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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <title>Diagnosis of the Problem Situation Related to the Retention of Stormwater From Road Surfaces in Poland</title>
      <link>https://trid.trb.org/View/2643349</link>
      <description><![CDATA[This study examines the challenges and potential solutions associated with the retention of stormwater from road surfaces – a critical component of urban infrastructure in the face of climate change. The research highlights that intensified urbanisation and the increasing prevalence of extreme weather events have exacerbated issues related to rapid rainwater runoff, leading to urban flooding and infrastructural degradation. Employing quantitative empirical methods, a survey was conducted among 362 road infrastructure managers in Poland, assessing the technical condition of roads, drainage system performance, and the barriers to adopting modern retention and infiltration solutions. Findings reveal a mixed perception of current drainage performance, with many respondents reporting inadequate solutions that compromise both safety and sustainability. Key barriers include high implementation costs, technical and infrastructural challenges, resistance to change, and limited public awareness. The results underscore the necessity for modern, integrated stormwater management practices that not only protect infrastructure but also enhance urban water balance and sustainability.]]></description>
      <pubDate>Tue, 24 Feb 2026 09:01:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643349</guid>
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    <item>
      <title>Road salt reduces plant cover in bioretention systems within road rights-of-way</title>
      <link>https://trid.trb.org/View/2578430</link>
      <description><![CDATA[Bioretention systems for managing urban runoff rely on healthy plants to reduce runoff and nutrient pollution via evapotranspiration and uptake. However, loss of plant cover is common and, in cold climates, potentially caused by the application of road salt. To investigate the impact of road salt on bioretention systems, the authors measured salt concentrations in the media and plant tissues and assessed plant cover at 19 sites in Toronto, Canada, in the field. Winter road salt was identified as the primary driver of plant cover loss: low-tolerance species accumulated excessive sodium and chloride, resulting in chlorotic and necrotic damage even under moderate salinity (median electrical conductivity (EC), 0.31–0.35 mS/cm, as measured in soil–water suspensions). Continuous EC monitoring showed no net salt buildup in any season, although salinity peaked in winter and was lower in summer. Low-tolerance species exhibited high salt ion uptake and substantial damage from legacy salt retained in the media. Although species-specific ion accumulation patterns were observed, they did not always align with species salt tolerance as described in the literature. Among the 14 species studied, Hemerocallis ‘Happy Returns’ (low tolerance) and Panicum virgatum (medium tolerance) significantly accumulated sodium, up to 2126 and 586 mg/kg, respectively, whereas Salvia officinalis (medium tolerance) significantly accumulated chloride (up to 20 mg/g); yet only Panicum virgatum displayed minimal damage (<5 %), while Hemerocallis ‘Happy Returns’ and Salvia officinalis displayed >50 % damage. These findings underscore the importance of selecting salt-tolerant species to ensure long-term bioretention performance.]]></description>
      <pubDate>Fri, 26 Sep 2025 13:39:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2578430</guid>
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      <title>Development of Biochar Specification Criteria as Soil Amendment for Slopes, Conveyances and Stormwater Treatment Systems (Phase 1)</title>
      <link>https://trid.trb.org/View/2582138</link>
      <description><![CDATA[The objective of this project is to develop knowledge, tools, and protocols to inform best practice standards for effective implementation of biochar in bioretention systems (BRSs) for treating roadway runoff. This project will be performed in two phases, with the first phase (this report) focusing on biochar production, characterization, and contaminant sorption performance. Results from the first phase will inform decisions for the second phase which will look at vegetation growth studies and soil hydrology evaluations. The authors anticipate the primary project output (following completion of Phase 2) to be a tool or protocol (e.g., a decision-making matrix) to provide standardized guidance for best practices regarding the practical implementation of biochar in BRSs treating roadway runoff. The work plan for Phase 1 is presented herein, which will result in following outputs: 1. Recommendations for locally available, suitable biomass feedstocks and feedstock-specific pyrolysis conditions which can be reproduced at scale. 2. Biochar physical property specification criteria associated with contaminant-removal targets which can be assessed at reasonable costs. 3. Protocols for screening-level contaminant-removal performance tests based on broadly accessible materials and methods. 4. Plans for further evaluations to verify treatment performance and evaluate hydraulic and soil health effects, to be proposed as a part of Phase 2 investigations.]]></description>
      <pubDate>Thu, 31 Jul 2025 09:19:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/2582138</guid>
    </item>
    <item>
      <title>Identifying Opportunities to Improve Temporary Sediment Basin</title>
      <link>https://trid.trb.org/View/2582218</link>
      <description><![CDATA[Temporary sediment basins are used to control the release of sediment laden stormwater runoff from active construction sites. If temporary sediment basins are constructed according to specifications, it is expected that 60% of sediment will be trapped by the sediment basin. Nonetheless, sediment basins can perform poorly in several instances such as in successive storm events, at sites with fine-grained soils, or due to maintenance issues. Releases of sediment laden stormwater runoff from construction sites can negatively impact the environment and require costly and sometimes time-consuming corrective actions. This project will identify common issues with sediment basins in Virginia and determine potential alternative designs to evaluate for future use in Virginia. First, interviews of Virginia’s National Pollutant Discharge Elimination System and Environmental Compliance Inspectors as well as personnel from other state departments of transportation (DOTs) will be conducted. Interviews will provide insights into potential common issues with sediment basins as well as opportunities for knowledge transfer. Then, select active sediment basins will be observed to better understand design limitations and contractor installation and maintenance practices. This research benefits the Virginia Department of Transportation (VDOT) by identifying potential sediment basin design shortcomings in Virginia, possible design modifications, and potential opportunities for knowledge transfer.  This research also establishes a basis for future research on potential temporary sediment basin design modifications to improve their performance. ]]></description>
      <pubDate>Sun, 27 Jul 2025 10:41:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2582218</guid>
    </item>
    <item>
      <title>Temporal Evolution of Stormwater Basin Soil Properties and Infiltration Rates</title>
      <link>https://trid.trb.org/View/2566016</link>
      <description><![CDATA[Maintaining the soil infiltration capacity of stormwater infiltration practices is essential to long-term performance and resilience to changing land use and climate conditions. To date, however, the ability to predict how infiltration capacities change over time has been limited by a lack of understanding of how soil properties evolve with the age of the practice and the associated impacts on infiltration rates. To address this limitation, this study measured soil properties and infiltration rates in 28 stormwater infiltration basins ranging in age from 2 to 20 years. Soil organic matter, clay content, and silt content increased with age, while bulk density decreased with age, indicating both vegetation and soil biota activity and fine sediment accumulation contribute to soil profile evolution. Infiltration rates decreased with age, with a precipitous decline at approximately 12 years. Silt content was the best predictor of infiltration rate. However, age alone provided some predictive power, allowing infiltration practices to be prioritized for inspection and maintenance based on age. Visual indicators of basin failure included the presence of hydric soils, ponding, sediment accumulation, impaired vegetation, and presence of wetland vegetation. Therefore, a combination of age, visual inspection, and measurement of soil properties and infiltration rates is recommended to identify practices for rehabilitation. Inspection at 5-year intervals is recommended and is consistent with the requirements of the Minnesota Department of Transportation (MnDOT) MS4 permit.]]></description>
      <pubDate>Wed, 16 Jul 2025 09:51:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2566016</guid>
    </item>
    <item>
      <title>Characterizing Stormwater Basin Conditions Using Tracked BMP Inspection and Rating Reports from the Virginia Department of Transportation</title>
      <link>https://trid.trb.org/View/2499150</link>
      <description><![CDATA[Studies have rarely used stormwater best management practice (BMP) condition rating data to quantify changes in condition ratings and characterize condition issues, making it challenging to implement proactive maintenance practices. To help address this knowledge gap, the authors answer the following questions pertaining to a widely used stormwater BMP: detention and retention basins. (1) How often do basin condition ratings change over time? (2) What are specific site and structural condition issues identified during condition inspections? (3) What issues and site characteristics correspond with basins that experience a rapid decline in condition rating, meaning a decrease in two or more condition rating levels within a single year? The authors do this by characterizing basin condition ratings and associated issues using information included in more than 5,500 basin inspection reports, each containing more than 200 questions, stored in the Virginia Department of Transportation (VDOT) asset management system. On average, between 5.6 and 8.3 issues were recorded per visit for D-rated and E-rated basins compared with 0.03 to 1.8 issues for A-rated and B-rated basins. Of the 901 basins with three consecutive years of inspections, 41% and 35% had condition ratings that changed from 2020 to 2021 and from 2021 to 2022, respectively. The most common issues associated with rapid condition rating decline included major corrosion on the low flow orifice trash/debris rack, control structure, and pipe. Rapidly declining condition ratings were observed in 67% of VDOT’s nine independent management districts, suggesting rapid declines occur independently of management practices. Higher median elevation and percent slope attributes and lower median population were correlated with basins experiencing rapid condition rating decline. Using these results as context, the authors discuss considerations for improving BMP inspection data quality and opportunities for supporting proactive BMP management practices that can benefit other agencies managing a large portfolio of stormwater assets.]]></description>
      <pubDate>Tue, 18 Feb 2025 08:57:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/2499150</guid>
    </item>
    <item>
      <title>Stormwater BMP Inspection and Maintenance Resource Guide</title>
      <link>https://trid.trb.org/View/2470492</link>
      <description><![CDATA[Stormwater treatment practices, often referred to as stormwater best management practices (BMPs), require a substantial commitment to maintenance, including regular inspections and assessments. Existing regulations require governmental units to develop a systematic approach for ongoing inspection and maintenance to ensure that they are achieving their desired treatment goals. A lack of maintenance will lead to a decrease in BMP performance and will often result in expensive rehabilitation or rebuild. In 2009, SRF Consulting produced a maintenance guide for the Local Road Research Board (LRRB) (Marti, et al. 2009). In 2023, the LRRB commissioned the University of Minnesota St. Anthony Falls Laboratory to update this guide to reflect new best practices. The Stormwater BMP Inspection and Maintenance Resource Guide (the Guide) is a supplement to the Minnesota Stormwater Manual (MPCA 2023) and will help the reader plan for recommended long-term maintenance activities through guidance on visual inspection, testing, and monitoring methods for identifying what maintenance is needed, and when it is needed. The Guide describes inspection and maintenance for constructed stormwater ponds (both dry and wet) and wetlands, underground sedimentation practices, infiltration practices, filtration practices, bioretention practices, permeable pavements, and stormwater harvesting. In addition, the Guide includes a section on Meeting Stormwater Management Objectives, which provides information on achieving reductions for sediment, phosphorus, nitrogen, metals, chloride, pathogens, and organic chemicals. The Guide also includes Field Inspections Resources, which contains inspection checklists and maintenance activity recommendations for all of the practices listed above.]]></description>
      <pubDate>Mon, 13 Jan 2025 10:24:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2470492</guid>
    </item>
    <item>
      <title>Engineering Design Procedures and Standard Drawings for Highway Construction Sediment Basins</title>
      <link>https://trid.trb.org/View/2475970</link>
      <description><![CDATA[Stormwater discharges from highway construction that disturb soil greater than five acres are permitted by the Tennessee Department of Environment and Conservation (TDEC) where runoff sediment must be controlled meeting General Permit (TNR100000) requirements including development and submittal of a Stormwater Pollution Prevention Plan (SWPPP). Within a SWPPP many Erosion Prevention and Stormwater Control (EPSC) devices can be used to control runoff sediment from entering a receiving stream. One EPSC that is not often used is the sediment basin for various reasons including unfamiliarity with design criteria and concern over meeting TDEC performance requirements. Phase I of the project developed general guidelines for sediment basin design based on catchment drainage area, land slope, and soil type. This study as Phase II evaluated the Phase I guidelines. Phase I design guidance for sediment basins were found to adequately to achieve 80% removal of runoff sediment for a 24-hour, 25-year return frequency storm. Research also found that particle size distribution of runoff sediment substantially determines basin performance, thus the sizing of a sediment basin therefore it needs to be incorporated into the design protocols. A design tool was created to accomplish this basin design need. A second object of this research investigated sediment basin performance on a pilot-scale test basin to compare the TDOT standard basin design and one with a rock check dam, and the TDEC standard design with a forebay. The TDOT standard design with a rock check dam at the basin inlet approach area performs similarly to the TDEC standard design with a forebay, where both basin designs achieved greater than 95% removal of sediment in stormwater runoff. The RUSLE2 model computed sediment yields and PSD (sand, silt, and clay fractions) necessary for sizing sediment basins. Further monitoring data expanding on this research would be valuable.]]></description>
      <pubDate>Tue, 17 Dec 2024 13:37:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2475970</guid>
    </item>
    <item>
      <title>Field performance of two stormwater bioretention systems for treating heavy metals and polycyclic aromatic hydrocarbons from urban runoff</title>
      <link>https://trid.trb.org/View/2454954</link>
      <description><![CDATA[The increasing urbanization and land development poses significant water quality challenges in urban areas. Stormwater control measures, such as bioretention basins, are implemented to mitigate these issues by managing storm volumes and improving water quality. Despite their widespread use, the effectiveness of bioretention basins in removing pollutants, particularly heavy metals and polycyclic aromatic hydrocarbons (PAHs), remains unclear. This study evaluates the treatment efficiency of two stormwater bioretention basins (Kyle and TPC) situated within the critical Edwards Aquifer recharge zone in Texas. Over a 1-year period, influent and effluent samples were collected and analyzed to assess removal of heavy metals and PAHs. Soil samples were also collected to assess the distribution of metals in basin soil. The results reveal significant differences in removal efficiency for Fe, Cu, and Zn between the two basins. Within Kyle, there was a significant load reduction of Fe (77%), Cr (74%), and Cu (65%). Within TPC, a significant load reduction was observed for Fe (68%), Cu (84%), and Zn (82%). The results from soil samples indicated significant difference between summer and winter samples for Fe, Mg, Zn and Pb in Kyle while Pb was the only metal that significantly varied between seasons in TPC samples. The high molecular weight PAHs detected in TPC suggested that the sources likely originated from industrial and transportation activities. These results carry significant implications for the operation and maintenance protocols governing such basins, necessitating careful consideration of their impact on groundwater quality and the broader ecosystem.]]></description>
      <pubDate>Wed, 04 Dec 2024 09:26:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2454954</guid>
    </item>
    <item>
      <title>A review of compaction effect on subsurface processes in soil: Implications on stormwater treatment in roadside compacted soil</title>
      <link>https://trid.trb.org/View/2457200</link>
      <description><![CDATA[Sustainable cities require spacious infrastructures such as roadways to serve multiple functions, including transportation and water treatment. This can be achieved by installing stormwater control measures (SCM) such as biofilters and swales on the roadside compacted soil, but compacted soil limits infiltration and other functions of SCM. Understanding the effect of compaction on subsurface processes could help design SCM that could alleviate the negative impacts of compaction. Therefore, the authors synthesize reported data on compaction effects on subsurface processes, including infiltration rate, plant health, root microbiome, and biochemical processes. The results show that compaction could reduce runoff infiltration rate, but adding sand to roadside soil could alleviate the negative impact of compaction. Compaction could decrease the oxygen diffusion rate in the root zone, thereby affecting plant root activities, vegetation establishment, and microbial functions in SCM. The impacts of compaction on carbon mineralization rate and root biomass vary widely based on soil type, aeration status, plant species, and inherent soil compaction level. As these processes are critical in maintaining the long-term functions of SCM, the analysis would help develop strategies to alleviate the negative impacts of compaction and turn road infrastructure into a water solution in sustainable cities.]]></description>
      <pubDate>Sat, 30 Nov 2024 15:27:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2457200</guid>
    </item>
    <item>
      <title>Tire and road wear particles in infiltration pond sediments: Occurrence, spatial distribution, size fractionation and correlation with metals</title>
      <link>https://trid.trb.org/View/2443959</link>
      <description><![CDATA[Stormwater systems, such as infiltration ponds or basins, play a critical role in managing runoff water and reducing particulate pollution loads in downstream environments through decantation. Road runoff carries several pollutants, including trace metals and tire and road wear particles (TRWP). To improve the understanding of infiltration ponds as regards TRWP and their capacity to reduce TRWP loads, the authors have studied the occurrence, spatial distribution and size distribution of TRWP, as well as their relationship with metals, in considering the input of metals as tire additives, in the sediments of an infiltration pond located along the Nantes urban ring road (Western France), which happens to be a high-traffic roadway site. The sediment was analyzed using pyrolysis coupled with gas chromatography–mass spectrometry to determine the polymeric content of tires, specifically in quantifying the styrene-butadiene rubber (SBR) and butadiene rubber (BR) pyrolytic markers. By applying an SBR + BR-to-TRWP conversion factor, the results showed significant TRWP contamination, up to 65 mg/g, with a spatial enrichment from the entrance to the overflow section of the pond. Size fractionation revealed a bimodal distribution, indicating two distinct types of TRWP. The first type is characterized by small diameters (63–160 μm), suggesting the presence of TRWP less integrated with mineral and organic particles. The second type, characterized by larger diameters (200–500 μm), suggests a more pronounced integration with these same mineral and organic particles. A significant positive correlation between TRWP and metals (As, Cd, Cr, Cu, Li, Mo, Ni, Sb, V, Zn) was found (r > 0.739, p < 0.05). This correlation implies that TRWP and/or their associated phases may act as an indicator of metal contamination in the pond sediments. Lastly, a mass balance between TRWP inputs and the amount retained in the sediments underscores the role of infiltration ponds as “sinks” for TRWP.]]></description>
      <pubDate>Thu, 14 Nov 2024 09:48:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2443959</guid>
    </item>
    <item>
      <title>Bioretention Design and Performance in Johnson County, KS</title>
      <link>https://trid.trb.org/View/2281142</link>
      <description><![CDATA[The Johnson County Stormwater Management Program provides funding for a number of research and development projects that implement structural BMPs to improve runoff water quality prior to discharge into local waterways. Since 2006, this program has helped cities in Johnson County install multiple bioretention systems to treat runoff from roads or parking lots. Due to their geographical clustering in northeastern Kansas, these bioretention systems have all been subjected to very similar weather patterns and storm events during this time. For this project, the authors are carrying out a comparative assessment study of identically designed bioretention systems installed at two locations in Overland Park, KS to determine how system design and operation interact with site-specific variables to impact effluent water quality. Available water quality data from 2008–2010 were analyzed to determine cell performance with respect to removal of suspended solids, Zn, Cu and nitrogen and phosphorus species. In both cases, influent runoff is primarily from paved parking lots, with substantial storm to storm variation in pollutant concentrations. Both systems remove suspended solids and Zn, but there is minimal effect on Cu concentrations, which are already quite low in the influent runoff. Nitrogen and phosphorus concentrations, however, increase as the runoff passes through the bioretention cells. Some of this increase is likely due to the breakdown of organic materials mixed into the cell soil matrix. At one site, however, leaf fall and other detritus appear to result in much higher effluent nutrient concentrations. Further work will assess the relative performance of these systems in high and low volume storm events and suggest improvements that should be incorporated in bioretention construction in order to meet regional specific challenges associated with Great Plains weather and climate patterns and native vegetation.]]></description>
      <pubDate>Thu, 31 Oct 2024 16:21:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2281142</guid>
    </item>
    <item>
      <title>Stormwater retention performance of tree integrated infiltration trenches designed for suburban streetscapes</title>
      <link>https://trid.trb.org/View/2438872</link>
      <description><![CDATA[The volume of stormwater generated by streetscapes in cities is a primary driver of urban stream degradation. Large infiltration trenches can be integrated into streetscapes to potentially retain large volumes of runoff and increase growth rates of nearby trees. To test this, a field study was conducted where three structural soil infiltration trenches receiving runoff (12 m long, 0.6 m wide and 0.6 deep) were installed alongside a carpark in Melbourne, Australia, with sizing determined by space constraints in a typical streetscape. The three structural soil trenches had raised outflow drainage, which created internal water storage for runoff received from a carpark. To separate the effects on tree growth of i) the presence of structural soil from ii) passive irrigation into the structural soil, three structural soil trenches (6 m long, 0.6 m wide and 0.6 deep) not receiving runoff and without outflow drainage were also installed. Runoff capture, exfiltration, outflow and tree growth was monitored over 19 months. Only one system performed close to the design intent and retained 18 % of runoff, due to slow soil exfiltration rates (<0.1 mm h−1). Compacted soil generated pervious-area runoff that filled the structural soil trenches not receiving impervious-area runoff from the carpark. Tree growth near these structural soil trenches was poor (59 % relative growth) compared with trees receiving runoff from the carpark (112 % relative growth), due to a lack of drainage, emphasising the need for drainage of stormwater systems in heavy textured soils to promote tree growth. This study highlights that options for creating storage for stormwater in streetscapes have the potential to meet local runoff infiltration targets. However, meeting local runoff volume reduction targets will require alternative ways to reduce surface runoff.]]></description>
      <pubDate>Tue, 29 Oct 2024 15:29:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2438872</guid>
    </item>
    <item>
      <title>Apple Creek Channel Relocation and Floodplain Lowering</title>
      <link>https://trid.trb.org/View/2270680</link>
      <description><![CDATA[The City of Appleton, Wisconsin has designed the relocation of a portion of Apple Creek North, located in the northern portion of the City. In conjunction with this design project, the floodplain in the Apple Creek Subwatershed is being remodeled to account for upstream storage and development changes that have occurred within the subwatershed. In 1999 a Floodplain analysis was performed to determine the extent of the Floodplain of the Apple Creek corridor. This floodplain was approved by WDNR, but was never formally approved by FEMA. In 2007 ACEOM conducted the Apple Creek Subwatershed Leverage Floodplain Mapping Study. Since the 1999 floodplain analysis was completed, the Subwatershed has experienced rapid development, and therefore, changes in stormwater discharges have occurred. Urbanized areas prior to 2004 have no detention unless they are tributary to Holland Pond (a regional on-line stormwater detention pond). Development within the City that has occurred since 2004 was required to follow the City Stormwater Ordinance and meet a requirement to reduce peak flow to presettlement conditions. A hydrologic model was created to determine the peak flow changes due to the changes in land use, detention facilities, and flow routing. A hydraulic model was created initially using the data from the 1999 hydraulic model, and then updated using additional field survey information that was gathered in areas where changes have occurred. Once all of the information was gathered and internally quality checked, a floodplain and floodway was created and submitted to WDNR. The WDNR approved the floodplain and used the elevations for the remapping of the Apple Creek Subwatershed as part of the statewide Digital Flood Insurance Rate Map (DFIRM) update process. The City of Appleton has prepared a CLOMR for the Apple Creek Subwatershed. The CLOMR includes the Apple Creek North relocation project, and additional upstream detention that was constructed since the 2007 floodplain analysis was completed. The Apple Creek North relocation project consists of channel naturalization and floodplain lowering project for a portion of Apple Creek North. The design included naturalizing approximately 4500 feet of channel and relocating the channel to the north. Design constraints involved the future development of adjacent lands, future widening of County Highway to south, expansion of existing waterway crossings, constructability of access to site, and earth work balancing. The goals of the project included the relocating the channel to allow for roadway expansion and to change the floodplain limits (through reduction of the floodplain elevation) to allow the adjacent lands to be removed from the floodplain (once a LOMR was issued). The flow splits were analyzed along Apple Creek North to determine floodplain effects of routing additional flow south towards the main branch of Apple Creek. Four waterway crossings are being designed to convey the 100-year flood flows. The channel naturalization and waterway crossing improvements reduced floodplain elevations from one to two feet within the project corridor and have water surface elevation reductions further downstream.]]></description>
      <pubDate>Mon, 14 Oct 2024 10:30:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2270680</guid>
    </item>
    <item>
      <title>Assessing the Flood Reduction Benefits of On-Road Structures</title>
      <link>https://trid.trb.org/View/2438011</link>
      <description><![CDATA[Conventional culverts are mainly designed to transport water underneath roadways with minimal headwater buildup, resulting in low to moderate peak flow attenuation. On-road structures (ORS) offer an alternative by using the roadway embankment as a dam, restricting flow into the culvert to provide flood storage during large precipitation events. In this project, statewide geographic information system (GIS) analyses were conducted that identified approximately 250,000 potential ORS locations with a combined storage capacity of 2 million acre-feet and a pool area covering 900,000 acres, representing about 2.7% of Iowa. A methodology was developed to automate the hydrologic design of individual ORS, enhancing the identification of those that offer significant peak flow reduction benefits. In addition, the peak flow reduction benefits were quantified at the HUC12 watershed scale for ORS systems. For a 50-year storm event, peak flows at watershed outlets were reduced by approximately 18%. The research outcomes are accessible through a web portal named the Iowa Department of Transportation (DOT) On-Road Structures (IDOT-ORS) information platform. This platform facilitates the dissemination of results, allowing various stakeholders to view information on ORS locations, expected pool and drainage areas, structure designs, and inflow and outflow hydrographs for several return periods. The platform can be accessed at https://hydroinformatics.uiowa.edu/lab/idot-ors/.]]></description>
      <pubDate>Fri, 11 Oct 2024 13:04:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2438011</guid>
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