Summer of 1978:  Flash Floods

During the summer of 1978, several flash floods impacted parts of the area between June 30th and September 12th.  Four flash floods (June 30-July 2, July 5-6, July 16-17, & September 12) affected southeast Minnesota and one flash flood (June 30-July 2) occurred in west central and southwest Wisconsin.  These flash floods/floods severely impacted Rochester and Austin, Minnesota and the residents along the Kickapoo River.  They also caused 13 deaths (June 30-July 2 - 8 deaths and July 5-6 - 5 deaths).

If you have your own stories of the flash flooding back in the summer of 1978 and would like them recorded on this webpage, please send them to the National Weather Service via e-mail at Jeff.Boyne@noaa.gov or via regular mail at N2788 County Rd. FA, La Crosse, WI 54601-3038.

Changes which came out of these flash floods:

Two major developments came out of these flash floods.

1. The flash floods of July 5-6 and September 12, 1978 prompted the construction of a major flood control project by the U.S. Army Corps of Engineers and the Natural Resources Conservation Service in and around Rochester. This project was completed in 1995, at a cost amounting to $92 million and protects the city against a 200-year recurrence interval flood event.
2. Due to the June 30-July 2nd flash flooding, the downtown area of Soldiers Grove was relocated to higher ground with the help of then-U.S. Senators William Proxmire and Gaylord Nelson.  The Secretary of the U.S. Department of Housing and Urban Development granted the village $900,000 in the fall of 1978 so that relocation could occur.

More details on each of the 1978 summer flash floods can be found below...

1. June 30th through July 2, 1978 - East Central & Southeast Minnesota and West Central & Southwest Wisconsin:

This was one of the greatest flash flood/flood events to affect the La Crosse Hydrologic Service Area (HSA) occurred from the last day of June into early July.  A huge area of southeast and east central Minnesota and west central and southwest Wisconsin saw excessive rainfall, ranging from 3 to possibly 11 inches of rain during the period from June 30 through July 2nd.  Seven to nine separate areas received 6 inches or more of rainfall.  The event was triggered by a nearly stationary boundary draped northwest to southeast across the area into which abundant moisture was available to feed the thunderstorms which continually redeveloped and moved southeast.  Nearly every major river basin in this area saw record or near-record crests and damage was widespread. 

In East Central and Southeast Minnesota:

Portions of Ramsey, Dakota, Goodhue, Wabasha, Olmsted, Winona, Fillmore, and Houston Counties received over 6 inches of precipitation from around 6 PM June 30th through 7 AM July 1st.  Six inches or more inch rainfall is considered a 100-year or greater storm for this area.  Greater than 8 inches of precipitation was reported in Mount Pleasant, Rushford, and Highland Townships in Fillmore County.  The largest recorded amount was 8.68 inches in Rushford Township.  Some additional 24-hour precipitation amounts included:  Red Wing 7.78", Hokah 6.68", Goodhue 5.85", and Lake City 5.25".  A 2,850 square mile area received greater than 4 inches of precipitation in Minnesota.  These rains also set the stage for the severe flooding in the Rochester area just a few days later.

Flash flooding was widespread over east central and southeast Minnesota.  Several roads were blocked or washed out, numerous bridges were impassable as the storm dumped up to 8 inches of rainfall.  Widespread damage to crops, gardens, and homes.  Cows, calves, and pigs were either struck by lightning or drowned by flash floods.  Basements were flooded and retaining walls collapsed.  The citizens of Elba and 600 campers were forced to evacuate.  Heavy property damage with many stalled and stranded cars.  Some vehicles and cattle were swept away.  There were many power outages and heavy tree damage. Lansing, Minnesota on the Cedar River had a record crest of 23.30 feet on July 1st (this was surpassed on September 15, 2004 when the crest reached 23.44 feet).  Five drowning deaths and one person was electrocuted while trying to pump out a basement in southeast Minnesota from the flooding.

The map below is from the Minnesota State Climatology Working Group and it shows the precipitation totals in southeast Minnesota from June 30 through July 1, 1978.  It was prepared from 115 precipitation reports.
 

In West Central and Southwest Wisconsin:

In west central and southwest Wisconsin, heavy rains up to 9 inches started on the evening of the June 30th and lasting into July 1st.  The highest rainfall totals were located over the Kickapoo watershed where they received 7 to possibly 9 inches of rain.  La Crosse, WI had its fourth highest 24-hour rainfall ever at 4.79" (greatest ever recorded is 5.55" on September 6, 1884).

These rains sent rivers in southwest and west central Wisconsin on a complete rampage.  Over 100 bridges, culverts, or bridge approaches were destroyed or damaged. The communities on the Kichapoo River took the brunt of the flood damage.  Evacuations of several communities were necessary along the Kickapoo where damage wad near $20 million alone.  The town of Soldiers Grove, WI was particularly hard-hit and it was later relocated to higher ground as a result.  Peak discharges along Kickapoo were considered to be near or above the 100-year recurrence interval.  At La Farge, Gays Mills and Steuben the peak discharges were 14,300, 15,000 and 16,500 cubic feet per second (cfs).  At La Farge this flow equated to a recurrence interval of 225 years, while at Steuben to 140 years.

Soldiers Grove - 1978 Flood Photo Courtesy of Betty France Soldiers Grove - 1978 Flood Photo Courtesy of Betty France

According to the USGS, Nedorlo Creek, a 9.46 square mile basin near Gays Mills, WI had a peak flow on June 30 of 8,500 cfs, which is 23% of the Probable Maximum Flood.  This equates to a discharge of 899 cfs per square mile.  These records on the Kickapoo River stood until June 8-9, 2008.

Total flood damage for Wisconsin was estimated at $55 million with agricultural damages being $33 million of the total.  Two fatalities were reported in Wisconsin.  One of these deaths occurred in La Crosse County where a woman was reported killed in a basement cave-in on the evening on June 30th.
 

2. July 5-6, 1978 - Austin and Rochester, MN:

Just a few days after the massive flood event June 30-July 1, a more concentrated heavy rainfall event occurred from Dodge county east to Winona county, with the heaviest band of 6 to 7 inches just south and east of the Rochester area. The National Weather Service (NWS) gage at Rochester International Airport measured 4.99" in 3 hours (between 5:53 p.m. and 8:53 p.m.) on the July 5th. Precipitation ended around 1:50 a.m. on the July 6th.  The total rainfall at Rochester International Airport was 6.74 inches.  The heaviest amount, 7.30 inches, occurred in Quincy Township in eastern Olmsted County.  The 4-inch or more rainfall band was about 12-15 miles wide and 74 miles long and covered 700 square miles. The South Fork Zumbro River and it’s tributaries (Bear Creek, Silver Creek, Cascade Creek) went into flood through Rochester causing extensive damage.

Rivers started rising during the evening and continued at a foot per hour during the night.  The July 6th crest (at 10 AM) at the Rochester river gage (on the south fork of the Zumbro River) established an all-time record of 23.36 feet (flood stage 12 feet) and 30,500 cfs, easily exceeding the previous record crest (1965) by over 4 feet. This flood and yet another on September 12, 1978 prompted the construction of a major flood control project by the U.S. Army Corps of Engineers and the Natural Resources Conservation Service in and around Rochester. This project was completed in 1995, at a cost amounting to $92 million and protects the city against a 200-year recurrence interval flood event.

This flood was considered Rochester's worst natural disaster in almost 100 years and the worst flood in the city's history.  One fourth of city, mainly south and northeast sections, was inundated by turbulent flood water 6 feet deep or more.  Four persons (a nurse's aide and 3 wheel chair patients) in nursing home were trapped in an elevator and drowned.  A fifth person died when her car plunged off County Road 10 southwest of Rochester.  Nearly 5,000 residents were forced to evacuate.  Dozens of campers at Whitewater and Beaver Creek State Parks were evacuated.  Flood waters carried tons of uprooted trees and other debris through downtown Rochester.  Several bridges were swept away.  Many cars were overturned or swept away.  Some were carried for blocks.  Basements flooded, a few with water above the first floor with some foundations collapsing.  Power and telephone lines were out in central Rochester with no traffic lights in operation.  Eighty percent of the city estimated without power with generators under water.  Many businesses and shopping centers were closed due to flooding and lack of electricity to operate computers and cash registers.  Sewage treatment plant was out of commission.  The pictures below show some of the flooding in Rochester (these were from the city of Rochester). 

Flooding along and near 2nd Ave SE looking west			Fiooding in and around the Apache Mall	Flooding along 37th Street & at the Rochester Sewage Plant
Flooding at the Corner of 6th Ave SE & 4th Street SE			Flooding at the Apache Mall	Flooding at KTTC

In addition 2 to 3 inch rains fell over the headwaters of the Cedar River in Mower and Dodge counties, which produced significant flooding.  Besides causing significant to record flooding, it set the stage for a more important event 10 days later. 

The map below is from the Minnesota State Climatology Working Group and it shows the precipitation totals from July 5-6, 1978 in southeast Minnesota.  It was prepared using 64 Future Farmer of America reports and 16 National Weather Service reports.
 

3. July 16-17, 1978 - Cedar River, Austin, MN:

This was the second major rainfall event in 11 days to affect southeast Minnesota.  It primarily affected Mower County and the Cedar River basin.  Both floods resulted in record-breaking flood levels at Austin.  In this case, the record surge of water came mostly in from creeks flowing in from the east. 

The heavy rains began approximately 9:00 PM CDT on July 16th and ended during the early morning hours of July 17th.  The highest unofficial rainfall total was in Waltham Township, northwestern Mower County, at 9.50" (2 miles southwest Sargeant) in northwestern Mower County.   Brownsdale (just northeast of Austin) received 8.00”.  Meanwhile only 2.41" fell in Austin and 3.71" at Grand Meadow, but the headwaters of the Cedar River were well placed beneath the heaviest rainfall which was oriented northwest to southeast.   The 4-inch or greater rainfalls were oriented northwest to southeast and covered an area of 160 square miles.

In Austin, roads and street flooding began in the north section about 4 AM on July 17th.  This urban flooding became widespread later on that morning.  The peak stage/discharge at Austin 3S USGS gage was 20.35 feet and 12,400 cfs on July 17th, both records which stood until July 10, 2000 (crest of 23.40").  No deaths were reported.

In the Grand Meadow area, all roads were under water for a time and many washouts reported with one bridge out.  Most basements were flooded and much silt and debris deposited on yards and fields in the area.  There was so much rain that the sewage ponds overflowed. 

The map below is from the Minnesota State Climatology Working Group and it shows the precipitation totals from July 16-17, 1978 in southeast Minnesota.

4. September 12, 1978 - Southeast MN:

The second major flash flood and flood event of summer of 1978 in Rochester began around 10:00 a.m. and precipitation ended around midnight.  Downtown Rochester received 7.07" of rain, 5.75" of which fell in six hour period between 10 AM and 4 PM (0.98", 0.16", 0.94", 0.64", 1.80", and 1.23").  Another 7-inch rainfall center was located over northeast Mower County.  The 4-inch or greater isohyet was about 12-24 miles wide and 80 miles long and covered 1,200 square miles.

The heavy rainfall resulted in some flooding of roads, and forced some small creeks out of their banks.  Zumbro River crested at 13.1 feet at 4 AM on September 13th.  Many streets flooded due to plugged storm sewers.  This caused traffic to back up for blocks. In addition, some power outages were reported.

The map below is from the Minnesota State Climatology Working Group and it shows the precipitation totals in southeast Minnesota from September 12, 1978.