Submerged Vanes for Flow Control and Bank Protection in Streams, HR-255, 1984

This study was conducted for the purpose of evaluating a new concept for a bank-protection structure: The Iowa Vane . The underlying idea involves countering the torque exerted on the primary flow by its curvature and vertical velocity gradient, thereby eliminating or significantly reducing the secondary flow and thus reducing the undermining of the outer banks and the high-velocity attack on it. The new structure consists of an array of short, vertical, submerged vanes installed with a certain orientation on the channel bed. A relatively small number of vanes can produce bend flows which are practically uniform across the channel. The height of the vanes is less than half the water depth, and their angle with the flow direction is of the order of l0 degrees. In this study, design relations have been established. The relations, and the vanes' overall performance, have been tested in a laboratory model under different flow and sediment conditions. The results are used for the design of an Iowa-Vane bank protection structure for a section of East Nishnabotna River along U.S. Highway 34 at Red Oak, Iowa.

Development of Non-Petroleum Based Binders for Use in Flexible Pavements, TR-594, 2010

Most bituminous adhesives or binders that are used for pavement materials are derived primarily from fossil fuels. With petroleum oil reserves becoming depleted and the drive to establish a bio-based economy, there is a push to produce binders from alternative sources, particularly from biorenewable resources. However, until now, no research has studied the applicability of utilizing bio-oils as a bitumen replacement (100% replacement) in the pavement industry. The main objective of this research was to test various properties of bio-oils in order to determine the applicability of using bio-oils as binders in the pavement industry. The overall conclusions about the applicability of using bio-oils as bio-binders in the pavement industry can be summarized as follows: 1. Bio-oils cannot be used as bio-binders/pavement materials without any heat pre-treatment/upgrading procedure. 2. Current testing standards and specifications, especially Superpave procedures, should be modified to comply with the properties of bio-binders. 3. The temperature range of the viscous behavior for bio-oils may be lower than that of bitumen binders by about 30°–40° C. 4. The rheological properties of the unmodified bio-binders vary in comparison to bitumen binders, but the rheological properties of these modified bio-binders change significantly upon adding polymer modifiers. 5. The high-temperature performance grade for the developed bio-binders may not vary significantly from that of the bitumen binders, but the low-temperature performance grade may vary significantly

Development of Non-Petroleum-Based Binders for Use in Flexible Pavements – Phase II, TR-650, 2015

Bio-binders can be utilized as asphalt modifiers, extenders, and replacements for conventional asphalt in bituminous binders. From the rheology results of Phase I of this project, it was found that the bio-binders tested had good performance, similar to conventional asphalt, except at low temperatures. Phase II of this project addresses this shortcoming and evaluates the Superpave performance of laboratory mixes produced with the enhanced bio-binders. The main objective of this research was to develop a bio-binder capable of replacing conventional asphalt in flexible pavements by incorporating ground tire rubber (GTR) into bio-oil derived from fast pyrolysis of agriculture and forestry residues. The chemical compatibility of the new bio-binder with GTR was assessed, and the low-temperature performance of the bio-binders was enhanced by the use of GTR. The newly developed binder, which consisted of 80 percent conventional binder and 20 percent rubber-modified bio-oil (85 percent bio-oil with 15 percent GTR), was used to produce mixes at two different air void contents, 4 and 7 percent. The laboratory performance test results showed that the performance of the newly developed bio-binder mixes is as good as or better than conventional asphalt mixes for fatigue cracking, rutting resistance, moisture sensitivity, and low-temperature cracking. These results need to be validated in field projects in order to demonstrate adequate performance for this innovative and sustainable technology for flexible pavements.

For Land’s Sake, February 2002

Grass and weeds are a problem because they grow faster and are often taller than young seedlings. They compete with your seedlings for the limited moisture, nutrients, light, and space. Grasses and broadleaf weeds may kill your seedlings. At the very least, they keep seedlings from growing as quickly and vigorously as they would without competition. In addition, a thick stand of grass or weeds next to your seedlings provides habitat for rabbits and rodents who can girdle or cut off your seedlings. The only way to avoid these problems are to control the grass and weeds that cause them.

Design Procedures and Field Monitoring of Submerged Barbs for Streambank Protection, June 2007

The main objective of this study was to evaluate the hydraulic performance of riprap spurs and weirs in controlling bank erosion at the Southern part of the Raccoon River upstream U.S. Highway 169 Bridge utilizing the commercially available model FESWMS and field monitoring. It was found based on a 2 year monitoring and numerical modeling that the design of structures was overall successful, including their spacing and stability. The riprap material incorporated into the structures was directly and favorably correlated to the flow transmission through the structure, or in other words, dictated the permeable nature of the structure. It was found that the permeable dikes and weirs chosen in this study created less volume of scour in the vicinity of the structure toes and thus have less risk comparatively to other impermeable structures to collapse. The fact that the structures permitted the transmission of flow through them it allowed fine sand particles to fill in the gaps of the rock interstices and thus cement and better stabilize the structures. During bank-full flows the maximum scour hole was recorded away from the structures toe and the scourhole size was directly related to the protrusion angle of the structure to the flow. It was concluded that the proposed structure inclination with respect to the main flow direction was appropriate since it provides maximum bank protection while creating the largest volume of local scour away from the structure and towards the center of the channel. Furthermore, the lowest potential for bank erosion also occurs with the present set-up design chosen by the IDOT. About 2 ft of new material was deposited in the area located between the structures for the period extending from the construction day to May 2007. Surveys obtained by sonar and the presence of vegetation indicate that new material has been added at the bank toes. Finally, the structures provided higher variability in bed topography forming resting pools, creating flow shade on the leeward side of the structure, and separation of bed substrate due to different flow conditions. Another notable environmental benefit to rock riprap weirs and dikes is the creation of resting pools, especially in year 2007 (2nd year of the project). The magnitude of these benefits to aquatic habitat has been found in the literature that is directly related to the induced scour-hole volume.

Camping in Iowa, 1968

This directory is intended to assist the general camping public and contains listings of both public and private facilities known to exist as a result of survey questionnaires.

Construction and Evaluation of Submerged Vanes for Stream Control, HR-274, 1988

The objective of this study was to determine the practicality and effectiveness of using submerged vanes ("Iowa Vanes") to control bank erosion in a bend of East Nishnabotna River, Iowa. The vane system was constructed during the summer of 1985. It functions by eliminating, or reducing, the centrifugally induced helical motion of the flow in the bend, which is the root cause of bank undermining. The system was monitored over a 2-year period, from September 1985 to October 1987. Two surveys were conducted in the spring of 1986 in which data were taken of depths and velocities throughout the bend and of water-surface slope. The movement of the bank was determined from aerial photos and from repeated measurements of the vane-to-bank distance. The bankfull scour depths and velocities along the bank have been reduced significantly; and the movement of the bank has been stopped or considerably reduced. The improvements were obtained without changing the energy slope of the channel. Areas of design improvements were identified.

Evaluation of Changes in Productivity Resulting from Removal of Soil for Highway Construction, HR-186, 1981

Borrow areas are created where soil is removed to provide needed fill material for highway and other construction projects. Where these areas are located beyond the highway right-of-way, they must be restored and returned to useful purposes. In Iowa, borrow areas are often developed on agricultural lands and therefore, it is necessary to return them to agricultural uses whenever possible. This research project was established to evaluate the changes in row crop productivity where borrow is removed for highway construction. Secondly, several reclamation techniques were selected to be applied to borrow area research sites and the response of crops to each treatment will be evaluated. All borrow area research sites were selected in 1977 from Iowa Department of Transportation construction plans. The Audubon and Buchanan County sites were completed in the fall of 1977 and May 1978, respectively. Both were used for research in 1978, 1979, and 1980. The two remaining sites in Hamilton and Lee Counties were completed in the fall of 1978 and research was conducted at these sites in 1979, 1980, and 1981. In this report, the 1981 results from the Hamilton and Lee County borrow sites will be presented. Secondly, a summary of the three years of research from each borrow area will be presented along with specific and general conclusions from the research project.

Scale Effects in Hydraulic Model Tests of Rock Protected Structures, HR-119, 1970

A laboratory investigation was undertaken to determine the limiting model Reynolds number above which the scour behavior of rock protected structures can be reproduced in hydraulic models scaled according to the Froude criterion. A submerged jet was passed over an initially full scour pocket containing uniform glass spheres and the rate of scour was measured as a function of time. The dimensions of the scour pocket and jet and the particle diameters were varied as needed to maintain strict geometric similarity. For each of two different Froude numbers the Reynolds number was varied over a wide range. The normalized scour rate was found to be practically independent of the Reynolds number, R, (based on the jet velocity and particle diameter) at values of R above about 2.5 x 10^3, and to decrease with Rat smaller values. A grid placed in the jet was found to have a very strong effect on the scour rate. In an attempt to explain the effect of R on the scour behavior, turbulent pressure and velocity fluctuations were measured in air flows and water flows, respectively, over rigid scour pockets having the same geometry as those formed in the scour experiments. The normalized spectra of the fluctuations were found to be nearly independent of R, but the flow pattern was found to be very sensitive to the inlet condition, the jet deflecting upward or downward in a not wholly explainable manner. This indicates that scour behavior can be modeled only if the approach flow is also accurately modeled.

Outdoor recreation in Iowa, 1966

The objectives of this "Statewide Comprehensive Outdoor Recreation Plan" are to inventory existing recreation areas in Iowa, determine current demand, define and analyze problems, determine needs, delineate responsibilities, correlate planning, present an action plan and establish a priority system for the development of outdoor recreational facilities.

Letter health consultation : Olin former petroleum bulk plant, Olin, Jones County, Iowa (2010)

This letter has been prepared as a consultation to evaluate human health impacts from residue contamination left from the operation of a bulk plant located in Olin, Iowa. The Iowa Department of Public Health’s priority is to ensure the Olin community has the best information possible to safeguard its health. That information is included in following paragraphs.

Health consultation : Silver City petroleum release and municipal wells, Silver City, Mills County, Iowa (2005)

A resident of Silver City, Iowa requested the Iowa Department of Public Health (IDPH) Hazardous Waste Site Health Assessment Program to evaluate the health impacts of a petroleum release in Silver City, Iowa, and the health impacts from the presence of chemicals detected in wells utilized as the source of municipal water for the citizens of Silver City and in the treated municipal water supply. This health consultation addresses exposure to residents of Silver City to organic chemicals within the groundwater and water supply and potential health effects at the levels of exposure. The information in this health consultation was current at the time of writing. Data that emerges later could alter this document’s conclusions and recommendations.

Health consultation : Rolfe aboveground storage tank petroleum bulk plant targeted brownfields assessment, Railroad Street and 300th Avenue, Rolfe, Pocahontas County, Iowa (2005)

The Iowa Department of Natural Resources (IDNR) has requested the Iowa Department of Public Health (IDPH) Hazardous Waste Site Health Assessment Program evaluate future health impacts of exposures at a former aboveground storage tank site located in Rolfe, Iowa. The former aboveground storage tank site is located to the southwest of the intersection of Railroad Street and 300th Avenue in Rolfe, Iowa. This site is undergoing a Targeted Brownfields Assessment conducted by the Contaminated Sites Section of the IDNR. This health consultation addresses potential health risks to people from future exposure to the soil within the property boundary, and any health impacts resulting from contaminated groundwater beneath the site property. The information in this health consultation was current at the time of writing. Data that emerges later could alter this document’s conclusions and recommendations.