011  
NOUS44 KJAN 172159  
PNSJAN  
 
PUBLIC INFORMATION STATEMENT  
NATIONAL WEATHER SERVICE JACKSON MS  
359 PM CST MON FEB 17 2020  
 
....FLOOD OF FEBRUARY 2020 IS SIMILAR IN FLOW TO THE FLOOD MAY OF  
1983...  
 
ON TUESDAY MAY 24, 1983, ROSS BARNETT RESERVOIR BEGAN DISCHARGING  
78,000 CUBIC FEET PER SECOND (CFS) OF WATER INTO PEARL RIVER  
BELOW. THIS DISCHARGE CONTINUED FOR 15 HOURS. THE PEARL RIVER AT  
JACKSON CRESTED AT 39.48 FEET ON WEDNESDAY MAY 25TH WHICH  
CORRESPONDS TO A FLOW PAST THE RIVER GAGE OF 79,500 CUBIC FEET PER  
SECOND.  
 
ON EARLY SUNDAY FEBRUARY 16TH,2020, ROSS BARNETT RESERVOIR BEGAN  
DISCHARGING 78,316 CUBIC FEET PER SECOND (CFS) OF WATER INTO THE  
PEARL RIVER BELOW. THIS DISCHARGE CONTINUED FOR 6 HOURS. THE  
PEARL RIVER IS NEAR CREST THIS AFTERNOON AROUND 36.60 FEET WHICH  
CORRESPONDS TO A FLOW PAST THE RIVER GAGE OF 76,550 CUBIC FEET PER  
SECOND.  
 
COMPARING OUR CURRENT FLOOD EVENT WITH THE MAY OF 1983 FLOOD  
EVENT, THEY BOTH HAVE NEARLY THE SAME DISCHARGES FROM THE  
RESERVOIR AND SIMILAR DISCHARGES AT THE RIVER GAGE ON HIGHWAY 80.  
THE BIGGEST DIFFERENCE OCCURS WHEN WE LOOK AT THE STAGE (WATER  
LEVEL). AT HIGHWAY 80, THE CREST OF MAY 1983 WAS 2.88 FEET  
HIGHER. WHY IS JACKSON NOT AS HIGH DURING OUR CURRENT FLOOD EVENT?  
FOR ONE REASON, THE RIVER IS MORE EFFICIENT WHICH MEANS THE RIVER  
COULD BE MUCH DEEPER AFTER PAST FLOODS HAVE CARRIED AWAY THE SILT  
OUT OF THE BOTTOM OF THE STREAM. ANOTHER POSSIBILITY, THE  
CLEARING OF TREES ALONG THE FLOOD PLAIN AFTER THE 1983 FLOOD. THIS  
WOULD ALLOW THE RIVER TO FLOW FASTER NOT BEING IMPEDED BY TREES.  
 
THIS SITUATION HAS BENEFITED THOSE IN DOWNTOWN JACKSON WHERE THE  
RIVER IS MUCH LOWER THAN EXPECTED. MOST WOULD ASK, "WHAT ABOUT  
THE AREAS THAT FLOODED IN NORTHEAST JACKSON?" MOST PEOPLE NORTH OF  
LAKELAND DRIVE EXPERIENCED SIMILAR FLOWS AS THE 1983 FLOOD;  
HOWEVER, LOOKING AT THE ROSS BARNETT RIVER GAGE BELOW THE DAM AND  
THE HEIGHT OF THE WATER THAT BACKED UP INTO HANGING MOSS CREEK,  
THE RIVER LOOKS TO HAVE CRESTED AT LEAST 1.5 FEET LOWER THAN 1983  
WHICH IS EQUIVALENT TO A 38 FOOT RIVER ON THE HIGHWAY 80 GAGE IN  
THE PAST. THE LOWER RIVER LEVELS IN THIS AREA WERE NOT AS GREAT AS  
AT HIGHWAY 80. ONE POSSIBLE REASON FOR NOT SEEING AN EVEN LOWER  
RIVER IN THESE AREAS MAY BE DUE TO THE CONTINUED BUILD UP OF  
PROPERTIES ALONG LAKELAND DRIVE TO THE 1 PERCENT FLOOD LEVEL (100  
YEAR FLOOD). A SECOND POSSIBILITY IS THE NARROWING OF THE RIVER  
CHANNEL BY LEVEES FROM LAKELAND DRIVE TO THE HIGHWAY 80 BRIDGE. A  
LOT OF THE WATER BEING DISCHARGED FROM ROSS BARNETT HAS TO WAIT  
TO FLOW THROUGH THE LEVEES TOWARDS JACKSON. THE WATER PONDS OR  
GOES INTO STORAGE ON THE RANKIN COUNTY SIDE OF THE RIVER WAITING  
TO FLOW SOUTH. THIS STORAGE OF WATER WILL KEEP THE RIVER LEVEL  
HIGH FOR A LONGER TIME PERIOD FROM THE DAM TO HIGHWAY 80 AS THE  
WATER DRAINS.  
 
OTHER PAST FLOODS HAVE ALSO SHOWN THIS TENDENCY TO STORE WATER  
EVEN BEFORE THERE WAS AS MUCH DEVELOPMENT ON LAKELAND DRIVE. THIS  
FLOOD JUST MADE IT MORE PRONOUNCED. THIS FLOOD WILL GO DOWN AS THE  
3RD HIGHEST FLOOD ON RECORD FOR THE JACKSON AREA. IT WILL ALSO BE  
THE FLOOD THAT MOST LIKELY RECOGNIZES THAT WE CAN HAVE 2  
SIGNIFICANTLY DIFFERENT FLOOD IMPACTS ALONG THE PEARL RIVER IN  
JACKSON, ONE NORTH OF LAKELAND DRIVE AND ANOTHER IN THE CITY AND  
AREAS JUST SOUTH OF HIGHWAY 80.  
 
WILL THIS DIFFERENCE ALWAYS EXIST? RIVER CHANNELS THAT EFFICIENTLY  
CARRY FLOW DOWNSTREAM CAN SILT UP AND BECOME INEFFICIENT CARRIERS  
OF WATER. WILL OTHER CHANGES IN THE FLOOD PLAIN OCCUR WHICH WILL ONCE  
AGAIN IMPEDE FLOW? ALL OF THESE ARE POSSIBLE. ONE AREA THAT WILL  
NOT CHANGE IS THE CONTINUED GROWTH OF LAKELAND DRIVE AND THE  
NARROWING OF THE RIVER CHANNEL BY THE LEVEE SYSTEM FROM LAKELAND  
DRIVE TO HIGHWAY 80. THESE QUESTIONS AND MORE WILL BE STUDIED  
AFTER THIS EVENT.  
 

 
MVP  
 
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