MANAGING THE 2019 FLOOD EVENTS: DIVISION HIGHLIGHTS
BY LOUIE WEIN, USACE Headquarters
2019 was the wettest year on record in the 124 years since the United States began tracking precipitation trends. Thus far this year, the U.S. Army Corps of Engineers (USACE) has dealt with record interior spring flooding in the Mississippi, Missouri, and Arkansas rivers’ basins, in addition to the Great Lakes basin to the north, as well as Hurricane Barry in July, as it struck the Gulf Coast and moved inland. Collectively, these events caused significant damage to levees and other structures, and affected the daily lives of thousands who live and work in these areas.
This record-setting year has followed the trend of continuously escalating storm events in both frequency and severity dating back to 2016, thus prompting Ray Alexander, USACE’s director of Contingency Operations and chief of Homeland Security, to deduce that “as this has been the reoccurring pattern for the past several years, it appears that long-term missions in response to large catastrophes may be the new normal.”
The 2019 and 2018 storm events occurred on the heels of hurricanes Harvey, Irma, Nate, and Maria in 2017, which occurred less than a year after the catastrophic Louisiana flooding in 2016 – at the time, categorized as the worst U.S. disaster since Hurricane Sandy in 2012. USACE was fully engaged in long-term recovery missions for each of these events, often simultaneously, which has forced USACE to continuously increase, mobilize, and reallocate internal resources and personnel to meet the mission requirements and recovery needs of the affected populations.
USACE is one of the nation’s leaders in storm damage reduction infrastructure, managing 50 percent of all federally owned dams nationwide, to include Puerto Rico, and owning and operating of six of the 10 largest U.S. reservoirs. USACE will continue to work closely with federal partners, key stakeholders, and the states in advance of, during, and following events such as these.
“Collectively, we need to identify and consider viable long-term options for reducing risk that include investments in more resilient infrastructure and smart planning on the part of state and local governments as they work with communities vulnerable to both coastal and inland flooding,” said Alexander.
Though the common theme of these events has been extensive storms with prolonged rainfall followed by widespread flooding, USACE routinely responds to all-hazards contingency events ranging from hurricanes to tornadoes, and from wildfires to periods of prolonged drought. In this capacity, USACE exercises its own response authorities under Public Law (PL) 84-99 (Flood Control
and Coastal Emergencies) and under the Stafford Act in support of the Federal Emergency Management Agency (FEMA) as part of the National Response Framework (NRF). Each event is uniquely complex and resource intensive in both the response and recovery phases. Therefore, in 2018, Congress passed a $17.4 billion emergency supplemental bill to begin the long-term road to recovery; and in 2019, Congress passed an additional $3.6 billion in emergency supplemental funds to bring relief to those states affected by hurricanes Florence and Michael as well as to the territories struck by typhoons in the Pacific.
SOUTH ATLANTIC DIVISION
Since 2017, the South Atlantic Division has continuously been directly affected by catastrophic events. Less than a year after sustaining severe impacts from hurricanes Irma, Maria, and Nate, Hurricane Florence made landfall on Wrightsville Beach, North Carolina, in September 2018, bringing 20 inches of rain over several days.
As tributaries conveyed the rain inundation to the Waccamaw, Black, Lumber, Lynches, Pee Dee, and Little Pee Dee rivers, the river elevations gradually rose to unprecedented heights as the water attempted to work its way to the coast. In anticipation of the potentially devastating affects, the USACE Charleston District, along with several partnering agencies, collaborated on efforts to reduce impacts to the population at risk. The district provided 10,000 linear feet of Hesco barriers, 26,000 linear feet of plastic sheeting, 5,000 sandbags, and 1,000 supersacks to successfully keep Highway 501, the main corridor to Myrtle Beach, South Carolina, open as the Waccamaw River did indeed flood as anticipated. The district also provided 300 linear feet of Hesco barriers that were installed around the Pawleys Island pump station in order to continue to provide clean water to the island. Utilizing resources available from other USACE districts, the Charleston District was able to provide 20,000 additional sandbags via the Louisville District’s sandbagging machine.
As a result of this series of hurricanes, South Atlantic Division Commander then-Brig. Gen. Diana Holland shared a similar assumption to that of Alexander: “In 2018, after everything we had been through in 2017, we were in such a better position to respond. Given everything the region and nation have faced with those storms, these are not normal times.”
GREAT LAKES AND OHIO RIVER DIVISION
Historic water levels generated by record levels of precipitation produced widespread flooding and shoreline erosion along the Great Lakes, subsequently leading to major ecological and economic impacts along approximately 4,530 miles of U.S. shoreline and the surrounding communities. The USACE Buffalo, Detroit, and Chicago districts worked closely with state, local, and federal officials to provide flood response support by providing sandbags and technical assistance on proper placement methods to protect shoreline property. Additionally, in coordination with the states, USACE’s Regulatory Program team developed an expedited permitting process for shoreline property owners to safeguard existing erosion control structures, roads, bridges, infrastructure, and property. These types of engagements stand to reinforce the importance of collaborations for longterm coastal resiliency planning to reduce the impacts from extreme storm-related events in the future.
The Louisville District has actively supported emergency deployments across the nation and within its civil works boundary by means of resources and workforce. This past February, the district responded to flooding on the Ohio River through partnering with state and local emergency management agencies for sandbagging efforts at Smithland, Kentucky. When flooding closed the Ohio River locks and stopped navigation, the district activated its Emergency Operations Center (EOC) to oversee communication efforts with navigation stakeholders and distribute updates on the dynamic river conditions.
The district manages an automatic sandbagging machine that serves as a vital resource for its capability to fill 500 to 1,000 sandbags per hour. Since the machine’s first deployment in September 2018 to support South Carolina following Hurricane Florence, teams have expended more than 100,000 sandbags. As part of their continuous preparedness and training protocol with local communities, the district currently has 10 trained operators, who have so far been requested for five flood-fight events and nine training events between USACE and local responders.
This past spring, the Southwestern Division’s Tulsa and Little Rock districts battled high waters as Oklahoma and southern Kansas received more than a foot of rain in early May. Record flooding was witnessed along the Arkansas River and tributaries (Grand Neosho River and Verdigris River basins). Within the Tulsa District, 22 reservoirs went into surcharge. At Keystone Dam, releases hit 275,000 cubic feet per second (cfs), the second highest in the dam’s history. At Muskogee, Oklahoma, near the confluence of the Arkansas, Grand Neosho, and Verdigris rivers, the river peaked at more than 46 feet (flood stage is 28 feet), with flows exceeding 600,000 cfs. Water elevations did not recede back to regulating stage until June 3.
In Little Rock District, record flows were recorded along the McClellan-Kerr Arkansas River Navigation System at five locations, resulting in several navigation locks falling out of service as dams were fully opened to accommodate the high flows. In total, 13 USACE multipurpose reservoirs set record-high pools, including five in the Arkansas River Basin and five in the Caney/Verdigris River Basin. The flooding continues to have lasting effects on recreation and navigation.
The Missouri River Basin is home to 45 USACE dams and 22 U.S. Bureau of Reclamation dams. From March 12-14, a storm called a “bomb cyclone,” due to explosive storm development and rapidly changing conditions, deposited 2.25 inches of rain on Plains snowpack in Nebraska and Iowa, holding 3-plus inches of snow-water equivalent, with even higher amounts in eastern South Dakota.
As floodwaters began receding, additional heavy storms in April and May across parts of Kansas, Missouri, Nebraska, South Dakota, and North Dakota led to high pool levels at many reservoirs, and pushed rivers beyond their containment limits. Since March, the Omaha and Kansas City districts have martialed in experts to support local communities assessing levee damages in order to initiate the rehabilitation process to restore the levees to their pre-storm conditions.
The recent flood impacts have been among, if not the most severe, in the region’s recorded history. More than 700 miles of federally and privately and state-owned levees have been severely structurally compromised. It is estimated that initial repairs will take until spring 2020 to complete, while full repairs will take longer.
MISSISSIPPI VALLEY DIVISION
By early February of this year, water levels on the Mississippi River and its tributaries steadily rose to the north of Memphis, Tennessee, prompting the Memphis District to engage in Phase I flood-fight activities in the Cairo, Lower St. Francis, White, Reelfoot-Obion, and Missouri rivers’ locations in the northern portion of the district’s area of responsibility. Employees deployed to the field to monitor all federal flood control structures including levees, flood walls, and pumping stations. The district also provided material assistance to local communities and flood control organizations to aid in their flood-fighting efforts.
By mid-February, the effects of flooding were being seen in Memphis. The district activated and recruited additional staffing from other internal divisions to oversee flood-fight operations.
In late February, the Vicksburg District experienced extreme rain in the Ohio Valley that caused major flooding on the lower Mississippi River and resulted in a top 10 record crest of 51.5 feet at Vicksburg, Mississippi, in March. During the same time frame, tributary flooding in the Yazoo Basin occurred and four flood control reservoirs (Grenada, Enid, Sardis, and Arkabutla lakes) were put into use to reduce the peak flow of runoff by approximately 90 percent. The use of these reservoirs provided tremendous benefits to the Mississippi Delta early on; however, after the March peak, heavy rains in the upper Missouri and Arkansas River basins caused the lower Mississippi River to remain high, thus preventing the Yazoo backwater area from draining. This continuation of high stages on the Mississippi River led to a second peak of 98.2 feet in the Yazoo backwater area in May, surpassing the previous all-time record set only two months prior in March 2019. Then, in mid-July, Tropical Storm Barry exasperated the extreme flooding in the Yazoo backwater area and, in all, more than 550,000 acres of hardwood timber and agricultural land, as well as numerous homes and camps, went under water.
In June, the Carrollton gage at the New Orleans District read just above 16 feet, which is approximately 5 feet above flood stage for the Mississippi River in New Orleans. In mid-July, when Barry arrived, the Mississippi River had been at flood stage for more than 250 days, which exceeded the 1973 flood of record at 225 days. This also meant that the New Orleans District had been in flood-fight operations for more than 250 consecutive days.
The Bonnet Carré Spillway was opened in February, and again in May, when the river rose to nearly 17 feet at the Carrollton gage. The spillway remained open into July, marking more than 100 total days that it had been open in 2019. This is the first time the spillway has been opened twice in a calendar year, and in back-to-back years.
As of mid-July, 11 dredges worked in the Mississippi River navigation channel from Baton Rouge, Louisiana, to the Gulf of Mexico this year, dredging 41 million cubic yards to date. The annual average is 43 million cubic yards, and dredging will continue throughout the rest of the year. The cost for dredging so far stands at $110 million for the year, with five dredges currently in operation.
Lock closures were experienced in Rock Island District due to flooding. At Lock and Dam 15, where the Rock Island District Headquarters resides, a record of 96 days above flood stage was set, more than doubling the prior record of 43 days set in 2001.
In FY 2019, a record-breaking $244.4 million were allocated for maintenance of the Mississippi River navigation channel from Baton Rouge to the Gulf of Mexico, compared to average annual funding of $158 million (FY 15-19). The majority of FY 19 funds were used for dredging of the deep-draft navigation channel from Baton Rouge to the Gulf of Mexico. A portion of the funds were used to supplement FY 18 ongoing dredging in the Hopper Dredge Disposal Area (HDDA) and FY 18 ongoing Southwest Pass foreshore stone repairs. Dredging began in November 2018 and is ongoing, with 85 million cubic yards of sediment – 81 percent over the annual average of 47 million cubic yards – removed thus far.
This high river year also provided opportunity for beneficial use of dredged material, which also began in November 2018 and is ongoing, with 22.8 million cubic yards placed beneficially for coastal habitat creation and bank stabilization to date. This breaks the previous beneficial use record of 20.8 million cubic yards in FY 17.
Of 13 bid openings for Mississippi River and Southwest Pass hopper dredge rental solicitations since November 2018, only seven yielded industry hopper dredges to respond to urgent dredging requirements. To address urgent requirements, approvals were granted for 225 days of emergency call-outs of government-ready reserve hopper dredges. Thirteen different dredges worked on the Mississippi River from Baton Rouge to the Gulf of Mexico. Channel restrictions were in place for 205 days or 56 percent of the year, compared to the annual average of 93 days or 26 percent of the year.
Despite the numerous missions of recent years, USACE continues to stand ready to respond to future disasters both under its own authorities and in support of FEMA mission assignments.
“The Corps’ focus is and will always remain to protect life, mitigate risks, and repair damages,” said Alexander.
However, this seemingly endless cycle of nonstop emergencies has taken an internal toll and affected the operations of basic USACE missions such as military construction and water resources, because the Army Corps personnel who deploy in support of emergency missions are the same personnel responsible for managing and executing such projects for their home districts.
USACE has persevered by continuing to do more with less, and smartly managing personnel deployments to avoid mission fatigue. To continue to meet the increasing challenges of emergency response, the U.S. Army Corps of Engineers will look to implement new and innovative strategies like delegating missions to local and federal agencies best suited to accomplish the task at hand. USACE continues to “revolutionize the way USACE does business” by utilizing current technologies, such as the use of unmanned vehicles to conduct aerial and underwater surveys and inspections, in addition to the development of internal USACE geographic information systems to increase the capability of real-time reporting of water elevations in rivers and reservoirs, thus facilitating real-time decision-making. Collectively, adopting such future standards and practices will reduce both costs and personnel requirements, thus helping the U.S. Army Corps of Engineers maintain a sustainable balance of emergency response efforts while concurrently managing basic USACE missions and responsibilities.