2019 April Flooding Spotlight

An unusually wet period occurred over the State of Oregon during the April 6 to 21, 2019 time period when an atmospheric river event transported a tremendous amount of moisture from the Pacific Ocean across Oregon. The heavy rainfall combined with snowmelt runoff set the stage for an extended period of flooding from the Willamette Valley to Eastern Oregon. Reservoirs were near full capacity in early April. The sequence of events of swollen rivers, full reservoirs, and record breaking rainfall caused widespread flooding, flash flooding, mudslides and landslides across the state, with Curry, Douglas, Grant, Linn, Umatilla and Wheeler counties being the most severely impacted. 

The unseasonal timing of the heavy rain was unusual; several locations recorded daily rainfall records, which exasperated the snowmelt runoff. The rainfall total in this event was unprecedented for April, and the winter storm of February 2019 played a role as that event provided an above normal snowpack that led to widespread snowmelt runoff.  

The event was driven by powerful west southwest winds laden with Pacific moisture. Heavy rain fell over Curry, Douglas and Linn counties. Multiple rain gauges recorded greater than 10 inches in a 72 hour period. The maximum three-day rain total in Southwest Oregon was 14.58 inches. The Chetco River experienced a peak flow return interval that can be expected about once every seven years, which is likely a record flow for April.

Oregon communities faced numerous hardships during this destructive event, most significantly the tragic loss of life in Douglas County as result of a swollen river. 

As Oregon remained in the weather pattern, the heavy rain and snowmelt complicated reservoir operations which compounded the flood situation. Several reservoirs had to spill water due to unprecedented runoff which only added to the water in the river systems. Reservoirs were already near-full capacity at the beginning of April to meet summer irrigation, recreation, and fish migration demands.

Several areas in Eastern Oregon received record to near record rainfall over a 48 hour period. This rainfall combined with snowmelt runoff caused many rivers, creeks and streams to overflow their banks, many exceeding flood stage. Several SNOTEL gauges in higher terrain showed 6 to 12 inches of snowmelt runoff during the month of April. McKay Creek in Umatilla County had significant rises with record inflows recorded at the McKay Reservoir in Pendleton. The snowmelt which was exasperated by the continued weather pattern, required increased releases from the McKay reservoir, which resulted in flooding downstream impacting the City of Pendleton, flooding residences and roadways, and damaging public infrastructure. The impacts of the release deposited rocky materials throughout the McKay Channel, reducing the capacity of the Channel, causing the water to overrun its banks and flood nearby residences.

Wheeler County recorded rainfall of 1.67 inches in a very short period of time, triggering flash flooding which caused landslides across the State Highway, and bringing large quantities of debris into the middle of the City of Mitchell, a small community of a population of approximately 140. This event was so significant that it changed the rerouted drainage, so that it is now directly impacting city infrastructure and roads.

The mainstream Willamette River rose above flood stage. The flooding of the Willamette made several roads impassable including Highway 34 near Corvallis in Benton County. This major highway was impassable for several days. Residential areas located in Lane County were also flooded, resulting in evacuations of and damage to homes. In addition the excess rainfall combined with saturated soils resulted in several landslides across that region, including one that caused the closure of Highway 58 near Oakridge. This area was also heavily impacted in the February event that was recently declared.

The snowmelt combined with heavy rain created saturated soils which caused mudslides and landslides and the closure of major highways, and also brought down sediment from hillsides leading to clogged basins and culverts. For example, the severe flooding on Hunter Creek near Gold Beach and the Winchuck River near Brookings in Curry County made for impassable roads in these areas. Flooding of the John Day River (Grant County) and Umatilla River (Umatilla County) left a great deal of debris on roadways, deposited many cubic yards of sediment, and washed out bridge abutments.

Beginning March 24, 2019 and continuing, these severe storms have resulted in rain, extreme snow melt, flooding, landslides, and erosion at various locations within Oregon, resulting in critical transportation failures. This storm system damaged state highways with scour, washouts, serious debris flows, and mudslides.

Many areas around the state were impacted due to flooding. Listed below are examples from jurisdictions listed in the disaster declaration request.

Throughout the event, the Oregon Office of Emergency Management helped provide coordination calls with relevant state agencies, impacted jurisdictions, and support entities. To support the response efforts at the local level, the Oregon Emergency Coordination Center activated on April 10th through 12th. Throughout this event, state support included:

• ODOT assistance cleaning culverts
• Sandbags
• Geologist evaluation of landslide
• Emergency management support for a local emergency manager
• Civil Air Patrol flight of Willamette River
• Oregon Department of Fish and Wildlife assistance to the Cow Creek Band of Umpqua Tribe of Indians to protect culturally important resources from damage

Among the noteworthy assistance provided through voluntary agency efforts were the following:

American Red Cross (ARC) assistance in this event may be summarized as follows:

• Level of Operations for ARC - Level 2
• 3 ARC shelters opened: Lane County, Grant County, Umatilla County
• Total number of overnight stays: 61
• Peak population: 40
• Shelters closed date: 4/9/19 in Grant County, 4/10/19 in Lane County, 4/15/19 in Umatilla County
• Number of meals served: 140
• Number of mental health contacts: 4 in Lane County
• Number of cleanup kits provided: 10 in Umatilla County

Other voluntary agency assistance included help provided by the Lane County Community Organizations Active in Disaster, search and rescue volunteers, and a non-ARC shelter operation in Lane County. Assistance in doing muck-ups was provided by Team Rubicon in Umatilla County, and there were many community members involved in sandbagging there, including a youth baseball team which had just finished a double-header.

A joint Preliminary Damage Assessment (PDA) was conducted for local governments and certain private non-profits for potential financial federal assistance under FEMA's Public Assistance (PA) program. The PDA was conducted on May 13 through May 17, 2019 to assess damages in Curry, Douglas, Linn, Umatilla and Wheeler Counties.

This process involved coordinating with local emergency managers, public works departments, and utilities to document damages and costs associated with the repair of roadways and impacted parks and facilities. The most severe impacts were damages to roads, culverts, utilities, debris removal and emergency protective measures. The insurance coverage of such costs and damages is very limited.

From these assessments, the estimated costs for this disaster are categorized as follows:

• Category A (Debris Removal): $154,675
• Category B (Emergency Protective Measures): $534,125
• Category C (Roads and Bridges): $5,368,829
• Category D (Water Control Facilities): $425,000
• Category E (Public Buildings): $15,000
• Category F (Utilities): $1,394,624
• Category G (Parks/Other): $317,840
• For a total estimated cost of roughly $8,210,093.

In addition to damages to local governments and certain private non-profits, the Oregon Department of Transportation has requested emergency relief under the Federal Highway Administration (FHWA) for damages to major transportation networks within Oregon. The total estimated cost requested underneath this program is roughly $3,705,695.

On July 9, 2019, President Donald J. Trump declared that a major disaster exists in the State of Oregon and ordered Federal assistance to supplement State, tribal, and local recovery efforts in the areas affected by severe storms, flooding, landslides, and mudslides from April 6 to April 21, 2019.

Federal funding is available to State, tribal, and eligible local governments and certain private nonprofit organizations on a cost-sharing basis for emergency work and the repair or replacement of facilities damaged by the severe storms, flooding, landslides, and mudslides in the counties of Curry, Douglas, Grant, Linn, Umatilla, and Wheeler.

Federal funding is available on a cost-sharing basis for hazard mitigation measures statewide.

Pete Gaynor, Acting Administrator, Federal Emergency Management Agency (FEMA), Department of Homeland Security, named Rosalyn L. Cole as the Federal Coordinating Officer for Federal recovery operations in the affected areas.

Additional designations may be made at a later date if requested by the State and warranted by the results of further damage assessments.

 https://www.whitehouse.gov/briefings-statements/president-donald-j-trump-approves-oregon-disaster-declaration-3/