Major Historical Floods and Flash Floods
in the La Crosse (ARX) Hydrologic Service Area

Peter Corrigan, Service Hydrologist; February 2004
June 7, 1847: Black River basin: One of the earliest known floods in the La Crosse Hydrologic Service Area took place in June 1847. The following quote is from a history of Clark county: "came the great flood, which wiped out many of the improvements , and caused general suffering throughout the settled portions of the Black River Valley. On the afternoon of the previous day the rain began to fall and the refreshing shower was hailed with delight. With each succeeding hour the area of the storm was increased, and from gentle drops, which were eagerly lapped up by the parched earth, it gradually assumed a violence never before witnessed. The rain fell in torrents until after midnight, and when morning dawned Black River had risen twenty-five feet and was flooding the country in all directions. As a result every mill on that stream was swept off, causing great damage, which required months to repair. But as day advanced, the sun came out, the waters receded, the river retired within its banks, and within twenty-four hours after the rains had ceased, the debris of mills, logs which had been left far in the woods, and other evidences of loss, were all that reminded one of the resent war with the elements".

June, 1880: Mississippi River: Flood crests established from June 19-22 of this year along the Mississippi River were not exceeded until 1965 at many locations along the river. At LaCrosse, WI and Lansing, IA the 1880 crests are still the second and third highest on record, respectively. Information about the causes of this flood is somewhat sketchy, but May and June in northeast Iowa and adjacent portions of southwest Wisconsin and southeast Minnesota were extremely wet. Clermont, IA had more than 9 inches of rain in June, Neillsville, WI, 7.40"; and LaCrosse, WI, 6.60". June, 1905: Southwest WI: Crests on June 6 were the third highest on record on the Black River at Neillsville. More than 4 inches of rain fell at Neillsville in the three days leading up to the 6th, helping to cause the flooding.

June 23, 1908 - Southeast MN: At least 4.1 inches of rain in the vicinity of Rochester caused severe flooding on the South Fork Zumbro. Antecedent conditions were clearly wet in southeast Minnesota: Grand Meadow, MN recorded 9.10" in May and 9.93" in June, which was the second wettest such period in the period of record (1873-present). This station recorded 2.78" for the 24-hours ending 12Z on the 21st and 4.25" on the 23rd, producing the high runoff into streams and rivers.

February 21-23, 1922 - Turkey River basin, NE IA: Major flooding occurred in the Turkey River basin as melting snow combined with storms over two days that dropped 2-3 inches of rain (3.20" at Fayette) on still-frozen ground. Discharge on the Turkey at Garber reached 32,300 cfs, the third highest on record. 24 railroad bridges and several miles of track were washed out.

September 10-16, 1938 - Southwest Wisconsin basins, WI: Intense rainfall from thunderstorms produced massive flooding and five fatalities in Wisconsin (not necessarily in ARX HSA). Rainfall at Neillsville exceeded 6 inches over a 6-day period ending on the 12th. The Black River at Neillsville established a crest and discharge record (23.8' and 48,800 cfs) on September 10, which has withstood all subsequent assaults. Downstream on the Black River, Galesville had its 3rd highest stage/discharge ever. Flooding was also observed on the Wisconsin River, where Muscoda also recorded its highest stage and flow ever (11.48' and 80,800 cfs).

May 27-30, 1941 - Upper Iowa River basin, IA: The flood event was triggered by 7.70" of rain which fell in less than 24 hours on the night of May 29 over Decorah and 5.98" at Waukon. Storm total rainfall centered around Decorah was over 10" (10.21" at Decorah) for the period from the 27th through 30th. This caused tremendous flooding in the Upper Iowa River basin, and especially along Dry Run Creek in Decorah. This creek flooded houses and businesses in low-lying areas and washed out roads and bridges in and around Decorah. The maximum discharge at Decorah was 28,500 cfs, still the highest ever recorded within that basin. The recurrence interval estimate for this event at Decorah was in excess of a 500-year event, one of the most severe from a statistical standpoint ever to occur in the LaCrosse HSA. The flood was only slightly less impressive downstream on the Upper Iowa, where Dorchester had its highest recorded discharge at 30,400 cfs , or more than twice the flow of any other recorded event. A USGS estimate gave the flood at this location a 425 year recurrence interval.

June 4, 1942 - Cascade Creek, Rochester, MN: A localized flash flood event occurred along Cascade creek which caused one death and flooded numerous homes along the creek. The Rochester Airport recorded 3.26" of rain from the June 3-5, and 2.33" in one day. Presumably there was higher local rainfall in the Cascade Creek sub-basin. Discharge was estimated at 10,000 cfs from this 37.6 mi2 basin,.

June, 1947 - Iowa: Flooding remarkable for its extent and duration occurred across much of Iowa, as the state average rainfall was 10.33 inches, second only to June, 1993 rainfall (10.50 in.). Flooding was widespread across the entire state and in the LaCrosse HSA area as well. The most outstanding event in northeast Iowa occurred when intense thunderstorms on June 12-13 produced 4 to 5 inches of rain over parts of Bremer, Chickasaw and Fayette counties. Flooding was most severe along the Volga, Turkey rivers and Wapsipinicon rivers, where several towns (Volga, Littleport, Elkader and Elkport) were inundated. Damage to structures, roads and agricultural land was extensive. The flood crest at Garber on the Turkey River was 29,000 cfs, still the third highest on record.

March 26-27, 1950 - Cedar and Root basins, Southeast MN: Heavy rains on top of snowmelt produced flooding that affected the Root and Cedar basins in late March . The crest at Austin, MN was 17.81 feet on March 26 which still ranks as the 7th highest crest on record. Newspaper accounts described significant flooding in town and attributed it to 1.94" of rain falling on frozen ground. For the Root at Houston the 16.56' crest and 31,000 cfs discharge is still tied as the 5th highest on record, exceeded only by 1952, 1961, 1965 and 2000.

July 16-17, 1950 - Southwest Wisconsin basins, WI: The Platte River at Rockville had by far its greatest flood event July 16th, 1950 with a peak discharge of 43,500 cfs and stage of 17.26'. This is more than double any other discharge in the 66-year continuous record at this location. Details on this flood are sketchy, but widespread heavy rainfall was certainly the major factor. Official rainfall totals included: Lancaster, 7.05" in three days; Muscoda, 6.09" and Richland Center, 5.93" in two days; and Platteville 2.98" in one day. The Grant River at Burton also had its flood of record on the 16th, producing 25,000 cfs and a gage reading of 24.82 feet.

April 6-7, 1951 - Cedar River, MN: The Cedar River in Austin flooded again as both Dobbins Creek and the Cedar River (crest of 15.12 feet at Austin) went out of their banks. Ice jam flooding was described as contributing to the high flows.

July 21-22, 1951 - Southwest WI and Southeast MN: One of the worst floods to affect the Kickapoo River Valley was caused by 8.2" of rain at Viroqua, 6.4" at Genoa, 5.5" at LaFarge and 2.8 to 3.6 inches in the basin above LaFarge. Soldiers Grove was hit by a 5-foot wall of water that caused severe damage to the town and contributed to it's decline over time. At Steuben the peak flow (10,300 cfs) is still the 4th highest on record. Flooding was also severe in southeast Minnesota, where officially 4.51" fell at Rochester, 4.30" at Beaver and 3.54" at Lake City. The Zumbro River at Zumbro Falls had its highest recorded stage and discharge, at 30.8 feet and 35,900 cfs on the 22nd. Th crest on the South Fork Zumbro at Rochester, MN was also among the highest (4th since 1951) on record. Flood impacts were severe in the city of Rochester, with widespread residential and business district flooding.

March-April, 1952 - Southeast MN and Mississippi River: Snowmelt and ice jams caused the highest observed discharge on the Root River at Houston (37,000 cfs) and inflicted substantial damage at Houston, Rushford and much of the lower basin. The 1952 floods were caused by similar factors to the 1951 floods, with heavy snow in the Upper Mississippi basin combined with prolonged rainfall on the melting snowpack in late March and April. Flood crests generally slightly exceeded those of April. 1951. For the third consecutive year the Cedar River in Austin flooded, cresting on March 31 at 15.82 feet, although damage was relatively light.

May 31, 1958: Clayton County, IA: A locally intense rainfall event beginning about noon produced incredible runoff on several small streams near Garber in southern Clayton county, IA. The streams, draining into the Turkey River, included Wayman Creek and Honey Creek. The closest rain gage report was from Strawberry Point, 14 miles southwest of Garber, where 4.38" fell from noon to 3:00 p.m. Unofficial amounts from Garber were estimated at 6 inches in three hours. Wayman Creek had a measured discharge of 15,500 cfs from a 6.98 mi2 basin, a unit discharge of 2,260 cfs per mi2. This peak flow was estimated by the U.S. Bureau of Reclamation to be 47% of the Probable Maximum Flood. The limited areal extent of heavy rains prevented any major river flooding.

March 26-28, 1961: Southern Minnesota and Northern IA: Heavy snow cover melted quickly causing moderate to major flooding on various rivers including the South Fork Zumbro, Root, Cedar, and Kickapoo. This was the highest crest on the Cedar River at Charles City, IA (21.53') to that date and still the second highest after July, 1999.

March 29-31, 1962 - Southern Minnesota and Northern IA: Floods again resulting from spring snowmelt and ice jams affected the South Fork Zumbro, Cedar, and Root Rivers. The Cedar at Austin crested at 17.18', but with a flow (9530 cfs) higher than any flood up to that time.

August 30-31, 1962: Little Wapsipinicon River, NE IA: Very heavy rains fell over a fairly small area in northeast Iowa, mainly in Howard and Winneshiek counties. The basin most affected was the Little Wapsipinicon River in Howard county. Storm total rainfall at Cresco was 7.68", with 6.20" in one day. Other nearby cooperative reports included Decorah, 4.52"; Waucoma, 4.42" and New Hampton, 3.25". A small portion of The Little Wapsipinicon River near Acme, IA (area 7.76 mi2) had a peak discharge of 2,380 cfs or 307 cfs per square mile. Further downstream on the Little Wapsipinicon, a 37.3 mi2 basin had a discharge of 5,740 cfs or 154 cfs per square mile.

March-April, 1965 - entire HSA: Record snowmelt floods affected much of the upper Midwest in March and again in April. The Mississippi River established crest records many of which still stand today. This includes LaCrosse, WI (17.9 ft. on April 21) and McGregor, IA (25.4 ft. on April 24). Nearly all the tributaries to the Mississippi, including the Cedar, Root, Black and South Fork Zumbro experienced flooding as well. At Rochester the crests on the South Fork Zumbro exceeded those of 1962 (19.12 feet vs. 18.5 feet). The conditions to bring about the floods were a long (March temperatures 6 to 10 degrees below normal) and snowy winter followed by a wet April with nearly normal temperatures. Many tributaries within the ARX HSA also experienced flood flows, many of which occurred in early March as warm air temporarily melted most of the snow cover in ARX area. This initial crest on March 1-2, produced the highest gage reading ever on the Root River at Houston (18.32') and the 3rd highest (18.87') on the Cedar at Austin. Major flooding was recorded in Rochester on the South Fork Zumbro and along Bear Creek. The snow cover across the was reestablished during March, reaching from 1 to 4 inches of snow water equivalent across the HSA and from 5 to 8 inches in the Upper Mississippi basin. The melting of this snowpack in early to mid-April was combined with two rainy periods, April 2-7 (0.5 to 1.0" across the region) and April 8-12 (0.5 to 3.0") to create a secondary flood maxima on many tributaries in early to mid-April. This maximum was generally higher than the early March peak in the southern parts of the HSA, and produced the 4th highest reading ever on the Cedar at Charles City, IA. Additional rainfall of 1 to 2 inches fell the week of April 23-28 adding to the crest occurring along the mainstem Mississippi during the period from April 20-25 in the LaCrosse reach of the river.

April, 1969 - entire HSA: The second or third greatest snowmelt flood of the past century affected much of the HSA beginning in early April. The meteorological setup for this event began with very wet October, dry November and then a wetter-than normal winter (December-February). March precipitation was well below normal, however temperatures were also roughly 3 to 6 degrees below normal (very similar to March 2001). This prevented substantial snowmelt during March, especially over the northern parts of the upper Midwest. Snow water equivalent in the snowpack at the end of March was substantially less than in 1965, especially in the Mississippi headwaters, generally 2 to 4 inches. April precipitation was well below (50%) to near normal across the HSA, but up to 150% of normal in the Mississippi headwaters. In addition the first two weeks of April were mostly dry from about LaCrosse northward, helping reduce the runoff. Crests in 1969 were generally 1 to 4 feet lower than in 1965. The Mississippi crested in the LaCrosse HSA within a day or two of the same dates as the 2001 flood (April 16 at Wabahsa and April 20 at LaCrosse). Crests were a little higher in 1969 than 2001 in the north (20.18 vs 20.13 feet at Lake City, MN) and one to two feet below 2001 further south. Tributary snowmelt flooding, mostly during the first week in April was also widespread, but not severe. The seriousness of the flood potential was demonstrated by the U.S. Army Corps of Engineers building of a number of emergency levees in the Root River basin.

May 27-28, 1970 - Wabasha County, MN: This event which also affected Goodhue county (MPX HSA) began in the late afternoon of May 27, ending in the early morning hours of the 28th. The rainfall was centered in Goodhue county, with 8.5 inches reported 3 miles southeast of White Rock. Cooperative stations at Wabasha and Lake City in Wabahsa county had 6.15 and 5.60", respectively, on the 28th. Flooding was worst in the Trout Brook/Zumbro River basin. Several cars were washed from roads drowning three persons. The Zumbro River at Zumbro Falls rose 11 feet in one hour and crested 3.4 feet above flood stage.

July 12, 1972 - Turkey River basin, IA: Intense localized thunderstorms on both the 9th and 12th (1 to 4" of rainfall on each night) in the upper Turkey watershed produced flooding in Spillville, Waucoma, and Saude and significant road and bridge damage.

June 20-21, 1974 - Southeast MN: This was a widespread major flash flood event, affecting the five counties of Wabasha, Winona, Olmsted, Fillmore and Houston. Rainfall was centered near Eyota just east of Rochester and began around 3 PM, ending around 1 AM.. Eyota measured 6.25 inches, with over 1,150 mi2 covered by the 4-inch isohyet. Other cooperative reports included Lanesboro, 5.28"; and Preston, 3.22". The Whitewater River at Beaver, MN (basin area 271 mi2) had a measured discharge of 31,200 cfs on June 21 from this event, the highest on record from 1939-1999. Both the North and South Forks of the Whitewater River near Elba and Altura, MN had their highest discharge on the 21st at 16,500 cfs and 5,620 cfs, respectively.

July 24, 1974 - Millville, MN, Wabasha county: Heavy rains began about 6:30 PM and ended around 8:00 p.m. The highest total was 7.20 inches 2 miles south of Millville, with a 4 inch isohyet covering around 25 square miles.

July 4-5, 1975 - Whitewater River, Olmsted, Wabasha and Winona counties: 6.4 inches of rain fell at Whitewater State Park and an area of 4-inch plus rains covered about 50 square miles. The limited area extent of the rainfall still produced the 5th highest discharge (9,860 cfs) on record on the Whitewater River near Beaver on July 5.

June 30-July 5, 1978 - Southeast MN and Southwest WI: One of the greatest flash flood/flood events to affect the LaCrosse HSA occurred from the last day of June into early July. A huge area of southeast Minnesota 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"+ 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. Five drowning deaths were reported in southeast Minnesota from the flooding. LaCrosse, WI had it's 2nd highest 24-hour rainfall ever at 4.79" (only 5.24" on July 27, 1987 was higher). The highest rainfall totals were over the Kickapoo watershed, a large portion of which received 7 to possibly 9 inches of rain. The town of Soldiers Grove was particularly hard-hit and 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 LaFarge, Gays Mills and Steuben the peak discharges were 14,300 , 15,000 and 16,500 cfs, respectively which are still standing records for the river. At LaFarge this flow equates to a recurrence interval of 225 years, while at Steuben to 140 years. Two fatalities were reported in Wisconsin and damage was estimated at $51 million. According to the USGS, Nedorlo Creek, a 9.46 mi2 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.

Flash flooding was widespread over southeast Minnesota as well. Rainfall was heaviest over Wabasha, Olmsted, Winona, Fillmore and Houston counties. The highest official point total was 8.68" recorded in Rushford township, Fillmore county. 2,850 square miles in Minnesota received more than 4 inches of rainfall. These rains also set the stage for the severe flooding in the Rochester area just a few days later.

July 5-6, 1978 - Austin and Rochester, MN: Just a few days after the massive flood event June 30-July, a more concentrated heavy rainfall event occurred from Dodge county east to Winona county, with the heaviest band of 6-7" just south and east of the Rochester area. An NWS gage measured 4.99" in 3 hours, beginning around 5:53 p.m on the 5th. Precipitation ended around 1:50 a.m. on the 6th, with over 6 inches total and a 7.3" storm total in eastern Olmsted county. The area of 4-inch rainfall covered an area of 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. The July 6 crest at the Rochester river gage established an all-time record of 23.36' and 30,500 cfs, easily exceeding the previous record crest (1965) by over 4 feet. This flood and yet another in September 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. In addition 2 to 3 inch rains fell over the headwaters of the Cedar River in Mower and Dodge counties, which produced significant flooding but also set the stage for a more important event 10 days later.

July 16-17, 1978 - Cedar River, Austin, MN: The second major rainfall event in 10 days to affect southeast Minnesota affected primarily Mower county and the Cedar River basin. Flash Flooding began late on the 16th and river flooding along the Cedar in Austin peaked on the 17th. The highest un official rainfall total was in Waltham Township, northwestern Mower county, at 9.50". Only 2.41" fell in Austin itself and 3.71" at Grand Meadow but the headwaters of the Cedar River were well placed beneath the heaviest rainfall. The peak stage/discharge at Austin 3S was 20.35' and 12,400 cfs, both records which stood until July 2000. There was widespread urban flooding in Austin from this event.

September 12, 1978 - Southeast MN: The second major flash flood and flood event of summer 1978 in Rochester began around 10:00 a.m. and precipitation ended around midnight. Downtown Rochester received 7.07" of rain, 5.74" of which fell in six hours. Another 7-inch rainfall center was located over northeast Mower county. The 4-inch or greater isohyet covered 1,200 mi2.

March 19, 1979 - Turkey/Volga Rivers, IA: Rapid snowmelt caused flooding mainly along the lower Turkey River from Garber to Osterdock. The peak discharge at Garber (26,000 cfs) has a recurrence interval of 13 years.

May 29-30, 1980 - Southeast MN and Southwest WI: Fillmore county, MN saw 6.65" of rain, mostly between 8:00 p.m. and midnight of the 29th, and on the afternoon of the 30th. The 4-inch isohyet covered 1,200 mi2 from Mower, through Fillmore and Winona counties. Little, if any, significant river flooding occurred as a result of these storms. September 20, 1980 - Fillmore and Winona counties, MN: A small, but intense flash flood event occurred from central Fillmore into southeast Winona counties late on the 20th. Precipitation began around 7:30 p.m. ending around 11:15 p.m. Homer township in Winona county received 7.45", and unofficial estimates of 8 to 11 inches in only 2 hours were reported. The flash flood destroyed seven bridges and two small dams and caused one death. Damage was concentrated in the small town of Pickwick, MN located near the Mississippi River and along Big Trout Creek. An analysis by the U.S. Bureau of Reclamation for this event estimated a discharge of 18,000 cfs for a 9.9 mi2 basin, which is 45% of the Probable Maximum Flood for a basin of this size.

July 11, 1981 - Rochester and Preston, MN: This was the third approximately 100-year rainfall (6-inches or greater) event to visit the Rochester area in 3 years. The NWS at the Rochester airport measured a record 7.47 inches of rain in a 24-hour period and an unofficial amount of 11.04 inches was measured seven miles west of the airport. Another isohyetal center was over central Fillmore county, with 7.70" falling at Preston on the Root River. 5.70" inches fell in less than 2 hours. The South Branch Root River at Lanesboro had a peak discharge on the 12th of 9,500 cfs and a stage of 13.48 feet, the highest on record.

June 15, 1991 - Turkey River basin, IA: Record flooding occurred on the Turkey river on the 15th of June. The flood was preceded by several months of well above normal precipitation. The spring (March-May) of 1991 was the second wettest to that time. Beginning late on the 14th and continuing into the 15th, torrential rainfall fell across the region. The official rainfall maximum was only 4.30" at Postville (Allamakee county), with 3.28" at Elkader and 3.05" at Waucoma. Unofficial and DCP reports however far exceeded these totals, with the USGS DCP at Luana (Clayton county) reporting 13.96" and 9.28" five miles south of Postville . Both Monona (Clayton county) and Fayette reported unofficial amounts of 13 inches. Five inches of rain in a two-hour period was reported late on the 14th in northern Clayton county prompting Flash Flood Warnings. Damage was widespread and nearly catastrophic across Fayette and Clayton counties, exceeding $3 million in non-agricultural losses. Numerous bridges and roads washed out and many homes were damaged. The flood discharge at Garber was 49,900 cfs, 1.5 times the previous record to that time set in 1922 and 1.4 times the estimated 100-year recurrence-interval discharge and greater than a 500-year event. In terms of statistics this was one of the worst floods to affect a river in the LaCrosse HSA.

July 21, 1991 - Stockton, MN: Torrential rains fell during the evening hours over the town of Stockton in Winona county, about 4 miles southwest of Winona. The headwaters of Garvin Brook and the drainage area of Stockton Valley Creek received about 5.5" of rain between 6 and 7 pm. This is about 1.9 times the 100-year, 1-hour rainfall of 2.9 inches for that area. Damages from this flash flood included 3 homes destroyed and 112 damaged, amounting to about $1.5 milllion.

September 14-18, 1992 - Western Wisconsin: A series of thunderstorms developed over a slow-moving frontal boundary, producing widespread flash flooding in western Wisconsin. The LaCrosse WFO issued 15 Flash Flood Warnings from September 14-16, all for counties in Wisconsin. 24-hour rainfall of 2 to 4 inches ending at 12Z on the 15th fell in a band from extreme southeast Minnesota through Vernon county. The activity resumed again on the 15th and produced extreme rainfall over the north central counties, including Buffalo, Trempealeau and Jackson. The heaviest rains were centered in lower Chippewa and the Buffalo River watershed, located between the Black and Chippewa basins, neither of which had major flooding. Mondovi, located in the headwaters of the ungaged Buffalo river, received 7.88" during this period, but 6.30" in the 24 hours ending at 12Z on the 16th. Rains were also tremendous in parts of the Kickapoo basin, including LaFarge, (9.5" over a five-day period from the 14-18th). The Trempealeau River at Dodge had its 8th highest discharge on September 18th from these rains. Another basin affected by these rains was the 250 mi2 Pine River basin , mostly in Richland County. Two distinct floods crests affected Richland Center, on the 15th and 17th. Analyses of this flood performed in conjunction with the installation of a flood control and warning system indicated that the initial event discharge of about 7,200 cfs had a 25-year recurrence interval. The second event on the 17th had a discharge around 11,000 cfs, with about a 70-year recurrence interval. The town of Richland Center was severely affected by these floods, however the flood control system in place now would easily handle floods of this magnitude.

June-August, 1993 - entire HSA: Severe flooding struck most of the upper Midwest during the memorable summer of 1993, although the worst flooding occurred somewhat south of the LaCrosse HSA.

June 20-21, 1993 - Black River basin, WI: June 16-21, 1993 - Black River basin, WI: Heavy rains fell across much of the La Crosse HSA, especially over western Wisconsin during this period. Rainfall was widespread and heavy across the Black River basin during the 5-day period from June 16 to 20. Over 6.4" fell at Neillsville, 4" fell at Black River Falls, and 4.79" at Galesville. No one day saw truly excessive rains, but soils were fully saturated and runoff consequently very high. The runoff produced a record flood crest at Black River Falls on June 21 of 61.19 feet (Flood Stage: 47 feet) and a record discharge of 64,000 cubic feet per second (cfs). Further downstream on the Black River at Galesville, with hydrologic records dating back to 1931, the flood also produced record stage of 16.64 feet (Flood Stage: 12 feet) and discharge of 64,000 cfs on the 21st . The USGS estimated a recurrence interval of 75 years for this discharge at Galesville. Over 100 homes in Black River Falls were flooded due to a levee failure on the river. Fifteen roads were closed due to flooding and a partial dam failure occurred at the Hatfield Dam, which impounds Lake Arbutus. Structural damage to the dam included a hole 8 feet deep and 6 feet across, as well as to damage to the tainter gates and flashboards. The USGS estimated a discharge of 80,000 cfs at this location.

June 25-July 1, 1993 - Mississippi River and major tributaries: Heavy rainfall June 17-18, combined with flows from the Black River basin floods (see above) caused some near-record crests on the mainstem river. At McGregor, IA the 22.0-foot crest on June 29 is the 3rd highest (after 1965 and 2001) and 1993 holds 6th place at both Guttenburg and Lansing.

August 14-16, 1993 - Southern MN and Northern IA: Torrential rainfall from a mesoscale convective system fell over extreme southern Minnesota and northern Iowa in the early morning hours of the 15th, with an unofficial 10.25" reported in Adams (southern Mower county), MN. The heavy rains fell near the 500 mb ridge axis over northern Iowa as strong southwesterly flow at 850 mb produced high theta-e advection over the heavy rain area. Precipitable water was roughly 150% of normal over the area and several weak short waves traversed the region helping to destabilize the atmosphere. Flooding occurred on the Cedar River in Austin with the second highest crest to that date (19.43 feet, less than one foot below the 1978 peak). The runoff into the Cedar caused the river at Charles City, IA to reach a record 21.44 feet on the 16th, a record since eclipsed by the 1999 flood. The Upper Iowa River basin also received heavy rains, with 6.1" of rain reported at Spillville, IA. Record flooding (19.0 feet) occurred on the 17th at Spillville, exceeding the June, 1947 record and Decorah had its third highest crest to that date. Downstream on the Upper Iowa River, the USGS gage near Dorchester had it's 2nd highest stage (20.0 feet - Flood Stage:14 feet) and discharge (22,000 cfs) since records began in 1941.

April, 1997 - Mississippi River: Snowmelt from a near record snowpack the Upper Mississippi River basin affected primarily the mainstem river. Flooding was far worse to the north and west of the LaCrosse HSA, especially along the Red River of the North and Minnesota River. The runoff still produced some significant crests in the LaCrosse HSA that are among the top five of all time at several locations including Winona, MN, Lansing and McGregor, IA.

May 17-20, 1999 - Northeast IA: Record flooding on the Turkey, Volga and Wapsipinicon rivers resulted from intense rainfall beginning late on May 16. The meteorological situation featured a slow moving warm frontal boundary south of the area, with deep moist air (surface dewpoints in the low to mid-70s) being lifted across this boundary by a strong low level jet. This produced a complex of thunderstorms during the afternoon of the 16th The synoptic and mesoscale conditions changed little into the early morning hours of the 17th over the area and a second complex of storms developed which created rainfall in excess of an inch an hour over many of the same river basins. 24-hour rainfall totals ending at 7:00 a.m. on the 17th exceeded 6 to 8 inches in an area centered on southwest Fayette and southeast Bremer counties, which are headwater areas for the Volga and Little Wapsipinicon rivers and Otter Creek . Flooding was severe on the Volga, hitting the towns of Volga and Littleport especially hard. No long-term stream gages existed at these sites, but the peak discharge was later estimated by the USGS to be 30,000 cfs. The crest on the Turkey at Garber, just below the confluence with the Volga, was 53,900 cfs with the bulk of the flow from the Volga. Fortunately, the rainfall in the upper Turkey was quite a bit less than in the Volga basin, generally 1 to 4 inches. Even at that, the crest at Garber eclipsed the incredible 1991 record and again was estimated to have a recurrence interval of greater than 500 years, the second such flood in less than 10 years. For more information, click here.

July 19-21, 1999 - Cedar and Wapsipinicon river basin, MN and IA: Record floods occurred throughout the Cedar and Wapsipinicon river basins from about July 19-25, 1999. The floods occurred as a result of two nights of thunderstorms July 18-19 and July 20-21. The first storm produced 4 to 6 inches of rainfall over parts of Chickasaw, Floyd and Worth counties, although unofficial amounts near the town of Manly (southeast Worth county) indicated that up to 13" may have fallen. This rainfall was centered in the Shell Rock, Cedar and upper Wapsipinicon basins. A nearly identical meteorological setup two nights later produced mesoscale convective system of training thunderstorms that dropped 6 to 8 inches of rain somewhat further to the southeast, centered over eastern Floyd and western Chickasaw counties, or somewhat lower in the same river basins. Charles City recorded 5.16" and 6.65", respectively on the two nights, close to or in excess of the 100-year rainfall for that location. Widespread flooding occurred across the area, with road closures, washouts and residential flooding. The Cedar at Charles City peaked on the 21st at 22.81 feet or 31,200 cfs, slightly more than a 100-year recurrence interval. This broke the 1961 record of 21.53 feet (29,200 cfs). The worst flooding on the Wapsipinicon River occurred south of the ARX HSA, although small streams within the basin flooded. July, 1999 rainfall was extraordinary at a few locations: 17.70" at New Hampton, IA (Chickasaw Co.) and 16.70" at Friendship, WI (Adams Co.) Remarkably, no flooding was reported in Wisconsin during the month. For more information, click here.

June, 2000 - Cedar and Root River basins, MN: Both the Cedar and Root rivers were the focus for flooding in early June. The first event began during the afternoon of May 31st as numerous thunderstorms dropped heavy rains over southeastern Minnesota and continued into the afternoon of June 1st. Precipitation of 2 to 5 inches fell across a multi-county area, much of it falling in the same location that received 3 to 6 inches of rain May 17-18. Flooding and flash flooding was reported in parts of Mower and Fillmore counties, with particularly bad flash flooding along Spring Creek in the town of Spring Valley, MN. The Cedar River at Austin crested at 17.4 feet early on the 1st, which was the highest crest since August, 1993. Flooding along the Root River also developed, inundating farmland and low-lying roads. The mainstem Root just north of Lanesboro undermined and destroyed the USGS gage house and later estimates indicated a record discharge (23,000 cfs) at this location with more than 60 years of data. In terms of flow this was worse than the severe snowmelt floods of 1952, 1961, 1962 or 1965. The flooding continued downstream at Houston where the 17.59' crest was the 2nd highest (after 1965's 18.32') and the discharge of 34,600 was second to the 1952 flood. At Hokah, near the mouth of the Root, the crest 52.2 feet exceeded flood stage by over 5 feet and also set a new record.

July, 2000 - Cedar and Root River basins, MN: The Cedar River basin and to a lesser extent the Root basin, received yet another heavy rain and flood event on July 9-10. Two nights of heavy rain produced 4 to 7 inches of rain primarily over western Fillmore and much of Mower county. 18 Flash Flood Warnings were issued by the NWS LaCrosse office. The wet antecedent conditions allowed for efficient runoff into area streams and rivers and helped to bring about record flooding in the Cedar basin. The Cedar at Austin, with significant contributions from its tributaries, crested at 23.4 feet, (15,300 cfs), eclipsing the 1978 records for stage and discharge. Flooding affected much of the town, covering roads and causing evacuations. Recurrence interval estimates from the USGS indicate that this flood was greater than a 200-year event at Austin. However, damage was less than in the 1978 flood owing to the extensive mitigation measures undertaken since that time. Moderate flooding also affected the Root River, although crests were substantially lower than the month before.

April 2001, entire HSA: Flooding from snowmelt and very heavy April rainfall (2nd wettest April in MN) produced the second or third highest crests along the Mississippi River through the LaCrosse HSA. The crests occurred from about the April 16-21 and in most locations only the 1965 and/or 1969 crests were higher. With seasonal snowfall well above average, the months of February and March were both colder than normal allowing for very little snowmelt entering April. Extremely heavy April precipitation (both snow and rain), especially over the upper Mississippi River basin combined with the melting snow to produce the high crests along the mainstem river. In Minnesota, statewide April precipitation was the 2nd highest on record, with many locations including Rocheseter (7.09") and Minneapolis (6.89") having their wettest April ever. The first major event precipitation occurred from April 6-7 and combined with the snowmelt moving downstream. Another major storm from April 21-23, which primarily affected areas north of the LaCrosse HSA, helped to sustain the duration of the cresting Mississippi. Despite the high levels, impacts were not nearly as severe as in 1965, primarily due to extensive levees along the river. The worst impacts occurred in Wabasha, MN, Fountain City, WI and north of Guttenburg, IA where there was some residential flooding. Nearly every tributary in the HSA also experienced some degree of flooding, although crests along these rivers were mostly in the minor to moderate category.


Sources of Data:

An Inventory of Water Resources and Water Problems, Northeastern Iowa River Basins; Iowa Natural Resources Council - 1958

Kickapoo River Valley, Flood Warning and Preparedness Plan; Wisconsin Department of Local Affairs and Development: Phase I - 1979

Flood Plain Information: South Fork Zumbro River and Tributaries, Rochester, MN; City of Rochester and St. Paul District, U.S. Army Corps of Engineers - 1968

Flood Plain Management: Iowa's Experience; Papers presented at the Conference on Flood Plain Management, 6th Water Resources Design Conference; The Iowa State University Press - 1969

Cedar River and Tributaries: Flood Plain Information, Austin, MN; Rock Island District, U.S. Army Corps of Engineers - 1969.

Root River Basin, Minnesota: Feasibility Report for Flood Control; St. Paul District, U.S. Army Corps of Engineers - 1975

ESSA Technical Report WB-4: The March-May 1965 Snowmelt Floods in the Red River of the North, Upper Mississippi and Missouri Basins; U.S. Dept. of Commerce, ESSA, Weather Bureau - 1966

NOAA Technical Report NWS 13: The March-April 1969 Snowmelt Floods in the Red River of the North, Upper Mississippi and Missouri Basins; U.S. Dept. of Commerce, NOAA, NWS - 1971

Floods of July 1-5, 1978 on the Kickapoo River, Southwestern Wisconsin; Hydrologic Investigations Atlas HA-653; USGS

Sixteen-Year Study of Minnesota Flash Floods; Minnesota DNR, Division of Waters, State Climatology Office - 1988

National Water Summary 1998-89: Hydrologic Events and Floods and Droughts; USGS Water Supply Paper 2375 - 1991

Iowa Precipitation Variations: Past, Present and Future; Iowa Dept. of Agriculture, State Climatology Office - 1986

Comparison of Estimated Maximum Flood Peaks with Historic Floods: U.S. Dept. of Interior, Bureau of Reclamation, Division of Planning, Technical Services, Hydrology Branch - 1986

Rainfall Frequency Atlas of the Midwest; Midwestern Climate Center - 1992

Emergency Action Plan for Flooding: Richland Center, Wisconsin; NRCS - 1992

Catalogue of Heavy Rainfall Cases of Six Inches or More Over the Continental United States During 1992; NOAA Technical Report NESDIS 66; U.S. Dept. of Commerce, NOAA, NESDIS - 1992

Catalogue of Heavy Rainfall Cases of Six Inches or More Over the Continental United States During 1993; NOAA Technical Report NESDIS 80; U.S. Dept. of Commerce, NOAA, NESDIS - 1993

The Great Flood of 1993; Natural Disaster Survey Report; U.S. Dept. of Commerce; NOAA, NWS - 1994

Techniques for Estimating Flood-Frequency Discharges for Streams in Iowa; USGS Water Resources Investigations Report 00-4233 - 2001

Floods of July 12, 1972, March 19, 1979, and June 15, 1991, in the Turkey River Basin, Northeast Iowa; USGS Open File Report 96-560 - 1996

Floods of July 19-25, 1999, in the Wapsipinicon and Cedar River Basins, Northeast Iowa; USGS Open-File Report 01-13 - 2000

Floods of May 17-20, 1999, in the Volga and Wapsipnicon River Basins, Northeast Iowa; USGS Open File Report 00-237 - 1999

Flood Frequency Characteristics of Wisconsin Streams; USGS Water Resources Investigation Report 91-4128 - 1992

Techniques for Estimating Peak Flow on Small Streams in Minnesota; USGS Water Resources Investigations Report 97-4249 - 1997

Peak Discharges and Flow Volumes for Streams in the Northern Plains, 1996-97; Circular 1185-B USGS - 2001

E-3/E-5 Reports: LaCrosse HSA - 1998-2001

Websites:

National Water Information Service, USGS (Iowa, Minnesota, Wisconsin): http://waterdata.usgs.gov/nwis

St. Paul District, U.S. Army Corps of Engineers: http://waterdata.usgs.gov/nwis

Midwest Climate Center: http://mcc.sws.uiuc.edu/

Minnesota Climatology Working Group: http://climate.umn.edu/

LaCrosse WFO: /arx/hydro.shtml

Source: http://www.rootsweb.com/~wiclark/history/CChistory2.html

Other:

Iowa State Climatologist: personal communications


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