Missouri River Flood Coordination Task Force Report, September 25, 2011

The Missouri River floods of 2011 will go down in history as the longest duration flooding event this state has seen to date. The combination of above normal snowfall in the upper Missouri River basin followed by the equivalent of nearly one year’s worth of rainfall in May created an above normal runoff situation which filled the Missouri River and the six main reservoirs within the basin. Compounding this problem was colder than normal temperatures which kept much of the snowpack in the upper basin on the ground longer into the spring, setting the stage for this historic event. The U.S. Army Corps of Engineers (USACE) began increasing the outflow at Gavin’s Point, near Yankton, South Dakota in May. On June 14, 2011, the outflow reached a record rate of over 160,000 cubic feet per second (cfs), over twice the previous record outflow set in 1997. This increased output from Gavin’s Point caused the Missouri River to flow out of its banks covering over 283,000 acres of land in Iowa, forcing hundreds of evacuations, damaging 255,000 acres of cropland and significantly impacting the levee system on the Missouri River basin. Over the course of the summer, approximately 64 miles of primary roads closed due to Missouri River flooding, including 54 miles of Interstate Highway. Many county secondary roads were closed by high water or overburdened due to the numerous detours and road closures in this area. As the Missouri River levels began to increase, municipalities and counties aided by State and Federal agencies began preparing for a sustained flood event. Citizens, businesses, state agencies, local governments and non‐profits made substantial preparations, in some cases expending millions of dollars on emergency protective measures to protect their facilities from the impending flood. Levee monitors detected weak spots in the levee system in all affected counties, with several levees being identified as at risk levees that could potentially fail. Of particular concern was the 28 miles of levees protecting Council Bluffs. Based on this concern, Council Bluffs prepared an evacuation plan for the approximately 30,000 residents that resided in the protected area. On May 25, 2011, Governor Branstad directed the execution of the Iowa Emergency Response Plan in accordance with Section 401 of the Stafford Act. On May 31, 2011, HSEMD Administrator, Brigadier General J. Derek Hill, formally requested the USACE to provide technical assistance and advanced measures for the communities along the Missouri River basin. On June 2, 2011 Governor Branstad issued a State of Iowa Proclamation of Disaster Emergency for Fremont, Harrison, Mills, Monona, Pottawattamie, and Woodbury counties. The length of this flood event created a unique set of challenges for Federal, State and local entities. In many cases, these organizations were conducting response and recovery operations simultaneously. Due to the length of this entire event, the State Emergency Operations Center and the local Emergency Operations Centers remained open for an extended period of time, putting additional strain on many organizations and resources. In response to this disaster, Governor Branstad created the Missouri River Recovery Coordination Task Force to oversee the State’s recovery efforts. The Governor announced the creation of this Task Force on October 17, 2011 and appointed Brigadier General J. Derek Hill, HSEMD Administrator as the chairman. This Task Force would be a temporary group of State agency representatives and interested stakeholders brought together to support the recovery efforts of the Iowa communities impacted by the Missouri River Flood. Collectively, this group would analyze and share damage assessment data, coordinate assistance across various stakeholders, monitor progress, capture best practices and identify lessons learned.

Floods of July 19-25, 1999, in the Wapsipinicon and Cedar River Basins, Northeast Iowa, HR-140

Severe flooding occurred during July 19-25, 1999, in the Wapsipinicon and Cedar River Basins following two thunderstorms over northeast Iowa. During July 18-19, as much as 6 inches ofrainfall was centered over Cerro Gordo, Floyd, Mitchell, and Worth Counties. During July 20-21, a second storm occurred in which an additional rainfall of as much as 8 inches was centered over Chickasaw and Floyd Counties. The cumulative effect of the storms produced floods with new maximum peak discharges at the following streamflow-gaging stations: Wapsipinicon River near Tripoli, 19,400 cubic feet per second; Cedar River at Charles City, 31,200 cubic feet per second (recurrence interval about 90 years); Cedar River at Janesville, 42,200 cubic feet per second (recurrence interval about 80 years); and Flood Creek near Powersville, 19,000 cubic feet per second. Profiles of flood elevations for the July 1999 flood are presented in this report for selected reaches along the Wapsipinicon, Cedar, and Shell Rock Rivers and along Flood Creek. Information about the river basins, rain storms, and flooding are presented along with information on temporary bench marks and reference points in the Wapsipinicon and Cedar River Basins.

Floods of September 15-16, 1992, in the Thompson, Weldon, and Chariton River Basins, South-Central Iowa, HR-140, 1997

Water-surface-elevation profiles and peak discharges for the floods of September 15-16, 1992, in the Thompson, Weldon, and Chariton River Basins, south-central Iowa, are presented in this report. The profiles illustrate the 1992 floods along the Thompson, Weldon, Chariton, and South Fork Chariton Rivers and along Elk Creek in the south-central Iowa counties of Adair, Clarke, Decatur, Lucas, Madison, Ringgold, Union, and Wayne. Water-surface-elevation profiles for the floods of July 4, 1981, along the Chariton River in Lucas County and along the South Fork Chariton River in Wayne County also are included in the report for comparative purposes. The September 15-16, 1992, floods are the largest known peak discharges at gaging stations Thompson River at Davis City (station number 06898000) 57,000 cubic feet per second, Weldon River near Leon (station number 06898400) 76,200 cubic feet per second, Chariton River near Chariton (station number 06903400) 37,700 cubic feet per second, and South Fork Chariton River near Promise City (station number 06903700) 70,600 cubic feet per second. The peak discharges were, respectively, 1.7, 2.6, 1.4, and 2.1 times larger than calculated 100-year recurrence-interval discharges. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Thompson, Weldon, and Chariton River Basins using flood information collected through 1995. Information on temporary bench marks and reference points established in the Thompson and Weldon River Basins during 1994-95, and in the Chariton River Basin during 1983-84 and 1994-95, also is included in the report. A flood history summarizes rainfall conditions and damages for floods that occurred during 1947, 1959, 1981, 1992, and 1993.

Floods of July 12, 1972, March 19, 1979, and June 15, 1991, in the Turkey River, Northeast Iowa, HR-140, 1996

Water-surface-elevation profiles and peak discharges for the floods of July 12, 1972, March 19, 1979, and June 15, 1991, in the Turkey River Basin, northeast Iowa, are presented in this report. The profiles illustrate the 1979 and 1991 floods along the Turkey River in Fayette and Clayton Counties and along the Volga River in Clayton County; the 1991 flood along Roberts Creek in Clayton County and along Otter Creek in Fayette County; and the 1972 flood along the Turkey River in Winneshiek and Fayette Counties. Watersurface elevations for the flood of March 19, 1979, were collected by the Iowa Natural Resources Council. The June 15, 1991, flood on the Turkey River at Garber (station number 05412500) is the largest known flood-peak discharge at the streamflow-gaging station for the period 1902-95. The peak discharge for June 15, 1991, of 49,900 cubic feet per second was 1.4 times larger than the 100-year recurrence-interval discharge. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Turkey River Basin using flood information collected during 1902-95. Information on temporary bench marks and reference points established in the Turkey River Basin during 1981, 1992, and 1996 also is included in the report. A flood history describes rainfall conditions for floods that occurred during 1922, 1947, 1972, 1979, and 1991.

Calibration and Validation of SWAT for the Upper Maquoketa River Watershed, June 2005

A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-offield flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which required translating the APEX subareas into SWAT hydrologic response units (HRUs). Calibration and validation of the SWAT output was performed by comparing predicted flow and NO3-N loadings with corresponding in-stream measurements at the watershed outlet from 1999 to 2001. Annual stream flows measured at the watershed outlet were greatly under-predicted when precipitation data collected within the watershed during the 1999-2001 period were used to drive SWAT. Selection of alternative climate data resulted in greatly improved average annual stream predictions, and also relatively strong r2 values of 0.73 and 0.72 for the predicted average monthly flows and NO3-N loads, respectively. The impact of alternative precipitation data shows that as average annual precipitation increases 19%, the relative change in average annual streamflow is about 55%. In summary, the results of this study show that SWAT can replicate measured trends for this watershed and that climate inputs are very important for validating SWAT and other water quality models.

Great River Regional Waste Authority, Auditor of State's Report, For the Period July 1, 2002 through June 30, 2003, and Selected Activity through June 30, 2005

Other Audit Reports

Monitoring of the Launched Girder Bridge over the Iowa River on US 20, March 2004

The objective of the study presented in this report was to document the launch of the Iowa River Bridge and to monitor and evaluate the structural performance of the bridge superstructure and substructure during the launch. The Iowa Department of Transportation used an incremental launching method, which is relatively unique for steel I-girder bridges, to construct the Iowa River Bridge over an environmentally sensitive river valley in central Iowa. The bridge was designed as two separate roadways consisting of four steel plate girders each that are approximately 11 ft deep and span approximately 301 ft each over five spans. The concrete bridge deck was not placed until after both roadways had been launched. One of the most significant monitoring and evaluation observations related to the superstructure was that the bottom flange (and associated web region) was subjected to extremely large stresses during the crossing of launch rollers. Regarding the substructure performance, the column stresses did not exceed reasonable design limits during the daylong launches. The scope of the study did not allow adequate quantification of the measured applied launch forces at the piers. Future proposed esearch should provide an opportunity to address this. The overall experimental performance of the bridge during the launch was compared with the predicted design performance. In general, the substructure design, girder contact stress, and total launching force assumptions correlated well with the experimental results. The design assumptions for total axial force in crossframe members, on the other hand, differed from the experimental results by as much as 300%.

Audit report on the Great River Regional Waste Authority for the years ended June 30, 2005 and 2006

Audit report on the Great River Regional Waste Authority for the years ended June 30, 2005 and 2006.

The Fox River Needs Your Help, 2007

The Fox River is on Iowa’s impaired waters list. By working to reduce pollution in the watershed, we can make the Fox River healthy again.

River and Stream Health in Iowa, 2001

A report by the Iowa Department of Natural Resources on how the health of Iowa's River and Stream are today.

Project AWARE 2006 Iowa River, 2007

This monthly report from the Iowa Department of Transportation is about the water quality management of Iowa's rivers, streams and lakes.

Project AWARE 2007 Raccoon River, 2008

This monthly report from the Iowa Department of Transportation is about the water quality management of Iowa's rivers, streams and lakes.

Audit report on the Great River Regional Waste Authority for the year ended June 30, 2007

Audit report on the Great River Regional Waste Authority for the year ended June 30, 2007

River Barge Terminal Directory, July 2005

The Barge Terminal Directory has been prepared by the Iowa Department of Transportation’s Modal Division to provide quick access to information on Iowa’s river terminals and fleeting/harbor services. The information is to assist those who may need barge transportation services. The information in the directory was provided by the terminal operators. The Modal Division would appreciate any help on corrections, additions or deletions.

Degradation and aggradation of the Missouri River, June 1978.

Proceedings of a workshop held in Omaha, Nebraska, 22-25 January, 1978. Edited by W.W. Sayre and J.F. Kennedy. Iowa Conservation Commission. IIHR Report No. 215. Iowa Institute of Hydraulic Research, the University of Iowa, Iowa City, Iowa.