The river's record · February 2018

19–22 FEBRUARY 2018

Eighteen months after the rain flood, the river itself came up higher than it had ever been measured: February 2018 began as the snowiest February on record at the South Bend cooperative observer — snow fell on ten of the month's first eleven days, some thirty inches by 17 February, about fifteen inches above normal, leaving a snowpack some fifteen inches deep. Temperatures then rose past sixty degrees, and from 19 to 21 February, four to six inches and more of rain fell on the melting pack across the basin. The month's precipitation reached 8.08 inches, the wettest February in a record running back to 1893, against a previous February record of five inches; the city's flood-study presentation records 3.75 inches of rain on 20 February alone. The St. Joseph River rose through its previous record and crested at 12.70 feet at the city's gauge at the wastewater treatment plant on Riverside Drive — 1.8 feet above the 10.90-foot mark of 1982 and 1993. The crest's date is carried two ways in the record and printed as found: the Tribune's anniversary account dates the crest to 21 February; its contemporary report, and the Weather Service's hydrograph summary, put the peak early on 22 February. The Geological Survey's flow figure, as the city's engineers presented it, was a peak of 25,300 cubic feet per second at the Niles gauge on 22 February — 14.5 billion gallons of water a day passing through South Bend. The city's study places the river's level at the 0.2-percent annual-chance flood — the 500-year level — on the federal flood-insurance maps.

The damage, at the record's several removes: City and county jointly declared an emergency. The county's emergency management director reported roughly 25 homes, mainly near the river, completely destroyed, and dozens more damaged; the county's figures as presented at the March flood meeting stood at 700 homes affected in St. Joseph County, 65 with major damage. The city's own losses included five pedestrian trails and the water filtration system's North Pumping Station in Leeper Park, with repairs designed at about $2.1 million. The governor declared a disaster for nine counties, and federal assistance was approved for five; a year on, the Tribune counted about 2,000 homes damaged across St. Joseph, Elkhart and Marshall counties together. The flood's place in this record is its rank: of the two floods that struck the city eighteen months apart, this is the one that rewrote the gauge's history — the river at its highest measured level in the city's existence, in the decade after the city's deepest economic collapse, in neighborhoods — the North Shore Triangle, Keller Park, Riverside — that the city's own engineers then spent a study learning how to defend.

Sources:

1. National Weather Service, Northern Indiana (IWX), "Heavy Rain & Flooding Event Summary: February 19th–21st, 2018," and the NWS climate report for February 2018 — the crest of 12.70 feet at South Bend breaking the previous record of 10.90 feet of 6 January 1993; February precipitation of 8.08 inches, the all-time February record in a period of record since 1893.
2. Lawson-Fisher Associates, Post-Flooding Investigation of Four Neighborhoods Along the St. Joseph River (August 2018), and the City of South Bend's flood-study meeting record of 20 August 2018 — the February snow (ten of the first eleven days; about thirty inches by 17 February, about fifteen above normal; snowpack about fifteen inches), the rain records and the 3.75 inches of 20 February, temperatures above sixty degrees, the crest of 12.7 feet, the Geological Survey's peak flow of 25,300 cubic feet per second at the Niles gauge on 22 February and the 14.5 billion gallons a day through the city, and the river's level at the 0.2% annual-chance (500-year) flood boundary of the FEMA maps; the four study neighborhoods named (Emerson Avenue, Riverside south of Bartlett, the North Shore Triangle, Keller Park).
3. South Bend Tribune, 23 February 2018 and the first-anniversary retrospective of February 2019 (via Insurance News Net) — the river cresting at nearly thirteen feet early Thursday in the contemporary report and the crest dated to 21 February in the retrospective, at the gauge at the wastewater treatment plant on Riverside Drive, the previous record of 10.9 feet "recorded in both 1982 and 1993"; about 25 homes destroyed and dozens damaged in the county (the county emergency management director); the joint city–county emergency declaration; the city's damaged trails and North Pumping Station and the roughly $2.1 million repair programme; about 2,000 homes damaged across the three counties.
4. St. Joseph County flood meeting of 20 March 2018, as reported from the meeting — 700 homes affected in St. Joseph County, 65 with major damage.
5. Ross and others, American Meteorological Society annual meeting abstract (2019), on the February 2018 flood — February the snowiest on record at the South Bend cooperative observer, four to six inches and more of rain 19–21 February on melting snow, rivers at record crests up to two feet past previous records, the governor's disaster declaration for nine counties and federal assistance approved for five.