The Raccoon River Valley Trail user study: summary and recommendations,1992.

This study is a concise summary of a study of trail users on the Raccoon River Valley Trail commissioned by the Dallas County Conservation Board. It provides information associated with natural and cultural resources.

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%.

A Return to Clear Creek, 2006

At one time, Clear Creek lived up to its name. Originally set among the prairie and oak savannah of the Iowa River valley, legend has it that early settler and Johnson County sheriff Samuel Trowbridge gave the creek its name because of its pristine waters. However, the stream’s natural protections began to weaken as more settlers moved into Iowa. Over time, the prairie disappeared, livestock trampled streambanks, the creek was dredged and straightened, wetlands were drained and urban areas began to take their toll.

RAGBRAI Learn about the Land; Day 5, July 2008

Today, after you descend into the valley of the Iowa River north of Marengo, the route turns east on county road F15 and approaches the historic Amana Society. Settled in the late 1850s by German immigrants of the Community of True Inspiration, the new arrivals utilized the local timber and stone resources to construct their buildings. During these early years several stone quarries were opened in the hills along the north wall of the Iowa River valley near East, Middle, and West Amana. Riders will pass close to one of these old quarries 0.7 miles west of West Amana. The stone taken from these quarries is beautiful quartz-rich sandstone that is cemented by light brown to orange tinged iron oxide. This stone was used in the construction of many buildings in Amana.

Sioux City's Grand Avenue Viaduct, 1936-2010

For almost 75 years, the Grand Avenue Viaduct (known today as the Gordon Drive Viaduct) has been a familiar feature of Sioux City's urban landscape. With the exception of bridges over the Mississippi River, the Grand Avenue Viaduct is Iowa's longest grade separation as well as its longest bridge. For nearly a mile, from the eastern suburbs west to the central business district, the viaduct carries Gordon Drive and the city route of U.S. 20 over the Floyd River valley, which includes the remnants of the city's famed stockyards and the South Bottoms neighborhood, as well as a maze of railroad tracks and the present channel of the Floyd River. Constructed in 1937 and known simply as "The Viaduct" to local residents, the massive structure is as fundamental to Sioux City as were its stockyards just a few decades ago.

Missouri riverfront parkway & scenic highway design study, 1973.

This report concerns a proposed Parkway and Scenic Highway along both sides of the Missouri River in Harrison, Pottawattamie and Mills County in Iowa and Washington, Douglas and Sarpy Counties in Nebraska. This Parkway will make the Missouri River valley accessible to the public, link existing and planned attractions and facilitate planned development while at the same time preserving for posterity the best of the natural attributes of the area.

Missouri River Studies: Alluvial Morphology and Engineering Soil Classification, HR-1, Progress Report, 1960

The primary purposes of this investigation are: 1) To delineate flood plain deposits with different geologic and engineering properties. 2) To provide basic data necessary for any attempt at stabilizing flood plain deposits. The alluvial valley of the Missouri River adjacent to Iowa was chosen as the logical place to begin this study. The river forms the western boundary of the state for an airline distance of approximately 139 miles; and the flood plain varies from a maximum width of approximately 18 miles (Plates 2 and 3, Sheets 75 and 75L) to approximately 4 miles near Crescent, Iowa (Plate 8, Sheet 66). The area studied includes parts of Woodbury, Monona, Harrison, Pottawattamie, Mills, and Fremont counties in Iowa and parts of Dakota, Thurston, Burt, Washington, Douglas, Sarpy, Cass and Otoe counties in Nebraska. Plate l is an index map of the area under consideration.

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.

City of Missouri Valley, Auditor of State's Report on Reaudit, For the Period July 1, 2003 through June 30, 2004

Other Audit Reports - Reaudit

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

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.

Buried Valley Aquifers of Iowa, 2004

Buried Valley Aquifers of Iowa in 2004

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.