Floods of 1986 and 1990 in the Raccoon River Basin, West-Central Iowa, HR-140, 1992

Water-surface-elevation profiles and peak discharges for the floods of 1973 and 1979 are compared to those of 1986 and 1990 in the Raccoon River basin, west-central Iowa. The profiles illustrate the 1979 and 1986 floods on the Raccoon, South Raccoon, and Middle Raccoon Rivers, the 1973 and 1986 floods on Walnut Creek, and the 1986 flood on Willow Creek and Mosquito Creek. The 1986 flood is the largest on record at U.S. Geological Survey streamflowgaging stations on the Middle Raccoon River tributary at Carroll, Middle Raccoon River near Bayard, Middle Raccoon River at Panora, and Walnut Creek at Des Moines. The 1990 flood discharge is the largest on record at U.S. Geological Survey crest-stage gaging stations on Hardin Creek near Farlin and on East Fork Hardin Creek near Churdan. The flood history given in this report describes rainfall conditions for floods that occurred during 1986 and 1990. Discharge for the 1990 flood on East Fork Hardin Creek near Churdan was 1.01 times larger than the 100-year recurrence-interval discharge.

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.

07043-017 North Fork Maquoketa Final Report

The North Fork Maquoketa River Headwaters (NFMRH) has been identified as impaired by nutrients, episodic slugs of ammonia and sediment. The NFMRH TMDL plan calls for a "phasing approach" to managing water quality when the origin is non-point source contaminants. This project will address phase 1 using a performance reward program for targeted cooperators to improve environmental index scores using cost-share, EQIP practices and flexible management alternatives. Pre-project assessments suggest that rewards should target refined management of erosion-prone fields and farms with livestock populations, which contribute to the P and N loads responsible for fertilizing filamentous algae blooms that depress dissolved oxygen concentrations in the NFMRH. The Phosphorus Index, Soil Conditioning Index and cornstalk nitrate test will be used by producers to determine effective alternatives, such as no-till planting, to reduce nutrient and sediment delivery. These evironmental indexes will be especially useful for livestock producers in the livestock dense watershed. This project will extend a NRCS-sponsored Conservation Innovation Grant currently offered to producers in the Coffee Creek sub-watershed to a three-year, watershed-wide effort that will be necessary to make significant improvements in environmental management.

1204-003 North Fork Maquoketa Watershed Final Report

The Headwaters North Fork Maquoketa River Project encompasses the Hewitt Creek, Bear Creek, and the Coffee Creek-North Fork Maquoketa subwatersheds. These three.sub-watersheds have intensive livestock agriculture production with manures applied generously on the landscape. Approximately 85% of the watershed area is cropland. Although livestock operations are not permitted to discharge waste directly into surface waters, the mishandling and over-application of animal waste and fertilizer have impacted water quality. Each of the subwatersheds has a strong locally led effort, concentrating significant efforts on monitoring, education, and conservation practice adoption. The original MRBI application was accepted by USDA with funding being extended to producers through FY14. A large component of this effort was the IJOBS funds awarded by IDALS to support the Project Coordinator for the first two years of this project. As previous funding for the support of the Project Coordinator has been exhausted, the local partners identified WIRB as a potential replacement funding source. The goal of the existing MRBI effort, in being consistent with this WIRB application, will help landowners and operators in the three selected watersheds voluntarily implement conservation systems that reduce nutrient loss; protect, restore, and enhance wetlands; maintain agricultural productivity; improve wildlife habitat; and achieve other objectives, such as flood reduction.

Department of Natural Resources - Special Investigation of The Lewis and Clark State Park in Onawa, July 1st, 2001 through November 30, 2004

Other Audit Reports - Special Investigation

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.