PITTSBURGH – The U.S. Army Corps of Engineers informed Congress this week that its flood risk management efforts in the Upper Ohio River Basin in fiscal year 2018 prevented an estimated $1.11 billion in flood damages in real dollars.
This amount is above the ten year average (FY09-FY18) of $310.3 million.
When a storm enters the basin, the district’s 16 dams and reservoirs impound runoff and precipitation to cut the downstream flood crest on rivers and then release the stored water in a controlled manner after the crest has passed to make space for the next storm’s runoff.
In total, the district’s system of 16 federal flood risk management reservoirs have prevent nearly $13 billion in flood damages in real dollars since their construction.
Pittsburgh experienced a wetter than average year during FY18 with 54.7 inches of precipitation compared to the average of 38.2 inches, according to the National Weather Service.
The most significant flood event of FY18 occurred in September 2018 when the remnants of two tropical storms – Gordon and Florence – entered the basin, according to NWS.
Of the 8.5 inches that occurred over the month in Pittsburgh, 5.61 inches fell as a result of Gordon in a 60-hour period from the September 8 – 10.
Close to ten inches of rain was recorded during this time frame, with the heaviest rain just south of the Pittsburgh International Airport. The 3.73 inches that occurred in the 24 hours period ending on the September 9 was the second highest rainfall total for Pittsburgh since the remnants of Hurricane Ivan hit the area in September 2004.
The peak event which passed Pittsburgh, Pennsylvania on September 11 and the flood elevations on the Ohio River were reduced by 6.77 feet at Pittsburgh and by 19.32 feet at Vandergrift, Pennsylvania.
Total flood damages prevented by the district’s 16 reservoirs during the September event were estimated at more than $340 million. Conemaugh, Loyalhanna and Youghiogheny River Lake contributed 67 percent of these benefits.
Total flood damage reduction for this event within the Pittsburgh District was $128.4 million in Pennsylvania, $96.8 million in Ohio, $134.4 million in West Virginia, $13 thousand in New York, and $396 thousand in Maryland.
Berlin Lake and Conemaugh River Lake Reservoir were the most productive facilities of 2018 -- preventing $284 million and nearly $218 million, respectively, in flood damages by reducing the crest of local rivers.
The district also oversees the inspection and rehabilitation of 42 federally built, locally maintain flood damage reduction projects in communities across eastern Ohio, western Pennsylvania, southwestern New York, and northern West Virginia. These project include channels, levees, flood walls and other features.
In FY18, these local project saved an estimated total of $63 million and a cumulative total of nearly $2.5 billion since the construction of the projects.
Attached to this release are the complete flood reduction effort totals for the district.
Pittsburgh District’s 26,000 square miles include portions of western Pennsylvania, northern West Virginia, eastern Ohio, western Maryland and southwestern New York. Our jurisdiction includes more than 328 miles of navigable waterways, 23 navigation locks and dams, 16 multi-purpose flood risk management reservoirs, 42 local flood protection projects and other projects to protect and enhance the nation’s water resources infrastructure and environment.
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