Floods of July 19-25,1999, Inthe Wapsipinicon and Cedar River Basins, Northeast Iowa

U.S. Department of the Interior U.S. Geological Survey

FLOODS OF JULY 19-25,1999, INTHE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA

fey Jan L. Ballew and David A. Eash

Open-File Report 01-13

Prepared in cooperation with the IOWA DEPARTMENT OF TRANSPORTATION and the IOWA HIGHWAY RESEARCH BOARD (Project HR-140) U.S. Department of the Interior Gale A. Norton, Secretary

U.S. Geological Survey Charles G. Groat, Director

For additional information write to:

District Chief U.S. Geological Survey, WRD P.O. Box 1230 Room 269, Federal Building 400 South Clinton Street Iowa City, Iowa 52244

Copies of this report can be purchased from:

U.S. Geological Survey Information Services Box 25286, Denver Federal Center Denver, Colorado 80225-0286 CONTENTS Page Abstract...... ^ 1 Introduction...... 1 Acknowledgments...... 2 River basins ...... 2 Storm description...... 5 Flood description...... 8 Profiles for the floods of July 19-25, 1999, in the Wapsipinicon and Cedar River Basins...... 12 Summary...... ^ 14 References...... 14 Appendix: Temporary bench marks and reference points in the Wapsipinicon and Cedar River Basins...... 14

FIGURES 1. Map showing river reaches profiled, location of bridge sites used for the flood profiles of July 19-25, 1999, and U.S. Geological Survey streamflow-gaging stations located in the Wapsipinicon and Cedar River Basins, Iowa...... 3 2-3. Maps showing areal distribution of rainfall for the: 2. July 18-19, 1999, storm in the Wapsipinicon and Cedar River Basins. Iowa...... 6 3. July 20-21, 1999, storm in the Wapsipinicon and Cedar River Basins, Iowa...... 7 4. Graph showing stage hydrograph of the Cedar River at Charles City, Iowa, streamflow-gaging station, July 17-30, 1999...... 12 5-8. Graphs showing profile of the July 1999 flood for the Wapsipinicon River, Iowa: 5. River miles 164 to 218...... 22 6. River miles 164 to 180...... 23 7. River miles 180 to 200...... 24 8. River miles 200 to 218...... 25 9-15. Graphs showing profile of the July 1999 flood for the Cedar River, Iowa: 9. River miles 139 to 250...... 27 10. River miles 139 to 155 ...... 28 11. River miles 155 to 175 ...... 29 12. River miles 175 to 195 ...... 30 13. River miles 195 to 215 ...... 31 14. River miles 215 to 235 ...... 32 15. River miles 235 to 250...... 33 16-20. Graphs showing profile of the July 1999 flood for the Shell Rock River, Iowa: 16. River miles 1 to 76 ...... 35 17. River miles 1 to 20...... 36 18. River miles 20 to 40...... 37 19. River miles 40 to 60...... 38 20. River miles 60 to 76...... 39 21-24. Graphs showing profile of the July 1999 flood for Flood Creek, Iowa: 21. River miles 1 to 40...... 41 22. River miles 1 to 15 ...... 42 23. River miles 15 to 30...... 43 24. River miles 30 to 40...... 44

CONTENTS III TABLES Page 1. Streamflow-gaging stations in the Wapsipinicon and Cedar River Basins, Iowa...... 4 2. Rainfall amounts at selected communities in northeast Iowa during July 19-21, 1999...... 9 3. Maximum stages and discharges, recurrence intervals, and unit runoff for the floods of July 1999 and selected additional years at selected streamflow-gaging stations in the Wapsipinicon and Cedar River Basins, Iowa...... 10 4-7. Elevations of high-water marks used in the flood profile of July 1999 for: 4. The Wapsipinicon River, Iowa...... 26 5. The Cedar River, Iowa...... 34 6. The Shell Rock River, Iowa...... 40 7. Flood Creek, Iowa...... 45

CONVERSION FACTORS, ABBREVIATIONS, AND VERTICAL DATUM Multiply By To obtain inch (in.) 25.4 millimeter foot (ft) 0.3048 meter mile (mi) 1.609 kilometer square mile (mi2) 2.590 square kilometer cubic foot per second (ft3/s) 0.02832 cubic meter per second cubic foot per second per 0.01093 cubic meter per second square mile [(ft3/s)/mi2] per square kilometer

Sea Level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 a geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929.

IV FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA Floods of July 19-25,1999, in the Wapsipinicon and Cedar River Basins, Northeast Iowa by Jan L. Ballew and David A. Eash

ABSTRACT at streamflow-gaging stations on the Wapsipinicon and Cedar Rivers and on Flood Creek. Severe flooding occurred during July 19-25, The flooding caused major damage in 1999, in the Wapsipinicon and Cedar River Basins Independence and Littleton along the Wapsipinicon following two thunderstorms over northeast Iowa. River; Charles City, Nashua, Waverly, and Cedar Falls During July 18-19, as much as 6 inches of rainfall along the Cedar River; Rock Falls, Rockford, and Shell was centered over Cerro Gordo, Floyd, Mitchell, Rock along the Shell Rock River; Rudd along Flood and Worth Counties. During July 20-21, a second Creek; and Manly, in Worth County from small-stream storm occurred in which an additional rainfall of as flooding. More than 1,000 homes in six counties were much as 8 inches was centered over Chickasaw damaged by the July 1999 floods. The number of homes reported as damaged is listed below (McGlynn and Floyd Counties. The cumulative effect of the and Chatterley, Des Moines Register, July 27, 1999); storms produced floods with new maximum peak damage to homes in Butler, Cerro Gordo, and Floyd discharges at the following streamflow-gaging Counties was not reported. stations: Wapsipinicon River near Tripoli, 19,400 cubic feet per second; Cedar River at Charles City, 31,200 cubic feet per second (recurrence interval Homes with Homes with Homes major minor about 90 years); Cedar River at Janesville, 42,200 County destroyed damage damage cubic feet per second (recurrence interval about 80 Bremer 0 24 104 years); and Flood Creek near Powersville, 19,000 Buchanan 10 118 61 cubic feet per second. Profiles of flood elevations Chickasaw 1 9 332 for the July 1999 flood are presented in this report Howard 0 0 40 for selected reaches along the Wapsipinicon, Mitchell 0 6 4 Cedar, and Shell Rock Rivers and along Flood Worth 2 56 249 Creek. Information about the river basins, rain storms, and flooding are presented along with The flood forced the evacuation of hundreds of information on temporary bench marks and people from their homes and caused many road reference points in the Wapsipinicon and Cedar closures throughout northeast Iowa. Governor Vilsack River Basins. declared a State disaster emergency for Bremer, Butler, Cerro Gordo, Chickasaw, Floyd, Howard, Mitchell, and Worth Counties. A Federal disaster proclamation INTRODUCTION followed that included Black Hawk and Jones Counties. As of early June 2000, the total economic Thunderstorms caused severe flooding on the damage from flooding in the Wapsipinicon and Cedar Wapsipinicon, Cedar, and Shell Rock Rivers and along River Basins was not completely evaluated. The Flood Creek in northeast Iowa in July 1999. New Federal Emergency Management Agency (FEMA) had maximum peak stages and discharges were measured approved nearly $6 million in financial assistance for INTRODUCTION 1 schools, businesses, private non-profit businesses, road Acknowledgments and bridge repairs, demolition of homes or businesses declared hazardous, and for repair of essential utilities The authors express their gratitude to Al Dietz, to recover from the flood damage. The FEMA financial City of Cedar Falls Land Surveyor's Office; Todd assistance did not include agricultural losses, losses Fonkert and Dennis Haverkamp, Bremer County sustained due to loss of commerce or unemployment, Engineer's Office; Denny Rops, Butler County and several large road and bridge projects not yet Engineer's Office; and Doug Franke, Floyd County completed (Jerry Ostendorf, Iowa Emergency Engineer's Office, for providing elevations for Management Division, written commun., June 2000). temporary bench marks at bridges. The authors also The July 1999 flood resulted in private home express their gratitude to the following: A.L. Donnelly buyout assistance totaling about $4 million for 75 and R.L. Kuzniar for collecting flood-elevation data homes in the Cedar River flood plain and for 4 homes and for collecting and processing global-positioning- in the Shell Rock River flood plain (Dennis Harper, system data for the establishment of sea-level Hazard Mitigation, Iowa Emergency Management elevations for temporary bench marks; J.D. Eash, M.S. Division, written commun., May 2000). Private home Linhart, J.C. McVay, M.J. Noon, and M.J. Turco for buyout assistance was not offered for any homes in the collecting flood-elevation data, and D.E. Christiansen Wapsipinicon River flood plain following the July 1999 for preparing the maps for this report. flood because 111 homes along the Wapsipinicon River were included in this program following the May 1999 flood at a cost of more than $6 million (Ballew and RIVER BASINS Fischer, 2000). In the agricultural sector, farmers were unable to The Wapsipinicon and Cedar River Basins are replant flooded fields because the flooding occurred too parallel river basins draining from the northwest to the late in the growing season. Agricultural losses were a southeast across northeast Iowa. The two drainage result of yield reductions and damage to farm basins, the river reaches profiled, the location of active infrastructure such as waterways and terraces. In Floyd and discontinued USGS streamflow-gaging stations in County, for example, crop damage was estimated at Iowa within these river basins, and the location of $3.3 million, the result of a 25-percent yield reduction bridge sites used in the July 19-25, 1999, flood profiles in corn and a 35-percent yield reduction in soybeans are shown in figure 1. Station numbers and names, (Dennis Sande, District Conservationist, Natural drainage areas, periods of flood records, types of gages, Resources Conservation Service, oral commun., June and status of gages for the gaging stations shown in 2000). figure 1 are listed in table 1. Archived streamflow data This report provides information about the July (peak-flow and daily values) can be accessed for these 1999 rainstorms and ensuing floods in the streamflow-gaging stations at the USGS web site URL Wapsipinicon and Cedar River Basins. Flood http://waterdata.usgs.gov/nwis-w/IA/. elevations at selected sites along the Wapsipinicon, The Wapsipinicon River originates in Cedar, and Shell Rock Rivers and along Flood Creek southeastern Minnesota and flows about 225 mi to the are presented as flood profiles. mouth at the Mississippi River (Iowa Natural This report was prepared in cooperation with the Resources Council, 1958, p. 8). The Wapsipinicon Iowa Department of Transportation and the Iowa River Basin is a long narrow basin with a total drainage Highway Research Board. Various Federal, State, and area of 2,540 mi2, of which all but 13 mi2 are in Iowa local agencies provide funding for the operation and (Schwob, 1971, p. 3). The topography of the basin maintenance of the streamflow-gaging stations in the changes from relatively flat in the upper part of the Wapsipinicon and Cedar River Basins. They are basin to gently rolling in the lower part. Land use in the acknowledged in the annual water resources data basin is primarily agricultural. reports of the U.S. Geological Survey (USGS) (Nalley The Cedar River Basin originates in southeastern and others, 2000). A list of other Iowa flood-profile Minnesota and flows approximately 320 mi to the reports published by the USGS can be obtained from mouth at the Iowa River. The total drainage area of the the World Wide Web at the uniform resource locator Cedar River Basin is 7,819 mi2, of which 1,024 mi2 are (URL) http://ia. water, usgs. gov/projects/prqfiles/. in Minnesota (Schwob, 1963, p. 1). Within Iowa, the

2 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA Boundary of Cedar River Basin

Boundary of Wapsipinicon River Basin 4^'^f* v-- si V"*1 1? \ie iS>J!^fe-

EXPLANATION Drainage-basin boundary River reach profiled in this report ' Primary roads USGS streamflow-gaging station and map number (table 1) Bridge sites Base from U.S. Geological Survey digital data, 1:2,000,000, 1991 Universal Transverse Mercator projection, Zone 15

Figure 1. River reaches profiled, location of bridge sites used for the flood profiles of July 19-25, 1999, and U.S. Geological Survey streamf low-gaging stations located in the Wapsipinicon and Cedar River Basins, Iowa.

RIVER BASINS 3 Table 1 . Streamflow-gaging stations in the Wapsipinicon and Cedar River Basins, Iowa [no., number; mi2, square miles; cont., continuous; csg, crest-stage gage; disc., discontinued]

Map Drainage Type Status no. Station area Period of flood record of of (fig. 1) number Station name (mi2) (water years)8 gage gage 1 05420560 Wapsipinicon River near Elma, IA 95.2 1959-92 cont. disc. 2 05420600 Little Wapsipinicon River tributary near Riceville, 1.10 1953-2000 csg active IA 3 05420620 Little Wapsipinicon River near Acme, IA 7.76 1953-93 csg disc. 4 05420640 Little Wapsipinicon River at Elma, IA 37.3 1953-93 csg disc. 5 05420650 Little Wapsipinicon River near New Hampton, IA 95.0 1966-93 csg disc.

6 05420680 Wapsipinicon River near Tripoli, IA 343 1969, 1996-99 cont. active 7 05420690 East Fork Wapsipinicon River near New Hamp 30.3 1966-93 csg disc. ton, IA 8 05420850 Little Wapsipinicon River near Oran, IA 94.1 1966-2000 csg active 9 05420875 Buck Creek near Oran, IA 37.9 1966-2000 csg active 10 05420960 Harter Creek near Independence, IA 6.17 1952-63 csg disc.

11 05421000 Wapsipinicon River at Independence. IA 1,048 1934-2000 cont. active 12 05421100 Pine Creek tributary near Winthrop, IA 0.334 1952-2000 csg active 13 05421200 Pine Creek near Winthrop, IA 28.3 1950-93 csg disc. 14 05421300 Wapsipinicon tributary at Winthrop, IA 0.70 1953-2000 csg active 15 05421500 Wapsipinicon River at Stone City, IA 1,324 1892, 1903-13 cont. disc

16 05421550 Buffalo Creek above Winthrop, IA 68.2 1957-90 csg disc. 17 05421600 Buffalo Creek near Winthrop. IA 71.4 1953-90 csg disc. 18 05421890 Silver Creek at Welton, IA 9.03 1966-2000 csg active 19 05422000 Wapsipinicon River near De Witt, IA 2.330 1935-2000 cont. active 20 05457440 Deer Creek near Carpenter, IA 91.6 1973-2000 csg active

21 05457500 Cedar River at Mitchell, IA 826 1934-42,1961-62 cont. disc. 22 05457700 Cedar River at Charles City, IA 1,054 1946-53,1961-62,1965-95, cont. active 1999 23 0545776680 Gizzard Creek tributary near Bassett, IA 3.42 1990-2000 csg active 24 05458000 Little Cedar River near Ionia, IA 306 1954-2000 cont. active 25 05458500 Cedar River at Janesville, IA 1,661 1905-06, 1915-21, 1923-27, cont. active 1933-42, 1945-2000

26 05458560 Beaverdam Creek near Sheffield, IA 123 1966-89 csg disc. 27 05458900 West Fork Cedar River at Finchford, IA 846 1929, 1946-2000 cont. active 28 05459000 Shell Rock River near Northwood, IA 300 1946-86 cont. disc. 29 05459010 Elk Creek at Kensett, IA 58.1 1966-90 csg disc. 30 05459490 Spring Creek near Mason City, IA 29.3 1966-2000 csg active

31 05459500 Winnebago River at Mason City, IA 526 1933-2000 cont. active 32 05460100 Willow Creek near Mason City, IA 78.6 1966-2000 csg active 33 05460500 Shell Rock River at Marble Rock, IA 1,318 1933-53,1961-62 cont. disc. 34 05461000 Shell Rock River at Greene IA 1,357 1933-42 cont. disc. 35 05461390 Flood Creek near Powersville, IA 127 1963, 1996-99 cont. active

4 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA Table 1 . Streamflow-gaging stations in the Wapsipinicon and Cedar River Basins, Iowa-Continued

Map Drainage Type Status no. Station area Period of flood record of of (fig. 1) number Station name (mi2) (water years)3 gage gage 36 05461500 Shell Rock River near Clarksville, IA 1,626 1916-27, 1933-34, 1961-62 cont. disc. 37 05462000 Shell Rock River at Shell Rock, IA 1,746 1856, 1954-2000 cont. active 38 05462750 Beaver Creek tributary near Aplington, IA 11.6 1966-91 csg disc. 39 05463000 Beaver Creek at New Hartford, IA 347 1946-2000 cont. active 40 05463090 Black Hawk Creek at Grundy Center. IA 56.9 1966-91 csg disc.

41 05463500 Black Hawk Creek at Hudson, IA 303 1952-95 cont. disc. 42 05464000 Cedar River at Waterloo, IA 5,146 1929, 1933, 1941-2000 cont. active 43 05464025 Miller Creek near Eagle Center, IA 9.14 1991-2000 csg active 44 05464130 Fourmile Creek near Lincoln, IA 13.78 1963-67, 1970-74, 1977-80 cont. disc. 45 05464133 Half Mile Creek near Gladbrook, IA 1.33 1963-67, 1970-74. 1977-80 cont. disc.

46 05464137 Fourmile Creek near Traer, IA 19.51 1963-74, 1976-80 cont. disc. 47 05464145 Twelvemile Creek near Traer, IA 43.8 1966-92 csg disc. 48 05464220 Wolf Creek near Dysart, IA 299 1996-98 cont. active 49 05464310 Pratt Creek near Garrison, IA 23.4 1966-94 csg disc. 50 05464318 East Blue Creek at Center Point, IA 17.6 1966-93 csg disc.

51 05464500 Cedar River at Cedar Rapids, IA 6,510 1851, 1903-2000 cont. active 52 05464535 Prairie Creek tributary near Van Home. IA 0.94 1991-2000 csg active 53 05464560 Prairie Creek at Blairstown, IA 87 1966-88 csg disc. 54 05464562 Thunder Creek at Blairstown, IA 0.96 1991-2000 csg active 55 05464640 Prairie Creek at Fairfax. IA 178 1967-82 com. disc.

56 05464880 Otter Creek at Wilton, IA 10.7 1966 93 csg disc. 57 05465000 Cedar River near Conesville, IA 7,785 1940-2000 cont. active "Period of flood record listed through water year 2000. topography of the basin ranges from flat to rolling and STORM DESCRIPTION the stream valleys alternate from reaches that are wide and flat to reaches that are narrow and almost gorge- The July 19-25, 1999, flood in the Wapsipinicon like. A number of low-head dams have been and Cedar River Basins was the result of two storms constructed across the main stems of the Cedar and that occurred during a 72-hour period over northeast Shell Rock Rivers, but the dams have small pools that Iowa. The first storm occurred during July 18-19 and do not substantially affect the peak discharge of the was followed by a second storm over the same area rivers during large floods (Schwob, 1963, p. 2). during July 20-21, resulting in a broader and more Although land use in the Cedar River Basin is primarily intense rainfall pattern. Figures 2 and 3, provided by agricultural, several areas within the basin are urban. State Climatologist Harry Hillaker, Iowa Department Tributary streams within the Cedar River Basin that are of Agriculture and Land Stewardship (written profiled in this report include the Shell Rock River and commun., July 1999), show areal distribution of Flood Creek. rainfall for the 24-hour periods ending July 19 and 21.

STORM DESCRIPTION 5 Boundary , of Cedar

V A Mower S /_ VjVHpnesota Iowa !\

Boundary of Wapsipinicon River Basin

Blackhawk /*~WJ Buchananl Benton

EXPLANATION 4 Line of equal rainfall for 24-hour period ending at 7:00 a.m., July 19,1999. Interval 2 inches; rainfall data shown only for Iowa

Drainage-basin boundary Base from U.S. Geological Survey digital data, 1:2,000,000, 1991 Universal Transverse Mercator projection. Zone 15

Figure 2. Areal distribution of rainfall for the July 18-19,1999, storm in the Wapsipinicon and Cedar River Basins, Iowa (lines of equal rainfall, in inches, provided by Harry Hillaker, State Climatologist, Iowa Department of Agriculture and Land Stewardship, written commun., July 1999).

6 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA Boundary of Cedar River Basin

Boundary of Wapsipinicon River Basin

EXPLANATION 4 Line of equal rainfall for 24-hour period ending at 7:00 a.m., July 21, 1999. Interval 2 inches; rainfall data shown only for Iowa

Drainage-basin boundary Base from U.S. Geological Survey digital data, 1:2,000,000, 1991 Universal Transverse Mercator projection. Zone 15

Figure 3. Areal distribution of rainfall for the July 20-21,1999, storm in the Wapsipinicon and Cedar River Basins, Iowa (lines of equal rainfall, in inches, provided by Harry Hillaker, State Climatologist, Iowa Department of Agriculture and Land Stewardship, written commun., July 1999).

STORM DESCRIPTION 7 Excerpts from records of the U.S. Department of westward to Rockford.The highest 24-hour gage Commerce, National Oceanic and Atmospheric report within the Cedar Basin was at Charles City Administration, and National Weather Service (URL with 6.65 inches. According to the Rainfall Frequency Atlas of the Midwest (Midwest Climate http://www4.ncdc.noaa.gov/cgi-win/ Center, 1992), the 100-year, 24-hour rainfall in wwcgi.dll?wwEvent~storms) describe the sequence of this part of Iowa is around 6 inches, meaning that storm events as follows: 2 out of 3 nights the rain gage in Charles City had (7/18 7/19/99) A nearly stationary frontal rains at or in excess of the 100-year frequency for boundary was draped across Iowa during the 24 hours. afternoon of the 18th into the night. Thunderstorms erupted in the vicinity of the front Excerpts from the records of the U.S. as dew point temperatures in the mid-70s to Department of Commerce, National Oceanic and around 80 pooled just south of the front. Most of Atmospheric Administration, and National Weather the storms produced heavy rain and gusty winds Service (1999) indicate that: with very few producing severe weather. The main Very heavy rains fell in the Cedar River problem was flash flooding over north central Basin from Mower County in Minnesota to Floyd Iowa. Near Manly in Worth County, 5.75 inches of County in Iowa on July 18th, and across Mitchell, rain was recorded in a four-hour period just after Floyd, and Chickasaw Counties in Iowa on July midnight. Heavy rains also fell over northeast 20th. Totals of 10 to 12 inches were reported for Cerro Gordo County, overtopping many roads Osage, Charles City, and New Hampton during with 1 to 2 feet of water. The heaviest rainfall this three-day period. Though no readings were available, a record or near-record flood crest likely occurred over Worth County. A bucket survey occurred on the upper reaches of the indicated spot 9- to 12-inch rainfall amounts Wapsipinicon River through Chickasaw County. northeast of Manly, with the highest unofficial measurement at 13.5 inches, though there was The Rainfall Frequency Atlas of the Midwest one report of an incredible 20 inches of rain. (Huff and Angel, 1992, p. 101) shows the 100-year, 72- (7/20 7/21/99) Another flash flood watch hour rainfall for northeast Iowa to be about 8 inches. was issued early on the 20th for roughly the north Rainfall amounts for six communities in northeast half of Iowa. Factors cited in discussions about Iowa, as reported by the U.S. Department of the potential for heavy rainfall included the presence of a very slow moving cold front, Commerce, National Oceanic and Atmospheric combined with 30- to 45-MPH low level winds Administration, and National Environmental Satellite, feeding abundant moisture into the boundary. The Data, and Information Service (1999), are listed in forecasts for extreme rainfall were verified by table 2. tremendous rains which began late on the afternoon of the 20th. A flash flood warning was already issued by the early evening hours for FLOOD DESCRIPTION southern Worth County with radar-estimated rainfall at 2 inches per hour. Storms continued to As a result of the intense storms, severe flooding develop over the same areas during the evening occurred in the upper and middle parts of the hours, causing additional flash flood warnings in Wapsipinicon and Cedar River Basins and in the both Bremer and Butler Counties. Rainfall was middle and lower parts of the Shell Rock River Basin. heaviest in the Cedar and Shell Rock River New maximum peak stages and discharges were Basins, as the band of intense rainfall sank slowly measured at streamflow-gaging stations on the southward with the frontal boundary. Unofficial Wapsipinicon River near Tripoli, on the Cedar River at reports of 7 to 8 inches of rain were reported near Charles City and Janesville, and on Flood Creek near Clarksville, located along the Cedar River in Powersville. In Cedar Falls, the Cedar River Butler County. River flood warnings were issued unofficially reached a new record-high stage on July before midnight, late on the 20th, for the Cedar 23,1999. After consulting with the U.S. Army Corps of River from the Bremer County line and into the Engineers, Ron Arends, City of Cedar Falls Engineer, Waterloo area. As additional rainfall reports were received early on Wednesday the 21st, the extent indicated that this record stage was about 0.5 ft higher and degree of possible river flooding became than the stage of 96.3 ft estimated for the 1961 flood at evident. Radar-estimated rainfall indicated a large the city's river gage (Encson and Jamison, Waterloo- area of greater than 6 inches of rainfall centered Cedar Falls Courier, July 23, 1999). Maximum stages over Floyd County with a center of 8 to 11 inches and discharges, recurrence intervals, and unit runoff for stretching from just south of Charles City the floods of July 1999 and selected additional years at

8 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA Table 2. Rainfall amounts at selected communities in northeast Iowa during July 19-21, 1999 [Blank entries indicate zero. T, trace]

24-hour rainfall, in inches3 72-hour rainfall Community July 19, 1999 July 20, 1999 July 21, 1999 total, in inches Osage 5.75 0.05 5.00 10.80 Mason City 3.04 0.15 3.88 7.07 Charles City 5.16 6.65 11.81

New Hampton 4.75 7.10 11.85

Tripoli 0.77 T 3.06 3.83 Independence 0.86 0.37 3.77 5.00

aChmatological Data, Iowa, July 1999 (U.S. Department of Commerce, National Oceanic and Atmospheric Administration, and National Environmental Satellite, Data, and Information Service). selected gaging stations in the Wapsipinicon and Cedar In Floyd County, U.S. Highway 218 at the River Basins are listed in table 3. Mitchell/Floyd County line and south of Charles City, The flooding inundated many roads throughout State Highway 14 at Charles City, and U.S. Highway northeast Iowa; on July 21 authorities closed all roads 18 between the towns of Floyd and Rudd were closed into Floyd County and travel was not recommended during the flood. According to Ken Mahler, Emergency within Bremer, Chickasaw, and Floyd Counties Management Coordinator, Rockford was the hardest because of secondary roads being inundated and some hit area in Floyd County following the first storm gravel roads being washed out. In Bremer County, road during July 18-19 (Lee and McGlynn, Des Moines closures during the flood included U.S. Highway 218 at Register, July 20, 1999). JimZirbel, Charles City Plainfield, U.S. Highway 63 at the Bremer/Chickasaw Police Chief, estimated that between 500 and 1,000 County line, and State Highway 3 in Waverly. In homes in Charles City sustained flood-related damage Waverly, the Cedar River inundated 65 city blocks on (Lynch, Cedar Rapids Gazette, July 22,1999). Because July 22 and forced 1,500 people from their homes; of the flooding in Charles City, many businesses were closed, as were all bridges crossing the Cedar River, between 600 and 650 homes and a dozen downtown with the exception of the Main Street Bridge (U.S. businesses were affected by the flooding (Waterloo- Department of Commerce, National Oceanic and Cedar Falls Courier, July 23, 1999). Atmospheric Administration, and National Weather In Chickasaw County, road closures during the Service, July 19-22, 1999, URL http:// flood included State Highway 346 at the Wapsipinicon www4. ncdc. noaa. gov/cgi-win/wwcgi. dll ?wwEvenT~storms). River bridge. U.S. Highway 18 at several places west of A fatality occurred on a county road crossing Flood Fredericksburg and around New Hampton, County Creek south of Rudd when flood water washed a car Road B76 east of Ionia, and County Road T76 south of downstream after the motorist entered the flooded Bassett. At Nashua, the Cedar River topped the dam at roadway (Wilde, Waterloo-Cedar Falls Courier, July Cedar Lake and flooded nearby homes. In addition, 20,1999). In the town of Nora Springs, a small earthen flood water crossing State Highway 346 backed up dambreak on the Shell Rock River may have increased along the railroad bridge, causing water to rise into flow downstream. Because flood water had already downtown Nashua (U.S. Department of Commerce, substantially overtopped the dam at the time of the National Oceanic and Atmospheric Administration, failure, the exact impact on flow downstream was and National Weather Service, July 19-22, 1999, URL difficult to determine (U.S. Department of Commerce, http://www4. ncdc. noaa.gov/cgi-win/ National Oceanic and Atmospheric Administration, wwcgi. dll ?wwEvent~storms). and National Weather Service, July 19-26, 1999, URL

FLOOD DESCRIPTION 9 Table 3. Maximum stages and discharges, recurrence intervals, and unit runoff for the floods of July 1999 and selected additional years at selected streamflow-gaging stations in the Wapsipinicon and Cedar River Basins, Iowa [mi2, square miles; ft3/s, cubic feet per second; [(ftVsVmi2], cubic feet per second per square mile; boldfaced type, flood profile included in this report; , not determined]

Drainage Peak Peak Recurrence area stage3 discharge interval11 Unit runoff Streamflow-gaging station (mi2) Date (feet) (ft3/s) (years) [(ft3/s)/mi2] Wapsipinicon River Basin 05420560 Wapsipinicon River 95.2 6/29/1969 14.53 5,500 6 57.8 near Elma 6/04/1974 14.94 10,100 25 106 6/17/1984 14.81 6.580 9 69.1 7/21/1999 14.15 3,800° 4 39.9 05420680 Wapsipinicon River 343 7/01/1969 17.26 18,900° 55.1 near Tripoli 5/17/1999 14.39 3,900 11.4 7/21/1999 18.50 19,400 56.6 05421000 Wapsipinicon River 1,048 7/18/1968 21.11 26,800 50 25.6 at Independence 5/18/1999 22.35 31,100 90 29.7 7/24/1999 18.80 20,900 20 19.9 Cedar River Basin 05457700 Cedar River 1,054 3/27/1961 21.53 29,200 60 27.7 at Charles City 8/16/1993 21.44 26,400 35 25.0 7/21/1999 22.81 31,200 90 29.6 05458000 Little Cedar River 306 3/27/1%! 15.58 10,800 19 35.3 near Ionia 8/16/1993 18.99 14,000 40 45.8 7/21/1999 17.52 12,200 25 39.9 05458500 Cedar River 1,661 3/28/1961 16.33 37,000 45 22.3 at Janesville 8/18/1993 15.74 35,000 35 21.1 7/22/1999 17.15 42,200 80 25.4 05460500 Shell Rock River at 1.318 3/27/1933 107.6d 36,400 180 27.6 Marble Rock 3/28/1961 11.97 32,000C 90 24.3 7/21/1999 9.77 - - -- 05461 390 Flood Creek 127 5/10/1963 8.00 6,500° ~ 51.2 near Powersville 7/21/1999 12.57 19,000° -- 150 05462000 Shell Rock River 1,746 -/-/1 856 17.7 45,000C 180 25.8 at Shell Rock 3/28/1961 16.26 33,500 45 19.2 7/22/1999 16.73 27,500 20 15.8 05464000 Cedar River 5,146 3/29/1961 21.86 76,700 35 14.9 at Waterloo 4/08/1965 21.67 69,500 25 13.5 7/23/1999 20.78 69,300 25 13.5 05464500 Cedar River 6,510 3/18/1929 20.00 64,000 20 9.83 at Cedar Rapids 3/31/1961 19.66 73,000 40 11.2 4/04/1993 19.27 71,000 35 10.9 7/25/1999 18.31 62,300 20 9.57 "All values at current datums. blnterpolated from Bulletin 17B flood-frequency analysis (Interagency Advisory Committee on Water Data, 1982) and rounded to nearest 5 years for 20- to 50-year recurrence intervals, to nearest 10 years for 50- to 100-year recurrence intervals, and to nearest 20 years for 100- to 200-year recurrence intervals. GEstimated. At different site and datum, in tailrace of power plant at Greene located 5.7 miles downstream.

10 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA http://www4. ncdc. noaa. gov/cgi- win/ approximately a 90-year recurrence interval flood wwcgi.dll?\vwEvent~storms). In Nora Springs and (table 3). Rockford, sewage backups and resulting water The Cedar River, at the gaging station in Charles contamination problems left many residents without City (station number 05457700), was at or higher than water service for several days (Waterloo-Cedar Falls the flood stage of 12 ft from 11:15 a.m. on July 19 to Courier, My 21, 1999). 8:45 a.m. on July 23; an initial peak stage of 18.24 ft In Black Hawk County, about 100 people were was recorded at 1:45 a.m. on July 20, which was evacuated from the Cedar Falls neighborhood known followed by a second peak stage of 22.81 ft recorded at as Cedar City. In Buchanan County, Bob Hummel, noon on July 21 (fig. 4). The second peak stage exceeds Emergency Management Director, reported that about the maximum stage measured in 1961 by about 1.3 ft. 100 families were evacuated from their homes (Lynch The peak discharge of 31,200 ft3/s represents about a and Gosch, Cedar Rapids Gazette, July 24, 1999). In 90-year recurrence interval flood compared to the 60- Butler County, State Highway 188 south of Clarksville year recurrence interval for the 1961 flood (table 3). was closed during the flood. The Cedar River, at the gaging station in Janesville In Cerro Gordo County, road closures during the (station number 05458500), was at or higher than the flood included U.S. Highway 65 (4.5 mi west of flood stage of 11 ft from 4:45 a.m. on July 21 to 10:30 Plymouth) and County Road B20. Flooding on the p.m. on July 24; a peak stage of 17.15 ft was measured Winnebago River in Mason City threatened a levee, at 6:00 p.m. on July 22, which exceeds the maximum causing the evacuation of vulnerable neighborhoods stage recorded in 1961 by about 0.8 ft. The peak and roads in town were inundated in more than 50 discharge of 42,200 ft3/s represents about an 80-year locations. Jim Witt, Cerro Gordo County Engineer, recurrence interval flood compared to the 45-year reported extensive damage to five bridges, and road recurrence interval for the 1961 flood. The Cedar River, at the gaging station in Waterloo (station number repairs were estimated to exceed $500,000. At the 05464000), was at or higher than the flood stage of 12 Camp in the Woods campground near Rock Falls, five ft from 2:30 p.m. on July 21 to 2:30 a.m. on July 26; the people were rescued from the tops of trailers and July 1999 flood produced the third highest peak stage campers by firefighters using boats on July 19th and discharge on record; a peak stage of 20.78 ft was (Zeleny, Des Moines Register, July 22, 1999). recorded at 5:00 p.m. on July 23, which is about L.I ft In Mitchell County, State Highway 9 was closed Lower than the maximum stage recorded in 1961. The west of Osage during the flood. In Worth County, State peak discharge of 69,300 ft3/s represents about a 25- Highway 9 was closed east of Manly and about one- year recurrence interval flood compared to the 35-year half of the 550 buildings in Manly were flooded recurrence interval for the 1961 flood. The Cedar River, (Zeleny, Des Moines Register, July 22, 1999). at the gaging station in Cedar Rapids (station number During the July 1999 flood, some reaches of the 05464500), was at or higher than the flood stage of 13 Wapsipinicon River were reported to be nearly 1 mi ft from 8:00 a.m. on July 24 to 6:30 p.m. on July 27; a wide. The July flood produced a new maximum peak peak stage of 18.31 ft was recorded at 11:30 p.m. on stage and discharge at the Wapsipinicon River near July 25, which is about 1.7 ft lower than the record peak Tripoli gaging station (station number 05420680); the stage of the 1929 flood. The peak discharge of 62,300 peak stage of 18.50 ft on July 21, 1999, is about 4.1 ft ft /s represents about a 20-year recurrence interval higher than the peak stage measured during the May flood. 1999 flood and about 1.2 ft higher than the previous On the Shell Rock River, the second highest peak maximum peak stage measured during the 1969 flood; stage on record was measured at Marble Rock and the new record peak discharge is 19,400 ft3/s. At the Shell Rock. The Shell Rock River at Marble Rock was Wapsipinicon River at Independence gaging station at or higher than the flood stage of 4 ft from July 19 to (station number 05421000), the river was at or higher July 25, and crested on July 21 (Brad Small, National than the flood stage of 12 ft from 8:00 a.m. on July 23 Weather Service, written commun., June 2000). The to 10:00 a.m. on July 26; a peak stage of 18.80 ft was Shell Rock River at the gaging station at Shell Rock recorded on July 24 at 4:00 a.m., which is about 3.5 ft (station number 05462000) was at or higher than the lower than the maximum peak stage recorded on May flood stage of 12 ft from 9:30 a.m. on July 20 to 11:30 18, 1999. The peak discharge of 20,900 ft3/s represents a.m. on July 29; the peak stage of 16.73 ft at 1:45 p.m. about a 20-year recurrence interval flood compared to on July 22 is about 0.5 ft higher than that for the flood the May 18 peak discharge, which represents of 1961. The peak discharge of 27,500 ft3/s represents

FLOOD DESCRIPTION 11 about a 20-year recurrence interval flood compared to 10 river mi. The flood profiles were determined from the 45-year recurrence interval for the 1961 flood. The HWM's generally located immediately downstream flood of 1856 reached a stage of 17.7 ft at a bridge 400 and 1 bridge length upstream from selected bridges. ft downstream from the gaging station (Nalley and The HWM's were surveyed to temporary bench marks others, 2000, p. 174). at bridges within a few days after the flood peak and At the Flood Creek near Powersville gaging were later referenced to sea level by differential station (station number 05461390), a record peak stage leveling or differential positioning using a global of 12.57 ft on July 21 is about 4.6 ft higher than that for positioning system (GPS). In figures 5-24, the line the flood of 1963. The peak discharge estimate of connecting the marks on the profiles is a linear 19,000 ft3/s is almost three times greater than that for interpolation and, therefore, only approximates the the 1963 flood. flood elevation between marks; the line does not depict the effects on the profile caused by intermediate PROFILES FOR THE FLOODS OF JULY bridges or flood-plain and channel features. The 19-25,1999, IN THE WAPSIPINICON AND HWM's used to profile the July 19-25, 1999, floods in CEDAR RIVER BASINS the Wapsipinicon and Cedar River Basins are listed in tables 4-7 and are plotted by river mile in figures 5-24 To develop flood profiles, the USGS measured (following references); each table of HWM's follows the elevation of high-water marks (HWM's) at selected the river profiled. Primary highways referred to in the bridge sites along the Wapsipinicon, Cedar, and Shell report are shown in figure 1: secondary roads and Rock Rivers and along Flood Creek. Most of the marks streets are not shown. were measured at Federal and State Highway bridges For comparison purposes, profiles of previous and at USGS streamflow-gaging stations. Additional floods are included with the July 1999 profiles where HWM's were measured at several county road bridges they are available. The Wapsipinicon River profile to keep the maximum distance between points at about includes a profile of the 1969 flood (Schwob, 1971) and

25 Flood peak July 21,1999,12:00 A.M. stage 22.81 feet, discharge 31,200 cubic feet per second

HI 0 20 sHI

HI > 15

iir uj Flood stage O HI < LL H (N ~ rf 10 t '*"'" o-1- ±rO

UJ O O

17 18 19 20 21 22 23 24 25 26 27 28 29 30 July 1999 Figure 4. Stage hydrograph of the Cedar River at Charles City, Iowa, streamflow-gaging station (station number 05457700), July 17-30,1999.

12 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA the May 1999 flood (Ballew and Fischer, 2000). The profiled on the Cedar River (Brandon Road at La Porte Cedar and Shell Rock River profiles include a profile of City), to Mullan Avenue in Waterloo, the July 1999 the 1961 flood (Schwob, 1963). The Flood Creek flood elevations are generally lower than the 1961 flood profile includes a profile of the 1963 flood (Schwob, elevations by 0.4 to 2.7 ft (Schwob, 1963). 1963). Low-flow profiles also are shown for each river The July 1999 flood on the Shell Rock River is reach profiled. The HWM's from previous floods were profiled from 265th Street near Waverly Junction not always measured at the same locations used for the July 1999 profiles. For locations where water-surface upstream to State Highway 9 near Plymouth. The 72- elevations were not measured for all years profiled, a mi river reach that was profiled is shown in figure 1 and note in the figure indicates which years were included figures 16-20; the locations of the 11 stream sites where in the profile. HWM's were measured are shown in figure 1 and their The July 1999 flood on the Wapsipinicon River is descriptions are listed in table 6 following the Shell profiled from State Highway 281 near Fairbank Rock River profile. The July 1999 flood profile for the upstream to County Road B17 near Elma. The 53-mi Shell Rock River can be compared to the March 1961 river reach that was profiled is shown in figure 1 and flood profile from Waverly Junction to Nora Springs figures 5-8; the locations of the nine stream sites where (figs. 17-20) (Schwob, 1963). In general, at the two HWM's were measured are shown in figure 1 and their most downstream sites included in the Shell Rock descriptions are listed in table 4 following the River profile, flood elevations for the 1999 flood Wapsipinicon River profile. The three most exceeded those measured for the 1961 flood by 0.1 to downstream bridges crossing the Wapsipinicon River 0.5 ft (fig. 17) (Schwob, 1963). However, upstream that were used to profile the July 1999 flood (figs. 6 and 7) were also the three most upstream bridge sites used from Shell Rock from approximately Clarksville to to profile the May 1999 flood (Ballew and Fischer, Rockford, elevations measured for the 1961 flood are 2000). In general, the July 1999 flood elevations generally higher than those measured for the 1999 exceeded both the June 1969 and May 1999 flood flood by 1.1 to 3.6 ft, with the exception of the County elevations throughout most of the profiled reach (figs. Road T47 bridge crossing the Shell Rock River south 6-8). For instance, the flood elevation measured for the of Packard, where the 1999 flood elevation exceeded July 1999 flood at the U.S. Highway 18 bridge crossing the 1961 flood elevation by about 1.5ft(figs. 17-19).At the Wapsipinicon River west of New Hampton is about Nora Springs, the elevation for the 1999 flood is 2.2 ft higher than the elevation measured at the same approximately 3.5 ft higher than the elevation location for the 1969 flood (fig. 8) (Schwob, 1971). measured for the 1961 flood (fig. 20) (Schwob, 1963). The July 1999 flood on the Cedar River is The July 1999 flood on Flood Creek is profiled profiled from Brandon Road near La Porte City from County Road C23 (140th Street) near Packard upstream to State Highway 9 near Osage. The 110-mi river reach that was profiled is shown in figure 1 and upstream to County Road S70 near Nora Springs. The figures 9-15; the locations of the 21 stream sites where 39-mi reach that was profiled is shown in figure 1 and HWM's were measured are shown in figure 1 and their figures 21-24; the locations of the six stream sites descriptions are listed in table 5 following the Cedar where HWM's were measured are shown in figure 1 River profile. In general, the Cedar River profile and their descriptions are listed in table 7 following the indicates that the July 1999 flood produced a new Rood Creek profile. The July 1999 flood profile for flood-elevation record and exceeded the elevation of Flood Creek can be compared to the May 1963 flood the March 1961 flood by 0.8 to 3.2 ft from about profile from southeast of Packard to east of Rockford Janesville upstream to about U.S. Highway 218 north (figs. 22 and 23) (Schwob, 1963). In general, elevations of Floyd (figs. 12-14). For instance, in Waverly at the measured for the 1999 flood were higher than those State Highway 3 bridge crossing the Cedar River, the measured for the 1963 flood throughout the river reach elevation for the 1999 flood is about 1.9 ft higher than the elevation of the 1961 flood (fig. 12) (Schwob, by 4.6 to 6.7 ft. For instance, the flood elevation 1963). Downstream from Cedar Falls (figs. 10 and 11) measured for the July 1999 flood at the County Road and upstream from Floyd (figs. 14 and 15), the profiled C23 bridge crossing Flood Creek southeast of Packard river reach elevations for the 1961 flood are still the is about 6.1 ft higher than the elevation measured for highest on record. From the most downstream bridge the 1963 flood (fig. 22).

PROFILES FOR THE FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS 13 SUMMARY data, Iowa, water year 1999: U.S. Geological Survey Water-Data Report IA-99-1, 2 v., 256 p. Severe flooding occurred during July 19-25, Schwob, H.H., 1963, Cedar River Basin floods: Iowa 1999, in the Wapsipinicon and Cedar River Basins Highway Research Board, Bulletin No. 27, 58 p. following two intense thunderstorms over northeast 1971, Floods in the Wapsipinicon River basin, Iowa: Iowa. As much as 6 inches of rainfall was centered over U.S. Geological Survey Open-File Report, Cerro Gordo, Floyd, Mitchell, and Worth Counties 52 p. during July 18-19. This storm was followed by rainfall U.S. Department of Commerce, National Oceanic and up to 8 inches that was centered over Chickasaw and Atmospheric Administration, and National Floyd Counties during July 20-21. The cumulative Environmental Satellite, Data, and Information Service, effect of the two storms produced floods with new 1999, Climatological data, Iowa: Asheville, N.C., maximum peak stages and discharges on the monthly summaries, v. 110, no. 7, p. 9. Wapsipinicon River near Tripoli, the Cedar River at U.S. Department of Commerce, National Oceanic and Atmospheric Administration, and National Weather Charles City and Janesville, and Flood Creek near Service, 1999, Monthly report of rivers and flood Powersville. Peak discharges of 31,200 ft3/s on the conditions, La Crosse, Wisconsin, Hydrologic Service Cedar River at Charles City and 42,200 ft3/s on the Area, July 1999: National Weather Service, WS Form Cedar River at Janesville represent recurrence intervals E-5, 2 p. of about 90 and 80 years, respectively. The peak U.S. Department of Commerce, National Oceanic and discharge on the Wapsipinicon River near Tripoli is Atmospheric Administration, and National Weather 19,400 ft3/s and on Flood Creek near Powersville is Service, National Climate Data Center, Storm Events: estimated to be 19,000 ft3/s. generated May 9, 2000, accessed June 2, 2000, at URL http://www4.ncdc.noaa.gov/cgi-win/ wwcgi. dll ?wwEvent~storms. REFERENCES Waterloo-Cedar Falls Courier, 1999, July 21and 23, newspaper articles. Ballew, J.L., and Fischer, E.E., 2000, Floods of May 17-20, Wilde, 1999, July 20, Waterloo-Cedar Falls Courier 1999, in the Volga and Wapsipinicon River Basins, newspaper article. northeast Iowa: U.S. Geological Survey Open-File Zeleny, 1999, July 22, Des Moines Register newspaper Report 00-237, 36 p. article. Ericson and Jamison, 1999, July 23, Waterloo-Cedar Falls Courier newspaper article. Huff, F.A., and Angel, J.R., 1992, Rainfall frequency atlas of APPENDIX: TEMPORARY BENCH MARKS the Midwest: Champaign, Illinois State Water Survey, AND REFERENCE POINTS IN THE Bulletin 71,141 p. WAPSIPINICON AND CEDAR RIVER Interagency Advisory Committee on Water Data, 1982, BASINS Guidelines for determining flood flow frequency: Hydrology Subcommittee Bulletin 17B, U.S. To facilitate measuring and referencing the Geological Survey, Office of Water Data Coordination, HWM's used in the flood profiles to a common datum, 28 p. and appendixes. temporary bench marks (TBM's) and reference points Iowa Natural Resources Council, 1958, An inventory of (RP's) were established by the USGS at many of the water resources and water problems, northeastern Iowa river basins: Des Moines, Iowa Natural Resources bridges along the profiled river reaches. All TBM and Council Bulletin no. 7, 74 p. RP elevations listed in this tabulation are referenced to Lee and McGlynn, 1999, July 20, Des Moines Register sea level. TBM's and RP's are listed only for those newspaper article. bridges used in the July 19-25,1999, flood profiles. The Lynch, 1999, July 22, Cedar Rapids Gazette newspaper TBM's and RP's were established in the Wapsipinicon article. and Cedar River Basins during 1958-67 and 1999- Lynch and Gosch, 1999, July 24, Cedar Rapids Gazette 2000, with the exception of reference marks (RM's) newspaper article. and RP's established at USGS streamflow-gaging McGlynn and Chatterley, 1999, July 27, Des Moines stations, which are identified in this tabulation with an Register newspaper article. RM or RP number. TBM and RP elevations were Nalley, G.M., German, J.G., Goodrich, R.D., Miller, V.E., determined from differential leveling, with the Turco, M.J., and Linhart, S.M., 2000, Water resources exception of 17 bridges, where elevations were

14 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA determined from post-processed differential are determined as viewed while facing in the positioning using the global positioning system (GPS). downstream direction. Elevations determined using GPS are noted in the TBM The TBM's and RP's are listed in the and RP descriptions. Level lines or GPS networks used downstream to upstream order with respect to their to establish the third-order accuracy of the TBM's and correspondence to bridges over the Wapsipinicon, RP's shown herein were surveyed or configured from Cedar, and Shell Rock Rivers and Flood Creek. The bench marks established and adjusted by the National user of this information is cautioned that TBM's and Mapping Division of the USGS and National Geodetic RP's listed herein might have been disturbed, Survey. GPS networks were also supplemented with destroyed, or moved since elevations were established. GPS-control sites established by Black Hawk and It is the responsibility of the user to determine the Butler Counties. Errors of closure in the USGS level condition and suitability of the TBM or RP. work were adjusted along level lines to balance TBM and RP elevations. Specific GPS-network and satellite- Wapsipinicon River constellation configurations, equivalent hours of data collection with multiple GPS receivers, and post 9011-04 SE (1) - Approximately 5 mi west of Fairbank, on processing quality controls were used to control the State Highway 281 bridge over Wapsipinicon River, on left downstream wingwall curb; chiseled square. effects of error in GPS-derived elevations. TBM's and Elevation determined using GPS. RP's established by other agencies are noted in the Elevation 958.09 ft descriptions where they occur. The TBM's and RP's are designated by an index 9011-04 SE (2) - (REFERENCE POINT) Approximately 5 number or legal description derived from their mi west of Fairbank, on State Highway 281 bridge over respective locations using Public Land Survey System Wapsipinicon River, on top of left downstream concrete coordinates (township, range, section). Within the guardrail and 15 ft right of the third drain; chiseled section, the quarter section in which the TBM or RP is arrow. Elevation determined using GPS. located is designated by NW, NE, SW, or SE. For Elevation 961.28 ft example, 9011-04 SE refers to a location in Township 9111-08 NW (1) - Approximately 3 mi northeast of Readlyn, 90 North, Range 11 West, southeast quarter of section on State Highway 3 bridge over Wapsipinicon River, on 4. A number in parentheses following the quarter- left downstream wingwall; Iowa Department of section designation indicates the number of the TBM Transportation bench mark. Elevation determined using or RP in that particular quarter section. The index GPS. number describes the legal description of the mark Elevation 978.22 ft without further reference in the body of the description. The physical location of the bench mark on a bridge 9111-08 NW (2) - (REFERENCE POINT) Approximately 3 dictates the appropriate legal description. mi northeast of Readlyn, on State Highway 3 bridge REFERENCE POINTS are listed with the related over Wapsipinicon River, on top of 30th guardrail post from left downstream end of bridge; three filed marks. bench marks and are identified by the same legal Elevation determined using GPS. description, though at times they are in a different Elevation 978.98 ft section, range, or township as determined by upstream or downstream location. 9312-27 SW (1) - Approximately 2 mi north of Tripoli, on Standard marks, such as squares, crosses, marks, State Highway 93 bridge over Wapsipinicon River, on or arrows, were chiseled or filed on concrete or metal, left downstream corner of abutment; Iowa Department or existing bolts on bridges were used as TBM's or of Transportation bench mark. Elevation determined RP's. Existing TBM's or RP's were used whenever using GPS. (RM 2) available, and the agency responsible for the mark, Elevation 1,016.23 ft when known, is indicated in the description. RP's are 9312-27 SW (2) - Approximately 2 mi north of Tripoli, on distinguished from TBM's by the notation State Highway 93 bridge over Wapsipinicon River, on "(REFERENCE POINT)" following the legal left upstream abutment; chiseled square. Elevation description. RPs were established to permit water- determined using GPS. (RM 4) surface elevations to be determined by use of a tape and weight. The terms "right" and "left" in the descriptions Elevation 1,018.62 ft

APPENDIX: TEMPORARY BENCH MARKS AND REFERENCE POINTS IN THE WAPSIPINICON AND CEDAR RIVER BASINS 15 9312-18 NW (1) - At Frederika, on County Road C16 bridge bridge; two chiseled marks. Elevation determined using over Wapsipinicon River, on left downstream wingwall; GPS. chiseled square. Elevation 1,094.62 ft Elevation 1,026.89 ft 9614-09 NW (1) - Approximately 4.5 mi east of Colwell, on 9312-18 NW (2) - (REFERENCE POINT) At Frederika, on County Road B28 bridge over Wapsipinicon River, on County Road C16 bridge over Wapsipinicon River, on right downstream bridge abutment; chiseled square. top of 18th handrail post (streetside) from right Elevation determined using GPS. downstream end of bridge; chiseled square. Elevation 1,125.46 ft Elevation 1,027.45 ft 9614-09 NW (2) - (REFERENCE POINT) Approximately 9312-07 SW (1) - At Frederika, at dam in city park, on left 4.5 mi east of Colwell, on County Road B28 bridge abutment 9 ft upstream from sloping wingwall on over Wapsipinicon River, on top of concrete guardrail at streamward edge of abutment; chiseled square. 10th post from right downstream end of bridge; two Elevation 1,019.87 ft chiseled marks. Elevation determined using GPS. Elevation 1,125.29 ft 9413-36 SW (1) - Approximately 2 mi northwest of Frederika, on U.S. Highway 63 bridge over 9714-08 NW (1) - Approximately 5 mi west of Elma, on Wapsipinicon River, on left upstream concrete wall; County Road B17 bridge over Wapsipinicon River, on Iowa Department of Transportation bench mark. right downstream end of guardrail post; top of bolt next Elevation determined using GPS. to lettering "RM" painted red. Elevation 1,037.01 ft Elevation 1,152.90 ft 9413-36 SW (2) - (REFERENCE POINT) Approximately 2 9714-08 NW (2) - (REFERENCE POINT) Approximately 5 mi northwest of Frederika, on U.S. Highway 63 bridge mi west of Elma, on County Road B17 bridge over over Wapsipinicon River, on top of concrete guardrail Wapsipinicon River, on top of metal railing and and between fifth and sixth drain from right between fourth and fifth drain from right downstream downstream end of bridge; two chiseled marks. end of bridge; filed arrow. Elevation determined using GPS. Elevation 1,038.04 ft Elevation 1,154.27 ft

9413-10 SE (1) - Approximately 2 mi west of Williamstown, Cedar River on State Highway 346 bridge over Wapsipinicon River, on left upstream bridge abutment; Iowa Department of 8711-19 NE (1) - Approximately 1.5 mi northeast of La Transportation bench mark. Elevation determined using Porte City, on Brandon Road bridge over Cedar River, GPS. on left downstream curb; National Geodetic Survey Elevation 1,053.39 ft (U.S. Coast and Geodetic Survey) brass cap. Elevation 816.05 ft 9413-10 SE (2) - (REFERENCE POINT) Approximately 2 mi west of Williamstown, on State Highway 346 bridge 8711-19 NE (2) - (REFERENCE POINT) Approximately over Wapsipinicon River, on top of concrete bridge rail 1.5 mi northeast of La Porte City, on Brandon Road and between third and fourth drain from right bridge over Cedar River, on guardrail and right of 10th downstream end of bridge; two chiseled marks. guardrail post from left downstream end of bridge; filed Elevation determined using GPS. arrow. Elevation 1,054.36 ft Elevation 818.10 ft

9514-01 SW (1) Approximately 7 mi west of New Hampton, 8812-23 SW (1) - At Gilbertville, on County Road D38 on U.S. Highway 18 bridge over Wapsipinicon River, bridge over Cedar River, on left upstream curb; USGS on right upstream concrete wall; Iowa Department of brass cap. Transportation bench mark. Elevation determined using Elevation 841.42 ft GPS. Elevation 1,093.80 ft 8812-23 SW (2) - (REFERENCE POINT) At Gilbertville, on County Road D38 bridge over Cedar River, on top of 9514-01 SW (2) - (REFERENCE POINT) Approximately 7 handrail at 20th handrail post from left downstream end mi west of New Hampton, on U.S. Highway 18 bridge of bridge; three filed marks. (RM 1) over Wapsipinicon River, on top of concrete guardrail and right of fourth drain from right downstream end of Elevation 841.32 ft

16 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA 8913-25 NW (1) - At Waterloo, on left bank of Cedar River 8913-18 NW (2) - At Cedar Falls, on State Highway 58 near East Seventh Street bridge and about 30 ft bridge over Cedar River, on left upstream concrete upstream from gage house, on upstream landward abutment; chiseled cross. corner of concrete foundation for pumping; USGS Elevation 873.44 ft bronze bench mark. (RM 1) Elevation 846.96 ft 8913-18 NW (3) - (REFERENCE POINT) At Cedar Falls, on State Highway 58 bridge over Cedar River, on top of 8913-26 NE (1) - At Waterloo, on Park Avenue bridge over concrete guardrail and at center of bridge at 41st drain from right downstream end of bridge; two chiseled Cedar River, on curb at left upstream end of bridge, top marks. of most upstream and landward bolt; chiseled cross. Elevation 887.48 ft Elevation determined using GPS. Elevation 853.02 ft 8914-12 NE (1) - At Cedar Falls, on State Highway 57 bridge over Cedar River, on right downstream wingwall 8913-26 NE (2) - (REFERENCE POINT) At Waterloo, on abutment; Iowa Department of Transportation bench Park Avenue bridge over Cedar River, on top of mark. Elevation supplied by City of Cedar Falls, Land guardrail and right of fifth guardrail post from left Survey Office. downstream end of bridge; filed arrow. Elevation Elevation 866.92 ft determined using GPS. Elevation 857.09 ft 8914-12 NE (2) - At Cedar Falls, on State Highway 57 bridge over Cedar River, on left downstream wingwall abutment; chiseled square. 8913-23 SE (1) - At Waterloo, on Mullan Avenue bridge over Elevation 870.77 ft Cedar River, on right downstream wingwall abutment behind concrete guardrail; chiseled cross. Elevation 8914-12 NE (3) - (REFERENCE POINT) At Cedar Falls, on surveyed from City of Waterloo bench mark. State Highway 57 bridge over Cedar River, on guardrail Elevation 856.80 ft at 45th guardrail post from right downstream end of bridge; three filed marks. 8913-23 SE (2) - (REFERENCE POINT) At Waterloo, on Elevation 872.87 ft Mullan Avenue bridge over Cedar River, on ledge behind concrete guardrail and between 15th and 16th 8914-12 NW (1) - At Cedar Falls, on Center Street bridge metal guardrail posts from right downstream end of over Cedar River, on right downstream end of sidewalk bridge; two chiseled marks. concrete barrier wall; Iowa Department of Transportation bench mark. Elevation supplied by City Elevation 861.33 ft of Cedar Falls, Land Survey Office. Elevation 873.69 ft 8913-16 SE (1) - At Waterloo, on U.S. Highway 218 bridge over Cedar River, on top of right downstream end of 8914-12 NW (2) At Cedar Falls, on Center Street bridge concrete barrier wall; Iowa Department of over Cedar River, on left downstream end of sidewalk Transportation bench mark. Elevation determined using concrete barrier wall; Iowa Department of GPS. Transportation bench mark. Elevation supplied by City Elevation 868.73 ft of Cedar Falls, Land Survey Office. Elevation 874.47 ft 8913-16 SE (2) - (REFERENCE POINT) At Waterloo, on U.S. Highway 218 bridge over Cedar River, on concrete 8914-12 NW (3) - (REFERENCE POINT) At Cedar Falls, guardrail and above fifth drain from right downstream on Center Street bridge over Cedar River, on concrete end of bridge; two chiseled marks. Elevation guardrail and below 43d metal post from left determined using GPS. downstream end of bridge; two chiseled marks. Elevation 869.00 ft Elevation 876.93 ft

8913-18 NW (1) - At Cedar Falls, on State Highway 58 9114-35 SW (1) - At Janesville, on left bank of Cedar River bridge over Cedar River, on left downstream concrete and 300 ft downstream from County Road C50 (275th abutment wall; Iowa Department of Transportation Street) bridge, set in concrete just above ground surface bench mark. Elevation supplied by City of Cedar Falls, and 3 ft northeast of gage house; USGS bench mark. Land Survey Office. (RM 16) Elevation 879.50 ft Elevation 877.95 ft

APPENDIX: TEMPORARY BENCH MARKS AND REFERENCE POINTS IN THE WAPSIPINICON AND CEDAR RIVER BASINS 17 9114-35 NW (1) - Approximately 0.50 mi north of 9314-29 NE (1) - Approximately 0.5 mi east of Plainfield, on Janesville, on northbound lane of U.S. Highway 218 State Highway 188 bridge over Cedar River, on left bridge over Cedar River (upstream bridge), on right upstream wingwall; Iowa Department of Transportation downstream end of concrete barrier wall: Iowa bench mark. Elevation supplied by Iowa Department of Department of Transportation bench mark. Elevation Transportation. supplied by [owa Department of Transportation. Elevation 946.59 ft Elevation 904.700 ft 9314-29 NE (2) - Approximately 0.5 mi east of Plainfield, on 9114-35 NW (2) - Approximately 0.50 mi north of Janesville, on southbound lane of U.S. Highway 218 State Highway 188 bridge over Cedar River, on right bridge over Cedar River (downstream bridge), on left upstream wingwall; Iowa Department of Transportation upstream end of concrete barrier wall; Iowa bench mark. Elevation supplied by Iowa Department of Department of Transportation bench mark. Elevation Transportation. supplied by Iowa Department of Transportation. Elevation 947.22 ft Elevation 911.140 ft 9314-29 NE (3) - (REFERENCE POINT) Approximately 9114-35 NW (3) - (REFERENCE POINT) Approximately 0.5 mi east of Plainfield, on State Highway 188 bridge 0.50 mi north of Janesville, on southbound lane of U.S. over Cedar River, on concrete curb at third drain from Highway 218 bridge over Cedar River (downstream right downstream end of bridge; two chiseled marks. bridge), on top of concrete guardrail and about 85 ft from right downstream end of bridge; two chiseled Elevation 945.63 ft marks. Elevation 907.31 ft 9414-18 SE (1) - At Nashua, on State Highway 346 bridge over Cedar River, on right upstream wingwall; [owa 9114-02 NW (1) - At Waverly, on State Highway 3 bridge Department of Transportation bench mark. Elevation over Cedar River, on right downstream handrail and supplied by Iowa Department of Transportation. north of lamp post: chiseled cross. Elevation 973.28 ft Elevation 920.27 ft 9414-18 SE (2) - (REFERENCE POINT) At Nashua, on 9114-02 NW (2) - At Waverly, on State Highway 3 bridge State Highway 346 bridge over Cedar River, on top of over Cedar River, about 30 ft upstream from right concrete guardrail at third drain from right upstream upstream end of bridge, on top of streamward corner of end of bridge; two chiseled marks. concrete retaining wall; chiseled square. Elevation 975.48 ft Elevation 914.69 ft 9515-34 NE (1) - Approximately 4 mi northwest of Nashua, 9114-02 NW (3) - (REFERENCE POINT) At Waverly, on State Highway 3 bridge over Cedar River, on top of on County Road B59 (240th Street) bridge over Cedar handrail and left of 15th post from left downstream end River, on left downstream concrete guardrail; Iowa of bridge; filed arrow. Department of Transportation bench mark. Elevation Elevation 921.19 ft supplied by Floyd County Engineer's Office. Elevation 985.48 ft 9214-21 NW (1) - Approximately 3.5 mi north of Waverly, on County Road C33 bridge over Cedar River, on right 9515-34 NE (2) - (REFERENCE POINT) Approximately 4 downstream curb near wingwall; chiseled square mi northwest of Nashua, on County Road B59 (240th enclosing Iowa Department of Transportation bench Street) bridge over Cedar River, on top of concrete mark. Elevation obtained from Bremer County Flood guardrail at fourth drain from left downstream end of Insurance Study (Federal Emergency Management bridge; two chiseled marks. Agency, 1990). Elevation 986.40 ft Elevation 931.77 ft 9516-12 NE (1) - At Charles City, on right bank of Cedar 9214-21 NW (2) - (REFERENCE POINT) Approximately 3.5 mi north of Waverly, on County Road C33 bridge River and 800 ft downstream from U.S. Highway 18 over Cedar River, on top of guardrail post at second bridge, 25 ft landward of gage house, and on landward drain from right downstream end of bridge; three filed downstream corner of concrete pedestal to walkway; marks. USGS bronze bench mark. (RM 5) Elevation 934.50 ft Elevation 993.28 ft

18 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA 9516-12 NE (2) - At Charles City, near Main Street bridge 9817-28 NE (3) - (REFERENCE POINT) Approximately over Cedar River, on top of bolt head on streamward 1.5 mi west of Osage, on State Highway 9 bridge over and upstream side of fire hydrant located on southeast Cedar River, on top of guardrail and above third drain corner of Main and Court Streets; chiseled cross. from right downstream end of bridge; two chiseled Elevation determined using GPS. marks. Elevation 1,003.52 ft Elevation 1,095.12 ft 9516-12 NE (3) - (REFERENCE POINT) At Charles City, on Main Street bridge over Cedar River, on concrete Shell Rock River sidewalk and below seventh handrail post from right downstream end of bridge; two chiseled marks. 9114-28 NW (1) - Approximately 0.25 mi east of Waverly Elevation determined using GPS. Junction, on 265th Street bridge over Shell Rock River, Elevation 1,002.32 ft on right upstream concrete wingwall; top of bolt. Elevation obtained from Bremer County Engineer's 9616-16 SE (1) - Approximately 0.25 mi north of Floyd, on Office. U.S. Highway 218 bridge over Cedar River, on right upstream wing wall guardrail; Iowa Department of Elevation 896.67 ft Transportation bench mark. Elevation determined using GPS. 9114-28 NW (2) - (REFERENCE POINT) Approximately Elevation 1,031.74 ft 0.25 mi east of Waverly Junction, on 265th Street bridge over Shell Rock River, on top of concrete 9616-16 SE (2) - (REFERENCE POINT) Approximately guardrail and between 20th and 21 st guardrail supports 0.25 mi north of Floyd, on U.S. Highway 218 bridge from left upstream end of bridge; chiseled square. over Cedar River, on top of concrete guardrail at second Elevation 900.36 ft drain from right downstream end of bridge; two chiseled marks. Elevation determined using GPS. 9115-11 NE (1) - At Shell Rock, on right bank of Shell Rock Elevation 1,030.65 ft River and 400 ft upstream from County Road C45 bridge, on downstream end of concrete footing for 9717-24 NE (1) - Approximately 1.5 mi southwest of Orchard, on 105th Street bridge over Cedar River, on walkway of gage house; USGS bronze bench mark. top of right downstream concrete guardrail; chiseled (RM2) square. Elevation 902.54 ft Elevation 1,047.99 ft 9215-19 SW (1) - Approximately 0.50 mi south of 9717-24 NE (2) - (REFERENCE POINT) Approximately Clarksville, on State Highway 188 bridge over Shell 1.5 mi southwest of Orchard, on 105th Street bridge Rock River, on right upstream end of abutment; Iowa over Cedar River, on handrail post above left concrete Department of Transportation bench mark. Elevation pier and between second and third drains from left supplied by Iowa Department of Transportation. downstream end of bridge; chiseled square. Elevation 934.74 ft Elevation 1,045.63 ft

9817-28 NE (1) - Approximately 1.5 mi west of Osage, on 9215-19 SW (2) - Approximately 0.50 mi south of State Highway 9 bridge over Cedar River, on right Clarksville, on State Highway 188 bridge over Shell downstream end of concrete guardrail; Iowa Rock River, on left upstream end of abutment; Iowa Department of Transportation bench mark. Elevation Department of Transportation bench mark. Elevation supplied by Iowa Department of Transportation. supplied by Iowa Department of Transportation. Elevation 1,092.20 ft Elevation 935.86 ft

9817-28 NE (2) - Approximately 1.5 mi west of Osage, on 9215-19 SW (3) - (REFERENCE POINT) Approximately State Highway 9 bridge over Cedar River, on left downstream end of concrete guardrail; Iowa 0.50 mi south of Clarksville, on State Highway 188 Department of Transportation bench mark. Elevation bridge over Shell Rock River, on top of concrete supplied by Iowa Department of Transportation. guardrail at first drain from right upstream end of Elevation 1,097.15 ft bridge; chiseled square. Elevation 935.69 ft

APPENDIX: TEMPORARY BENCH MARKS AND REFERENCE POINTS IN THE WAPSIPINICON AND CEDAR RIVER BASINS 19 9317-01 SW (1) - At Greene, on Traer Street bridge over Flood Creek Shell Rock River, on left downstream abutment; chiseled square. Elevation supplied by Butler County 9416-34 SE (1) - Approximately 4 mi east of Greene, on left Engineer's Office. bank of Flood Creek and 20 ft downstream from Floyd Elevation 962.33 ft Line Road bridge, near northwest corner of gage house; USGS brass bench mark. Elevation determined using 9317-01 SW (2) - (REFERENCE POINT) At Greene, on GPS. (RM 1) Traer Street bridge over Shell Rock River, on handrail Elevation 964.63 ft bolt at 22d post from left downstream end of bridge; three filed marks. 9416-34 SE (2) - Approximately 4 mi east of Greene, on Elevation 962.80 ft Floyd Line Road bridge over Flood Creek, on left downstream wingwall; chiseled square. Elevation 9417-08 SE (1) - At Marble Rock, 200 ft upstream from left determined using GPS. (RM 2) upstream end of County Road B60 bridge over Shell Elevation 968.09 ft Rock River, on upstream side of abandoned power plant, in foundation and 3 inches from north side of 9416-34 SE (3) - (REFERENCE POINT) Approximately 4 building; USGS bronze bench mark. mi east of Greene, on Floyd Line Road bridge over Elevation 970.91 ft Flood Creek, on guardrail and between seventh and eighth supports from left downstream end of bridge; two chiseled marks. Elevation determined using GPS. 9518-11 SW (1) - At Rockford, on Main Avenue bridge over (RP1) Shell Rock River, on right upstream end post of Elevation 970.31 ft handrail; chiseled square. Elevation determined using GPS. 9517-36 SW (1) - Approximately 3.5 mi northeast of Marble Elevation 1,004.79 ft Rock, on State Highway 14 bridge over Flood Creek, on right downstream concrete abutment; chiseled 9618-07 SE (1) - At Nora Springs, on First Street bridge over square. Shell Rock River, on handrail near right downstream Elevation 1,023.29 ft end of bridge; chiseled cross. Elevation 1,054.47 ft 9517-36 SW (2) - (REFERENCE POINT) Approximately 3.5 mi northeast of Marble Rock, on State Highway 14 9618-07 SE (2) - (REFERENCE POINT) At Nora Springs, bridge over Flood Creek, on top of metal guardrail at on First Street bridge over Shell Rock River, on sixth post from left downstream end of bridge; chiseled handrail and approximately 30 ft right of second light arrow. structure from left downstream end of bridge; chiseled Elevation 1,024.68 ft square. Elevation 1,055.66 ft 9517-15 NW (1) - Approximately 5 mi east of Rockford, on State Highway 147 bridge over Flood Creek, on righl 9719-21 NE (1) - At Rock Falls, on County Road B20 bridge downstream wingwall; chiseled square. Elevation over Shell Rock River, on left upstream wingwall; determined using GPS. USGS bronze bench mark. Elevation 1,053.78 ft Elevation 1,102.541 ft 9517-15 NW (2) - (REFERENCE POINT) Approximately 5 9819-30 NE (1) - Approximately 2.5 mi north of Plymouth, mi east of Rockford, on State Highway 147 bridge over on State Highway 9 bridge over Shell Rock River, on Flood Creek, on guardrail at the fifth post from left right downstream wingwall; chiseled cross. Elevation downstream end of bridge; filed arrow. Elevation determined using GPS. determined using GPS. Elevation 1,137.30 ft Elevation 1,053.61 ft

9819-30 NE (2) - (REFERENCE POINT) 2 mi north of 9618-14 NW (1) - Approximately 2 mi northwest of Rudd, Plymouth, on State Highway 9 bridge over Shell Rock on State Highway 122 (old U.S. Highway 18) bridge River, on guardrail and left of seventh post from right over Flood Creek, on left downstream wingwall; Iowa downstream end of bridge; chiseled square. Elevation Department of Transportation bench mark. Elevation determined using GPS. determined using GPS. Elevation 1,134.99 ft Elevation 1,105.48 ft

20 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA 9618-14 NW (2) - (REFERENCE POINT) Approximately 2 mi northwest of Rudd, on State Highway 122 (old U.S. Highway 18) bridge over Flood Creek, on concrete guardrail at 11th post from left downstream end of bridge; two chiseled marks. Elevation determined using GPS. Elevation 1,105.20 ft

9718-29 NW (1) - Approximately 3 mi north of Nora Springs, on County Road S70 bridge over Flood Creek, on right downstream abutment; chiseled square. Elevation determined using GPS. Elevation 1,147.68 ft

9718-29 NW (2) - (REFERENCE POINT) Approximately 3 mi north of Nora Springs, on County Road S70 bridge over Flood Creek, on concrete guardrail and between the third and fourth posts from left downstream end of bridge; chiseled square. Elevation determined using GPS. Elevation 1,147.36 ft

APPENDIX: TEMPORARY BENCH MARKS AND REFERENCE POINTS IN THE WAPSIPINICON AND CEDAR RIVER BASINS 21 N> N>

O 1,160 O O (A 1,140 O n c_ s 1,120 _L «P 1,100 S fc toCD u.LU 1,080 m uj 1,060 >S iu< 1,040 (A LiJ i § o 5 1,020

1,000 Flood profile, July 1999 u O Flood profile, May 1999 (Ballew and Fischer, 2000) m 980 Flood profile, June 1969 (Schwob, 1971) Low-flow profile, November 1999 960 Low-flow profile, October 1966 (Schwob, 1971) m Bridge elevations: DO 940 Upper flange = bridge deck Lower flange = low chord (A

(A 920 O

| Locations indicated by these vertical lines are described in figures 6-8 § IO

160 165 170 175 180 185 190 195 200 205 210 215 220

DISTANCE UPSTREAM FROM MOUTH OF WAPSIPINICON RIVER, IN MILES

Figure 5. Profile of the July 1999 flood for the Wapsipinicon River, Iowa; river miles 164 to 218. 1,020

1,010

1,000

990 LLJ LLJ LL -. 980

O> 960

1 p 950

Flood profile, July 1999 940 Flood profile, May 1999 (Ballew and Fischer, 2000) Flood profile, June 1969 (Schwob, 1971) Low-flow profile, November 1999 930 Low-flow profile, October 1966 (Schwob, 1971) Bridge elevations: 920 Upper flange = bridge deck I Lower flange = low chord

910

DCO I* « II

8° OS

160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 TJ 33 O DISTANCE UPSTREAM FROM MOUTH OF WAPSIPINICON RIVER, IN MILES 3 tns Figure 6. Profile of the July 1999 flood for the Wapsipinicon River, Iowa; river miles 164 to 180. N> U K

Q 1 ,080 : I

O n 1 ,070 ^^ e_ ^ ^ [< 1,060 : - r _^-fT*'" _L

> fS*****^ ...-- " 'If"*^ ..j.^-J'-^-f*^^'* § s -^ftf*^ sfile, July 1999 O 1 ,000 Flood profile, May 1 999 (Ballew and Fischer, 2000) . m ^- "" .. ' ""'' ..^""r' "' Flood profile, June 1969 (Schwob. 1971) ; Low-flow profile, November 1 999 33 "° profile, October 1 966 (Schwob, 1 971 ) < m Bridge elevations: : CD 98° Upper flange = bridge deck I Lower flange = low chord

W 970

a> § § s S .2 z z 1 QC c«J I 5 ; 1 x 1 1 c 1 S3 §5 £ 1 e t s B £ » ! J o *o co co w 5 S g° S W LLJ I?) ° S 1 .2 1 £ 3 3 21 «^5 <" V I. S if § 3 C/) O> LLJ 0> . = (0 " 0 C Lf 35 (0 "c "^t o> ^;" o> Q S3 S m Si?i S| | ^ c 2 | I E > 0) Z 8 = 2 I SS Sg C "D ^~ T3 ^~ *> ! 1 gg_ i iuj §i o> = 1 § 5 111 ra c ra c 2BZ -gs £ 1 8 i 6 Z o - o ~ s= Ss1 l| 1 1 1 g,£i^ o1 8 .a a *rj Pr u rr u CO (/) iE5 > L O m 3-2 G) CM ^ i s ^ "?5 c 1 «^ T* *- 55 (D UJ 3 55S3 c E B m )5S c/)5

DISTANCE UPSTREAM FROM MOUTH OF WAPSIPINICON RIVER, IN MILES

Figure 7. Profile of the July 1999 flood for the Wapsipinicon River, Iowa; river miles 180 to 200. gg saiidoad

ELEVATION ABOVE SEA LEVEL, IN FEET

g S 8

(Q C U.S. Highway 18, W of New Hampton 9514-01 SW CD 00 Exeter Street, N of Ionia (not used in 1999) 9514-01 SW

a0) ro g 180th Street, N of Ionia (not used in 1999) 9614-35 NW E< 1z -1 m S <= County Road B33, E of North Washington (not used in 1999) 9614-27 NE 33 m County Road T76 (Cheyenne St.) S of Deerfield (not used in 1999) 9614-22 NW S1 3° O o

0) o i I Io o Tl OT5' I County Road B28, E of Colwell 9614-09 NW o o o O 130th Street, NW of Deerfield (not used in 1999) 9614-05 NE

County Road B23, SE of Q) p Alia Vista (not used in 1999) m -i co 9714-29 SE

Chickasaw/Howard County line 0) 100th Street (not used in 1999) (0 9714-20NW NJ O O 200th Street, SW of Elma (not o used in 1999) 9714-17 NW NJ 00 USGS gaging station 05420560 (Discontinued) County Road B17, W of Elma 9714-08 NW Table 4. Elevations of high-water marks used in the flood profile of July 1999 for the Wapsipinicon River, Iowa [HWM, high-water mark; USGS, U.S. Geological Survey]

Distance upstream from Downstream Upstream mouth of HWM HWM Wapsipinicon Bridge-site and streamfiow-gaging (feet above (feet above River (river miies) station description sea ievei) sea ievei) 164.62 State Highway 281, W of Fairbank 950.54 952.09 171.27 State Highway 3, NE of Readlyn 968.84 970.50 181.50 USGS gaging station 05420680, 1,004.92 1.005.40 State Highway 93, N of Tripoli 186.10 County Road C16, Frederika 1,020.97 1,023.83

188.70 U.S. Highway 63, NW of Frederika 1,027.55 1,028.40 193.67 State Highway 346, W of Williamstown 1,043.06 1,045.31 203.2 U.S. Highway 18, W of New Hampton 1,083.01 1,083.95 211.15 County Road B28, E of Colwell 1,114.90 1.115.80 217.88 Discontinued USGS gaging station 1,144.20 1,145.02 05420560, County Road B17, W of Elma

26 FLOODS OF JULY 19-25,1999, iN THE WAPSiPiNiCON AND CEDAR RiVER BASINS, NORTHEAST IOWA 1,100

1,080

1,060

1,040

1,020

1,000 z 980 is a 960

940

920

900 Flood profile, July 1999 880 . Flood profile, March 1961 (Schwob, 1963) Low-flow profile, November 1999 860 _._.. Low-flow profile, August 1960 (Schwob, 1963) Low-flow profile, November 1961 (Schwob, 1963) 840 Bridge elevations: Upper flange = bridge deck 820 Lower flange = low chord

800

780 JIL Locations indicated by these vertical lines are described in figures 10-15

f i i i 130 140 150 160 170 180 190 200 210 220 230 240 250 260 TJ 33 DISTANCE UPSTREAM FROM MOUTH OF CEDAR RIVER, IN MILES O

55 Figure 9. Profile of the July 1999 flood for the Cedar River, Iowa; river miles 139 to 250. 00

5 850 o D

840

830 I 5 82°

_J 810 m LJJ _l > LJJ 800 LJJ

8 790

Flood profile, July 1999 D 780 O Flood profile, March 1961 (Schwob, 1963) m Low-flow profile, November 1999 Low-flow profile, August 1960 (Schwob, 1963) I 770 3J Bridge elevations: m Upper flange = bridge deck JO I Lower flange = low chord QJ 760

750

s? b UJ-A s

135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155

DISTANCE UPSTREAM FROM MOUTH OF CEDAR RIVER, IN MILES

Figure 10. Profile of the July 1999 flood for the Cedar River, Iowa; river miles 139 to 155. 900

890

Flood-peak arid low-flow discharges, in cubic feet per second, 880 at USGS gaging station 05464000 Date March 29, 1961 76,700 ED 870 July 23, 1999 69,300 August 1,1960 937 November 15, 1999 1,260

ai 860 a s 850

840 Flood profile, July 1999 Flood profile, March 1961 (Schwob, 1963) Low-flow profile, November 1999 (Schwob, 1963) 830 Low-flow profile, August 1960 (Schwob, 1963) Low-flow profile, November 1961 (Schwob, 1963)

820 Bridge elevations: Upper flange = bridge deck Lower flange = low chord

810 Cedar Falls 800

cr D £

o 1 8

155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 o DISTANCE UPSTREAM FROM MOUTH OF CEDAR RIVER, IN MILES 3 m CO Figure 11. Profile of the July 1999 flood for the Cedar River, Iowa; river miles 155 to 175. ro CD 940

930

Flood-peak and low-flow discharges 920 in cubic feet per second, at USGS gaging station 05458500 Date March 28, 1961 37,000 July 22, 1999 42,200 LU November 15,1999 471 LL z 900

LU 03 890 LU ,.,-- ....< ' ** > 880 ...- -""' .»' "" ** *' I _.- *"

Lu 870 Flood p rofile. Ju y 1999 Flood p rofile, Ma rch1961 (Schwob, 1 963) 860 Low-flow profile, Novemb 3r 1999 w profile, Novemb 3M961 (Schwob, 1963) Bridge elevation s: Uppe r flange = bridge d eck 850 I Lowe r flange = low chord Janesville 840 lg > w Js?p 85 §

es 55

175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195

DISTANCE UPSTREAM FROM MOUTH OF CEDAR RIVER, IN MILES Figure 12. Profile of the July 1999 flood for the Cedar River, Iowa; river miles 175 to 195. 990

Flood profile, July 1999 Flood profile, March 1961 (Schwob, 1963) Low-flow profile, November 1999 Low-flow profile, November 1961 (Schwob, 1963) Bridge elevations: Upper flange = bridge deck Lower flange = low chord

195 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215

TJ DISTANCE UPSTREAM FROM MOUTH OF CEDAR RIVER IN MILES 3 3 Figure 13. Profile of the July 1999 flood for the Cedar River, Iowa; river miles 195 to 215.

W CO ro 1,040 oe 5 1,030 Flood peak and low-flow discharges, in cubic feet per second, T c 1,020 at IISGS gaging station 05457700: D ate Discharge W arch 27, 1961 29,200 J Jly21,1999 31,200 1 - November 16, 1999 217 i S 1,010 i LL !f> z -,- _f Z 1,000 m

990 l^f^ ^' § I h 980 -I __ * 4 """"" _-- r *

I Qj 970 Flood profile, July 1999 D Flood profile, March 1961 (Schwob, 1963) Low-flow profile, November 1999 960 Low-flow profile, November 1961 (Schwob, 1963) J] 3J Bridge elevations: Upper flange = bridge deck m I Lower flange = low chord DO 950

Charles City -w 940 A ' ' i i o 53 yj

215 216 217 218 219 220 222 223 224 225 226 227 228 229 230 232 233 234 235

DISTANCE UPSTREAM FROM MOUTH OF CEDAR RIVER, IN MILES Figure 14. Profile of the July 1999 flood for the Cedar River, Iowa; river miles 215 to 235. 1,090

1,080

1,070

ft 1,060 LL

1 ,050 a 2 1 ,040

1 ,030 Q

1,020 Flood profile, July 1999 Flood profile, March 1961 (Schwob, 1963) Low-flow profile, November 1999 1,010 Low-flow profile, November 1961 (Schwob, 1963) Bridge elevations: Upper flange = bridge deck 1,000 Lower flange = low chord

990

CO C\J (f) O B£ CO CD CO

a SLU o

235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255

TJ DISTANCE UPSTREAM FROM MOUTH OF CEDAR RIVER IN MILES 31 O m Figure 15. Profile of the July 1999 flood for the Cedar River, Iowa; river miles 235 to 250. en Table 5. Elevations of high-water marks used in the flood profile of July 1999 for the Cedar River, Iowa [HWM, high-water mark; USGS, U.S. Geological Survey; -, not measured]

Distance upstream from Downstream Upstream mouth of Cedar HWM HWM River Bridge-site and streamfiow-gaging (feet above (feet above (river miies) station description sea ievei) sea ievei) 139.28 Brandon Road, NE of La Porte City 810.46 811.52 147.35 County Road D38, Gilbertville 823.60 823.90 158.78 USGS gaging station 05464000, Waterloo 844.92 - 159.1 Park Avenue, Waterloo 846.36 846.80 159.47 Mullan Avenue, Waterloo 847.52 849.14

163.0 U.S. Highway 218, Waterloo 853.55 854.09 165.9 State Highway 58, Cedar Falls 857.14 858.72 166.9 State Highway 57, Cedar Falls 859.66 859.86 167.15 Center Street, Cedar Falls 862.80 863.45 178.6 USGS gaging station 05458500, Janesville 885.41 -

179.0 U.S. Highway 218, N of Janesville 886.64 887.97 188.70 State Highway 3, Waverly 912.10 914.84 194.3 County Road C33, N of Waverly 924.43 925.38 200.9 State Highway 188, E of Plainfield 934.73 936.33 211.55 State Highway 346, Nashua 964.86 967.71

216.9 County Road B59 (240th Street), NW of 977.39 -- Nashua 223.9 USGS gaging station 05457700, Charles City 995.83 - 224.19 Main Street, Charles City 997.54 1,000.07 232.5 U.S. Highway 218, N of Floyd 1,016.48 1.016.88

240.4 105th Street, SW of Orchard 1,038.37 1,038.80 249.58 State Highway 9, W of Osage 1.075.92 1,076.20

34 FLOODS OF JULY 19-25,1999, IN THE WAPSiPiNiCON AND CEDAR RiVER BASiNS, NORTHEAST iOWA 1,140

1,120

1,100

1,080

Qj 1 ,060 LU LL ^ 1,040 _T LU 2 1 ,020

« 1 ,000 LU

§ 980

K 960 5 LU Lu 940 Flood profile, July 1999 Flood profile, March 1961 (Schwob, 1963) Low-flow profile, November 1999 920 Low-flow profile, November 1961 (Schwob, 1963) 900 Bridge elevations: Upper flange = bridge deck I Lower flange = low chord 880

860 I Locations indicated by these vertical lines are described in figures 17-20

10 20 30 40 50 60 70 80

DISTANCE UPSTREAM FROM MOUTH OF SHELL ROCK RIVER, IN MILES

Figure 16. Profile of the July 1999 flood for the Shell Rock River, Iowa; river miles 1 to 76.

(Jlw 940

Flood-peak and low-flow discharges 930 in cubic feet per second, S at USGS gaging station 05462000 o n Date Discharge c_ 920 March 28, 1961 33,500 July 22, 1999 27,500 November 16, 1999 392 910

NS LU en LU 900 890 -I- < LU m 880 1 T3 1 (A < 870 2 z o o 860 a Flood profile, July 1999 LU Flood profile, March 1961 (Schwob, 1963) 850 o Low-flow profile, November 1999 o Low-flow profile, November 1961 (Schwob, 1963) 840 Bridge elevations: 3J Upper flange = bridge deck 3J I Lower flange = low chord 830 3 03 Shell Rock 820

| (0 IS! O 3(0 I* 33 OT QC LO

? I 1 > .5

to -& DO 1

10 11 12 13 14 15 16 17 18 19 20

DISTANCE UPSTREAM FROM MOUTH OF SHELL ROCK RIVER, IN MILES

Figure 17. Profile of the July 1999 flood for the Shell Rock River, Iowa; river miles 1 to 20. 1,000

3o DISTANCE UPSTREAM FROM MOUTH OF SHELL ROCK RIVER, IN MILES 3 Figure 18. Profile of the July 1999 flood for the Shell Rock River, Iowa; river miles 20 to 40. CO 00 1,060 o D 1,050 CO on c_ 1 040

1,030

K LU ,020 \ 1 _f > 1,010 _J m s 1/3 1.000 1 £2 § TJ < 990

980 Ill Flood profile, July 1999 _] 111 Flood profile, March 1961 (Schwob, 1963) 970 Low-flow profile, November 1999 Low-flow profile, November 1961 (Schwob, 1963)

960 Bridge elevations: Upper flange = bridge deck Lower flange = low chord m n 950 CD

940 en tn ^ g °

O DO

o< C/3C 1

40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

DISTANCE UPSTREAM FROM MOUTH OF SHELL ROCK RIVER, IN MILES Figure 19. Profile of the July 1999 flood for the Shell Rock River, Iowa; river miles 40 to 60. - Elevation of -bridge deck - FJrst Street Flood profile, July 1999 Flood profile, March 1961 (Schwob, 1963) Low-flow profile, November 1999 Low-flow profile, November 1961 (Schwob, 1963) Bridge elevations: Upper flange = bridge deck Lower flange = low chord

3TJ DISTANCE UPSTREAM FROM MOUTH OF SHELL ROCK RIVER, IN MILES Figure 20. Profile of the July 1999 flood for the Shell Rock River, Iowa; river miles 60 to 76. CO CO Table 6. Elevations of high-water marks used in the flood profile of July 1999 for the Shell Rock River, Iowa [HWM, high-water mark; USGS, U.S. Geological Survey; -, not measured]

Distance upstream from Downstream Upstream mouth of Shell HWM HWM Rock River Bridge-site and streamflow-gaging (feet above (feet above (river miles) station description sea level) sea level) 3.9 265th Street, E of Waverly Junction 885.91 885.91 10.44 USGS gaging station 05462000, Shell Rock 902.07 - 11.27 State Highway 3, Shell Rock 907.79 909.34 18.7 State Highway 188. S of Clarksville 922.63 924.19 27.1 County Road T47, S of Packard 943.49 -

34.67 Traer Street, Greene 953.54 956.37 41.09 Discontinued USGS gaging station 968.63 970.94 05460500, County Road B60, Marble Rock 51.72 Main Avenue, Rockford 993.60 995.94 60.57 First Street, Nora Springs 1,046.78 1,048.46

67.75 County Road B20, Rock Falls 1.091.81 1,095.37 76.38 State Highway 9, N of Plymouth 1,134.31

40 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA Flood profile, July 1999 Flood profile, May 1963 (Schwob, 1963) Low-flow profile, November 1999 Low-flow profile. May 1963 (Schwob, 1963) Bridge elevations: Upper flange = bridge deck Lower flange = low chord

Locations indicated by these vertical lines are described in figures 22-24

DISTANCE UPSTREAM FROM MOUTH OF FLOOD CREEK, IN MILES 3 § Figure 21. Profile of the July 1999 flood for Flood Creek, Iowa; river miles 1 to 40. E AAS9S-Z196 (6661 U| pesn iou) >pou eiqjEiM )O 3N 'leans 41092

MN ZO-9Ifr6 (6661- u| pesn iou) jpoy BIQJEIM jo 3 'leans uiogg in s (6661 "! Pesn iou) >pOH 9|qjE|M in 10 3 '099 PEOH Ajunoo

AAS L 1-9^6 (6661 U! pesn iou) 05 d § ? O

in 0) crHI Jr(U AAN BZ-9^6 (6661. "! pssn iou) eiijftSjeMOd jo AA 'laeJis 41062

3N ££-91*6 (6661 u| pesn iou) 8||!ASJ8MOd )0 AAS 'IS9JIS MlOOe

(6661 "! pesn iou) JO AAS 'Zfrl PEOU Aiunoo

8 3S Mi-git* (panuiiuoosiQ) 1o> 06Et9frSO uoiieis BuiBeB SOSH 2 9u|| Ajunoo pAoy/jgung DC _>. -33

HI (U O \< "o AAN U-91S6 (6661"! pesn iou) 9U99JS jo 3 'eiO PEOU Aiunoo Q i S Q.

3NH-91S6 (6661"! Pesn CM iou) pjE>|OEd jo 3N '169JIS u.1021 I O)

3NSZ-91S6 (6661"! pesn iou) pje>|OEd jo 3N 'ieejis moei

AAN 9Z-9 Vee pJE>|OEd )0 3S '(ieejis iflott) e20 PEOU Ajunoo ______MN92-91S6 pjE>pEd jo 35 '

133d Nl 'H3A3T V3S 3AOSV NOI1VA3H3

42 FLOODS OF JULY 19-25,1999, IN THE WAPSIPINICON AND CEDAR RIVER BASINS, NORTHEAST IOWA Elevation of bridge deck State Highway 147

Flood profile, July 1999 Flood profile, May 1963 (Schwob. 1963) Low flow profile, November 1999 Low flow profile, May 1963 (Schwob, 1963) Bridge elevations: Upper flange = bridge deck Lower flange = low chord

DISTANCE UPSTREAM FROM MOUTH OF FLOOD CREEK. IN MILES

Figure 23. Profile of the July 1999 flood for Flood Creek, Iowa; river miles 15 to 30.

CO 1,170 O O O 1,160

1,150

1,140

130

1,120 m 1,110 LJJ > 3 < 1,100 i I 1,090 I m > _i m o 1,080 Flood profile, July 1999 8 Low-flow profile, November 1999 1,070 Bridge elevations: Upper flange = bridge deck Lower flange = low chord m 1,060 31 CD 1,050 w o

I III CD 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

DISTANCE UPSTREAM FROM MOUTH OF FLOOD CREEK, IN MILES

Figure 24. Profile of the July 1999 flood for Flood Creek, Iowa; river miles 30 to 40. Table 7. Elevations of high-water marks used in the flood profile of July 1999 for Flood Creek, Iowa [HWM, high-water mark; USGS, U.S. Geological Survey]

Distance upstream from Downstream Upstream mouth of Flood HWM HWM Creek Bridge-site and streamflow-gaging (feet above (feet above (river miles) station description sea level) sea level) 1.04 County Road C23 (140th Street), 946.46 946.47 SE of Packard 6.08 Discontinued USGS gaging station 968.06 968.96 05461390, Floyd Line Road, E of Greene 15.28 State Highway 14, NE of Marble Rock 1,020.00 1,021.18

19.76 State Highway 147, E of Rockford 1,051.94 1,052.56 31.79 State Highway 122 (old U.S. Highway 18), 1,101.95 1,102.87 NWofRudd

39.66 County Road S70, N of Nora Springs 1,141.64 1,143.69

PROFILES 45