SITE SINCE 1958.

• WIND DAMAGE IN THE WILMINGTON AREA WAS WORSE THAN OTHER RECENT HURRICANES INCLUDING DIANA IN 1984. HOWEVER, WIND DAMAGE IN AREAS SOUTHWEST OF WILMINGTON WAS WORSE DURING HURRICANE MATTHEW.

NWS Wilmington Hurricane Florence Information HURRICANE FLORENCE RAINFALL

A period of well below normal rainfall from mid August to mid September allowed antecedent conditions that were Several rainfall reports exceed 1000 year return interval near normal to slightly dry to develop. This was despite the amount of about 20 inches. Thirteen to nineteen inch official observation site in Wilmington being the wettest amounts are in the 100 to 500 year return interval. beginning to a year ever prior to Florence. HURRICANE FLORENCE FLOODING MATTHEW WAS BUT A GRASSHOPPER

• LITTLE PEE DEE RIVER AT GALIVANTS FERRY – RECORD FLOOD, CREST OF 17.2 FEET EXCEEDED MATTHEW BY ABOUT AN INCH. • WACCAMAW RIVER AT CONWAY – RECORD FLOOD, CREST OF 21.2 FEET EXCEEDED RECORD FROM MATTHEW BY OVER 3 FEET. • NORTHEAST CAPE FEAR NEAR BURGAW – RECORD FLOOD, CREST OF 25.57 FEET EXCEEDED THE RECORD SET BY HURRICANE FLOYD IN 1999 BY OVER 3 FEET. • LUMBER RIVER AT LUMBERTON – RECORD FLOOD, CREST OF 29 FEET EXCEEDED LEVELS FROM MATTHEW BY ABOUT A FOOT. • CAPE FEAR RIVER AT WILLIAM O HUSKE – MAJOR FLOOD, CREST OF 70.73 FEET EXCEEDED MATTHEW BY OVER 2 FEET AND WAS THE HIGHEST THERE SINCE 1945 (75.5 FEET). • CAPE FEAR RIVER AT ELIZABETHTOWN – MODERATE FLOOD, CREST OF 42.51 FEET WAS SECOND HIGHEST EVER (43.2 FEET IN 1945). • CAPE FEAR RIVER AT LOCK 1 NEAR KELLY – RECORD FLOOD, CREST OF 30.68 FEET EXCEEDED 1945 FLOOD BY ABOUT 1 FOOT AND MATTHEW BY OVER 2 FEET. • PEE DEE RIVER AT PEE DEE – MAJOR FLOOD, CREST OF 31.83 FEET WAS SECOND ONLY TO THE 1945 FLOOD (33.3 FEET , RECORDS TO 1920S) • CAPE FEAR RIVER AT WILMINGTON EXCEEDED THE LEVEL FROM HURRICANES HAZEL AND MATTHEW BY ABOUT AN INCH DUE TO A COMBINATION OF STORM SURGE AND RUNOFF. • BLACK CREEK NEAR QUINBY – RECORD FLOOD, CREST OF 17.36 FEET EXCEEDED 2015 FLOOD BY ABOUT ONE-HALF FOOT. RECORDS BEGAN IN EARLY 2000S AND A FLOOD IN 1994 MAY HAVE BEEN HIGHER. • LYNCHES RIVER AT EFFINGHAM – MODERATE FLOOD • BLACK RIVER AT KINGSTREE DID NOT REACH FLOOD STAGE HURRICANE FLORENCE FLOODING MATTHEW WAS BUT A GRASSHOPPER

US 421 NW of Wilmington US 421 Breach

Duke Energy Sutton Plant

Flooding from Florence became the benchmark for most residents in many locations around the area including those along the Cape Fear River, NE Cape Fear River, Waccamaw River, Pee Dee River, Little Pee Dee River, Lumber River, and many of their tributaries including the ICWW at Socastee. HURRICANE FLORENCE FLOODING MATTHEW WAS BUT A GRASSHOPPER

NE Cape Fear near Burgaw

Flooding along Harrison’s Creek off NE Cape Fear

Lumberton

Conway (before peak) arrived HURRICANE FLORENCE FLOODING MATTHEW WAS BUT A GRASSHOPPER

• FLOODING EXCEEDED AREAS DEFINED AS 100 AND 500 YEAR FLOOD ZONE IN MANY LOCATIONS • AS A RESULT, MANY FLOOD VICTIMS DID NOT HAVE FLOOD INSURANCE • FLORENCE FLOODED ALL OF THE SAME AREAS AS MATTHEW BUT TO A MUCH GREATER MAGNITUDE IN SOME CASES • SMALL TOWNS ALONG THE LUMBER RIVER LIKE FAIRBLUFF NC AND NICHOLS SC WERE DEVASTATED BY MATTHEW AND DEVASTATED AGAIN 2 YEARS INTO THEIR RECOVERY • NATIONAL HISTORIC LANDMARK – PATRIOTS HALL AT MOORES CREEK NATIONAL BATTLEFIELD WAS JUST RESTORED FROM MATTHEW’S FLOODING WHEN FLORENCE FLOODED THE STRUCTURE EVEN MORE SEVERELY. NATIONAL PARK SERVICE MAY INVESTIGATE CREATING A SMALLER REPLICA ON HIGHER GROUND IN THE PARK.